Re-openings in Europe, coping with COVID-19 in India, kayak racing in Italy, artistic swimming in Budapest, an elephant seal pup in California, a candlelight commemoration in Prague, a skateboard park in Texas, a Victory Day parade in Russia, protests in Colombia, and much more
The great thing about amateur construction projects is that it provides opportunities to learn about new things. I was curious about a device called a VNA (Vector Network Analyzer) after Les Tocko VA7OM showed me his home-built VNA which he was using to tune up the triplexer, diplexer and bandpass filters currently under construction. Here is what I learned from a Tektronix website.
Vector Network Analyzers are used to test component specifications and verify design simulations to make sure systems and their components work properly together.
From mobile phone networks, to Wi-Fi networks, to computer networks and the to the cloud, all of the most common technological networks of today were made possible using the Vector Network Analyzer that was first invented over 60 years ago.
R&D engineers and manufacturing test engineers commonly use VNAs at various stages of product development. Component designers need to verify the performance of their components such as amplifiers, filters, antennas, cables, mixers, etc.
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| Above: The NanoVNA, a very affordable instrument Below: It can be connected via USB to your smart device or computer for a larger screen and many additional functions |
How does a VNA work?
A Vector Network Analyzer contains both a source, used to generate a known stimulus signal, and a set of receivers, used to determine changes to this stimulus caused by the device-under-test or DUT.
The stimulus signal is injected into the DUT and the Vector Network Analyzer measures both the signal that's reflected from the input side, as well as the signal that passes through to the output side of the DUT. The Vector Network Analyzer receivers measure the resulting signals and compare them to the known stimulus signal. The measured results are then processed by either an internal or external PC and sent to a display.
VNAs perform two types of measurements – transmission and reflection. Transmission measurements pass the Vector Network Analyzer stimulus signal through the device under test, which is then measured by the Vector Network Analyzer receivers on the other side.
Examples of transmission measurements include gain, insertion loss/ phase, electrical length/delay and group delay. Reflection measurements measure the part of the VNA stimulus signal that is incident upon the DUT, but does not pass through it. Instead, the reflection measurement measures the signal that travels back towards the source due to reflections.
It sounds like every serious amateur experimenter should own one of these devices. While most of the available devices are expensive lab quality instruments usable at microwave frequencies, many are affordable and suitable for amateur use at HF.
Next month, we will feature an article describing Les VA7OM’s VNA and reflection bridge, and how he used them to tune up the triplexer, diplexer and bandpass filters.
~ John VA7XB
19-04
NOTE: We are currently offering a series on the practical use of the Nano VNA for Amateurs. See the 2021 Communicator issues on this blog.
I enjoyed The Falcon and the Winter Soldier. I especially appreciated the bickering-brothers energy they gave Sam and Bucky. The only thing I would have added would be to have Bucky annoy Sam by always pronouncing Falcon as “Fall-con.”
As always, thanks for using my Amazon Affiliate links (US, UK, Canada).
If you are upgrading an older 5.8.x system to DragonFly 6, and get a lua error when updating pkg: manually copy over a config file, and you’ll be set.
We’ve all been there, you hook things up to a breadboard, only to find that you need to figure out a simple LED indicator to see what’s going on, or have to use a wire or two as an input “button.” This is fine, but not really optimal. You can of course add actual buttons and switches, and perhaps cut down your LEDs to make them more presentable, but this takes up valuable space and time.
If you’d like a little shortcut to this problem, then the Atom IO may be just what you need. The device plugs in to the + and – rails of a breadboard, with 5 lines that connect to 3 LEDs, as well as 2 buttons. The LEDs are routed to the ground rail, so if you apply 2-ish volts, each will light up. The buttons are normally pulled low, but supply voltage from the positive rail when engaged.
Read more: AtomIO Simplifies Your Breadboard UI — Tindie Blog
President Biden signed an executive order to improve government cybersecurity, setting new security standards for software sold to the federal government.
For the first time, the United States will require all software purchased by the federal government to meet, within six months, a series of new cybersecurity standards. Although the companies would have to “self-certify,” violators would be removed from federal procurement lists, which could kill their chances of selling their products on the commercial market.
I’m a big fan of these sorts of measures. The US government is a big enough market that vendors will try to comply with procurement regulations, and the improvements will benefit all customers of the software.
Are y’all aware?
The Muslim Eid al-Fitr festival, marking the end of the month of Ramadan, began this week in parts of the world where sightings of the new moon were made. During Ramadan, the Islamic month of fasting, devout Muslims abstain from food, drink, and sex from dawn until sunset. The fast, one of the five pillars of Islam, is seen as a time for spiritual reflection, prayers, and charity. After sunset, Muslims traditionally break the fast by eating three dates, performing the Maghrib prayer, and sitting down to iftar, the main evening meal, where communities and families gather together. Collected below are images of Muslims around the world observing Eid al-Fitr and Ramadan this year.
This week’s BSD Now leads with that article about how the GPL isn’t fit for purpose; read it if you have not yet.
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| Image Credit NASA/JPL Caltech |
Wally Schirra, Alan Shepard and Gordo Cooper outside Mercury Control around the MR-1 flight, December 1960.
Wally is thinking to himself, “Gordo, it is not a good idea to box in Al.”
Every time I remember that Yuri Gagarin was 27 when he flew it blows my mind guys
He’s a baby
yuri gagarin was a manlet
yet he reached higher than any tall man ever had before… Отдохни в славе, товарищ
This is a major story: a probably Russian cybercrime group called DarkSide shut down the Colonial Pipeline in a ransomware attack. The pipeline supplies much of the East Coast. This is the new and improved ransomware attack: the hackers stole nearly 100 gig of data, and are threatening to publish it. The White House has declared a state of emergency and has created a task force to deal with the problem, but it’s unclear what they can do. This is bad; our supply chains are so tightly coupled that this kind of thing can have disproportionate effects.
EDITED TO ADD (5/12): It seems that the billing system was attacked, and not the physical pipeline itself.
Over at Tiny Transistor labs, [Robo] took it upon himself to reproduce the classic 555 timer in discrete transistor form. For bonus points, he also managed to put it in a package that’s the same basic size, pin compatible with, and a plug-in replacement for the original. The first task was deciding which 555 circuit to implement. He examined a handful of different implementations — and by examined, we mean dissected them and studied the die circuitry under a microscope. In the end, he went with Hans Camenzind’s original circuit, both as a tribute and because it used the fewest transistors — a point which helped manage the final size, which is only a little bit bigger than the IC!
Tensions have escalated in recent weeks between Palestinians and Israelis, triggered in part by recent protests related to a decades-long land dispute that could lead to the removal of Palestinian families from their homes in an East Jerusalem neighborhood. Israeli security forces confronted demonstrators on the site known to Muslims as Haram al-Sharif and to Jews as the Temple Mount, injuring hundreds of Palestinians. Militants in the Gaza Strip began firing rockets into Israel, and Israeli forces have conducted air strikes in Gaza in response, leading to the deaths of more than 55 Palestinians and seven Israelis over the past few days.
Sascha Wildner has added the PCI IDs for various recent ichsmb(4) devices. This I think just means a correct device name in dmesg, but unidentified smbus devices has plagued me for years, even with other operating systems.
Folks. Things are busy.
I’ve said that before, and I am well past the time in my life when “I am really busy” is a brag. It is really a failure to plan. I just wish my busyness right now meant leaving my house more. Go get your shots.
I do have a job in real life, and it is eating up a bit of time these days. I also have a couple of completely volunteer Board gigs, and this week is the Lower Mainland Local Government Association annual conference and AGM, which requires a bit of planning, and as a VP, I have some duties to perform and prepare for – including one session where I have to interview someone who is rather intimidatingly smart. And then we have some resolutions to go through, which maybe I’ll get a chance to write a blog post about after, but if you want to know where Lower Mainland local government elected type’ minds are at these days, this package is a pretty good read. And i’m not one for clickbait, but Resolution #28 will Blow. Your. Mind.
So the only reason I’m here is to tell you we had a very brief Council Meeting on Monday with one item on the agenda:
Consumption of Liquor in Public Spaces Bylaw No. 8264, 2021
This report gave us a first draft of the Bylaw that would meet the Provincial requirements to permit adults to responsibly drink alcohol in a few City parks on a trial basis in 2021. Due to some back-and-forth on Council and feedback from Staff, an area of Queens Park was added to the original proposal.
This coincides with recent Bylaws in the West Vancouver and Delta, existing bylaws in North Van City and PoCo, and pending motions in the District of North Vancouver and Vancouver Parks. This is a regional trend, and each City is approaching it slightly differently, I think New West is pretty “in the middle” in the range of options available to us. Let’s hope our community of park users can raise to the occasion, be respectful of other park users, act responsibly and make it easy for us to continue or expand the program in 2022.
Council, in a split vote agreed to give the Bylaw three readings, and will consider adoption on May 17th, which means the change should take place and signage installed by the May Long Weekend.
And that was the meeting. Hope you are all getting out there and getting your shots! Talk to you again when my head is back above water.
What are the long-lasting waves detected by Voyager 1? Our first working interstellar probe — admittedly never designed for that task — is operating beyond the heliosphere, which it exited back in 2012. A paper just published in Nature Astronomy explores what’s going in interstellar space just beyond, but still affected by, the heliosphere’s passage through the Local Interstellar Medium (LISM).
We have a lot to learn out here, for even as we exit the heliosphere, the picture is complex. The so-called Local Bubble is a low-density region of hot plasma in the interstellar medium, the environment of radiation and matter — gas and dust — that exists between the stars. Within this ‘bubble’ exists the Local Interstellar Cloud (LIC), about 30 light years across, with a slightly higher hydrogen density flowing from the direction of Scorpius and Centaurus. The Sun seems to be within the LIC near its boundary with the G-cloud complex, where the Alpha Centauri stars reside.
Image: Map of the local galactic neighborhood showing the Sun located near the edge of our local interstellar cloud (LIC). Alpha-Centauri is located just over 4 light-years away in the neighboring G-cloud complex. Outside these clouds, the density may be lower than 0.001 atoms/cc. Our Sun and the LIC have a relative velocity of 26 km/sec. Credit: JPL.
But if the interstellar medium is a sparse collection of widely spaced particles and radiation, it proves to be anything but quiet. We learn this from Voyager 1’s Plasma Wave Subsystem, which involves two antennae extending 30 meters from the spacecraft (see image below). What the PWS can pick up are clues to the density of the medium that show up in the form of waves. Some are produced by the rotation of the galaxy; others by supernova explosions, with smaller effects from the Sun’s own activity.
Vibrations of the ionized gas — plasma — in the interstellar medium have been detectable since late 2012 by Voyager 1 in the form of ‘whistles’ that show up only occasionally, but offer ways to study the density of the medium. The new work in Nature Astronomy, led by Stella Koch Ocker (Cornell University), sets about finding a more consistent measure of interstellar medium density in the Voyager data.
Image: An illustration of NASA’s Voyager spacecraft showing the antennas used by the Plasma Wave Subsystem and other instruments. Credit: NASA/JPL-Caltech.
A weak signal appearing at the same time as a ‘whistle’ in the 2017 Voyager data seems to have been the key finding. Ocker describes it as “very weak but persistent plasma waves in the very local interstellar medium.” When whistles appear in the data, the tone of this plasma wave emission rises and falls with them. Adds Ocker:
“It’s virtually a single tone. And over time, we do hear it change – but the way the frequency moves around tells us how the density is changing. This is really exciting, because we are able to regularly sample the density over a very long stretch of space, the longest stretch of space that we have so far. This provides us with the most complete map of the density and the interstellar medium as seen by Voyager.”
So we have an extremely useful instrument, Voyager 1’s Plasma Wave Subsystem, continuing to return data with increasing distance from the Sun. Analyzing the data over time, we learn that the electron density around the spacecraft began rising in 2013, just after its exit from the heliosphere, and reached current levels in 2015. These levels, which persist to the end of 2020 through the dataset, show a 40-fold increase in electron density. Up next for Ocker and team is the development of a physical model of the plasma wave emission that will offer insights into its proper interpretation.
As we begin to think seriously about interstellar probes in this century, it’s striking how much we have to learn about the medium through which they will pass. Voyager 1 is helping us learn about conditions immediately outside the heliosphere. A probe sent to Alpha Centauri will need to cross the boundary between the Local Interstellar Cloud and the B-cloud, a region we have yet to penetrate. The nature of and variation within the interstellar medium will require continuing work with our admittedly sparse data.
The paper is Ocker et al., “Persistent plasma waves in interstellar space detected by Voyager 1,” Nature Astronomy 10 May 2021. Abstract / Preprint.
I have 80 copies of my 2000 book Beyond Fear available at the very cheap price of $5 plus shipping. Note that there is a 20% chance that your book will have a “BT Counterpane” sticker on the front cover.
Order your signed copy here.
Roughly 500 million years ago, something that would forever change the course of eukaryotic development was brewing in the genome of some lucky organism: a gene called Pax6. The gene is thought to have orchestrated the formation of a primitive visual system, and in organisms today, it initiates a genetic cascade that recruits more than 2,000 genes to build different parts of the eye.
Pax6 is only one of thousands of genes encoding transcription factors that each have the powerful ability to amplify and silence thousands of other genes. While geneticists have made leaps in understanding how genes with relatively simple, direct functions could have evolved, explanations for transcription factors have largely eluded scientists. The problem is that the success of a transcription factor depends on how usefully it targets huge numbers of sites throughout the genome simultaneously; it’s hard to picture how natural selection enables that to happen. The answer may hold the key to understanding how complex evolutionary novelties such as eyes arise, said Cédric Feschotte, a molecular biologist at Cornell University.
For more than a decade, Feschotte has pointed to transposons as the ultimate innovators in eukaryotic genomes. Transposons are genetic elements that can copy themselves and insert those copies throughout the genome using a splicing enzyme they make. Feschotte may have finally found the smoking gun he has been looking for: As he and his colleagues recently reported in Science, these jumping genes have fused with other genes nearly 100 times in tetrapods over the past 300 million years, and many of the resulting genetic mashups are likely to encode transcription factors.
The study provides a plausible explanation for how so-called master regulators like Pax6 could have been born, said Rachel Cosby, the first author of the new study, who was a doctoral student in Feschotte’s lab and is now a postdoc at the National Institutes of Health. Although scientists had theorized that Pax6 arose from a transposon hundreds of millions of years ago, mutations since that time have obscured clues about how it formed. “We could see that it was probably derived from a transposon, but it happened so long ago that we missed the window to see how it evolved,” she said.
David Adelson, chair of bioinformatics and computational genetics at the University of Adelaide in Australia, who was not involved with the study, said, “This study provides a good mechanistic understanding of how these new genes can form, and it squarely implicates the transposon activity itself as the cause.”
Scientists have long known that transposons can fuse with established genes because they have seen the unique genetic signatures of transposons in a handful of them, but the precise mechanism behind these unlikely fusion events has largely been unknown. By analyzing genes with transposon signatures from nearly 600 tetrapods, the researchers found 106 distinct genes that may have fused with a transposon. The human genome carries 44 genes likely to have been born this way.
The structure of genes in eukaryotes is complicated, because their blueprints for making proteins are broken up by introns. These noncoding sequences are transcribed, but they get snipped out of the messenger RNA transcripts before translation into protein occurs. But according to Feschotte’s new study, a transposon can occasionally hop into an intron and change what gets translated. In some of these cases, the protein made by the fusion gene is a mashup of the original product and the transposon’s splicing enzyme (transposase).
Once the fusion protein is created, “it has a ready-made set of potential binding sites scattered all over the genome,” Adelson said, because its transposase part is still drawn to transposons. The more potential binding sites for the fusion protein, the higher the likelihood that it changes gene expression in the cell, potentially giving rise to new functions.
“These aren’t just new genes, but entire new architectures for proteins,” Feschotte said.
Cosby described the 106 fusion genes described in the study as the “tiniest tip of the iceberg.” Adelson agreed and explained why: Events that randomly create fusion genes for functional, non-harmful proteins rely on a series of coincidences and must be exceedingly rare; for the fusion genes to spread throughout a population and withstand the test of time, nature must also positively select for them in some way. For the researchers to have found the examples described in the study so readily, transposons must surely cause fusion events much more often, he said.
“All of these steps are very unlikely to happen, but this is how evolution works,” Feschotte said. “It’s very quirky, opportunistic and very unlikely in the end, yet you see it happen over and over again on the timescales of hundreds of millions of years.”
To test whether the fusion genes acted as transcription factors, Cosby and her colleagues homed in on one that evolved in bats 25 million to 45 million years ago — a blink of an eye in evolutionary time. When they used CRISPR to delete it from the bat genome, the changes were striking: The removal dysregulated hundreds of genes. As soon as they restored it, normal gene activity resumed.
To Adelson, this shows that Cosby and her co-authors practically “caught one of these fusion events in the act.” He added, “It’s especially surprising because you wouldn’t expect a new transcription factor to cause wholesale rewiring of transcriptional networks if it had been acquired relatively recently.”
Although the researchers didn’t determine the function of the other fusion proteins definitively, the genetic hallmarks of transcription factors are there: Around a third of the fusion proteins contain a part called KRAB that is associated with repressing DNA transcription in animals. Why transposases tended to fuse with KRAB-encoding genes is a mystery, Feschotte said.
Transposons comprise a hefty chunk of eukaryotic DNA, yet organisms take extreme measures to carefully regulate their activity and prevent the havoc caused by problems such as genomic instability and harmful mutations. These dangers made Adelson wonder if fusion genes sometimes endanger orderly gene regulation. “Not only are you perturbing one thing, but you’re perturbing this whole cascade of things,” he said. “How is it that you can change expression of all these things and not have a three-headed bat?” Cosby, however, thinks it’s unlikely that a fusion gene leading to harmful morphogenic changes would readily propagate through a population.
Damon Lisch, a plant geneticist at Purdue University who studies transposable elements and was not involved with the study, said he hopes this study pushes back against a widespread but misguided notion that transposons are “junk DNA.” Transposable elements generate tremendous amounts of diversity and have been implicated in the evolution of the placenta and the adaptive immune system, he explained. “These are not junk — they’re living little creatures in your genome that are under very active selection over long periods of time, and what that means is that they evolve new functions to stay in your genome,” he said.
Though this study highlights the mechanism underlying transposase fusion genes, the vast majority of new genetic material is thought to form through genetic duplication, in which genes are accidentally copied and the extras diverge through mutation. But a large quantity of genetic material does not mean that new protein functions will be significant, said Cosby, who is continuing to investigate the function of the fusion proteins.
“Evolution is the ultimate tinkerer and ultimate opportunist,” said David Schatz, a molecular geneticist at Yale University who was not involved with the study. “If you give evolution a tool, it may not use it right away, but sooner or later it will take advantage of it.”
Last year, just for the heck of it, Scott Field and Gaurav Khanna tried something that wasn’t supposed to work. The fact that it actually worked quite well is already starting to make some ripples.
Field and Khanna are researchers who try to figure out what black hole collisions should look like. These violent events don’t produce flashes of light, but rather the faint vibrations of gravitational waves, the quivers of space-time itself. But observing them is not as simple as sitting back and waiting for space to ring like a bell. To pick out such signals, researchers must constantly compare the data from gravitational wave detectors to the output of various mathematical models — calculations that reveal the potential signatures of a black hole collision. Without reliable models, astronomers wouldn’t have a clue what to look for.
The trouble is, the most trustworthy models come from Einstein’s general theory of relativity, which is described by 10 interlinked equations that are notoriously difficult to solve. To chronicle the complex interactions between colliding black holes, you can’t just use a pen and paper. The first so-called numerical relativity solutions to the Einstein equations for the case of a black hole merger were calculated only in 2005 — after decades of attempts. They required a supercomputer running on and off for two months.
A gravitational wave observatory like LIGO needs to have a large number of solutions to draw upon. In a perfect world, physicists could just run their model for every possible merger permutation — a black hole with a certain mass and spin encountering another with a different mass and spin — and compare those results with what the detector sees. But the calculations take a long time. “If you give me a big enough computer and enough time, you can model almost anything,” said Scott Hughes, a physicist at the Massachusetts Institute of Technology. “But there’s a practical issue. The amount of computer time is really exorbitant” — weeks or months on a supercomputer. And if those black holes are unevenly sized? The calculations would take so long that researchers consider the task practically impossible. Because of that, physicists are effectively unable to spot collisions between black holes with mass ratios greater than 10-to-1.
Which is one reason why Field and Khanna’s new work is so exciting. Field, a mathematician at the University of Massachusetts, Dartmouth, and Khanna, a physicist at the University of Rhode Island, have made an assumption that simplifies matters greatly: They treat the smaller black hole as a “point particle” — a speck of dust, an object with mass but zero radius and no event horizon.
“It’s like two ships passing in the ocean — one a rowboat, the other a cruise liner,” Field explained. “You wouldn’t expect the rowboat to affect the cruise liner’s trajectory in any way. We’re saying the small ship, the rowboat, can be completely ignored in this transaction.”
They expected it to work when the smaller black hole’s mass really was like a rowboat’s compared to a cruise ship’s. “If the mass ratio is on the order of 10,000-to-1, we feel very confident in making that approximation,” Khanna said.
But in research published last year, he and Field, along with graduate student Nur Rifat and Cornell physicist Vijay Varma, decided to test their model at mass ratios all the way down to 3-to-1 — a ratio so low it had never been tried, mainly because no one considered it worth trying. They found that even at this low extreme, their model agreed, to within about 1%, with results obtained by solving the full set of Einstein’s equations — an astounding level of accuracy.
“That’s when I really started to pay attention,” said Hughes. Their results at mass ratio 3, he added, were “pretty incredible.”
“It’s an important result,” said Niels Warburton, a physicist at University College Dublin who was not involved with the research.
The success of Field and Khanna’s model down to ratios of 3-to-1 gives researchers that much more confidence in using it at ratios of 10-to-1 and above. The hope is that this model, or one like it, could operate in regimes where numerical relativity cannot, allowing researchers to scrutinize a part of the universe that has been largely impenetrable.
After black holes spiral toward each other and collide, the massive bodies create space-time-contorting disturbances — gravitational waves — that propagate through the universe. Eventually, some of these gravitational waves might reach Earth, where the LIGO and Virgo observatories wait. These enormous L-shaped detectors can sense the truly tiny stretching or squishing of space-time that these waves create — a shift 10,000 times smaller than the width of a proton.
The designers of these observatories have made herculean efforts to muffle stray noise, but when your signal is so weak, noise is a constant companion.
The first task in any gravitational wave detection is to try to extract a weak signal from that noise. Field compares the process to “driving in a car with a loud muffler and a lot of static on the radio, while thinking there might be a song, a faint melody, somewhere in that noisy background.”
Astronomers take the incoming stream of data and first ask if any of it is consistent with a previously modeled gravitational wave form. They might run this preliminary comparison against tens of thousands of signals stored in their “template bank.” Researchers can’t determine the exact black hole characteristics from this procedure. They’re just trying to figure out if there’s a song on the radio.
The next step is analogous to identifying the song and determining who sang it and what instruments are playing. Researchers run tens of millions of simulations to compare the observed signal, or wave form, with those produced by black holes of differing masses and spins. This is where researchers can really nail down the details. The frequency of the gravitational wave tells you the total mass of the system. How that frequency changes over time reveals the mass ratio, and thus the masses of the individual black holes. The rate of change in the frequency also provides information about a black hole’s spin. Finally, the amplitude (or height) of the detected wave can reveal how far the system is from our telescopes on Earth.
If you have to do tens of millions of simulations, they’d better be quick. “To complete that in a day, you need to do each in about a millisecond,” said Rory Smith, an astronomer at Monash University and a member of the LIGO collaboration. Yet the time needed to run a single numerical relativity simulation — one that faithfully grinds its way through the Einstein equations — is measured in days, weeks or even months.
To speed up this process, researchers typically start with the results of full supercomputer simulations — of which several thousand have been carried out so far. They then use machine learning strategies to interpolate their data, Smith said, “filling in the gaps and mapping out the full space of possible simulations.”
This “surrogate modeling” approach works well so long as the interpolated data doesn’t stray too far from the baseline simulations. But simulations for collisions with a high mass ratio are incredibly difficult. “The bigger the mass ratio, the more slowly the system of two inspiraling black holes takes to evolve,” Warburton explained. For a typical low-mass-ratio computation, you need to look at 20 to 40 orbits before the black holes plunge together, he said. “For a mass ratio of 1,000, you need to look at 1,000 orbits, and that would just take too long” — on the order of years. This makes the task virtually “impossible, even if you have a supercomputer at your disposal,” Field said. “And without a revolutionary breakthrough, this won’t be possible in the near future either.”
Because of this, many of the full simulations used in surrogate modeling are between the mass ratios of 1 and 4; almost all are less than 10. When LIGO and Virgo detected a merger with a mass ratio of 9 in 2019, it was right at the limit of their sensitivity. More events like this haven’t been found, Khanna explained, because “we don’t have reliable models from supercomputers for mass ratios above 10. We haven’t been looking because we don’t have the templates.”
That’s where the model that he and Khanna have developed comes in. They started with their own point particle approximation model, which is specially designed to operate in the mass ratio range above 10. They then trained a surrogate model on it. The work opens up opportunities to detect the mergers of unevenly sized black holes.
What kinds of situations might create such mergers? Researchers aren’t sure, since this is a newly opening frontier of the universe. But there are a few possibilities.
First, astronomers can imagine an intermediate-mass black hole of perhaps 80 or 100 solar masses colliding with a smaller, stellar-size black hole of about 5 solar masses.
Another possibility would involve a collision between a garden-variety stellar black hole and a relatively puny black hole left over from the Big Bang — a “primordial” black hole. These could have as little as 1% of a solar mass, whereas the vast majority of black holes detected by LIGO so far weigh more than 10 solar masses.
Earlier this year, researchers at the Max Planck Institute for Gravitational Physics used Field and Khanna’s surrogate model to look through LIGO data for signs of gravitational waves emanating from mergers involving primordial black holes. And while they didn’t find any, they were able to place more precise limits on the possible abundance of this hypothetical class of black holes.
Furthermore, LISA, a planned space-based gravitational wave observatory, might one day be able to witness mergers between ordinary black holes and the supermassive varieties at the centers of galaxies — some with the mass of a billion or more suns. LISA’s future is uncertain; its earliest launch date is 2035, and its funding situation is still unclear. But if and when it does launch, we may see mergers at mass ratios above 1 million.
Some in the field, including Hughes, have described the new model’s success as “the unreasonable effectiveness of point particle approximations,” underscoring the fact that the model’s effectiveness at low mass ratios poses a genuine mystery. Why should researchers be able to ignore the critical details of the smaller black hole and still arrive at the right answer?
“It’s telling us something about the underlying physics,” Khanna said, though exactly what that is remains a source of curiosity. “We don’t have to concern ourselves with two objects surrounded by event horizons that can get distorted and interact with each other in strange ways.” But no one knows why.
In the absence of answers, Field and Khanna are trying to extend their model to more realistic situations. In a paper scheduled to be posted early this summer on the preprint server arxiv.org, the researchers give the larger black hole some spin, which is expected in an astrophysically realistic situation. Again, their model closely matches the findings of numerical relativity simulations at mass ratios down to 3.
They next plan to consider black holes that approach each other on elliptical rather than perfectly circular orbits. They’re also planning, in concert with Hughes, to introduce the notion of “misaligned orbits” — cases in which the black holes are askew relative to each other, orbiting in different geometric planes.
Finally, they’re hoping to learn from their model by trying to make it break. Could it work at a mass ratio of 2 or lower? Field and Khanna want to find out. “One gains confidence in an approximation method when one sees it fail,” said Richard Price, a physicist at MIT. “When you do an approximation that gets surprisingly good results, you wonder if you are somehow cheating, unconsciously using a result that you shouldn’t have access to.” If Field and Khanna push their model to the breaking point, he added, “then you’d really know that what you are doing is not cheating — that you just have an approximation that works better than you’d expect.”
Steve Jobs had a uniform. Reportedly, he had a closet full of one specific type of black turtleneck and one specific brand of jeans. People say he did it so that clothes would be one less decision he’d have to make every day.
I suspect part of the reason he chose to go the uniform route was that he realized that he was Steve Jobs. Everyone he ever met knew exactly who he was and already had an opinion of him. If people were impressed with him, they would continue to be impressed no matter what he wore. If, on the other hand, they weren’t impressed with him, no outfit was going to be cool enough to change that.
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SEDCO W4DXCC Co-Founder, Noted DXer Lynn Lamb, W4NL, SK
ARRL Life Member Lynn Lamb, W4NL, of Maryville, Tennessee, died on May 10 following a lengthy illness. He was 83. Lamb co-founded SEDCO W4DXCC DX and Contest Convention in 2005.
Licensed in 1954, Lamb retired from a career with the US Department of Defense (US Navy and Air Force). He was a founding member of the National Capitol DX Association (NCDXA) and belonged to Potomac Valley Radio Club, the International DX Association, and other amateur radio organizations. He was 339/371 in the DXCC standings.
Lamb was a member of the CQ DX and University of Tennessee Amateur Radio Club Halls of Fame. Survivors include his wife Rosie, KA4S. A memorial service will be held at a later date.
Microsoft today released fixes to plug at least 55 security holes in its Windows operating systems and other software. Four of these weaknesses can be exploited by malware and malcontents to seize complete, remote control over vulnerable systems without any help from users. On deck this month are patches to quash a wormable flaw, a creepy wireless bug, and yet another reason to call for the death of Microsoft’s Internet Explorer (IE) web browser.
While May brings about half the normal volume of updates from Microsoft, there are some notable weaknesses that deserve prompt attention, particularly from enterprises. By all accounts, the most pressing priority this month is CVE-2021-31166, a Windows 10 and Windows Server flaw which allows an unauthenticated attacker to remotely execute malicious code at the operating system level. With this weakness, an attacker could compromise a host simply by sending it a specially-crafted packet of data.
“That makes this bug wormable, with even Microsoft calling that out in their write-up,” said Dustin Childs, with Trend Micro’s ZDI program. “Before you pass this aside, Windows 10 can also be configured as a web server, so it is impacted as well. Definitely put this on the top of your test-and-deploy list.”
Kevin Breen from Immersive Labs said the fact that this one is just 0.2 points away from a perfect 10 CVSS score should be enough to identify just how important it is to patch.
“For ransomware operators, this kind of vulnerability is a prime target for exploitation,” Breen said. “Wormable exploits should always be a high priority, especially if they are for services that are designed to be public facing. As this specific exploit would not require any form of authentication, it’s even more appealing for attackers, and any organization using HTTP.sys protocol stack should prioritize this patch.”
Breen also called attention to CVE-2021-26419 — a vulnerability in Internet Explorer 11 — to make the case for why IE needs to stand for “Internet Exploder.” To trigger this vulnerability, a user would have to visit a site that is controlled by the attacker, although Microsoft also recognizes that it could be triggered by embedding ActiveX controls in Office Documents.
“IE needs to die – and I’m not the only one that thinks so,” Breen said. “If you are an organization that has to provide IE11 to support legacy applications, consider enforcing a policy on the users that restricts the domains that can be accessed by IE11 to only those legacy applications. All other web browsing should be performed with a supported browser.”
Another curious bug fixed this month is CVE-2020-24587, described as a “Windows Wireless Networking Information Disclosure Vulnerability.” ZDI’s Childs said this one has the potential to be pretty damaging.
“This patch fixes a vulnerability that could allow an attacker to disclose the contents of encrypted wireless packets on an affected system,” he said. “It’s not clear what the range on such an attack would be, but you should assume some proximity is needed. You’ll also note this CVE is from 2020, which could indicate Microsoft has been working on this fix for some time.”
Microsoft also patched four more security holes its Exchange Server corporate email platform, which recently was besieged by attacks on four other zero-day Exchange flaws that resulted in hundreds of thousands of servers worldwide getting hacked. One of the bugs is credited to Orange Tsai of the DEVCORE research team, who was responsible for disclosing the ProxyLogon Exchange Server vulnerability that was patched in an out-of-band release back in March.
Researcher Orange Tsai commenting that nobody guessed the remote zero-day he reported on Jan. 5, 2021 to Microsoft was in Exchange Server.
“While none of these flaws are deemed critical in nature, it is a reminder that researchers and attackers are still looking closely at Exchange Server for additional vulnerabilities, so organizations that have yet to update their systems should do so as soon as possible,” said Satnam Narang, staff research engineer at Tenable.
As always, it’s a good idea for Windows users to get in the habit of updating at least once a month, but for regular users (read: not enterprises) it’s usually safe to wait a few days until after the patches are released, so that Microsoft has time to iron out any kinks in the new armor.
But before you update, please make sure you have backed up your system and/or important files. It’s not uncommon for a Windows update package to hose one’s system or prevent it from booting properly, and some updates have been known to erase or corrupt files.
So do yourself a favor and backup before installing any patches. Windows 10 even has some built-in tools to help you do that, either on a per-file/folder basis or by making a complete and bootable copy of your hard drive all at once.
And if you wish to ensure Windows has been set to pause updating so you can back up your files and/or system before the operating system decides to reboot and install patches on its own schedule, see this guide.
If you experience glitches or problems installing any of these patches this month, please consider leaving a comment about it below; there’s a better-than-even chance other readers have experienced the same and may chime in here with some helpful tips.
The FBI confirmed this week that a relatively new ransomware group known as DarkSide is responsible for an attack that caused Colonial Pipeline to shut down 5,550 miles of pipe, stranding countless barrels of gasoline, diesel and jet fuel on the Gulf Coast. Here’s a closer look at the DarkSide cybercrime gang, as seen through their negotiations with a recent U.S. victim that earns $15 billion in annual revenue.
Colonial Pipeline has shut down 5,500 miles of fuel pipe in response to a ransomware incident. Image: colpipe.com
New York City-based cyber intelligence firm Flashpoint said its analysts assess with a moderate-strong degree of confidence that the attack was not intended to damage national infrastructure and was simply associated with a target which had the finances to support a large payment.
“This would be consistent with DarkSide’s earlier activities, which included several ‘big game hunting’ attacks, whereby attackers target an organization that likely possesses the financial means to pay the ransom demanded by the attackers,” Flashpoint observed.
In response to public attention to the Colonial Pipeline attack, the DarkSide group sought to play down fears about widespread infrastructure attacks going forward.
“We are apolitical, we do not participate in geopolitics, do not need to tie us with a defined government and look for other our motives [sic],” reads an update to the DarkSide Leaks blog. “Our goal is to make money, and not creating problems for society. From today we introduce moderation and check each company that our partners want to encrypt to avoid social consequences in the future.”
First surfacing on Russian language hacking forums in August 2020, DarkSide is a ransomware-as-a-service platform that vetted cybercriminals can use to infect companies with ransomware and carry out negotiations and payments with victims. DarkSide says it targets only big companies, and forbids affiliates from dropping ransomware on organizations in several industries, including healthcare, funeral services, education, public sector and non-profits.
Like other ransomware platforms, DarkSide adheres to the current badguy best practice of double extortion, which involves demanding separate sums for both a digital key needed to unlock any files and servers, and a separate ransom in exchange for a promise to destroy any data stolen from the victim.
At its launch, DarkSide sought to woo affiliates from competing ransomware programs by advertising a victim data leak site that gets “stable visits and media coverage,” as well as the ability to publish victim data by stages. Under the “Why choose us?” heading of the ransomware program thread, the admin answers:
An advertisement for the DarkSide ransomware group.
“High trust level of our targets. They pay us and know that they’re going to receive decryption tools. They also know that we download data. A lot of data. That’s why the percent of our victims who pay the ransom is so high and it takes so little time to negotiate.”
In late March, DarkSide introduced a “call service” innovation that was integrated into the affiliate’s management panel, which enabled the affiliates to arrange calls pressuring victims into paying ransoms directly from the management panel.
In mid-April the ransomware program announced new capability for affiliates to launch distributed denial-of-service (DDoS) attacks against targets whenever added pressure is needed during ransom negotiations.
DarkSide also has advertised a willingness to sell information about upcoming victims before their stolen information is published on the DarkSide victim shaming blog, so that enterprising investment scammers can short the company’s stock in advance of the news.
“Now our team and partners encrypt many companies that are trading on NASDAQ and other stock exchanges,” DarkSide explains. “If the company refuses to pay, we are ready to provide information before the publication, so that it would be possible to earn in the reduction price of shares. Write to us in ‘Contact Us’ and we will provide you with detailed information.”
DarkSide also started recruiting new affiliates again last month — mainly seeking network penetration testers who can help turn a single compromised computer into a full-on data breach and ransomware incident.
Portions of a DarkSide recruitment message, translated from Russian. Image: Intel 471.
“We have grown significantly in terms of the client base and in comparison to other projects (judging by the analysis of publicly available information), so we are ready to grow our team and a number of our affiliates in two fields,” DarkSide explained. The advertisement continued:
“Network penetration testing. We’re looking for one person or a team. We’ll adapt you to the work environment and provide work. High profit cuts, ability to target networks that you can’t handle on your own. New experience and stable income. When you use our product and the ransom is paid, we guarantee fair distribution of the funds. A panel for monitoring results for your target. We only accept networks where you intend to run our payload.”
DarkSide has shown itself to be fairly ruthless with victim companies that have deep pockets, but they can be reasoned with. Cybersecurity intelligence firm Intel 471 observed a negotiation between the DarkSide crew and a $15 billion U.S. victim company that was hit with a $30 million ransom demand in January 2021, and in this incident the victim’s efforts at negotiating a lower payment ultimately reduce the ransom demand by almost two-thirds.
The DarkSide ransomware note.
The first exchange between DarkSide and the victim involved the usual back-and-forth establishing of trust, wherein the victim asks for assurances that stolen data will be deleted after payment.
Image: Intel 471.
When the victim counter-offered to pay just $2.25 million, DarkSide responded with a lengthy, derisive reply, ultimately agreeing to lower the ransom demand to $28.7 million.
“The timer it [sic] ticking and in in next 8 hours your price tag will go up to $60 million,” the crooks replied. “So, you this are your options first take our generous offer and pay to us $28,750 million US or invest some monies in quantum computing to expedite a decryption process.”
Image: Intel 471.
The victim complains that negotiations haven’t moved the price much, but DarkSide countered that the company can easily afford the payout. “I don’t think so,” they wrote. “You aren’t poor and aren’t children if you f*cked up you have to meet the consequences.”
Image: Intel 471.
The victim firm replies a day later saying they’ve gotten authority to pay $4.75 million, and their tormentors agree to lower the demand significantly to $12 million.
Image: Intel 471.
The victim replies that this is still a huge amount, and it tries to secure additional assurances from the ransomware group if it agrees to pay the $12 million, such as an agreement not to target the company ever again, or give anyone access to its stolen data. The victim also tried to get the attackers to hand over a decryption key before paying the full ransom demand.
Image: Intel 471.
The crime gang responded that its own rules prohibit it from giving away a decryption key before full payment is made, but they agree to the rest of the terms.
Image: Intel 471.
The victim firm agrees to pay an $11 million ransom, and their extortionists concur and promise not to attack or help anyone else attack the company’s network going forward.
Image: Intel 471
Flashpoint assesses that at least some of the criminals behind DarkSide hail from another ransomware outfit called “REvil,” a.k.a. “Sodinokibi” (although Flashpoint rates this finding at only “moderate” confidence). REvil is widely considered to be the newer name for GandCrab, a ransomware-as-a-service offering that closed up shop in 2019 after bragging that it had extorted more than $2 billion.
Experts say ransomware attacks will continue to grow in sophistication, frequency and cost unless something is done to disrupt the ability of crooks to get paid for such crimes. According to a report late last year from Coveware, the average ransomware payment in the third quarter of 2020 was $233,817, up 31 percent from the second quarter of last year. Security firm Emsisoft found that almost 2,400 U.S.-based governments, healthcare facilities and schools were victims of ransomware in 2020.
Last month, a group of tech industry heavyweights lent their imprimatur to a task force that delivered an 81-page report to the Biden administration on ways to stymie the ransomware industry. Among many other recommendations, the report urged the White House to make finding, frustrating and apprehending ransomware crooks a priority within the U.S. intelligence community, and to designate the current scourge of digital extortion as a national security threat.
Further reading: Intel 471’s take on the Colonial Pipeline attack.
From Avionics Anonymous on Tindie:
UAVCAN Air Data Computer / Airspeed Sensor
Airspeed, Altitude and Air Temperature sensing with UAVCAN interface for Pixhawk and other autopilots
A tiny, richly-featured Air Data Computer (ADC) for small unmanned airplanes. Includes an MS5611 barometric pressure sensor for 10cm-resolution altitude, a Honeywell RSC-series differential pressure transducer for extremely accurate airspeed, and a thermistor interface with high-resolution convertor for air temperature measurement with less than 1 degree precision. All of this interfaces to your autopilot via robust UAVCAN interface – no sketchy I2C wiring! Comes fully assembled, ready to use!
Microsoft researchers just released an open-source automation tool for security testing AI systems: “Counterfit.” Details on their blog.
At first, topology can seem like an unusually imprecise branch of mathematics. It’s the study of squishy play-dough shapes capable of bending, stretching and compressing without limit. But topologists do have some restrictions: They cannot create or destroy holes within shapes. (It’s an old joke that topologists can’t tell the difference between a coffee mug and a doughnut, since they both have one hole.) While this might seem like a far cry from the rigors of algebra, a powerful idea called homology helps mathematicians connect these two worlds.
The word “hole” has many meanings in everyday speech — bubbles, rubber bands and bowls all have different kinds of holes. Mathematicians are interested in detecting a specific type of hole, which can be described as a closed and hollow space. A one-dimensional hole looks like a rubber band. The squiggly line that forms a rubber band is closed (unlike a loose piece of string) and hollow (unlike the perimeter of a penny).
Extending this logic, a two-dimensional hole looks like a hollow ball. The kinds of holes mathematicians are looking for — closed and hollow — are found in basketballs, but not bowls or bowling balls.
But mathematics traffics in rigor, and while thinking about holes this way may help point our intuition toward rubber bands and basketballs, it isn’t precise enough to qualify as a mathematical definition. It doesn’t clearly describe holes in higher dimensions, for instance, and you couldn’t program a computer to distinguish closed and hollow spaces.
“There’s not a good definition of a hole,” said Jose Perea of Michigan State University.
So instead, homology infers an object’s holes from its boundaries, a more precise mathematical concept. To study the holes in an object, mathematicians only need information about its boundaries.
The boundary of a shape is the collection of the points on its periphery, and a shape’s boundary is always one dimension lower than the shape itself. For example, the boundary of a one-dimensional line segment consists of the two points on either end. (Points are considered zero-dimensional.) The boundary of a solid triangle is the hollow triangle, which consists of one-dimensional edges. Similarly, the solid pyramid is bounded by a hollow pyramid.
If you stick two line segments together, the boundary points where they meet disappear. The boundary points are like the edge of a cliff — they are close to falling off the line. But when you connect the lines, the points that were on the edges are now securely in the center. Separately, the two lines had four total boundary points, but when they are stuck together, the resulting shape only has two boundary points.
If you can attach a third edge and close off the structure, creating a hollow triangle, then the boundary points disappear entirely. Each boundary point of the component edges cancels with another, and the hollow triangle is left with no boundary. So whenever a collection of lines forms a loop, the boundaries cancel.
Loops circle back on themselves, enclosing a central region. But the loop only forms a hole if the central region is hollow, as with a rubber band. A circle drawn on a paper forms a loop, but it is not a hole because the center is filled in. Loops that enclose a solid region — the non-hole kind — are the boundary of that two-dimensional region.
Therefore, holes have two important rigorous features. First, a hole has no boundary, because it forms a closed shape. And second, a hole is not the boundary of something else, because the hole itself must be hollow.
This definition can extend to higher dimensions. A two-dimensional solid triangle is bounded by three edges. If you attach several triangles together, some boundary edges disappear. When four triangles are arranged into a pyramid, each of the edges cancels with another one. So the walls of a pyramid have no boundary. If that pyramid is hollow — that is, it is not the boundary of a three-dimensional solid block — then it forms a two-dimensional hole.
To find all the types of holes within a particular topological shape, mathematicians build something called a chain complex, which forms the scaffolding of homology.
Many topological shapes can be built by gluing together pieces of different dimensions. The chain complex is a diagram that gives the assembly instructions for a shape. Individual pieces of the shape are grouped by dimension and then arranged hierarchically: The first level contains all the points, the next level contains all the lines, and so on. (There’s also an empty zeroth level, which simply serves as a foundation.) Each level is connected to the one below it by arrows, which indicate how they are glued together. For example, a solid triangle is linked to the three edges that form its boundary.
Mathematicians extract a shape’s homology from its chain complex, which provides structured data about the shape’s component parts and their boundaries — exactly what you need to describe holes in every dimension. When you use the chain complex, the processes for finding a 10-dimensional hole and a one-dimensional hole are nearly identical (except that one is much harder to visualize than the other).
The definition of homology is rigid enough that a computer can use it to find and count holes, which helps establish the rigor typically required in mathematics. It also allows researchers to use homology for an increasingly popular pursuit: analyzing data.
That’s because data can be visualized as points floating in space. These data points can represent the locations of physical objects, such as sensors, or positions in an abstract space, such as a description of food preferences, with nearby points indicating people who have a similar palate.
To form shapes from data, mathematicians draw lines between neighboring points. When three points are close together, they are filled in to form a solid triangle. When larger numbers of points are clustered together, they form more complicated and higher-dimensional shapes. Filling in the data points gives them texture and volume — it creates an image from the dots.
Homology translates this world of vague shapes into the rigorous world of algebra, a branch of mathematics that studies particular numerical structures and symmetries. Mathematicians study the properties of these algebraic structures in a field known as homological algebra. From the algebra they indirectly learn information about the original topological shape of the data. Homology comes in many varieties, all of which connect with algebra.
“Homology is a familiar construction. We have a lot of algebraic things we know about it,” said Maggie Miller of the Massachusetts Institute of Technology.
The information provided by homology even accounts for the imprecision of data: If the data shifts just slightly, the numbers of holes should stay the same. And when large amounts of data are processed, the holes can reveal important features. For example, loops in time-varying data can indicate periodicity. Holes in other dimensions can show clusters and voids in the data.
“There’s a real impetus to have methods that are robust and that are pulling out qualitative features,” said Robert Ghrist of the University of Pennsylvania. “That’s what homology gives you.”
This is a newly unclassified NSA history of its reaction to academic cryptography in the 1970s: “NSA Comes Out of the Closet: The Debate over Public Cryptography in the Inman Era,” Cryptographic Quarterly, Spring 1996, author still classified.
The ChiBUG May 11th Meeting is today, and it’s virtual – so you can go and should.
Regular Acceptance: Abstracts Due June 30, 2021
The Interstellar Research Group (IRG) hereby invites participation in its 7th Interstellar Symposium, hosted by the University of Arizona to be held from Friday, September 24 through Monday, September 27, 2021, in Tucson, Arizona. The Interstellar Symposium has the following elements:
The Interstellar Symposium focuses on all aspects of interstellar travel (human and robotic), including power, communications, system reliability/maintainability, psychology, crew health, anthropology, legal regimes and treaties, ethics, and propulsion with an emphasis on possible destinations (including the status of exoplanet research), life support systems, and habitats.
Working Tracks are collaborative, small group discussions around a set of interdisciplinary questions on an interstellar subject with the objective of producing “roadmaps” and/or publications to encourage further developments in the respective topics. This year we will be organizing the Working Tracks to follow selected plenary talks with focused discussions on the same topic.
Sagan Meetings. Carl Sagan famously employed this format for his 1971 conference at the Byurakan Observatory in old Soviet Armenia, which dealt with the Drake Equation. Each Sagan Meeting will invite five speakers to give a short presentation staking out a position on a particular question. These speakers will then form a panel to engage in a lively discussion with the audience on that topic.
Seminars are 3-hour presentations on a single subject, providing an in depth look at that subject. Seminars will be held on Friday, September 24, 2021, with morning and afternoon sessions. The content must be acceptable to be counted as continuation education credit for those holding a Professional Engineer (PE) Certificate.
Other Content includes, but is not limited to, posters, displays of art or models, demonstrations, panel discussions, interviews, or public outreach events.
Publications: Since the IRG serves as a critical incubator of ideas for the interstellar community. We intend to publish the work of the 7th Symposium in many outlets, including a complete workshop proceedings in book form. No Paper, No Podium: If a written paper is not submitted by the final manuscript deadline (To Be Announced), authors will not be permitted to present their work at the event. Papers should be original work that has not been previously published. Select papers may be submitted for journal publication, such as in the Journal of the British Interplanetary Society (JBIS).
Video and Archiving: All symposium events may be captured on video or in still images for use on the IRG and other sponsors websites, in newsletters and social media. All presenters, speakers and selected participants will be asked to complete a Release Form that grants permission for IRG to use this content as described.
Abstracts for the Interstellar Symposium must relate to one or more of the many interstellar mission related topics, such as power, communications, system reliability/maintainability, psychology, crew health, anthropology, legal regimes and treaties, ethics, and propulsion with an emphasis on possible destinations (including the status of exoplanet research), life support systems, and habitats.
All abstracts must be submitted online here. Submitters must create accounts on the IRG website in order to submit abstracts.
PRESENTING AUTHOR(S) – Please list ONLY the author(s) who will actually be in attendance and presenting at the conference. (first name, last name, degree – for example, Susan Smith, MD)
ADDITIONAL AUTHORS – List all authors here, including Presenting Author(s) – (first name, last name, degree(s) – for example, Mary Rockford, RN; Susan Smith, MD; John Jones, PhD)
ABBREVIATIONS within the body should be kept to a minimum and must be defined upon first use in the abstract by placing the abbreviation in parenthesis after the represented full word or phrase. Proprietary drug names and logos may NOT be used. Non-proprietary (generic) names should be used.
ABSTRACT LENGTH – The entire abstract, (EXCLUDING title, authors, presenting author’s institutional affiliation(s), city, state, and text), including any tables or figures should be a maximum of 350 words. It is your responsibility to verify compliance with the length requirement.
ABSTRACT STRUCTURE – abstracts must include the following headings:
Questions and responses to this Call for Papers, Workshops and Participation should be directed to: info@irg.space.
For updates on the meeting, speakers, and logistics, please refer to the website: https://irg.space/irg-2021/
The Tennessee Valley Interstellar Workshop (doing business as the Interstellar Research Group, IRG) is a non-profit scientific, educational corporation in the state of Tennessee. For U.S. tax purposes, IRG is a tax-exempt, 501(c)(3) educational, non-profit corporation.
From Ken Olsen of The Maker’s Box on Tindie:
A 3D printed drawing robot you can build, program, and modify.
Robotics is the exciting intersection of a number of engineering fields including mechanical engineering, electrical engineering, and computer science. This project was designed as the basis for a two-day workshop for high school age students to introduce them to engineering principles and giving them a jumping off point for exploring their interests further. There is something for everyone here, even if it is just for the art it creates. The design goals were:
Easy to build.
Easy to program.
Did something interesting.
Low-cost so participants could take it home and continue to learn.
Molecular biology has something in common with kite-flying competitions. At the latter, all eyes are on the colorful, elaborate, wildly kinetic constructions darting through the sky. Nobody looks at the humble reels or spools on which the kite strings are wound, even though the aerial performances depend on how skillfully those reels are handled. In the biology of complex cells, or eukaryotes, the ballet of molecules that transcribe and translate genomic DNA into proteins holds centerstage, but that dance would be impossible without the underappreciated work of histone proteins gathering up the DNA into neat bundles and unpacking just enough of it when needed.
Histones, as linchpins of the apparatus for gene regulation, play a role in almost every function of eukaryotic cells. “In order to get complex, you have to have genome complexity, and evolve new gene families, and you have to have a cell cycle,” explained William Martin, an evolutionary biologist and biochemist at Heinrich Heine University in Germany. “And what’s in the middle of all this? Managing your DNA.”
New work on the structure and function of histones in ancient, simple cells has now made the longstanding, central importance of these proteins to gene regulation even clearer. Billions of years ago, the cells called archaea were already using histones much like our own to manage their DNA — but they did so with looser rules and much more variety. From those similarities and differences, researchers are gleaning new insights, not only into how the histones helped to shape the origins of complex life, but also into how variants of histones affect our own health today. At the same time, though, new studies of histones in an unusual group of viruses are complicating the answers about where our histones really came from.
Eukaryotes arose about 2 billion years ago, when a bacterium that could metabolize oxygen for energy took up residence inside an archaeal cell. That symbiotic partnership was revolutionary because energy production from that proto-mitochondrion suddenly made expressing genes much more metabolically affordable, Martin argues. The new eukaryotes suddenly had free rein to expand the size and diversity of their genomes and to conduct myriad evolutionary experiments, laying the foundation for the countless eukaryotic innovations seen in life today. “Eukaryotes are an archaeal genetic apparatus that survives with the help of bacterial energy metabolism,” Martin said.
But the early eukaryotes went through serious growing pains as their genomes expanded: The larger genome brought new problems stemming from the need to manage an increasingly unwieldy string of DNA. That DNA had to be accessible to the cell’s machinery for transcribing and replicating it without getting tangled up in a hopeless spaghetti ball.
The DNA also sometimes needed to be compact, both to help regulate transcription and regulation, and to separate the identical copies of DNA during cell division. And one danger of careless compaction is that DNA strands can irreversibly bind together if the backbone of one interacts with the groove of another, rendering the DNA useless.
Bacteria have a solution for this that involves a variety of proteins jointly “supercoiling” the cells’ relatively limited libraries of DNA. But eukaryotes’ DNA management solution is to use histone proteins, which have a unique ability to wrap DNA around themselves rather than just sticking to it. The four primary histones of eukaryotes — H2A, H2B, H3 and H4 — assemble into octamers with two copies of each. These octamers, called nucleosomes, are the basic units of eukaryotic DNA packaging.
By curving the DNA around the nucleosome, the histones prevent it from clumping together and keep it functional. It’s an ingenious solution — but eukaryotes didn’t invent it entirely on their own.
Back in the 1980s, when the cellular and molecular biologist Kathleen Sandman was a postdoc at Ohio State University, she and her adviser, John Reeve, identified and sequenced the first known histones in archaea. They showed how the four principal eukaryotic histones were related to each other and to the archaeal histones. Their work provided the early evidence that in the original endosymbiotic event that led to eukaryotes, the host was likely to have been an archaeal cell.
But it would be a teleological mistake to think that archaeal histones were just waiting for the arrival of eukaryotes and the chance to enlarge their genomes. “A lot of these early hypotheses looked at histones in terms of their ability to allow the cell to expand its genome. But that doesn’t really tell you why they were there in the first place,” said Siavash Kurdistani, a biochemist at the University of California, Los Angeles.
As a first step toward those answers, Sandman joined forces several years ago with the structural biologist Karolin Luger, who solved the structure of the eukaryotic nucleosome in 1997. Together, they worked out the crystallized structure of the archaeal nucleosome, which they published with colleagues in 2017. They found that the archaeal nucleosomes are “uncannily similar” in structure to eukaryotic nucleosomes, Luger said — despite the marked differences in their peptide sequences.
Archaeal nucleosomes had already “figured out how to bind and bend DNA in this beautiful arc,” said Luger, now a Howard Hughes Medical Institute investigator at the University of Colorado, Boulder. But the difference between the eukaryotic and archaeal nucleosomes is that the crystal structure of the archaeal nucleosome seemed to form looser, Slinky-like assemblies of varying sizes.
In a paper in eLife published in March, Luger, her postdoc Samuel Bowerman, and Jeff Wereszczynski of the Illinois Institute of Technology followed up on the 2017 paper. They used cryo-electron microscopy to solve the structure of the archaeal nucleosome in a state more representative of a live cell. Their observations confirmed that the structures of archaeal nucleosomes are less fixed. Eukaryotic nucleosomes are always stably wrapped by about 147 base pairs of DNA, and always consist of just eight histones. (For eukaryotic nucleosomes, “the buck stops at eight,” Luger said.) Their equivalents in archaea wind up between 60 and 600 base pairs. These “archaeasomes” sometimes hold as few as three histone dimers, but the largest ones consist of as many as 15 dimers.
They also found that unlike the tight eukaryotic nucleosomes, the Slinky-like archaeasomes flop open stochastically, like clamshells. The researchers suggested that this arrangement simplifies gene expression for the archaea, because unlike eukaryotes, they don’t need any energetically expensive supplemental proteins to help unwind DNA from the histones to make them available for transcription.
That’s why Tobias Warnecke, who studies archaeal histones at Imperial College London, thinks that “there’s something special that must have happened at the dawn of eukaryotes, where we transition from just having simple histones … to having octameric nucleosomes. And they seem to be doing something qualitatively different.”
What that is, however, is still a mystery. In archaeal species, there are “quite a few that have histones, and there are other species that don’t have histones. And even those that do have histones vary quite a lot,” Warnecke said. Last December, he published a paper showing that there are diverse variants of histone proteins with different functions. The histone-DNA complexes vary in their stability and affinity for DNA. But they are not as stably or regularly organized as eukaryotic nucleosomes.
As puzzling as the diversity of archaeal histones is, it provides an opportunity to understand the different possible ways of building systems of gene expression. That’s something we cannot glean from the relative “boringness” of eukaryotes, Warnecke says: Through understanding the combinatorics of archaeal systems, “we can also figure out what’s special about eukaryotic systems.” The variety of different histone types and configurations in archaea may also help us deduce what they might have been doing before their role in gene regulation solidified.
Because archaea are relatively simple prokaryotes with small genomes, “I don’t think that the original role of histones was to control gene expression, or at least not in a manner that we are used to from eukaryotes,” Warnecke said. Instead, he hypothesizes that histones might have protected the genome from damage.
Archaea often live in extreme environments, like hot springs and volcanic vents on the seafloor, characterized by high temperatures, high pressures, high salinity, high acidity or other threats. Stabilizing their DNA with histones may make it harder for the DNA strands to melt in those extreme conditions. Histones also might protect archaea against invaders, such as phages or transposable elements, which would find it harder to integrate into the genome when it’s wrapped around the proteins.
Kurdistani agrees. “If you were studying archaea 2 billion years ago, genome compaction and gene regulation are not the first things that would come to mind when you are thinking about histones,” he said. In fact, he has tentatively speculated about a different kind of chemical protection that histones might have offered the archaea.
Last July, Kurdistani’s team reported that in yeast nucleosomes, there is a catalytic site at the interface of two histone H3 proteins that can bind and electrochemically reduce copper. To unpack the evolutionary significance of this, Kurdistani goes back to the massive increase in oxygen on Earth, the Great Oxidation Event, that occurred around the time that eukaryotes first evolved more than 2 billion years ago. Higher oxygen levels must have caused a global oxidation of metals like copper and iron, which are critical for biochemistry (although toxic in excess). Once oxidized, the metals would have become less available to cells, so any cells that kept the metals in reduced form would have had an advantage.
During the Great Oxidation Event, the ability to reduce copper would have been “an extremely valuable commodity,” Kurdistani said. It might have been particularly attractive to the bacteria that were forerunners of mitochondria, since cytochrome c oxidase, the last enzyme in the chain of reactions that mitochondria use to produce energy, requires copper to function.
Because archaea live in extreme environments, they might have found ways to generate and handle reduced copper without being killed by it long before the Great Oxidation Event. If so, proto-mitochondria might have invaded archaeal hosts to steal their reduced copper, Kurdistani suggests.
The hypothesis is intriguing because it could explain why the eukaryotes appeared when oxygen levels went up in the atmosphere. “There was 1.5 billion years of life before that, and no sign of eukaryotes,” Kurdistani said. “So the idea that oxygen drove the formation of the first eukaryotic cell, to me, should be central to any hypotheses that try to come up with why these features developed.”
Kurdistani’s conjecture also suggests an alternative hypothesis for why eukaryotic genomes got so big. The histones’ copper-reducing activity only occurs at the interface of the two H3 histones inside an assembled nucleosome wrapped with DNA. “I think there’s a distinct possibility that the cell wanted more histones. And the only way to do that was to expand this DNA repertoire,” Kurdistani said. With more DNA, cells could wrap more nucleosomes and enable the histones to reduce more copper, which would support more mitochondrial activity. “It wasn’t just that histones allowed for more DNA, but more DNA allowed for more histones,” he said.
“One of the neat things about this is that copper is very dangerous because it will break DNA,” said Steven Henikoff, a chromatin biologist and HHMI investigator at the Fred Hutchinson Cancer Research Center in Seattle. “Here’s a place where you have the active form of copper being made, and it’s right next to the DNA, but it doesn’t break the DNA because, presumably, it’s in a tightly packaged form,” he said. By wrapping the DNA, the nucleosomes keep the DNA safely out of the way.
The hypothesis potentially explains aspects of how the architecture of the eukaryotic genome evolved, but it has met with some skepticism. The key outstanding question is whether archaeal histones have the same copper-reducing ability that some eukaryotic ones do. Kurdistani is investigating this now.
The bottom line is that we still don’t definitively know what functions histones served in the archaea. But even so, “the fact that you see them conserved over long distances strongly suggests that they are doing something distinct and important,” Warnecke said. “We just need to find out what it is.”
Although the complex eukaryotic histone apparatus has not changed much since its origin about a billion years ago, it hasn’t been totally frozen. In 2018, a team at the Fred Hutchinson Cancer Research Center reported that a set of short histone variants called H2A.B is evolving rapidly. The pace of the changes is a sure sign of an “arms race” between genes vying for control over regulatory resources. It wasn’t initially clear to the researchers what the genetic conflict was about, but through a series of elegant crossbreeding experiments in mice, they eventually showed that the H2A.B variants dictated the survival and growth rate of embryos, as reported in December in PLOS Biology.
The findings suggested that paternal and maternal versions of the histone variants are mediating a conflict over how to allocate resources to the offspring during pregnancy. They are rare examples of parental-effect genes — ones that don’t directly affect the individual carrying them, but instead strongly affect the individual’s offspring.
The H2A.B variants arose with the first mammals, when the evolution of in utero development rewrote the “contract” for parental investment. Mothers had always invested a lot of resources in their eggs, but mammalian mothers also suddenly became responsible for the early development of their progeny. That set up a conflict: Paternal genes in the embryo had nothing to lose by demanding resources aggressively, while the maternal genes benefited from moderating the burden to spare the mother and let her live to breed another day.
“That negotiation is still ongoing,” said Harmit Malik, an HHMI investigator at the Fred Hutchinson Cancer Research Center who studies genetic conflicts. Exactly how the histones affect the growth and viability of offspring is still not completely understood, but Antoine Molaro, the postdoctoral fellow who led the work and who now leads his own research group at the University of Clermont Auvergne in France, is investigating it.
Some histone variants may cause health problems, too. In January, Molaro, Malik, Henikoff and their colleagues reported that short H2A histone variants are implicated in some cancers: More than half of diffuse large B cell lymphomas carry mutations in them. Other histone variants are associated with neurodegenerative diseases.
But little is yet understood about how a single copy of a histone variant can produce such dramatic disease effects. The obvious hypothesis is that the variants affect the stability of nucleosomes and disrupt their signaling functions, changing gene expression in a way that alters cell physiology. But if histones can act as enzymes, then Kurdistani suggests another possibility: The variants may alter enzymatic activity inside cells.
Despite the decades-old evidence from Sandman and others that eukaryotic histones evolved from archaeal histones, some intriguing recent work has unexpectedly opened the door to an alternative theory about their origins. According to a paper published on April 29 in Nature Structural & Molecular Biology, giant viruses of the Marseilleviridae family have viral histones that are recognizably related to the four main eukaryotic histones. The only difference is that in the viral versions, the histones that routinely pair up within the octamer (H2A with H2B, and H3 with H4) in eukaryotes are already fused into doublets. The fused viral histones form structures that are “virtually identical to canonical eukaryotic nucleosomes,” according to the paper’s authors.
Luger’s team posted a preprint on biorxiv.org about viral histones the same day, showing that in the cytoplasm of infected cells, viral histones stay near the “factories” that produce new viral particles.
“Here’s the thing that is really compelling,” said Henikoff, who was among the authors on the new Nature Structural & Molecular Biology paper. “All of the histone variants turn out to be derived from a common ancestor that was shared between eukaryotes and giant viruses. By standard phylogenetic criteria, these are a sister group to eukaryotes.”
It makes a compelling case that this common ancestor is where the eukaryotic histones came from, he says. A “proto-eukaryote” that had histone doublets might have been ancestral to both the giant viruses and eukaryotes and could have passed the proteins along to both lines of organisms a very long time ago.
Warnecke, however, is skeptical about inferring phylogenetic relationships from viral sequences, which are notoriously mutable. As he explained in an email to Quanta, reasons other than shared ancestry might explain how the histones ended up in both lineages. In addition, the idea would require that the histone doublets later “unfused” into the H2A, H2B, H3 and H4 histones, because there are no doublets of those histones in extant eukaryotes. “How and why that would have happened is unclear,” he wrote.
Although Warnecke is not convinced that the viral histones tell us much about the origin of eukaryotic histones, he is fascinated by their possible functions. One possibility is that they help to compact the viral DNA; another idea is that they could be disguising the viral DNA from the host’s defenses.
Histones have had myriad roles since the dawn of time. But it was really in the eukaryotes that they became the linchpins for complex life and countless evolutionary innovations. That’s why Martin calls the histone “a basic building block that never could realize its full potential without the help of mitochondria.”
DragoFly 6.0 is tagged and ready for download. There’s ISO images and of course you can upgrade using the notes on the release page. One of the improvements in this release cycle is improved dsynth support, so of course there are many prebuilt packages available; don’t forget to update those too.
How much is your payroll data worth? Probably a lot more than you think. One financial startup that’s targeting the gig worker market is offering up to $500 to anyone willing to hand over the payroll account username and password given to them by their employer, plus a regular payment for each month afterwards in which those credentials still work.
This ad, from workplaceunited[.]com, promised up to $500 for people who provided their payroll passwords, plus $25 a month for each month those credentials kept working.
New York-based Argyle.com says it’s building a platform where people who work multiple jobs and/or side hustles can improve their credit and employment options by pooling all of their gig work data in one place.
“Consumers’ access to financial security and upward mobility is dependent on their access to and control over their own employment records and how easily they can share those records with financial institutions,” Argyle explained in a May 3 blog post. “We enable access to a dataset that, for too long, has gone unstandardized, unregulated, and controlled by corporations instead of consumers, contributing to system-wide inequalities.”
Argyle’s app flow. Image: Argyle.com.
In that sense, Argyle is making a play for a discrete chunk of a much larger employment data market dominated by the major credit bureaus, which have been hoovering up and selling access to employment data for years.
The 800-lb. gorilla there is Equifax, whose The Work Number product has for years purchased employment data flows from some of the world’s largest companies (employees consent to this sharing as part of their employment contract, and The Work Number makes it fairly easy for anyone to learn how much you earn).
The Work Number is designed to provide automated employment and income verification for prospective employers, and tens of thousands of companies report employee salary data to it. It also allows anyone whose employer uses the service to provide proof of their income when purchasing a home or applying for a loan.
On its blog, Argyle imagines a world in which companies choose to integrate its application platform interface (API) and share their employee payroll data. At the same time, the company appears to be part of an effort in which non-salaried workers are prompted to repay their erstwhile employers’ trust by selling payroll credentials.
If Argyle is worried these two goals might somehow conflict, that is not obvious by looking at some of its direct-to-consumer efforts.
The website pictured below prompts visitors to “connect payroll,” and those who proceed agree to have their payroll data shared with a company called Earnin, a mobile payday loan app that lets users get an advance on their upcoming paycheck.
Clicking “Connect Payroll” brings up a list of payroll login pages for brand name companies, including Walmart, Starbucks, Amazon, Uber, Chipotle, etc., with a search feature that reveals login pages for everyone from the Federal Bureau of Investigation (FBI) to the Federal Reserve and Federal Trade Commission (FTC).
The default Argyle list of payroll login pages for major companies.
Here’s what comes up when you search by “Department of” at this site:
Drilling down into individual companies listed here produces a username and password form that in some cases is modified to request an employee identifier other than a username, such as a employee ID, associate or partner number instead. Here’s the login page for Starbucks employees:
The site pictured above actively checks if any submitted credentials are working, by submitting them directly to the employer in question. This Argyle status page indicates the system’s “data connection status” to countless employers.
Some of you may be thinking, “How many of us actually know or have our payroll passwords?” According to Argyle, plenty of people do.
“At Argyle, we are intimately familiar with how likely someone is to know the password for their employment account or payroll system, because we’ve seen hundreds of thousands of users successfully (and unsuccessfully) provide their credentials,” Argyle’s Billy Mardsen wrote on Apr. 1. “We closely monitor their success rate—what we call conversion—because it drives the performance of the products and applications that our clients build on top of Argyle.”
Argyle’s “conversion” numbers by employer. Image: Argyle.com
KrebsOnSecurity first heard about this company via Twitter from security researcher Kevin Beaumont, who pointed to a nest of domains associated with Argyle’s API — nearly all of which are offline now. At the time, Beaumont and others digging into this suspected the sites were part of an elaborate phishing scam.
These sites, which seemed to be grouped around a recent recruitment effort variously called “Workers United,” “UniteAtWork,” “WageCompete” and “CommonGrounds,” indicate that Argyle’s platform has been pivotal in a slew of campaigns paying employees at specific companies up to $100 for their payroll account passwords. Here’s one seeking T-Mobile employees:
A promotion offering T-Mobile employees $100 to give up their T-Mobile payroll account passwords.
Another recent promotion targeted employees at J.P. Morgan Chase, the largest financial institution in the United States:
Argyle declined multiple interview requests for this story, so it’s not clear how much of a role — if any — the company may have played in these various sites. But code prebuilds and instructions published in the company’s name on Github strongly suggest Argyle was instrumental in the WageCompete initiative.
Also, this page over at Scopeinc.com says the WageCompete program is provided by Argyle Expert Services.
Here’s a graphical look at the various websites mentioned here and their ties to Argyle’s API (click to enlarge):
The network of sites paying people for payroll passwords and their connections to Argyle’s API. Click to enlarge. Image: Virustotal
One of the sites in that graphic above that’s connected to Argyle’s API — workerresearchalliances[.]com — is currently live and includes the same verbiage about participants getting paid for their payroll credentials. The terms and conditions of the “WorkersApp beta program” were set by a company called Workers Research Alliances LLC, incorporated in February. The address for Workers Research Alliances is just a few blocks from Argyle’s office in New York City.
Steve Friedl, an IT consultant in the payroll service bureau industry, said it appears Argyle has been paying people to help them refine their API and data scraping technology.
“They are not paying this money just to be able to sell people services, they are doing so to maintain their screen-scraping software API,” Friedl said. “This is essentially paying employees to help Argyle hack their payroll provider.”
Last fall Argyle announced it had landed a $20 million investment from Bain Capital, among others. The company’s co-founder, Shmulik Fishman, is described as a “disruptor” who says he wants to make credit scores obsolete.
“We’re fearless,” Fishman told Authority Magazine. “We do things other people dare not do.”
That much is clear. Hey, I can get behind almost anything that disintermediates the creaky old credit bureaus in a straightforward and consumer-friendly way. And the last time I checked, it’s not against the law to give someone your password, or to induce someone to do so willingly in exchange for something else (unless maybe you work for a federal agency).
But I wonder how many of the companies listed on all these payroll connect sites will respond to knowing their brands and logos are associated with a site that asks their employees to give away passwords.
KrebsOnSecurity contacted multiple high-level sources at major companies whose login pages are shown in these payroll connect programs running on Argyle’s platform. None of those sources were authorized to talk to the media, but all seemed fairly horrified at what they were seeing, and each said their employer’s legal departments were launching their own investigations.
Beaumont said he’s worried that in some companies, an employee’s payroll credentials may work to gain access to other parts of the organization — meaning some employees may be giving away more than they realize.
“My concern is some companies use single sign-on for payroll,” Beaumont said. “That’s a lot of access for a data harvesting company.”
“GB2RS can now also be heard via the QO-100 amateur radio satellite. The transmission is provided by Keith, GU6EFB at 0800UTC, using upper sideband on 10489.900 MHz, which is in the mixed-mode section of the narrowband transponder. QO-100 is a geostationary satellite with a footprint that covers Europe, Africa and India, so this news bulletin is a specially-adapted international version. The RSGB would like to thank AMSAT-DL for their kind cooperation in making this broadcast possible.”
I made myself a reminder about this when I first saw the news item because I’m a frequent listener of QO-100 via streaming audio and thought it would just be cool to give a listen.
I could have downloaded the news but where’s the fun in that?
This way requires the audio to be uploaded to the satellite transponder with the resulting signal being received by the Goonhilly Earth Station in Cornwall and streamed around the world to little old me me via WebSDR.
That’s certainly more satisfying than just downloading a file!
Alas, that didn’t work out because the weak-link in that long chain of communication was me. I must have glossed right over the part where this was scheduled for broadcast at 4am my time.
Ouch! Maybe I’ll set an early morning alarm to monitor this one of these days, but having to be awake at that hour has caused me to slide this one down a few spots on my “to-do” list…
It is surprisingly difficult to build a carbon neutral sailing ship. This is even more the case today, because our standards for safety, health, hygiene, comfort, and convenience have changed profoundly since the Age of Sail.
On board the ship `Garthsnaid' at sea. A view from high up in the rigging. Image by Allan C. Green, circa 1920.
The sailing ship is a textbook example of sustainability. For at least 4,000 years, sailing ships have transported passengers and cargo across the world’s seas and oceans without using a single drop of fossil fuels. If we want to keep travelling and trading globally in a low carbon society, sailing ships are the obvious alternative to container ships, bulk carriers, and airplanes.
However, by definition, the sailing ship is not a carbon neutral technology. For most of history, sailing ships were built from wood, but back then whole forests were felled for ships, and those trees often did not grow back. In the late nineteenth and early twentieth century, sailing ships were increasingly made from steel, which also has a significant carbon footprint.
The carbon neutrality of sailing in the 21st century is even more elusive. That’s because we have changed profoundly since the Age of Sail. Compared to our forebears, we have higher demands in terms of safety, comfort, convenience, and cleanliness. These higher standards are difficult to achieve unless the ship also has a diesel engine and generator on-board.
The sailing ship has seen a modest revival in the last decade, especially for the transportation of cargo. In 2009, Dutch company Fairtransport started shipping freight between Europe and the Americas with the Tres Hombres, a sailing ship built in 1943. The company remains active today and has a second ship in service since 2015, the Nordlys (built in 1873).
Since then, others have joined the sail cargo business. In 2016, the German company Timbercoast started shipping cargo with the Avontuur, a ship built in 1920. [1] In 2017, the French Blue Schooner Company started transporting cargo between Europe and the Americas with the Gallant, a sailing ship that was built in 1916. [2] All these sailing ships were constructed in the twentieth or nineteenth century, and were restored at a later date. However, a revival of sail cannot rely on historical ships alone, because there’s not enough of them. [3]
The Noach, built in 1857.
At the moment, there are at least two sailing ships in development that are being built from scratch: the Ceiba and the EcoClipper500. The first ship is being constructed in Costa Rica by a company named Sailcargo. She is built from wood and inspired by a Finnish ship from the twentieth century. The second ship is designed by a company called EcoClipper, which is led by one of the founders of the Dutch FairTransport, Jorne Langelaan. Their EcoClipper500 is a steel replica of a Dutch clipper ship from 1857: the Noach.
“Old designs are not necessarily the best", says Jorne Langelaan, "but whenever proven design is used, one can be sure of its performance. A new design is more of a gamble. Furthermore, in the 20th and 21st century, sailing technology developed for fast sailing yachts, which is an entirely different story compared to ships which need to be able to carry cargo.”
These two ships – one under construction and one in the design phase – have the potential to make sail cargo a lot more economical than it is today. That’s because they have a much larger cargo capacity than the sailing ships currently in operation. As a ship becomes longer, her cargo capacity increases more than proportionally.
The EcoClipper500 is a full-scale replica of the Noach.
The 46 metre long Ceiba is powered by 580 m2 of sails and carries 250 tonnes of cargo. The 60 metre long EcoClipper500 is powered by almost 1,000 m2 of sails and takes 500 tonnes of cargo. For comparison, the Tres Hombres is not that much shorter at 32 metres, but she takes only 40 tonnes of cargo – twelve times less than the EcoClipper500. A larger ship is also faster and saves labour. The Tres Hombres requires a crew of seven, while the EcoClipper500 only has a slightly larger crew of twelve.
Although the EcoClipper500 is still in the design phase, she will be the focus of this article. This is because the company conducted a life cycle analysis of the ship prior to building it. [9] As far as I know, this is the first life cycle analysis of a sailing ship ever made. The study reveals that it takes around 1,200 tonnes of carbon to build the ship.
Half of those emissions are generated during steel production, and roughly one third is generated by steel working processes and other shipyard activities. Solvent-based paints as well as electric and electronic systems each account for roughly 5% of emissions. The emissions produced during the manufacturing of the sails are not included because there are no scientific data available, but a quick back-of-the-envelope calculation (for sails based on aramid fibres) signals that their contribution to the total carbon footprint is very small. [4]
The EcoClipper500 has a carbon footprint of 2 grammes of CO2 per tonne-kilometre, which is five times less than the carbon footprint of a container ship.
If these 1,200 tonnes of emissions are spread out over an estimated lifetime of 50 years, then the EcoClipper500 would have a carbon footprint of about 2 grammes of CO2 per tonne-kilometre of cargo, concludes researcher Andrew Simons, who made the life cycle analysis for the ship. This is roughly five times less than the carbon footprint of a container ship (10 grammes CO2/tonne-km) and three times less than the carbon footprint of a bulk-carrier (6 grammes CO2/tonne-km). [5]
Looking aft from aloft on the 'Parma' while at anchor. Alan Villiers, 1932-33. Villiers's work vividly records the period of early 20th century maritime history when merchant sailing vessels or ‘tall ships’ were in rapid decline.
Transporting one ton of cargo over a distance of 8,000 km (roughly the distance between the Caribbean and the Netherlands) would thus produce 16 kg of carbon with the EcoClipper500, compared to 80 kg on a container ship and 48 kg on a bulk carrier. The proportions are similar for other environmental factors, such as ozone depletion, ecotoxicity, air pollution, and so on.
Although the sailing ship boasts a convincing advantage, it may not be as big as you might have expected. First, as Simons explains, there’s scale. A container ship or bulk carrier enjoys the same benefits over the EcoClipper500 as the EcoClipper500 enjoys over the Tres Hombres. It can take a lot more cargo – on average 50,000 tonnes instead of 500 tonnes – and it needs only a slightly larger crew of 20-25 people. [6]
Second, fossil fuel powered ships are faster than sailing ships, meaning that fewer ships are needed to transport a given amount of cargo over a given period of time. The original ship on which the EcoClipper500 is based, sailed between the Netherlands and Indonesia in 65 to 78 days, while a container ship does it in about half the time (taking the short cut through the Suez canal).
There’s two ways to further lower the carbon emissions of sailing ships in comparison to container ships and bulk carriers. One is to build ships from wood instead of steel, such as the Ceiba. If the harvested trees are allowed to grow back (which the makers of the Ceiba have promised), such a ship may even be considered a carbon sink.
However, there’s a good reason why the EcoClipper500 will be made from steel: the company’s aim is to build not just one ship, but a fleet of them. Jorne Langelaan: “There are few shipyards who can deliver wooden ships nowadays. Steel makes it easier to build a fleet in a shorter period.”
A possible compromise would be a composite construction, in which a steel skeleton is clad with timber keel, planks, and deck. Andrew Simons: “This would reduce the carbon footprint of construction by half. It could also be feasible to make superstructures and some of the mast sections and spars from timber instead of steel.”
Driving sprays over the main deck of the 'Parma'. Alan Villiers, 1932-33.
Towards the future, another possibility to further decrease a sailings ship’s emissions per tonne-km is to build it even larger. While the EcoClipper500 has much more cargo capacity than the cargo sailing ships now in operation, she is far from the largest sailing ship ever built.
Historical ships such as the Great Republic (5,000 tonnes), the Parma (5,300 tonnes), the France II (7,300 tonnes), and the Preussen (7,800 tonnes), were more than 100 metres long and could take more than ten times the freight capacity of the EcoClipper500. Langelaan already dreams of a EcoClipper3000.
Most cargo sailing ships travelling across the oceans today can also take some passengers. Fully loaded with cargo, the EcoClipper500 takes 12 crew members, 12 passengers, and 8 trainees (passengers who learn how to sail). If the upper hold deck is not used for cargo, another 28 trainees can join, so that the ship can take up to 60 people on board (with a smaller cargo volume: 480 m3 instead of 880 m3).
The carbon footprint for passengers amounts to 10 g per passenger-km, compared to roughly 100 g per passenger-km on an airplane.
Consequently, and since ocean liners have disappeared, the EcoClipper500 also becomes an alternative to the airplane. According to the results of the life cycle analysis, the carbon footprint for passengers on the EcoClipper500 amounts to 10 grammes per passenger-kilometre, compared to roughly 100 grammes per passenger-kilometre on an airplane. Transporting one passenger thus produces as much carbon emissions as transporting 1 tonne of freight.
Importantly, the life cycle analysis of the EcoClipper500 assumes that there is no diesel engine on-board. On a sailing ship, a diesel engine can serve two purposes, which can be combined. First, it allows to propel the ship when there is no wind or when sails cannot be used, for example when leaving or entering a harbour. Second, combined with a generator, a diesel engine can produce electricity for daily life on board of the ship.
For most of history, energy use on-board of a sailing ship was not too problematic. There was firewood for cooking and heating, and there were candles and oil lamps for lighting. There were no refrigerators for food storage, no showers or laundry machines for washing and cleaning, no electronic instruments for navigation and communication, no electric pumps in case of leaks or fire.
However, we now have higher standards in terms of safety, health, hygiene, thermal comfort, and convenience. The problem is that these higher standards are difficult to achieve when the ship does not have an engine that runs on fossil fuels. Modern heating systems, cooking devices, hot water boilers, refrigerators, freezers, lighting, safety equipment, and electronic instruments all need energy to work.
Crewman of the 'Parma' with a model of his ship. Alan Villiers, 1932-33.
Modern sailing ships often use a diesel engine to provide that energy (and to propel the ship if necessary). An example is the Avontuur from Timbercoast, who has an engine of 300 HP, a 20 kW generator, and a fuel tank of 2,330 litres. Large sail training vessels and cruising ships have several engines and generators on-board. For example, the 48m long Brig Morningster has a 450 HP engine and three generators with a total capacity of 100 kW, while the 56m long Bark Europa has two 365 HP engines with three generators – and burns hundreds of litres of oil per day.
Depending on the lifestyle of the people on board, the emissions per passenger-km may rise to, or surpass, the levels of those of an airplane.
Obviously, the emissions and other pollutants of these engines need to be taken into account when the environmental footprint of a sail trip is calculated. Depending on the lifestyle of the people on board, the emissions per passenger-km may rise to, or surpass, the levels of those of an airplane. To a lesser extent, electricity use on-board also increases the emissions of cargo transportation.
The EcoClipper500 has no diesel engine on board, which is a second reason to focus on this ship. Obviously, a sailing ship without an engine cannot proceed her voyage when there’s no wind. This is easily solved in the old-fashioned way: the EcoClipper500 stays where she is until the wind returns. A ship without an engine also needs tug boats – which usually burn fossil fuels – to get in and out of ports. For the EcoClipper500, these tug services account for 0.3 g/tkm of the total carbon footprint of 2 g/tkm.
Without a diesel engine, the ship also needs to generate all energy for use on board from local energy sources, and this is the hard part. Renewable energy is intermittent and has low power density compared to fossil fuels, meaning that more space is needed to generate a given amount of power – which is more problematic at sea than it is on land.
Renewing caulking on the poop of the 'Parma'. Alan Villiers, 1932-33.
To make the EcoClipper500 self-sufficient in terms of energy use, a first design decision was to shift energy use away from electricity whenever possible. This is especially important for high temperature heat, which cannot be supplied by electric heat pumps. The ship will have a pellet-stove on board to provide space heating, as well as a biodigester – never before used on a ship – to convert human and kitchen waste into gas for cooking. Thermal insulation of the ship is another priority.
Nevertheless, even with pellet-stove and biodigester (which themselves require electricity to operate), and with thermal insulation, energy demand on the ship can be as high as 50 kilowatt-hours of electricity per day (2 kW average power use). This concerns a “worst-case normal operation” scenario, when the ship is sailing in cold weather with 60 people on board. Power use will be lower in warmer weather and/or when less people are taken. During an emergency, the power requirements can amount to 8 kW, while more than 24 kWh of energy can be needed in just three hours.
How to produce this power? Solar panels and wind turbines are only a small part of the solution. Producing 50 kWh of energy per day would require at least 100 square metres of solar panels, for which there is little space on a 60 m long sailing ship. Vulnerability and shading by the sails make for further problems. Wind turbines can be attached in the rigging, but their power output is also limited. The low potential of solar and wind power are demonstrated by the earlier mentioned sailing ship Avontuur. She has a 20 kW generator, powered by the diesel engine, but only 2.1 kW of solar panels and 0.8 kW of wind turbines.
The hydrogenerator is the only renewable power source that can provide a large sailing ship with enough energy for the use of modern technology on board.
The hydrogenerator is the only renewable power source that can provide a large sailing ship with enough energy for the use of modern technology on board. Hydrogenerators are attached underneath the hull and work in the opposite way as a ship’s propeller. Instead of the propeller powering the ship, the ship powers the propeller, which turns a generator that produces electricity. In spite of its name and appearance, the hydrogenerator is actually a form of wind energy: the sails power the propellers. Obviously, this only works when the ship is sailing fast enough.
Furling sail on the main yard of the Parma. Alan Villiers, 1932-33.
The EcoClipper500 will be equipped with two large hydrogenerators, for which Simons calculated the power output at different speeds, taking into account the fact that the extra drag they produce slows down the ship somewhat. He concludes that the EcoClipper500 needs to sail at a speed of at least 7.5 knots to generate enough electricity. At that speed, the hydrogenerators produce an estimated 2,000 watts of power, which converts to roughly 50 kWh of electricity per day (24 hours of sailing).
At a lower speed of 4.75 knots, the generators produce 350 watts, which comes down to 8.4 kWh of energy over a period of 24 hours – only 1/6th of the maximum required energy. On the other hand, at higher speeds, the hydrogenerators produce more energy than necessary. At a speed of almost 10 knots they provide 120 kWh/day, at a speed of 12 knots this becomes 182 kWh/day – 3.5 times more than needed.
According to her hull speed, the EcoClipper500 will be able to sail a little over 16 knots at absolute top speed – this is double the minimum speed required to generate enough power. Achieving this speed will be rare, because it needs calm seas and strong winds from the right direction. Nevertheless, in good wind conditions, the ship easily sails fast enough to produce all electricity for use on board.
Good wind conditions can last for days, especially on the oceans, where winds are more powerful and predictable than on land. However, they are not guaranteed, and the ship will also sail at lower speeds, or find herself in becalmed conditions – when hydrogenerators are as useless as solar panels in the middle of the night.
Because she has no engine, the EcoClipper500 faces a double problem when there’s no wind: she cannot continue her voyage, and she has no energy to maintain life on board.
Because she has no engine, the EcoClipper500 faces a double problem when there’s no wind: she cannot continue her voyage, and she has no energy to maintain life on board. The first problem is easily solved but the second is not. Life on board goes on, and so there is a continued need for power. To provide this, the ship needs energy storage.
To cover the needs for three days drifting in cold weather, an energy storage of 150 kWh would be required, not taking into account charge and discharge losses. Five or seven days of energy use on-board would require 250 to 350 kWh of storage. For emergency use, another 25 kWh of energy storage is needed.
Scraping the deck onboard the 'Parma'. Alan Villiers, 1932-33.
Not having an engine, generator and fuel tank saves space on board, but this advantage can be quickly lost again when one starts to add batteries for the hydrogenerators. Lithium-ion batteries are very compact, but they cannot be considered sustainable and bring safety risks. That’s why Jorne Langelaan and Andrew Simons see more potential in – very aptly – saltwater batteries, which are non-flammable, non-toxic, easy to recycle, have wide temperature-tolerance, and can last for more than 15 years. Like the biodigester, they have never been used on a sailing ship before.
Unlike lithium-ion batteries, saltwater batteries are large and heavy. At 60 kg per kWh of storage capacity, a 150 kWh battery storage would add a weight of 9 tonnes, while a 350 kWh storage capacity would add 21 tonnes. Still, this compares favourably to the total cargo capacity (500 tonnes), and the batteries can serve as ballast if they are placed in the lower part of the ship’s hull. The space requirements are not too problematic, either. Even a 350 kWh energy storage only requires 14 to 29m3 of space, which is small compared to the 880m3 of cargo volume.
The emissions that are produced by the manufacturing of the hydrogenerators, biodigester, and batteries are not included in the life cycle analysis of the ship, because there are no data available. However, these emissions must be relatively small. Hydrogenerators have much higher power density than wind turbines, and thus a relatively low embodied energy. A quick back-of-the-envelope calculation learns that the carbon footprint of 350 kWh saltwater batteries is around 70 tonnes of CO2. [7]
There’s another renewable power source and energy storage on board of the EcoClipper, and that’s the humans themselves. Like the pellet stove and the biodigester, the use of human power could reduce the need for electricity. Nowadays, cargo ships and most large sailing ships have electric or hydraulic winches, pumps, and steering gear, saving manual labour at the expense of higher energy use. In contrast, EcoClipper sticks to manual handling of the ship as much as possible.
Crew at the capstan of the Parma, weighing anchor. Alan Villiers, 1932-33.
Simons and Langelaan are also considering the addition of a few rowing machines, coupled to generators, to produce emergency power. Two rowing machines could provide roughly 400 watts of power. If they are operated around the clock in shifts, they could supply the ship with an extra 9.6 kWh of energy per day (ignoring energy losses) – one fifth of the total maximum electricity use.
In fact, as I tell Simons and Langelaan ten rowing machines operated continually in shifts would provide as much power as the hydrogenerators at a speed of 7.5 knots. If there are 60 people on board, and everybody would generate power for less than one hour per day, no hydrogenerators and batteries would be needed at all. “A very interesting thought”, answers Simons, “but what impression would we be painted with?”
Even with a biodigester, hydrogenerators, batteries, and rowing machines, the passengers and crew on board the EcoClipper500 would be far short of luxurious, and perhaps too short of comfortable for some. For example, if 60 people on board the ship would take a daily hot shower – which requires on average 2.1 kilowatt-hours of energy and 76.5 litres of water on land – total electricity use per day would be 126 kWh, more than double the energy the ship produces at a speed of 7.5 knots.
The ship could supply this energy at a higher sailing speed, but there would also be a need for 4,590 liters of water per day, a quantity that could only be produced from seawater – a process that requires a lot of energy. Even a crew of 12 taking a daily hot shower would require 25.2 kWh of energy per day, half of what the hydrogenerators produce at a sailing speed of 7.5 knots. The Bark Europa is the only sailing ship mentioned in this article that has hot showers in every (shared) cabin, but it is also the ship with the biggest generators and the highest fuel use.
On the forecastle head of the Parma in fine weather. Image by Alan Villiers, 1932.
Andrew Simons: “On the EcoClipper500 there needs to be a manageable compromise between energy use and comfort. Energy use on board will have to be actively managed. Resources are finite, just like for the planet. In many ways the ship is a microcosm of challenges that the wider world has to face and find solutions to.”
Jorne Langelaan: “At sea you are in a different world. It doesn’t matter anymore if you can take a daily shower or not. What matters are the people, the movements of the ship, and the vast wilderness of ocean around you”.
This article has compared the EcoClipper500 sailing ship with the average container ship, bulk carrier, and airplane in terms of emissions per tonne- or passenger-kilometer. However, these values are abstractions that obscure much more important information: the total emissions that are produced by all passengers and all cargo, over all kilometres.
The international ocean freight trade increased from 4 billion tonnes of cargo in 1990 to 11.2 billion tonnes in 2019, resulting in more than 1 billion tonnes of emissions. International air passenger numbers grew from 1 billion in 1990 to 4.5 billion in 2019, resulting in 915 million tonnes of emissions. Consequently, lowering the emissions per tonne- and passenger-kilometre is neither a necessity nor a guarantee for a reduction in emissions.
If we cut international cargo traffic more than fivefold, and passenger traffic more than tenfold, then the emissions of all container ships and airplanes would be lower than the emissions of all sailing ships carrying 11.2 billion tonnes of cargo and 4.5 billion of passengers. Vice versa, if we switch to sailing ships, but keep on transporting more and more cargo and passengers across the planet, we will eventually produce just as much in emissions as we do today with fossil fuel powered transportation.
The mizzen of the 'Grace Harwar'; view aft from the main crosstrees. Alan Villiers, 1932-33.
Of course, none of this would ever happen. The amount of cargo that was traded across the oceans in 2019 equals the freight capacity of 22.4 million EcoClippers. Assuming the EcoClipper500 can make 2-3 trips per year, we would need to build and operate at least 7.5 million ships, with a total crew of at least 90 million people. Those ships could only take 0.5 billion passengers (12 passengers and 8 trainees per ship), so we would need millions of ships and crew members more to replace international air traffic.
We should not be fooled by abstract relative measurements, which only serve to keep the focus on growth and efficiency.
All of this is technically possible, and as we have seen, it would produce less in emissions than the present alternatives. However, it’s more likely that a switch to sailing ships is accompanied by a decrease in cargo and passenger traffic, and this has everything to do with scale and speed. A lot of freight and passengers would not be travelling if it were not for the high speeds and low costs of today’s airplanes and container ships.
It would make little sense to transport iPhones parts, Amazon wares, sweatshop clothes, or citytrippers with sailing ships. A sailing ship is more than a technical means of transportation: it implies another view on consumption, production, time, space, leisure, and travel. For example, a lot of freight now travels in different directions for each next processing stage before it is delivered as a final product. In contrast, all sail cargo companies mentioned in this article only take cargo that cannot be produced locally, and which is one trip from producer to consumer. [8]
This also means that even if sailing ships have diesel engines on board, they would still bring a significant decrease in the total emissions for freight and passenger traffic, simply because they would reduce the absolute number of passengers, cargo, and kilometers. We should not be fooled by abstract relative measurements, which only serve to keep the focus on growth and efficiency.
Kris De Decker
Proofread by Alice Essam. More about the EcoClipper500. Most images: Alan Villiers collection.
[1] Between 1978 and 2004, the Avontuur was operated as sail cargo vessel under Captain Paul Wahlen. The Apollonia, originally built in 1946, is another cargo sailing ship in operation since 2014. It is 19.5 metres long and carries 10 tonnes of cargo.
[2] Very recently, Grain de Sail was buillt and launched for Trans-Atlantic shipping of wine and cocoa. She is a modern sailing ship without an engine, built from aluminium, and can take 35 tonnes of cargo.
[3] Andrew Simons: “There are plenty historical sailing ships, but either very costly to get into service as a regulatory compliant cargo vessel, because they are still used for other purposes, or not suitable.”
[4] Unfortunately the envelope got lost.
[5] In the case of the EcoClipper, most of the emissions are produced during the construction of the ship, while in the case of bulk carriers and container ships, they are mainly produced during operation and fuel production.
[6] The largest container ships now take 190,000 tonnes of cargo.
[7] There is not much data available on saltwater batteries, but they are less energy-intensive to build than many other types of batteries. The calculation is based on an estimate of 66 kg CO2/kWh of storage capacity and three generations of batteries over a period of 50 years.
[8] Almost one third of all cargo transported are fossil fuels themselves.
[9] The study can be downloaded when you subscribe to EcoClipper’s newsletter. The research is based on a typical life cycle analysis, but note that this is not a peer reviewed study.
Note: This post is adapted from my journal paper, which was accepted to Aerospace Science and Technology in Spring 2021. You can read the full paper here
With the adoption of efficient low-thrust propulsion methods, the probability of a missed thrust event occurring has become a significant concern for short and long-duration missions. If the missed thrust event occurs during a critical portion of the trajectory, the mission can be compromised. Therefore, it is essential to develop trajectories that are resilient to missed thrust events. This paper investigates the use of expected thrust fraction, which embeds the stochastic nature of missed thrust events into a deterministic optimal control problem. The Technique is applied to a sample Mars-to-Earth trajectory. The performance of trajectories designed using expected thrust fraction is compared with traditionally designed trajectories and trajectories with a forced terminal coast. Thus, the changes in resiliency to missed thrust events are quantified. In this investigation, trajectories designed using expected thrust fraction arrive with a median lateness which is approximately half that of traditionally designed trajectories for a negligible change in delivered mass. Expected thrust fraction can help astrodynamicists mitigate risks posed by the use of low-thrust propulsion.
How the Control Angle Changes as Expected Thrust Fraction Becomes More Conservative
The full paper is online here, but here are, in my opinion, the most interesting aspects
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In the ranks of exoplanets we can actually see, we can include the gas giant PDS 70b, a young world orbiting the K-dwarf PDS 70. Bear in mind that of the more than 4,000 exoplanets thus far catalogued, only about 15 have been directly imaged, an indication of how tricky this work is and how far we have to go as we contemplate imaging Earth-size planets and taking spectroscopic measurements of their atmospheres. The most recent PDS 70b work was performed with the Hubble instrument, and is to my knowledge the first direct detection of an exoplanet in the ultraviolet.
About 370 light years from Earth, PDS 70 (also known as V1032 Centauri) is a T Tauri star, a class of variables less than 10 million years old; this one appears to be no more than 5 million years old, and its largest planet is still in the process of building mass. The star is known to host at least two actively forming planets within its circumstellar disk of gas and dust, although only the larger is apparent in these UV observations.
Image: Hubble observations pinpoint planet PDS 70b. A coronagraph on Hubble’s camera blocks out the glare of the central star for the planet to be directly observed. Though over 4,000 exoplanets have been cataloged so far, only about 15 have been directly imaged to date by telescopes. The team’s fresh technique for using Hubble to directly image this planet paves a new route for further exoplanet research, especially during a planet’s formative years. Credit: Joseph DePasquale (STScI).
What we’re seeing here is planet formation as flagged by the radiation produced by hot gas falling onto the planet, allowing estimates of how fast PDS 70b is gaining mass. In its short (in astronomical terms) history, the world has grown to roughly 5 Jupiter masses. The accretion rate is now dwindling, and the team studying the planet, led by Yifan Zhou (University of Texas at Austin), describes it as being at the end of the formation process.
Two disks are actually at play here, the first being the circumstellar disk that is supplying growth materials in the form of gas and dust to the entire infant system; the second is the disk around PDS 70b, which is drawing off material from the larger disk, producing hot patches apparent at ultraviolet wavelengths on the forming planet. We can hypothesize that a system of satellites like Jupiter’s could form here as well.
Image: This illustration of the newly forming exoplanet PDS 70b shows how material may be falling onto the giant world as it builds up mass. By employing Hubble’s ultraviolet light (UV) sensitivity, researchers got a unique look at radiation from extremely hot gas falling onto the planet, allowing them to directly measure the planet’s mass growth rate for the first time. The planet PDS 70b is encircled by its own gas-and-dust disk that’s siphoning material from the vastly larger circumstellar disk in this solar system. The researchers hypothesize that magnetic field lines extend from its circumplanetary disk down to the exoplanet’s atmosphere and are funneling material onto the planet’s surface. The illustration shows one possible magnetospheric accretion configuration, but the magnetic field’s detailed geometry requires future work to probe. The remote world has already bulked up to five times the mass of Jupiter over a period of about five million years, but is anticipated to be in the tail end of its formation process. Credit: NASA, ESA, STScI, Joseph Olmsted (STScI).
According to the paper, the luminosity we see in these data is low compared to the mass accretion rate the researchers had expected through their shock modeling, leading to this note at the end of the paper. The hydrogen alpha (Hα) spectral line referenced below is the brightest hydrogen line in the visible spectral range:
The discrepancy suggests that either Hα production in planetary accretion shocks is more efficient than these models predicted, or we underestimated the accretion luminosity/rate. By combining our observations with planetary accretion shock models that predict both UV and Hα flux, we can improve the accretion rate measurement and advance our understanding of the accretion mechanisms of gas giant planets.
So when it comes to probing the accretion of giant planets, we’re making progress, as witness Hubble’s ability to examine ultraviolet emissions from this growing young world. This is crafty work that extends Hubble’s capabilities by a factor of five when it comes to observing a planet close to its star, a tribute to skillful image processing. Co-author Brendan Bowler, a college of Zhou at the University of Texas at Austin, adds:
“Thirty-one years after launch, we’re still finding new ways to use Hubble, Yifan’s observing strategy and post-processing technique will open new windows into studying similar systems, or even the same system, repeatedly with Hubble. With future observations, we could potentially discover when the majority of the gas and dust falls onto their planets and if it does so at a constant rate.”
Image: The European Southern Observatory’s Very Large Telescope caught the first clear image of a forming planet, PDS 70b, around a dwarf star in 2018. The planet stands out as a bright point to the right of the center of the image, which is blacked out by the coronagraph mask used to block the light of the central star. Credit: ESO, VLT, André B. Müller (ESO).
The paper is Yifan Zhou et al., “Hubble Space Telescope UV and Hα Measurements of the Accretion Excess Emission from the Young Giant Planet PDS 70 b,” Astronomical Journal Vol. 161, No. 5 (29 April 2021), 244. Abstract / Preprint.
Last week, a petition was started to name NASA’s Lunar Gateway the Collins Lunar Gateway in honor of Apollo 11 Command Module Pilot Michael Collins, who passed away at the age of 90 on April 28th. It only needs less than 2,000 more signatures before it reaches the next goal. Let’s do it!!
I believe I drew the brand new (at the time) pose for Rocket Hat in panel 3 just so that I could use that joke about him putting on the chains of honor, as the only other drawing of him features him already wearing handcuffs.
In retrospect, I could have just said “now that you are wearing the chains of honor,” and saved myself the trouble. You know, the trouble of drawing even one fresh image for my comic strip.
As always, thanks for using my Amazon Affiliate links (US, UK, Canada).
I ran across a brief post from Jim, N3JT, in the January 2021 Solid Copy (CWops magazine), that described a online mapping tool that shows hams around the point you choose. I chose FN41fn, and saw the following (after zooming out a bit):
Pretty cool tool! Available here: https://haminfo.tetranz.com/map
The Hardrock-50 (see Figure 1) is a US-designed, 5W-in to 50W-out HF amplifier that operates on the 160 through 6m amateur bands. It includes automatic band switching, does not require tuning, and integrates seamlessly with popular rigs such as the Elecraft KX3 or Yaesu FT-817 series. An optional QSK board and automatic antenna tuner are available. The amplifier runs on 13.8 VDC and draws under 10 amps at full output.
The HR-50 is provided as a well-documented kit and can be assembled in about ten hours. It aligns easily using common test equipment and performs well. My own kit easily out-performed the amplifier’s design specs. Price is US$299 from Hobby PCB in Florida at https://hobbypcb.com.
Having recently returned to amateur radio, I was interested in the new digital modes, and especially the new digital HF mode FT8. My new Elecraft KX3 performed very well on the mode, and I was able to achieve WAS (Worked All States) in about three weeks using the radio’s maximum recommended digital output of 5 watts into my 23-metre longwire antenna.
That said, working DX using FT8 while QRP was quite difficult, and although I worked a small number of foreign stations, I found that it took quite a bit of effort to be heard among the other stations who were using higher power and better antennas than I have. I had no problem hearing considerable DX; the problem was that they usually did not hear me. Something had to be done!
I started researching linear amplifiers with an output of 50 to 100 watts, thinking that being able to boost my signal at the antenna would likely make me more competitive and allow me to work much of the interesting DX that I had been hearing.
I learned that 100-watt class amplifiers were either low quality and affordable, or of high quality, but more expensive than my limited budget would allow. Reviews of some of the cheap amplifiers showed them to generate high amounts of distortion and even spurious illegal emissions. Not something that I would allow in my station!
Additionally, I doubted the necessity of running 100 watts on FT8 (my main communication interest) as the mode performs so well on very weak signals that more than 10-30 watts is hardly ever required to work global DX. 50 watts would give me enough “edge” to work a lot of DX.
My extensive research led me to a US-designed amplifier kit called the “Hardrock-50”, from a small firm called “Hobby PCB”1 in the eastern US. The amplifier covers 160 through 10 metres with an output of approximately 50 watts for 5 watts input, and about 40 watts output on 6 metres.
The prototype for the Hardrock-50 was a winner in a design contest sponsored by the ARRL in 2010. The much-evolved production version, now called the HR-50, is FCC “type accepted” and meets all legal requirements for amateur band operation.
Reviews of the HR-50 were excellent, and the documentation on the Hobby PCB website showed that the assembly and operation manuals were complete and well-designed, and reminiscent of the classic “Heathkit” manuals of the 1950s-1990s. It looked like a good solution to my needs.
At US$299, the price for the kit met my budget, so in late January I “took the plunge” and ordered the amplifier kit. I ordered the optional full break-in (QSK) board as a US$30 option, but decided against the internal automatic antenna tuner (a US$179 option) as I already own a nice external auto-tuner from LDG. I planned to use that with the new amplifier.
The kit arrived in a few days. The parts were all of good quality, and the kit was organized into sub-packs of parts for each main component of the assembly process (front panel; back panel; main PCB, et cetera).
I downloaded the HR-50 assembly manual to my iPad and followed it step-by-step. The manual is well-written and clear. There are three PCBs provided: for the front panel, the back panel, and the larger main PCB. My kit contained a fourth PCB for the optional QSK board. All the PCBs come pre-populated with the key surface mount components such as the microprocessors which control the amplifier. The PCBs are manufactured off-shore but quality is good. No SMD soldering is required.
Assembly starts with the front panel and works through the back panel, the main PCB, and lastly, the QSK board for those customers who have purchased this option. Assembly consists of inserting and soldering through-hole devices such as the four MOSFET power transistors, band switching relays, connectors, and headers and short jumper cables which link the amplifier’s boards together.
The optional QSK board is installed above the main PCB through provided headers and nylon spacers. Hardware is of excellent quality (stainless steel) and everything fit together perfectly.
Assembly was straightforward and I encountered only a few issues with the assembly steps. For example, in one step in assembly of the main PCB, I failed to read the step to the very end, and unfortunately installed two 2-pin terminal blocks which were NOT required if one is installing the QSK board. I had to de-solder the two terminal blocks as they would mechanically interfere with the QSK board to be installed above. A minor inconvenience, and technically my error, as I should have read the step to the very end!
An amplifier is an analog device, so the main PCB contains about 15 toroidal inductors which are part of the different ham band filters. The ~1.5 cm cores and a generous supply of enameled wire are provided. Alternatively, a full set of pre-wound toroids is available as a kit option for US$30.
I chose to wind my own toroids for the experience, as I had never wound smaller toroids such as these. The directions in the manual were clear and photographs of what the finished toroids should look like are included in the assembly manual, so I decided to do the winding myself. I thought that it would be a great opportunity to learn a new skill. See Figure 2 below.
Amplifier filter “Q” (and consequently, amplifier performance) is improved by taking care to wind quality toroids, so it is worth the time to complete these assembly steps properly. The turns need to be tightly wound and spaced evenly. Critical is proper counting of the turns through each core. The toroid winding steps took me about two hours.
The hardest part of winding the toroids is removal of the insulation from the wire ends. This can be accomplished either by scraping (Exacto knife or Dremel tool) or via application of heat from a soldering iron. I used a combination of the soldering iron method and scraping with an Exacto knife. This took a couple of hours, but I got it done. After building the kit, I discovered a great tool for stripping enameled wire3. It’s designed for this purpose and works really well. I ordered one for US$14 on Amazon and would definitely recommend using one, as it makes stripping the enameled wire quick and easy!
Three small transformers must also be wound using supplied wire, but these were straightforward once I had completed the big toroid winding job.
The kit includes a large extruded aluminum heatsink to dissipate heat from the four power MOSFETs. This serves also as the chassis for the entire amplifier. The main PCB is secured to the heatsink, and the front and back panels are bolted to the ends of the heatsink. The four MOSFETs and a helpful temperature sensor are also mechanically attached to the heatsink. The provided aluminum cover then integrates everything into a nice-looking device, as can be seen in the attached photos of my amplifier.
After about ten hours of (fun) work over three days, my amplifier was complete and ready for alignment and testing. See Figure 3 below.
Alignment of the HR-50 requires a 13.8 VDC power supply capable of about 10 amps, a small screwdriver and an ammeter such as available on common DMMs. The process consists of setting zero-drive bias current on the four MOSFETs.
This was a straightforward process and my new amplifier tuned up easily and quickly.
Next came the moment of truth! I connected the amplifier RF input to my KX3, and the amplifier output to a good quality dummy load. For the automatic control signals, I connected my KX3’s control output signals and serial port to the amplifier through a small KX3 interface board that I bought from Hobby PCB as a US$30 option.
I could have made my own (simple) control cable but chose the easy route in this case! Cable pinouts are provided in the assembly manual for those who want to “roll their own” interface cable.
Three settings on the KX3 had to be changed to set the inter-device baud rate and route PTT to the HR-50. Similarly, three settings had to be set on the HR-50s control menus. Then, I was ready to go!
First, I wanted to confirm that the HR-50 was receiving band change information from my KX3. I reduced my KX3’s output power to 0 watts and cycled up and down through the amateur bands on my KX3. The HR-50 received the band change data and nicely tracked band changes.
Next came a test of amplifier performance. I keyed the transmitter (still into the dummy load) and increased power to 0.5 watts. The HR-50 was working! I cycled through the bands and noted that power output was working well. On some bands, for example, I could easily exceed 50 watts output with only 2 to 3 watts of drive. I was suitably impressed!
On other bands, notably 20 and 80 metres, however, I noted that the HR-50’s output was strangely low. What could be the cause?
I’m as human as the next guy, and this section describes how I resolved this odd “low power on some bands” anomaly.
I investigated the low power situation, particularly on 20 metres, for a few days without resolution. I suspected that perhaps I had made an error in winding one of the toroids. I emailed Hobby PCB with a few questions and was honestly surprised when I got an email back from the amplifier’s inventor, Jim Veatch (WA2EUJ) within an hour.
Jim was very supportive and gave me some suggestions for testing. He reminded me early that “Hobby PCB guarantees a working amplifier for every customer”, and that if we could not resolve the problem, that I could simply ship my HR-50 to him and that he would personally find the problem and fix it himself. Impressive customer service!
I did some troubleshooting using Jim’s suggestions, and the HR-50 seemed to be “normal” in all respects. Very odd; I pondered this overnight.
The next morning, I decided to go “back to basics” and troubleshoot from the KX3 outward. I put a wattmeter on the KX3’s output – something that I had not done before as I was relying on the rig’s internal (more accurate) digital wattmeter.
I noted that on 20 and 80 metres (the bands with the lowest HR-50 output) that even if I set my KX3 to read 5 watts on its internal wattmeter, that my external meter only read about 1 watt output. How could this be? The rig was almost new. Had I “blown the finals”, as we used to say in the old tube-based rig days?
Then, a glance at the KX3’s display caused something to “twig”: the KX3’s internal ATU was still on! The KX3 had previously been used with my non-resonant-on-20-and-80 longwire antenna and still assumed that it was feeding that antenna, not the amplifier. The rig was now connected to the (resonant) HR-50. Eureka!
I disabled the KX3’s ATU, and the external wattmeter now showed 5 watts output on each band. The HR-50’s output into the dummy load jumped to what it should be, 50 watts+ on 160 through 10, and 40 – 50 watts on 6 metres. I was in business! See Figure 4 below.
I hit the bands with my longwire and noted vastly improved reception of my signal by both NA and DX stations. The option to run up to 50 watts is great and has allowed me to make many more contacts that I could with 3 (maximum 5) watts digital on my “barefoot” KX3.
Now, about three weeks in, the HR-50 continues to perform perfectly. The front panel user interface is easy to use, and the amplifier tracks band changes automatically.
Also appreciated is the fact that the amplifier is unaffected by high SWR at the antenna connector. An open circuit, or even a dead short at the antenna terminal will not damage the MOSFETs. Of course, I have not made either of these errors, but it is nice to know that the finals cannot be “blown”, like in the “olden days”!
The heatsink gets quite hot using digital modes like FT8 with its 50-percent duty cycle, and heatsink temperature can reach 50 to 60 degrees Celsius. However, these heatsink temperatures are within the amplifier’s “normal” range, and the HR-50 operating manual says that external cooling should only be considered if the heatsink temperature goes above 90 degrees C. This is unlikely, in my experience.
The QSK board in the amplifier also works well and provides silent and extremely fast T/R switching, including “inter-dit” reception when using CW.
For my station and operating profile, the Hardrock-50 was a great investment. The kit is professionally designed and well documented, the amplifier works as specified, and it is backed by excellent support. Assembly was straightforward and fun, and I learned something about winding toroids. I will also not forget to turn off my KX3’s ATU when I return from portable to base operation!
I am extremely happy with the HR-50 kit and would highly recommend it to anyone running QRP and looking for a moderate boost in output power.
That’s it for this review. Please feel free to send comments and questions to me at mcquiggi@sfu.ca.
~ Kevin VE7ZD/K7MCQ
19-03
Guys.
Guys.
Guys.
Remember that awkward Gemini 12 gag photo?
THERE IS NOW ANOTHER ONE OF THESE.
THIS IS NOT A DRILL.
Nostalgia mini-theme this week, or maybe “classical”?
Exciting announcement from Kevin Bates, creator of Arduboy, on Hackster:
Make your own Arduboy-compatible game system and win the brand new Arduboy FX!
Arduboy is an open source game system based on Arduino that has been supported by an awesome community for over five years with over 200 games available to play!
Arduboy community members have already made hundreds if not thousands of homemade versions of their very own Arduboy, now is your chance to share yours on Hackster!
The Arduboy consists of an OLED display (SSD1306), ATmega32U4 processor (same as Leonardo, Micro or Pro Micro), six tactile buttons and an optional speaker and RGB LED. You are encouraged to try and port Arduboy games to other microprocessor platforms and displays for bonus points!
All the instructions on how to make your own Arduboy game system are available for free online. If you have already documented your project on the Arduboy community or elsewhere you can import it to Hackster and join the contest too.
Because Arduboy is open source all of the information about how it is made is published for others to learn and understand from. Learning to make and program an Arduboy helps teach critical thinking and problem solving skills! Make an Arduboy today, you just might learn something!
Alternate Processor or Display – Get extra points for going beyond the ATmega32U4 and SSD1306!
Custom PCBÂ – Projects that use a custom circuit board made for this contest will receive bonus points!
— Kevin Bates (@bateskecom) May 6, 2021
Big Announcement Time!
I'm joining the @Hacksterio team as the new Contest Manager! Help me celebrate by joining the DIY Arduboy Contest and compete to win a brand new Arduboy FX!https://t.co/iP9YvkjKo1
I noticed a tweet by Ei2iP today that showed his satellite ground station. He’s done a nice job of integrating an IC-9700 with his Mac mini, a couple of monitors and AzEl rotor. He was using MacDoppler for satellite tracking and MacLoggerDX for logging.
There’s an IC-7300 on the desk for good measure.
This is almost identical to my own setup though I keep futzing around with the station layout. I asked him what he was using to control the rotor and he replied that chore was handled by a GSB-232B interface from JZG Electronics which wasn’t familiar to me.
You can follow the link above for additional details. My interest was because the rotor interface was the last component added to my satellite station and I went with the S.A.T. by CSN Technologies. I’m pleased as punch with the unit I purchased, but this seemed an oddity to me because long ago we almost always built these interfaces from kits provided by AMSAT or TAPR.
Those options didn’t seem to exist when I started the current satellite station build so I purchased off the shelf. There are several options available, but it’s good to know that there’s at least one more available too, even if it’s in Europe.
The Naval Academy station was transmitting on 7,535.0 KHz, while listening to 7,028.0 KHz. I was able to work NSS on CW today at 17:46 UTC. (Subsequently worked NSS on SSB 7.536.5/7.197 MHz, and NAF on SSB 7.542/7.275 MHz)
Boy, is it hard to get a non-ham call and frequency logged in DXkeeper (but doable). I understand QSLs can be exchanged through K3LU, their QSL manager.
I was pleased to hear yesterday that I had been nominated and sponsored for membership in CWops. I’m member 2903.
I’ve been active for the past seven weeks in their CWT (mini contests that run every Wednesday at 1300, 1900 & 0300Z (actually Thursday in the states). I suspect that helped to get recognized.
Since I love teaching, and their mission is education and getting folks involved in Morse Code, I am thinking of helping this fall.
