News Feeds

Many people are familiar with facial recognition systems that unlock smartphones and game systems or allow access to our bank accounts online. But the current technology can require boxy projectors and lenses. Now, researchers report on a sleeker 3D surface imaging system with flatter, simplified optics. In proof-of-concept demonstrations, the new system recognized the face of Michelangelo's David just as well as an existing smartphone system.

Many people are familiar with facial recognition systems that unlock smartphones and game systems or allow access to our bank accounts online. But the current technology can require boxy projectors and lenses. Now, researchers report on a sleeker 3D surface imaging system with flatter, simplified optics. In proof-of-concept demonstrations, the new system recognized the face of Michelangelo's David just as well as an existing smartphone system.

Oxidation can degrade the properties and functionality of metals. However, a research team recently found that severely oxidized metallic glass nanotubes can attain an ultrahigh recoverable elastic strain, outperforming most conventional super-elastic metals. They also discovered the physical mechanisms underpinning this super-elasticity. Their discovery implies that oxidation in low-dimension metallic glass can result in unique properties for applications in sensors, medical devices and other nanodevices.

When we look up at the sky on a particularly dark night, there is a sense of timelessness. We might see the flash of a meteor, and occasionally a comet is visible to the naked eye, but the cold and distant stars are unchanging. Or so it seems. There can also be a sense of calm, that despite all the uncertainty of the world, the stars will always watch over us. So it’s hard to imagine that light years away there could be a lurking event that poses an existential threat to humanity. That threat is extremely tiny, but not zero, and it is the focus of a recent paper published in The Astrophysical Journal.

The study focuses on kilonovae, which can occur when either two neutron stars collide, or a neutron star collides with a stellar-mass black hole. Kilonovae are similar to supernovae, but much more intense. In the paper, the authors look at a particular kilonova known as GW170817. It was detected by the LIGO and Virgo gravitational wave observatories in 2017, and seen as a gamma-ray burst by the Fermi and INTEGRAL space telescopes. Since we have both optical and gravitational observations, the energy of the kilonova can be calculated quite well.

The team took this data and combined it with computer simulations on kilonovae. They wanted to estimate the minimum safe distance of a kilonova. In other words, how close to us could one go off and still be a harmless light show? What they found was that there are several safe distances, depending on which aspect of the supernova poses a threat.

Diagrams of emissions from a binary neutron star merger. Credit: Perkins, et al

One threat would be the X-ray afterglow. When neutron stars collide, a jet of high-energy gamma rays can stream from their common polar region. These jets collide with interstellar gas and create an afterglow of intense X-rays. The intensity of this glow could ionize Earth’s atmosphere, leaving us exposed to things like solar flares and ultraviolet radiation. But only if the kilonova occurred within about 16 light-years of Earth. The gamma rays themselves could pose a similar threat, but only to within about 13 light-years.

But as the team found, the greater threat wouldn’t reach us at the speed of light. After the explosion, a shockwave from the collision would expand away from the kilonova over the span of about a thousand years. When the shockwave collides with interstellar gas and dust, it creates intense cosmic rays. If such a stream of cosmic rays reached us it could vaporize our atmosphere, killing almost all life on Earth. But this would only pose a threat to a distance of about 40 light-years.

GW170817 occurred about 130 million light-years away, so it poses absolutely no threat to us. Even if one were to occur in our stellar neighborhood, it would likely be too distant to pose any harm. As far as we know, there are no binary neutron stars within 40 light-years that will merge any time soon. So there is nothing for us to worry about. Mostly what this study shows is that throughout the cosmos kilonovae can pose a threat to life from time to time, but that threat is not large enough to wipe out a large fraction of worlds. We can face cosmic dangers, but thankfully a kilonova isn’t one of them.

Reference: Perkins, Haille ML, et al. “Could a Kilonova Kill: A Threat Assessment.” The Astrophysical Journal 961.2 (2024): 170.

The post How Dangerous are Kilonovae? appeared first on Universe Today.

Researchers have succeeded in generating a logical qubit from a single light pulse that has the inherent capacity to correct errors.

Researchers have succeeded in generating a logical qubit from a single light pulse that has the inherent capacity to correct errors.

Astronomers have shown new atmospheric detail in a set of 15 exoplanets similar to Neptune. While none could support humanity, a better understanding of their behavior might help us to understand why we don't have a small Neptune, while most solar systems seem to feature a planet of this class.

A research team develops edge-to-edge assembly technique for 2D nanosheets.

Swedish astronaut Marcus Wandt took control of a series of robots in Germany while on board the International Space Station, zipping around the Earth at 28,000 kilometers per hour (17,500 mph.) Researchers want to understand how time delays can affect the remote control of robots from an orbiting platform. Future astronauts could control rovers on the Moon’s or Mars’s surface from a spacecraft in orbit. Until now, only wheeled rovers have been part of the tests, but now they have added a dog-like robot called Bert.

This robot research session, called ‘Surface Avatar’ follows initial experiments carried out in July 2023. Wandt operated the robots from a control station in the space station’s Columbus module, commanding three different robots at the German Space Agency’s (DLR) Robotics and Mechatronics Center in Oberpfaffenhofen, Germany. The goal is to develop innovative technologies that will allow humans to control several robots with precision, and have them act semi- or fully autonomously and even have different robots perform a task together.

As part of the ‘Surface Avatar’ experiment, Swedish ESA astronaut Marcus Wandt commanded various robotic systems from the International Space Station (ISS). Credit: ESA/NASA

“Future stations on the Moon and Mars, including astronaut habitats, will be built and maintained by robots operating under the guidance of astronauts,” said Alin Albu-Schäffer, Director of the DLR Institute of Robotics and Mechatronics, in a DLR article. “Our latest control and AI algorithms enable a single astronaut to command an entire team of different robots. Our DLR-ESA team is a world leader when it comes to this technology.”

The remote operation of the dog-like robot Bert was marked the first time a non-wheel-driven robot was controlled remotely from space by astronauts. Previously, DLR’s humanoid service robot Rollin’ Justin and ESA’s Interact Rover have been teleoperated from space.

During the session, Wandt, who is part of the private Axiom Mission 3 (Ax-3), was able to command Bert to utilize several types of gaits and, because of his leg-based locomotion, Bert was able to explore rough terrain, including small caves — areas that the rolling robots cannot reach. At one point, Wandt allowed Bert to explore the lab’s surroundings independently and monitor the terrain with his camera eyes. Meanwhile, Wandt operated Rollin’ Justin and the Interact Rover.

The ‘Surface Avatar’ series of telerobotics experiments is aimed in particular at the further development of collaborative robots to support astronauts. The project is being led by the DLR Institute of Robotics and Mechatronics, in collaboration with the European Space Agency (ESA) and the German Space Operations Center. Credit: © DLR.

The time delay between the ISS and Earth is usually less than one second.

“That’s because my radio call comes from ISS first to White Sands in the USA,” explained German Space Agency astronaut Matthias Maurer, in a video from DLR. “From there it goes to Houston at NASA. From there it will be forwarded to Munich where our control center is in Oberpfaffenhofen.”

Maurer added that the delay experienced is like what sometimes happens on a Skype call, which occasionally has delays in communications. And of course, the round-trip delay time might be close to 2 seconds, which is deficiently noticeable, especially during conversations.

DLR said that future operations of robots and humans working together must be well planned out in order for them to work as a team. When building a habitat, for example, combining the different skills of several robots is very helpful.

Successful collaboration between two intelligent robots: ESA’s Interact Rover and DLR’s Rollin’ Justin robot jointly installed a short pipe that reproduces a scientific measuring device. The task was coordinated by ESA astronaut Marcus Wandt, who was in control of the robot team in DLR’s Mars laboratory in Oberpfaffenhofen from on board the ISS. Credit: DLR.

Wandt also tested out this concept and for the first time two robots worked together to accomplish a task: Rollin’ Justin and the Interact Rover jointly installed a short pipe representing a scientific measuring device. Under the command of Wandt, Rollin’ Justin used his dexterous hands to safely grasp the pipe and carefully guide it to the measuring point. Wandt then used the Interact rover’s remote control to install the pipe held in position by Justin.

Robots have also been used in space on board the ISS. Robonaut is a joint DARPA–NASA project that created a humanoid torso robot to test out robotics in space. Additionally, three free-flying robots on the space station, known as Astrobees, support multiple demonstrations of technology for various types of robotic assistance on space exploration missions and on Earth.

The post An Astronaut Controls a Robotic Dog From Orbit appeared first on Universe Today.

Did a meeting of chiropractors from around the world come to a historic consensus on the true causes of the chiropractic subluxation? No, this is satire. Still read the post though. Please.

The post Science-Based Satire: Historic Conference Clarifies Vertebral Subluxation Causes first appeared on Science-Based Medicine.

Large proportions of users posting on Twitter – now X – about the Chinese balloon that drifted over the US and Canada in 2023 were bots attempting to shape the debate

Researchers studying fruit fly egg cells have discovered that they stir up the fluid inside them with a twister-like current

Homer: Not a bear in sight. The Bear Patrol must be working like a charm.
Lisa: That’s specious reasoning, Dad.
Homer: Thank you, dear.
Lisa: By your logic I could claim that this rock keeps tigers away.
Homer: Oh, how does it work?
Lisa: It doesn’t work.
Homer: Uh-huh.
Lisa: It’s just a stupid rock.
Homer: Uh-huh.
Lisa: But I don’t see any tigers around, do you?
[Homer thinks of this, then pulls out some money]
Homer: Lisa, I want to buy your rock.
[Lisa refuses at first, then takes the exchange]

 

This memorable exchange from The Simpsons is one of the reasons the fictional character, Lisa Simpson, is a bit of a skeptical icon. From time to time on the show she does a descent job of defending science and reason, even toting a copy of “Jr. Skeptic” magazine (which was fictional at the time then created as a companion to Skeptic magazine).

What the exchange highlights is that it can be difficult to demonstrate (let alone “prove”) that a preventive measure has worked. This is because we cannot know for sure what the alternate history or counterfactual would have been. If I take a measure to prevent contracting COVID and then I don’t get COVID, did the measure work, or was I not going to get COVID anyway? Historically the time this happened on a big scale was Y2K – this was a computer glitch set to go off when the year changed to 2000. Most computer code only encoded the year as two digits, assuming the first two digits were 19, so 1995 was encoded as 95. So when the year changed to 2000, computers around the world would think it was 1900 and chaos would ensue. Between $300 billion and $500 billion were spent world wide to fix this bug by upgrading millions of lines of code to a four digit year stamp.

Did it work? Well, the predicted disasters did not happen, so from that perspective it did. But we can’t know for sure what would have happened if we did not fix the code. This has lead to speculation and even criticism about wasting all that time and money fixing a non-problem. There is good reason to think that the preventive measures worked, however.

At the other end of the spectrum, often doomsday cults, predicting that the world will end in some way on a specific date, have to deal with the day after. One strategy is to say that the faith of the group prevented doomsday (the tiger-rock strategy). They can now celebrate and start recruiting to prevent the next doomsday.

The question is – how do we know when our preventive efforts have been successful or if they were not needed. In either scenario above you can use the absence of anything bad happening as both evidence that the problem was fake all along, or that the preventive measures worked. The absence of disaster fits both narratives. The problem can get very complicated. When preventive measures are taken and negative outcomes happen anyway, can we argue that it would have been worse? Did the school closures during COVID prevent any deaths? What would have happened if we tried to keep schools open? The absence of a definitive answer means that anyone can use the history to justify their ideological narrative.

How do we determine if a preventive measure works. There are several valid methods, mostly involving statistics. There is no definitive proof (you can’t run history back again to see what happens), but you can show convincing correlation. Ideally the correlation will be repeatable with at least some control of confounding variables. For public health measures, for example, we can compare data from either a time or a place without the preventive measures to those with the preventive measures. This can vary by state, province, country, region, demographic population, or over historic time. In each country where the measles vaccine is rolled out, for example, there is an immediate sharp decline in the incidence of measles. And if vaccine compliance decreases there is a rises in measles. If this happens often enough, the statistical data can be incredibly robust.

This relates to a commonly invoked (but often misunderstood) logical fallacy, the confusion of correlation with causation. Often people will say “correlation does not equal causation”. This is true but can be misleading. Correlation is not necessarily due to a specific causation, but it can be. Over applying this principle is a way to dismiss correlational data as useless – but it isn’t. The way scientists use correlation is to look for multiple correlations and triangulate to the one causation that is consistent with all of them. Smoking correlates with an increased risk of lung cancer. But also, duration and intensity also correlate, as does filtered vs unfiltered, and quitting correlates with reduced risk over time back to baseline. There are multiple correlations that only make sense in total if smoking causes lung cancer. Interestingly, the tobacco industry argued for decades that this data does not prove smoking causes cancer, because it was just correlation.

Another potential line of evidence is simulations. We cannot rerun history, but we can simulate it to some degree. Our ability to do so is growing fast, as computers get more powerful and AI technology advances. So we can run the counterfactual and ask, what would have happened if we had not taken a specific measure. But of course, these conclusions are only as good as the simulations themselves, which are only as good as our models. Are we accounting for all variables? This, of course, is at the center of the global climate change debate. We can test our models both against historical data (would they have predicted what has already happened) and future data (did they predict what happened after the prediction). It turns out, the climate models have been very accurate, and are getting more precise. So we should probably pay attention to what they say is likely to happen with future release of greenhouse gases.

But I predict that if by some miracle we are able to prevent the worst of climate change through a massive effort of decarbonizing our industry, future deniers will argue that climate change was a hoax all along, because it didn’t happen. It will be Y2K all over again but on a more massive scale. That’s a problem I am willing to have, however.

Another way to evaluate claims for prevention is plausibility. The tiger rock example that Lisa gives is brilliant for two reason. First, the rock is clearly “just a stupid rock” that she randomly picked up off the ground. Second, there is no reason to think that there are any tigers anywhere near where they are. For any prevention claim, the empirical data from correlation or simulations has to be put into the context of plausibility. Is there a clear mechanism? The lower the plausibility (or prior probability, in statistical terms) then the greater the need for empirical evidence to show probable causation.

For Y2K, there was a clear and fully understood mechanism at play. They could also easily simulate what would happen, and computer systems did crash. For global climate change, there is a fairly mature science with thousands of papers published over decades. We have a pretty good handle on the greenhouse effect. We don’t know everything (we never do) and there are error-bars on our knowledge (climate sensitivity, for example) but we also don’t know nothing. Carbon dioxide does trap heat, and more CO2 in the atmosphere does increase the equilibrium point of the total heat in the Earth system. There is no serious debate about this, only about the precise relationship. Regarding smoking, we have a lot of basic science data showing how the carcinogens in tobacco smoke can cause cancer, so it’s no surprise that it does.

But if the putative mechanism is magic, then a simple unidirectional correlation would not be terribly convincing, and certainly not the absence of a single historical event.

Of course there are many complicated example about which sincere experts can disagree, but it is good to at least understand the relevant logic.

The post How To Prove Prevention Works first appeared on NeuroLogica Blog.

A nationwide electronic warfare system called Pokrova can disrupt satellite navigation – Ukraine may already be using it to prevent strikes by Russian drones and missiles, but doing so will also affect satnavs in the country

A game that prompts players to step on different arrows, like a dance mat, reduced falls among older people

Skeptoid is looking for institutional partners and/or title sponsors for a proposed video series.

Plastics from organic sources are touted as environmentally friendly, but they appear to make an appealing meal for some marine creatures

Scientists developed a new method to map exactly how a fungus works with leafcutter ants in a complex microbial community to degrade plant material at the molecular level. The team's insights are important for biofuels development.

It's an achievement with important implications for scientists studying the brain and working on treatments for a broad range of neurological and neurodevelopmental disorders, such as Alzheimer's and Parkinson's disease.

Researchers have been skeptical that recent AI advances can tell us much about human learning and development. To address this, a team training an AI model, not on massive data, but on the input that a single child receives. Their findings showed that the model could learn a substantial number of words and concepts using limited slices of what the child experienced.