Science

Researchers have developed a digital display screen where the LEDs themselves react to touch, light, fingerprints and the user's pulse, among other things. Their results could be the start of a whole new generation of displays for phones, computers and tablets.

Chemists show that a machine-based method prevents widespread 'bias' in chemical publications.

When scuba divers need to say 'I'm okay' or 'Shark!' to their dive partners, they use hand signals to communicate visually. But sometimes these movements are difficult to see. Now, researchers have constructed a waterproof 'e-glove' that wirelessly transmits hand gestures made underwater to a computer that translates them into messages. The new technology could someday help divers communicate better with each other and with boat crews on the surface.

When scuba divers need to say 'I'm okay' or 'Shark!' to their dive partners, they use hand signals to communicate visually. But sometimes these movements are difficult to see. Now, researchers have constructed a waterproof 'e-glove' that wirelessly transmits hand gestures made underwater to a computer that translates them into messages. The new technology could someday help divers communicate better with each other and with boat crews on the surface.

Researchers showed that AI assistance potentially could improve breast-cancer screening by reducing the number of false positives without missing true positives.

In a new breakthrough that could revolutionise medical and material engineering, scientists have developed a first-of-its-kind molecular device that controls the release of multiple small molecules using force.

My partner in crime, biologist Luana Maroja at prestigious Williams College, is once again making heterodox statements that will peeve a number of students—and perhaps faculty. But she is brave.

In this case, some Williams students got the bright idea last winter that the College should do away with all grades for first-semester students because those students want to play and socialize without any “pressure”. Further, the stress of getting grades could supposedly damage their mental health.

But of course one of the motivations (see below) also seems to be achieving “equity”—a motivation designed to cast opponents of the suggestion as bigots or racists. The “equity excuse” has been made by a number of colleges to not only eliminate grades for incoming students, but also to omit standardized tests like the SAT as requirements for applying to college. In its place some schools have installed “holistic admissions”, a way to get around the Supreme Court ruling that colleges cannot use race-based admissions.  In fact, required standardized tests seem have the effect of boosting minority achievement, by highlighting those students who do particularly well in comparison with others.

It appears, and this is not rocket science, that most student groups at Williams are in favor of the proposal. They don’t really want to bust their hump first semester; they want to play and hang out. Luana, of course, thinks this is slacking off, as you can see from her letter, which was published this morning in The Williams Record (the student newspaper). I agree because I’m an old-school professor, but Luana is young. It appeared today because the faculty will be discussing the propsal this afternoon.

Click below to read it:

I’ll quote the first four paragraphs of the letter, but the whole letter is about three times longer:

This winter, the student members of the Committee on Educational Affairs (CEA) brought an argument that the College should adopt a mandatory Credit/No Credit (C/NC) grading policy for students in their first semester at the College. On April 3, faculty were informed about this argument, which will be a topic of discussion at the faculty meeting this afternoon.

This suggestion was based on similar policies at peer institutions, like Swarthmore, MIT, and Wellesley, where first-year students still receive letter grades on all course components, but receive “credit” or “no credit” designations on their official transcripts (i.e. shadow grading). The argument claims that grade-induced academic expectations are stressful and that students’ mental health and social relationships will improve under a C/NC system while keeping students’ long-term academic performance intact. 

What proponents of the argument fail to realize is that adopting the policy could, in fact, result in significant academic harm, especially for students who do not come from elite academic backgrounds. Although there will not be a motion to adopt the policy at this afternoon’s meeting — the CEA brought this topic to the general faculty for discussion to build consensus on the “underlying value of the goals” — I think it is important to share my opinion here, because many students are not familiar with this argument and many professors who share my feelings are afraid to voice opposition due to the framing’s focus on mental health, grades, and minorities.

The argument claims that grades given in the first semester harm various marginalized groups. It asserts that “isolation, stress and a myopic focus on academics … are differentially demanding for marginalized students, whether based on their racial identity, class, sexual orientation or any otherness.” While I appreciate the empathy for marginalized groups, this framing stifles debate. Because the argument is framed as “reducing harm towards minorities,” professors and students opposed to the argument will be afraid of voicing concerns or offering arguments against it lest they be perceived as callous or bigoted. 

As Luana points out later, she herself, as a Brazilian student entering an American graduate school (Cornell), and coming from a dysfunctional educational system, well knows motivating value of assessing merit. You can’t do that with a pass/no pass system.

Today’s Jesus and Mo strip, called “rogues”,  came with an email note:

It must be true. It’s in a hadith!

Yep, it’s the old “turtles all the way down” answer to the question “But who made “Allah,”, except this time delivered with pebbles!

And here’s that hadith:

The Messenger of Allah (may peace be upon him) said to me: they (the people) will constantly ask you, Abu Huraira, (about different things pertaining to religion) then they would say: Well, there is Allah, but after all who created Allah? He (Abu Huraira) narrated: Once we were in the mosque that some of the Bedouins came there and said: Well, there is Allah, but who created Allah? He (the narrator) said: I took hold of the pebbles in my fist and flung at them and remarked: Stand up, stand up (go away) my friend (the Holy Prophet) told the truth.

Reader Don McCrady sent some lovely photos of the eclipse (I thought readers would send ’em in en masse, but it didn’t happen). Don’t captions are indented, and you can enlarge the photos by clicking on them.

I thought you might like to show your readers some photos from this past Total Eclipse.

I flew down to a spot near Lampasas, Texas. Unfortunately, we had some issues with the clouds, but we did have sporadic clearing that allowed me to get some fairly good shots.

Here’s a shot from the partial phase as the moon encroaches the sun, here about to cover up the huge sunspot numbered 3628. This sunspot was easily visible to the naked eye through our eclipse glasses. (Even the Trumpanzees I was with were smart enough to wear them when looking at the eclipse.)

In this shot, the totality is just beginning and we can see Bailey’s Beads. These are the last vestiges of the sun as they become eclipsed behind the mountains and valleys of the moon’s surface, and are one of the most beautiful phenomenon to photograph during the eclipse.

Finally we have a shot near the end of totality showing the huge solar prominences, again visible to the naked eye.

These images were shot using a Canon EOS R5, a Canon RF100-500mm extended all the way to 500mm at f/8. Partial phases were shot through a mylar solar filter, and the totality was shot with no filter.

And from Susan Harrison:

The eclipse as seen from New York City:

 

We are living in a time of technology advancing so rapidly it is challenging to keep up. This has multiple ramifications, and in the area of biomedical research, there is an important ethical and regulatory dimension. Confronting the ethical considerations of our own technology is nothing new, and fresh debate seems to erupt with every new development – including in-vitro fertilization, transplanting […]

The post The Ethics of Artificial Brains first appeared on Science-Based Medicine.

Inflamed gum tissue may allow bacteria in the mouth to enter the bloodstream, which could affect the heart

Avi Wigderson has won the 2023 Turing award for his work on understanding how randomness can shape and improve computer algorithms

Adding more masts could reduce the overall energy use of phone networks by two-thirds and boost handset battery life by 50 per cent

In 2013, the Hubble Space Telescope spotted water vapour on Jupiter’s moon Europa. The vapour was evidence of plumes similar to the ones on Saturn’s moon Enceladus. That, and other compelling evidence, showed that the moon has an ocean. That led to speculation that the ocean could harbour life.

But the ocean is obscured under a thick, global layer of ice, making the plumes our only way of examining the ocean. The plumes are so difficult to detect they haven’t been confirmed.

The lead author of the paper presenting Hubble’s 2013 evidence is Lorenz Roth of Southwest Research Institute. He said, “By far, the simplest explanation for this water vapour is that it erupted from plumes on the surface of Europa. If those plumes are connected with the subsurface water ocean we are confident exists under Europa’s crust, then this means that future investigations can directly investigate the chemical makeup of Europa’s potentially habitable environment without drilling through layers of ice. And that is tremendously exciting.”

It is, but first, scientists have to find the plumes.

“We pushed Hubble to its limits to see this very faint emission. These could be stealth plumes because they might be tenuous and difficult to observe in visible light,” said Joachim Saur of the University of Cologne, co-author of the 2013 paper.

This artist’s illustration shows plumes erupting through Europa’s icy surface. Gigantic Jupiter lurks in the background. Image Credit: NASA/ESA/K. Retherford/SWRI

Describing them as tenuous stealth plumes turned out to be prophetic.

Recently, a team of researchers went looking for the plumes. Their results are in a presentation given to the IAU Symposium 383 titled “ALMA Spectroscopy of Europa: A Search for Active Plumes.” The lead author is M.A. Cordiner from the Solar System Exploration Division at NASA’s Goddard Space Flight Center.

“The subsurface ocean of Europa is a high-priority target in the search for extraterrestrial life, but direct investigations are hindered by the presence of a thick exterior ice shell,” the authors write. The researchers used ALMA to search for molecular emissions from atmospheric plumes. They were investigating processes under the ice that could help them understand Europa’s ocean and its chemistry.

The Solar System is full of icy bodies, including comets, Kuiper Belt Objects, dwarf planets, and moons like Europa. Europa has a high density compared to other icy bodies, indicating a substantial rocky interior. Its ocean makes up about 10% of the moon and is covered by an icy shell of uncertain thickness. It could be several tens of kilometres thick. Scientists learned much of this from NASA’s Galileo mission.

In recent years, Europa and its ocean have leapt to the top of the list of targets in the search for life. The reasons aren’t obscure: liquid water is an irresistible beacon in our search for habitable places. The plumes from Europa’s ocean are our only way to study the ocean and its potential habitability.

This illustration shows what the interior of Europa might look like. Geysers might erupt through cracks and fissures in the ice. Image Credit: NASA/JPL-Caltech/Michael Carroll)

Over the years, different telescopes have examined Europa, searching for more evidence of the plumes. They’ve found potential intermittent plume activity near the moon’s south pole. But confirmation of the plumes the Hubble spotted in 2013 is elusive. In 2023, the JWST examined Europa. Those observations “found no evidence for active plumes, indicating that any present-day activity must be localized and weak; robust confirmation of the initial HST plume results also remains challenging,” the authors write.

In an attempt to find the plumes, the authors employed ALMA, the Atacama Large Millimeter/submillimeter Array. They observed Europa on four separate days to cover the moon’s surface. Unfortunately, they found no plumes.

These are four ALMA images of Europa. The researchers observed the moon on four different days so they could image almost the entire surface. They found no plumes. Image Credit: Cordiner et al. 2024.

“Despite near-complete coverage of both Europa’s leading and trailing hemispheres, we find no evidence for gas phase molecular absorption or emission in our ALMA data,” the researchers write. “Using ALMA’s unique combination of high spectral/spatial resolution and sensitivity, our observations have enabled the first dedicated search for HCN, H2CO, SO2 and CH3OH in Europa’s exosphere and plumes. No evidence was found for the presence of these molecules.”

Finding no evidence doesn’t quite mean that those molecules aren’t there. Rather, it means that if they are there, their concentrations are so low they’re below the detection threshold. In this case, some concentrations would be lower than those detected in Enceladus’ plumes, which are confirmed.

One chemical in particular illustrates this point: CH3OH (methanol.) “For the CH3OH abundance, on the
other hand, our ALMA upper limit of < 0.86% would not have been sensitive enough to detect this molecule at the Enceladus plume abundance of 0.02%,” the authors write.

There are some interesting relationships between Europa and other icy objects in the Solar System. It has to do with abundance limits. The researchers established upper limits for H2CO (formaldehyde) on Europa. “Indeed, our H2CO abundance upper limit is significantly lower than measured by Cassini in the Enceladus plume, implying a possible chemical difference.”

Despite the fact that it didn’t find any plumes, the observations were still valuable. By setting detection limits it helps subsequent efforts to search for them. And this won’t be scientists’ final attempt at finding plumes. Anything that provides clues to Europa’s ocean is too tantalizing to ignore, and this research shows that ALMA is suited to this type of investigation.

“Our results show that ALMA is a powerful tool in the search for outgassing from icy bodies within the Solar System and that follow-up searches for other molecules at additional epochs (on Europa and other icy bodies) are justified,” the researchers conclude.

The post If Europa has Geysers, They’re Very Faint appeared first on Universe Today.

New research shows that people recognize more of their biases in algorithms' decisions than they do in their own -- even when those decisions are the same.

NASA’s Parker Solar Probe has been in studying the Sun for the last six years. In 2021 it was hit directly by a coronal mass ejection when it was a mere 10 million kilometres from the solar surface. Luckily it was gathering data and images enabling scientists to piece together an amazing video. The interactions between the solar wind and the coronal mass ejection were measured giving an unprecedented view of the solar corona. 

The Sun is a fascinating object and as our local star, has been the subject of many studies. There are still mysteries though and it was hoping to unravel some of these that the NASA Parker Solar Probe was launched. It was sent on its way by the Delta IV heavy back in 2018 and has flown seven times closer to the Sun than any spacecraft before it. 

Illustration of the Parker Solar Probe spacecraft approaching the Sun. Credits: Johns Hopkins University Applied Physics Laboratory

By the time Parker completes its seven year mission it will have completed 24 orbits of the Sun and flown to within 6.2 million kilometres to the visible surface. For this to happen, its going to get very hot so the probe has a 11.4cm thick carbon composite shield to keep its components as cool as possible in the searing 1,377 Celsius temperatures. 

Flying within the Sun’s outer atmosphere, the corona, the probe picked up turbulence inside a coronal mass ejection as it interacted with the solar wind. These events are eruptions of large amounts of highly magnetised and energetic plasma from within the Sun’s corona. When directed toward Earth they can cause magnetic and radio disruptions in many ways from communications to power systems. 

Image of a coronal mass ejection being discharged from the Sun. (Credit: NASA/Goddard Space Flight Center/Solar Dynamics Observatory)

Using the Wide Field Imager for Parker Solar Probe (WISPR) and its prime position inside the solar atmosphere, unprecedented footage was captured (click on this link for the video). The science team from the US Naval Research Laboratory revealed what seemed like turbulent eddies, so called Kelvin-Helmholtz instabilities (KHIs) in one of the images. Turbulent eddy structures like these have been seen in the atmosphere of terrestrial planets. Strong wind shear between upper and lower cloud levels causes thin trains of crescent wave like clouds. 

Member of the WISPR team Evangelos Paouris PhD was the eagle eyed individual that spotted the disturbance. Paouris and team analysed the structure to verify the waves. The discovery of these rare features in the CME have opened up a whole new field of investigations.  

The KHIs are the result of turbulence which plays a key role in the movement of CMEs as they flow through the ambient solar wind. Understanding the CMEs and their dynamics of CMEs and a more fuller understanding of the Sun’s corona. This doesn’t just help us understand the Sun but also helps to understand the effect of CMEs on Earth and our space based technology.

Source : WISPR Team Images Turbulence within Solar Transients for the First Time

The post WISPR Team Images Turbulence within Solar Transients for the First Time appeared first on Universe Today.

In a couple billion years, our Sun will be unrecognizable. It will swell up and become a red giant, then shrink again and become a white dwarf. The inner planets aren’t expected to survive all the mayhem these transitions unleash, but what will happen to them? What will happen to the outer planets?

Right now, our Sun is about 4.6 billion years old. It’s firmly in the main sequence now, meaning it’s going about its business fusing hydrogen into helium and releasing energy. But even though it’s about 330,000 times more massive than the Earth, and nearly all of that mass is hydrogen fuel, it will eventually run out.

In another five billion years or so, its vast reservoir of hydrogen will suffer depletion. As it burns through its hydrogen, the Sun will lose mass. As it loses mass, its gravity weakens and can no longer counteract the outward force driven by fusion. A star is a balancing act between the outward expansion of fusion and the inward force of gravity. Eventually, the Sun’s billions-of-years-long balancing act will totter.

With weakened gravity, the Sun will begin to expand and become a red giant.

This illustration shows the current-day Sun at about 4.6 billion years old. In the future, the Sun will expand and become a red giant. Image Credit: By Oona Räisänen (User:Mysid), User:Mrsanitazier. – Vectorized in Inkscape by Mysid on a JPEG by Mrsanitazier (en:Image: Sun Red Giant2.jpg). CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=2585107

The Sun will almost certainly consume Mercury and Venus when it becomes a red giant. It will expand and become about 256 times larger than it is now. The inner two planets are too close, and there’s no way they can escape the swelling star. Earth’s fate is less certain. It may be swallowed by the giant Sun, or it may not. But even if it isn’t consumed, it will lose its oceans and atmosphere and become uninhabitable.

The Sun will be a red giant for about one billion years. After that, it will undergo a series of more rapid changes, shrinking and expanding again. But the mayhem doesn’t end there.

The Sun will pulse and shed its outer layers before being reduced to a tiny remnant of what it once was: a white dwarf.

An artist’s impression of a white dwarf star. The material inside white dwarfs is tightly packed, making them extremely dense. Image credit: Mark Garlick / University of Warwick.

This will happen to the Sun, its ilk, and almost all stars that host planets. Even the long-lived red dwarfs (M-dwarfs) will eventually become white dwarfs, though their path is different.

Astronomers know the fate of planets too close to the stars undergoing these tumultuous changes. But what happens to planets further away? To their moons? To asteroids and comets?

New research published in The Monthly Notices of the Royal Astronomical Society digs into the issue. The title is “Long-term variability in debris transiting white dwarfs,” and the lead author is Dr. Amornrat Aungwerojwit of Naresuan University in Thailand.

“Practically all known planet hosts will evolve eventually into white dwarfs, and large parts of the various components of their planetary systems—planets, moons, asteroids, and comets—will survive that metamorphosis,” the authors write.

There’s lots of observational evidence for this. Astronomers have detected planetary debris polluting the photospheres of white dwarfs, and they’ve also found compact debris disks around white dwarfs. Those findings show that not everything survives the main sequence to red giant to white dwarf transition.

“Previous research had shown that when asteroids, moons and planets get close to white dwarfs, the huge gravity of these stars rips these small planetary bodies into smaller and smaller pieces,” said lead author Aungwerojwit.

This Hubble Space Telescope shows Sirius, with its white dwarf companion Sirius B to the lower left. Sirius B is the closest white dwarf to the Sun. Credit: NASA, ESA, H. Bond (STScI) and M. Barstow (University of Leicester).

In this research, the authors observed three white dwarfs over the span of 17 years. They analyzed the changes in brightness that occurred. Each of the three stars behaved differently.

When planets orbit stars, their transits are orderly and predictable. Not so with debris. The fact that the three white dwarfs showed such disorderly transits means they’re being orbited by debris. It also means the nature of that debris is changing.

“The unpredictable nature of these transits can drive astronomers crazy—one minute they are there, the next they are gone.”

Professor Boris Gaensicke, University of Warwick

As small bodies like asteroids and moons are torn into small pieces, they collide with one another until nothing’s left but dust. The dust forms clouds and disks that orbit and rotate around the white dwarfs.

Professor Boris Gaensicke of the University of Warwick is one of the study’s co-authors. “The simple fact that we can detect the debris of asteroids, maybe moons or even planets whizzing around a white dwarf every couple of hours is quite mind-blowing, but our study shows that the behaviour of these systems can evolve rapidly, in a matter of a few years,” Gaensicke said.

“While we think we are on the right path in our studies, the fate of these systems is far more complex than we could have ever imagined,” added Gaensicke.

This artist’s illustration shows the white dwarf WD J0914+1914 (Not part of this research.) A Neptune-sized planet orbits the white dwarf, and the white dwarf is drawing material away from the planet and forming a debris disk around the star. Image Credit: By ESO/M. Kornmesser – https://www.eso.org/public/images/eso1919a/, CC BY 4.0, https://commons.wikimedia.org/w/index.php?curid=84618722

During the 17 years of observations, all three white dwarfs showed variability.

The first white dwarf (ZTF J0328?1219) was steady and stable until a major catastrophic event around 2011. “This might suggest that the system underwent a large collisional event around 2011, resulting in the production of large amounts of dust occulting the white dwarf, which has since then gradually dispersed, though leaving sufficient material to account for the ongoing transit activity, which implies continued dust production,” the researchers explain.

The second white dwarf (ZTF J0923+4236) dimmed irregularly every couple of months and displayed chaotic variability on the timescale of minutes. “These long-term changes may be the result of the ongoing disruption of a planetesimal or the collision between multiple fragments, both leading to a temporarily increased dust production,” the authors explain in their paper.

The third star (WD 1145+017) showed large variations in numbers, shapes and depths of transits in 2015. This activity “concurs with a large increase in transit activity, followed by a subsequent gradual re-brightening,” the authors explain, adding that “the overall trends seen in the brightness of WD?1145+017 are linked to varying amounts of transit activity.”

But now all those transits are gone.

“The unpredictable nature of these transits can drive astronomers crazy—one minute they are there, the next they are gone,” said Gaensicke. “And this points to the chaotic environment they are in.”

But astronomers have also found planetesimals, planets, and giant planets around white dwarfs, indicating that the stars’ transitions from main sequence to red giant don’t destroy everything. The dust and debris that astronomers see around these white dwarfs might come from asteroids or from moons pulled free from their giant planets.

“For the rest of the Solar System, some of the asteroids located between Mars and Jupiter, and maybe some of the moons of Jupiter may get dislodged and travel close enough to the eventual white dwarf to undergo the shredding process we have investigated,” said Professor Gaensicke.

When our Sun finally becomes a white dwarf, it will likely have debris around it. But the debris won’t be from Earth. One way or another, the Sun will destroy Earth during its red giant phase.

“Whether or not the Earth can just move out fast enough before the Sun can catch up and burn it is not clear, but [if it does] the Earth would [still] lose its atmosphere and ocean and not be a very nice place to live,” explained Professor Gaensicke.

The post What Happens to Solar Systems When Stars Become White Dwarfs? appeared first on Universe Today.

An oral vaccine in the form of a pineapple-flavoured spray prevented recurrent urinary tract infections in 53.9 per cent of clinical trial participants

Wirelessly connected devices perform an expanding array of applications, such as monitoring the condition of machinery and remote sensing in agricultural settings. These applications hold much potential for improving the efficiency, but how do you power these devices where reliable electrical sources are not available? Research points to a possible solution in the form of a novel type of battery.

Medical researchers have performed a successful transcatheter tricuspid valve repair procedure with a groundbreaking catheter.