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Ice cream-inspired physics: Team uncovers a quantum Mpemba effect, with a host of 'cool' implications

Computers and Math from Science Daily Feed - Tue, 10/08/2024 - 9:25am
Researchers have just described the existence of the paradoxical Mpemba effect within quantum systems. Initially investigating out of pure curiosity, the discovery has bridged the gap between Aristotle's observations two millennia ago and modern-day understanding, and opened the door to a whole host of 'cool' -- and 'cooling' -- implications.
Categories: Science

New insights into ammonia decomposition

Matter and energy from Science Daily Feed - Tue, 10/08/2024 - 9:23am
Using ammonia is regarded as a promising method of transporting hydrogen. However, an efficient process is also needed to convert it back into hydrogen and nitrogen.
Categories: Science

Holographic 3D printing has the potential to revolutionize multiple industries

Matter and energy from Science Daily Feed - Tue, 10/08/2024 - 9:22am
Researchers have developed a novel method of 3D printing that uses acoustic holograms. The process is called holographic direct sound printing (HDSP). It builds on a method introduced in 2022 that described how sonochemical reactions in microscopic cavitations regions -- tiny bubbles -- create extremely high temperatures and pressure for trillionths of a second to harden resin into complex patterns. Now, by embedding the technique in acoustic holograms that contain cross-sectional images of a particular design, polymerization occurs much more quickly. It can create objects simultaneously rather than voxel-by-voxel.
Categories: Science

Intersectional feminism and chemistry: the fracas continues

Why Evolution is True Feed - Tue, 10/08/2024 - 9:00am

Over a year ago I read this article in the Journal of Chemical Education and found it ideologically biased and deeply problematic.

Here’s the article’s abstract:

This article presents an argument on the importance of teaching science with a feminist framework and defines it by acknowledging that all knowledge is historically situated and is influenced by social power and politics. This article presents a pedagogical model for implementing a special topic class on science and feminism for chemistry students at East Carolina University, a rural serving university in North Carolina. We provide the context of developing this class, a curricular model that is presently used (including reading lists, assignments, and student learning outcomes), and qualitative data analysis from online student surveys. The student survey data analysis shows curiosity about the applicability of feminism in science and the development of critical race and gender consciousness and their interaction with science. We present this work as an example of a transformative pedagogical model to dismantle White supremacy in Chemistry.

I read the paper and then wrote the post below about it. I wasn’t keen on the paper, to say the least. You can read my critique for yourself—though you may be tired of the ideological camel sticking its nose into the tent of science. I’ll quote my review very briefly.

Click to read my post (there’s another post that mentions this paper critically, as one of many science-and-ideology tirades, in a WSJ op-ed by Lawrence Krauss).

Below, indented quotes from my piece. Quotes from the Reyes et al paper are doubly indented:

The abstract gives an idea of the purpose of the course: to indoctrinate students in the authors’ brand of feminism, CRT, and other aspects of woke ideology.  It wants to rid chemistry of White Supremacy, for the unquestioned assumption is that chemistry education is riddled with white supremacy. If you read the authors seriously, you’d think that all chemistry teachers put on white robes and burned crosses after school. . .

. . . .At the outset they get off on the wrong foot: by asserting that sex is not binary (all bolding is mine):

When scientifically established facts, such as the nonbinary nature of both sex and gender are seen by students of science as a belief, one might ask: Are we being true to scientific knowledge? We use this student comment as a reflection of the subjectivity of how the pedagogical decisions are made in teaching “true science” vs what existing scientific knowledge tells us. This has resulted in the propagation of scientific miseducation for generations.

. . . .Besides the reading assignments, there are essays in which students are expected to parrot back the woke pabulum they’ve been fed:

The final assignment was a full paper with an intervention plan that might be implemented in their own institution/department which will enable students to create a STEM identity which acknowledges and respects their personal identity. For 2021 and 2022 classes, the intervention topics that students wrote about were as follows: the importance of all-gender bathrooms in STEM buildings, the importance of teaching how race, gender, sexuality, etc. are created and pathologized by STEM as a medical college course, how to increase accessibility of STEM as a discipline without erasing the lived experiences of URM students, and how the American STEM identity can incorporate the immigrant student/scholar experience.

At this point I wondered if this course had anything to do with science beyond using the “field” (excuse me) as an example of racism and white supremacy. I don’t think so. It’s ideological propaganda, pure and simple, and even worse than the forms dished out in “studies” courses. ‘

They also confused the Tuskegee airmen, a band of brave black pilots in WWII, with the Tuskegee Syphilis Study, a misguided and racist study of syphilis that’s an exemplar of how not to do medical studies on ethnic groups. This kind of confusion bespeaks a deep ignorance by Reyes et al, for nearly everyone knows the difference, and they could have looked it up. (There were NINE authors!)]

Here’s my conclusion:

The Upshot: This is without doubt the most annoying, misguided, and misplaced paper on science education I’ve read in the last five years. The American Chemical Society should be ashamed of itself.

Now two authors from Florida International University have written a short but trenchant critique of the first article, replete with references. Click below to read it, or you can find the pdf here .

Here are the three errors that, the authors say, dominate the paper. I’ll put them in bold and also indent some Landrum and Lichter quotes that support their critique:

In this commentary, we provide criticism of this work based on the following three points:

(1) the authors claim this course can “dismantle White Supremacy in Chemistry” yet fail to provide valid evidence for “White Supremacy.”

Nowhere within the text is the phrase “White supremacy in Chemistry” again found, nor is the term White supremacy again mentioned. The authors cannot be unaware of how the term White supremacy is often received. (3,28,29) This term is historically pejorative having arisen etymologically from the 19th century racist screeds of John H. Van Evrie and subsequently becoming identified with Jim Crowism and the racial violence of the Ku Klux Klan. (30) To suggest a connection exists between such historical racism and the contemporary nature of the discipline of chemistry and chemists is disingenuous. (28−30) The authors eschew discussion of “White supremacy” and instead fixate on the lesser known neologism “dysconscious racism”, apparently expecting readers to uncritically overlook this equivocation. It is our opinion that the choice in interchanging “dysconscious racism” and “white supremacy” within this paper, without demonstrable and valid evidence of either, is poor scholarship and delegitamizes the claimed course objective.

(2) the paucity of content directly related to chemistry and the evangelical presentation of a sociological and politically charged perspective producing a course more identifiable as political indoctrination than chemistry education.

Most of the topics of Reyes et al.’s course, 8 are listed in Table 2 of ref (1), have little to do with chemistry and more to do with medical or STEM-related historical events dealing with racial and gender inequality. Content appears to have been selected to advocate the authors’ sociopolitical preconceptions, and there is a noted absence of balance. We identified two topics as having connection to the history of (bio)chemistry: “HeLa cells” and “DNA and Rosalind Franklin”. The 6 other topics seem completely unrelated to chemistry: “Perfecting the C-section”? “Social Darwinism”? “Tuskegee Airmen”? It seems, referring to the latter, the authors have mistakenly written Tuskegee Airmen when referring to the Tuskegee Syphilis study. These are different historical events, and both are unrelated to chemistry or chemists. . . .

(3) the evaluation of the course which is both flawed and statistically meaningless.

The sample size is pathetically small, some evaluations were omitted without giving a reason, and there are no statistical tests (Reyes admit this in their rebuttal below)

Reyes et al. (1) evaluated their course using an online qualitative, four-question free response survey. A subset of 6 of 8 responses collected were included in the Supporting Information; no explanation is given to explain the exclusion of the 2 unreported responses. Of these 8 students, only four students had completed the course. A separate group of four students who had not taken the course also submitted responses. The authors appear to suggest the latter group’s responses might represent a valid control group.

 

The authors report comparison of the responses of 3 students who had not taken the course to those of 3 students who had completed the course. It is unclear why the authors did not include and compare two responses, one from each group. The longer-length responses given by those who completed the course is claimed by the authors to be a measure of student mastery of the course objectives. This conclusion amounts to conjecture and speculation.

Finally, Reyes and one co-author (why not the rest?) wrote a response to the critique above; you can see it by clicking on the link below, or find the pdf  here.

It’s tiring to have to deal with the two authors’ (non)reply, but I’ll summarize how they respond to the accusations. Their quotes are indented; mine are flush left.

White Supremacy

Scores of research articles published in peer-reviewed and well reputed journals have documented white supremacy in Chemistry and other STEM departments in US Universities and linked the above-mentioned negative outcomes to white supremacist practices. (19−30) As such, we are not the first one to claim white supremacy in STEM/Chemistry based on just one or two personal experiences, but we grounded the pedagogy for this class in well researched observations. (31) Given the presence of white supremacy in STEM, (19−30) it is wrong to not provide ALL students an opportunity to engage with these ideas in an honest conversation as it robs them from crucial professional development training on working with a diverse work force. Our class is one example of such an effort, and although one class does not ensure systemic changes, it does try to create a more unified society in Chemistry/STEM. In fact, like us, other scholars have also suggested teaching history and consequences of bias in STEM as a strategy to dismantle white supremacy and other forms of systemic discriminations in STEM. (30−32)

I suggest looking at references 19-30 to see if they really do document “white supremacy in STEM”. Of the first nine references I looked at, only two even mention “white supremacy”.  That is, of course, different from racism.  And a lack of opportunity for minority chemistry students is not necessarily due to white supremacy.

Paucity of chemistry content.  The authors argue that this is irrelevant because this was a special topics course in chemistry that didn’t affect whether a student could or could not graduate with a chemistry major. Instead, they say, “with the changing demographic of STEM/Chemistry higher education disciplines and the continued observation that students of color feel alienated in STEM/Chemistry fields, this class intended to provide all students with training on how to engage with identity and its influence on one’s ability to learn. Students chose this class from the list of all available classes, further reinforcing the idea that there was student interest in learning about intersectional feminism and its connection to STEM/Chemistry.”  In other words, this wasn’t really a chemistry course, but an ideology course (though they loudly decry that there was an ideology involved, yet cite bell hooks, who is not a chemist but an ideologue).

The vacuous nature of the claim that this course was successful.  Here’s the response, though note that the class “is not offered at present”:

We agree that the survey data presented in the original article is not statistically significant (and because of that reason we did not make any overarching generalization or provide any statistical analysis). However, the open-response (qualitative data) nature of this survey allowed us to gather rich data which could be analyzed for thematic analysis using standard protocols (coding, thematic analysis) as described in the original article. (1) Due to institutional changes and restrictions nationally, (33−35) this class is not offered at present which makes it impossible to gather further data. We suggest any interested reader to consult a review that compiles the potential application of critical race theory (CRT) in physics which might be useful in designing similar classes in STEM.

This is word salad; and yes, they do make generalizations. Here’s one from the first paper:

 Analysis of the survey from students who took this class appreciated that the historical situatedness of knowledge and knowledge production and could explain the benefits that those can provide to one’s professional success as well as the society at large. This being the overarching learning objective for this class, the authors argue that students gained the ability to analyze information presented to them and express those using both scientific and feminist language.

But please, read for yourself (take these articles, please!).  It’s a paradigm of how authors can infuse science with ideology and then, when called out on it, wriggle and waffle in trying to deny the accusations.

Categories: Science

A cave in France is revealing how the Neanderthals died out

New Scientist Feed - Tue, 10/08/2024 - 9:00am
Discoveries from the genomes of the last Neanderthals are rewriting the story of how our own species came to replace them
Categories: Science

Growing number of Earth's ‘vital signs’ endangered by climate change

New Scientist Feed - Tue, 10/08/2024 - 8:00am
Key climate indicators from greenhouse gas levels to ice loss have reached record levels this year in what researchers call a “critical and unpredictable new phase of the climate crisis”
Categories: Science

Mental health app could help prevent depression in young people at high risk

Computers and Math from Science Daily Feed - Tue, 10/08/2024 - 7:38am
A cognitive behavioral therapy (CBT) app has been found to significantly prevent increases in depression in young people who are at high risk -- and could be implemented as a cost effective public mental health measure.
Categories: Science

Solar-powered desalination system requires no extra batteries

Matter and energy from Science Daily Feed - Tue, 10/08/2024 - 7:38am
Engineers built a solar-powered desalination system that produces large quantities of clean water despite variations in sunlight throughout the day. Because it requires no extra batteries, it offers a much more affordable way to produce drinking water, compared to other solar-driven designs.
Categories: Science

New apps will enable safer indoor navigation for visually impaired

Computers and Math from Science Daily Feed - Tue, 10/08/2024 - 7:38am
Two new apps will enable blind people to navigate indoor buildings with spoken directions from a smartphone app, providing a safe method of wayfinding where GPS doesn't work.
Categories: Science

Microscopic gears powered by light could be used to make tiny machines

New Scientist Feed - Tue, 10/08/2024 - 6:00am
Gears just a few micrometres wide can be carved from silicon using a beam of electrons, enabling tiny robots or machines that could interact with human cells
Categories: Science

TESS Finds a Triple Star System that Could Fit within Mercury’s Orbit

Universe Today Feed - Tue, 10/08/2024 - 5:41am

TESS, the Transiting Exoplanet Survey Satellite has been on the lookout for alien worlds since 2018. It has just hit the news again having identified an extreme triple star system where two stars orbit each other every 1.8 days. The third component circles them both in 25 days – this puts the entire system within the orbit of Mercury with a little wriggle room to spare! To visual observers, it looks like a single star but the power of TESS revealed a flicker as the stars line up and pass one another along our line of sight. Eventually, the two inner stars will merge, triggering a supernova event!

Exoplanets are planets in orbit around other star systems. Unlike the familiar planets in our own Solar System, their size and composition varies widely. To date gas giants larger than Jupiter have been found and small rocky worlds similar to Earth have been spotted. The techniques to hunt down the alien worlds vary from the transit method to the radial velocity method which detects a star’s wobble caused by the presence of a planet. Using these various different techniques, over 5,000 exoplanets have been identified.

“Icy and Rocky Worlds” is a new exoplanet infographic from Martin Vargic, an artist and space enthusiast from Slovakia. It’s available as a wall poster on his website. Image Credit and Copyright: Martin Vargic.

TESS was launched by NASA in April 2018 with the purpose of hunting down exoplanets. It uses the technique that relies upon searching for transit events as planets cross the face of their host star. Since it began operations, TESS has monitored the brightness of over 200,000 stars looking for tiny dips in brightness. It’s been particularly focussed on looking for Earth sized planets orbiting within a stars habitable zone. Here the conditions are such that a planet could support liquid water and therefore may harbour life. 

Illustration of NASA’s Transiting Exoplanet Survey Satellite. Credit: NASA’s Goddard Space Flight Center

In an exciting twist to the usual approach for hunting exoplanets, a team of professional and amateur astronomers have joined forces with artificial intelligence and found a strange new multiple star system. Called TIC 290061484 it consists of twin stars orbiting each other every 1.8 days and a third star that orbits them both in just 25 days.  The discovery beats the existing record for the shortest outer orbital period of a stellar system that was set in 1956 by 8 days! 

The edge-on presentation of the system is perfectly aligned for analysis. Monitoring the movement and brightness changes it is possible to measure orbits, masses, sizes and temperatures of the stellar components. The team, led by Veselin Kostov from NASA’s Goddard Space Flight Center published their findings in the Astrophysical Journal. 

Using TESS’ sensitivity to pickup flickering and brightness changes, the nature of the triple star system was revealed. Located in the constellation Cygnus almost 5,000 light years away the team monitored the dips in brightness as one star passed in front of the other. Using the capability of AI and machine learning, the team were able to filter the immense amounts of data to identify dimming events from transits rather than just the flicking of light caused by our own atmosphere. 

The data was then analysed by teams of citizen scientists who had formed ‘The Planet Hunters’ in 2010 to support exoplanet surveys. They later joined forces with professional astronomers as ‘the Visual Survey Group’ where they would provide real visual assessment of survey results. The team have now developed the model for the system and even forecast that, in between 20 to40 million years, the inner stars will expand and trigger a supernova explosion. 

The hunt is now on for more close multiple star systems with the Nancy Grace Roman Space Telescope (NGRST) joining the hunt. With its far higher resolution, NGRST will offer 36,000 pixels where TESS only offered 1, giving a new window on the same region of the Galaxy.

Source : NASA’s TESS Spots Record-Breaking Stellar Triplets

The post TESS Finds a Triple Star System that Could Fit within Mercury’s Orbit appeared first on Universe Today.

Categories: Science

AI Copilots Are Coming

neurologicablog Feed - Tue, 10/08/2024 - 5:24am

I’m going to do something I rarely do and make a straight-up prediction – I think we are close to having AI apps that will function as our all-purpose digital assistants. That’s not really a tough call, we already have digital assistants and they are progressing rapidly. So I am just extending an existing trend a little bit into the future. My real prediction is that they will become popular and people will use them. Predicting technology is often easier than predicting public acceptance and use (see the Segway and many other examples.) So this is more of a risky prediction.

I know, for those who lived through the early days of personal computers, if you mention “personal digital assistant” the specter of “Clippy” immediately comes to mind. Such assistants can be intrusive and annoying. That has something to do with the fact that they are intrusive and annoying, coupled with the fact that they are not that useful. Siri and similar apps are great for a few things – acting as a verbal interface for Google searchers or serving up music, or basic functions like setting an alarm on your phone. But I am talking next level. Siri is to the AI-fueled assistants I am talking about as the PDAs of the 80s and 90s are to the smartphones of today.

With that analogy I am getting into real tricky prediction territory – predicting a transformative or disruptive technology. This is the kind of technology that, shortly after using it regularly you lose the ability to conceive of life without it. Nor would you want to go back to the dark days before your life was transformed. Think microwave, the ability to record and play pre-recorded content for TV, the web, GPS, and the smartphone. This is what Segway wanted to be.

Clearly I am thinking of some idealized version of a personal AI assistant, and I am. But there is no reason we can’t get there. All the elements are already there, someone just has to put it all together in a functional and pretty package (like the iPhone). Microsoft thinks we are one year away from such an application, and clearly they are planning on being the ones to bring it to market. They will likely have competition.

Let’s think first about what a personal AI assistant can be in that idealized form, and then consider the potential downsides. I am envisioning an app that lives on multiple of your electronic devices – your phone, tablet, laptop and desktop. It uses all the devices you do and is always there for you. You can interact with it by voice or text. It has access to whatever information you give it access to, such as your calendar, contact list, accounts, passwords, and digital assets. And essentially it can do anything you want within those digital contents at a command. It can manage your schedule, take the initiate to remind you about upcoming appointments or deadlines, and schedule new events.

Further, it can sift through your e-mail, getting rid of spam, warning about dangerous e-mails, organizing the rest by priority or whatever scheme you wish, even respond to some e-mails automatically or by your command. It can interact with all your other apps – “Find the quickest route to my destination, load it up into GPS, and remind me 10 minutes before I have to leave.” Or you can tell it to prepare a summary for you on some topic, after searching the web for the latest information. It can manage your computer hygiene – “Your anti-spyware software is out of date, and there is a notice of a virus coming you are not protected from. Shall I download and install the update?” You can tell it to always download and install security updates without asking first. Yes – Windows can already to this, for Windows, but not third party apps.

A feature I would love to see – find me flights with these parameters, or you could tell it to book you a hotel, rental car, or anything. It knows your preferences, your frequent flyer numbers, your seating preferences, and which airports you prefer. Or you could ask it to find 20 gift options for Mother’s Day.

What will make an AI assistant better than anything that has come before (using the new AI tech) is that it can remember all of its interactions with you and learn. Over time, it becomes more and more personalized. It will know when not to disturb you, for example. It will learn to become less annoying and more helpful, as you learn how best to leverage this technology. This kind of tech has the potential to relieve a significant amount of the digital drudgery that we have foisted upon ourselves. I know some people will say – just disconnect. But that is not a viable option for many people, and we should not have to surrender all the benefits of computers simply to avoid that drudgery.

What about the downsides? The biggest potential weakness is that such apps will just suck. They won’t do their jobs well enough to reduce your digital burden. They can also be a security risk, if they have access to all your personal information. Security would need to be an iron-clad feature of such apps. They can also just get information wrong. This is a universal problem with the latest crop of AI, the so-called hallucinations. But this is something the industry is working on and it is getting better. It’s also less of a problem with focused (rather than open-ended) tasks.

There will eventually also be some optional features that some people will want in such an app, such as personal AI counseling or life-coaching. This can have different levels. At its most basic level, the AI can be just a rational friend who is a good listener, and gives really basic time-tested and expert-approved advice. It can function as a first-level counselor who is always there for you, and remembers all your previous conversations. You can select its personality, and level of intrusiveness. You may be able to have certain optional “nag” settings, such as keeping you on that diet, or reminding you not to be too sarcastic. It could make you more thoughtful, reminding you of all the social niceties that often slip through the cracks of our busy lives.

Then there will be those features that I am not thinking of, but that someone will think of when you have hundreds or even thousands of companies competing with each other and using feedback from billions of users. There may also be negative unintended consequences, and culture wars about social engineering. We will have to see how it all shakes out.

But I stick by my prediction – the potential of relieving us of digital drudgery and all the potential value-added of such an AI assistant – when it works really well – is just too great. I do think this will be like the next smartphone. We will probably know soon enough.

Note: I suspect the comments will fill with people giving examples of how the various pieces of this functionality already exists. I know, and I use a lot of them. You can cobble together password managers, an app to go through your photos, a schedule reminder, and e-mail sorters. Individual applications of a smartphone also predated the smartphone. The power was having everything in one device. Same here – one AI to bring it all together and add new functionality.

The post AI Copilots Are Coming first appeared on NeuroLogica Blog.

Categories: Skeptic

This is it! The Best Week for Comet A3!

Science blog of a physics theorist Feed - Tue, 10/08/2024 - 5:04am

A busy news week: a Nobel prize, another chance of auroras, and… a comet. It’s probably not the comet of the century, but comets like this one show up only about once every ten years. This one has already been visible in early morning skies. This week it enters our evening skies, and will likely be a lovely sight after dark for the rest of October.

Day by day, the comet will move up and to the left, beginning at the Sun’s right. Look there once the Sun is significantly below the true horizon and the sky has darkened a bit.

Later in the month it will be visible longer into the evening, but much less bright.

What is a comet? Its core (or “nucleus”) is a large ball of ice and dust, perhaps 20 miles [40 kilometers] across, traveling on an orbit of the Sun and moving through the solar system among the planets. That core is far too small and far away to see. But when the comet approaches the Sun, the Sun heats the core, which throws off dust and gas that is blown by the solar wind into a big cloud around the core and into huge trails that stretch tens of millions of miles [km]. These trails reflect sunlight, and can be seen from Earth despite being millions of miles [km] away.

Please do not confuse this comet with Earth’s temporary second moon, which has gotten a ridiculous amount of overheated press, causing both distraction and confusion. Here’s how this itty-bitty “moonlet” compares with comet A3.

  • Moonlet temporarily orbits Earth; comet A3 orbits the Sun
  • Moonlet is a rock the size of a bus; comet A3’s core is the size of a big city, and its tails are tens of millions of miles long
  • Moonlet at its closest will be tens of thousands of miles [km] away; comet A3 at its closest will be 44 million miles [71 million km] away
  • Moonlet can only be seen with powerful professional telescopes; comet A3’s head and tails may be dramatic to the naked eye and may even be visible, for a few days, during daylight

The last bullet point is the most important. Moonlet is of intellectual interest only; there’s absolutely nothing to see, despite the crazed news stories in the media. Comet A3 might turn out to be one of the better celestial objects to see in a lifetime. Get the word out!

Categories: Science

Nobel prize for physics goes to pair who invented key AI techniques

New Scientist Feed - Tue, 10/08/2024 - 3:53am
The 2024 Nobel prize in physics has gone to John Hopfield and Geoffrey Hinton for discoveries that enabled machine learning and are key to the development of artificial intelligence models like ChatGPT
Categories: Science

Skeptoid #957: Dogs Who Type

Skeptoid Feed - Tue, 10/08/2024 - 2:00am

Can dogs be taught to speak intelligently using floor buttons that represent words?

Categories: Critical Thinking, Skeptic

Despite progress, China remains tethered to coal as climate change pressures mount

Matter and energy from Science Daily Feed - Mon, 10/07/2024 - 7:28pm
A new paper details how China faces numerous political, economic and technological obstacles as it tries to transition away from coal while balancing the need to combat climate change with the need for energy security.
Categories: Science

AI speeds up the discovery of energy and quantum materials

Computers and Math from Science Daily Feed - Mon, 10/07/2024 - 7:27pm
Unearthing new LEDs, solar cells, and photodetectors requires extensive knowledge surrounding the optical properties of materials. Calculating these takes time and resources. Yet researchers unveiled a new AI tool that can accurately, and crucially much faster than quantum simulations, for predicting optical properties.
Categories: Science

AI speeds up the discovery of energy and quantum materials

Matter and energy from Science Daily Feed - Mon, 10/07/2024 - 7:27pm
Unearthing new LEDs, solar cells, and photodetectors requires extensive knowledge surrounding the optical properties of materials. Calculating these takes time and resources. Yet researchers unveiled a new AI tool that can accurately, and crucially much faster than quantum simulations, for predicting optical properties.
Categories: Science

The JWST Reveals New Things About How Planetary Systems Form

Universe Today Feed - Mon, 10/07/2024 - 4:37pm

Every second in the Universe, more than 3,000 new stars form as clouds of dust and gas undergo gravitational collapse. Afterward, the remaining dust and gas settle into a swirling disk that feeds the star’s growth and eventually accretes to form planets – otherwise known as a protoplanetary disk. While this model, known as the Nebular Hypothesis, is the most widely accepted theory, the exact processes that give rise to stars and planetary systems are not yet fully understood. Shedding light on these processes is one of the many objectives of the James Webb Space Telescope (JWST).

In a recent study, an international team of astronomers led by University of Arizona researchers and supported by scientists from the Max Planck Institute of Astronomy (MPIA) used the JWST’s advanced infrared optics to examine protoplanetary disks around new stars. These observations provided the most detailed insights into the gas flows that sculpt and shape protoplanetary disks over time. They also confirm what scientists have theorized for a long time and offer clues about what our Solar System looked like roughly 4.6 billion years ago.

The research was led by Ilaria Pascucci, a Professor of astrophysics and planetary science from the Lunar and Planetary Laboratory (LPL) at The University of Arizona. She was joined by researchers from the Space Telescope Science Institute (STScI), the Observatoire de Paris, the National Optical-Infrared Astronomy Research Laboratory (NOIRLab), the Carl Sagan Center at the SETI Institute, the Max-Planck-Institute for Astronomy, and multiple universities. The paper that describes their findings recently appeared in Nature Astronomy.

Artist’s impression of a young star surrounded by a protoplanetary disk made of gas and dust. Credit: LMU/Thomas Zankl, crushed eyes media

In order for young stars to grow, they must draw in gas from the protoplanetary disk surrounding them. For that to happen, the gas must lose angular momentum (inertia); otherwise, it would consistently orbit the star and never accrete onto it. However, the mechanism that allows this to happen has remained the subject of debate among astronomers. In recent years, magnetically driven disk winds have emerged as a possible mechanism. Primarily powered by magnetic fields, these “winds” funnel streams of gas away from the planet-forming disk into space at dozens of kilometers per second.

This causes it to lose angular momentum, allowing the leftover gas to fall inward toward the star. For their study, the researchers selected four protoplanetary disk systems that appear edge-on when viewed from Earth. Using Webb’s Near Infrared Spectrograph (NIRSpec), the team could trace various wind layers by tuning the instrument to detect distinct atoms and molecules in certain transition states. The team also obtained spatially resolved spectral information across the entire field of view using the spectrograph’s Integral Field Unit (IFU).

This allowed the team to trace the disk winds in unprecedented detail and revealed an intricate, three-dimensional layered structure: a central jet nested inside a cone-shaped envelope of winds at increasing distances. The team also noted a pronounced central hole inside the cones in all four protoplanetary disks. According to Pascucci, one of the most important processes at work is how the star accretes matter from its surrounding disk:

“How a star accretes mass has a big influence on how the surrounding disk evolves over time, including the way planets form later on. The specific ways in which this happens have not been understood, but we think that winds driven by magnetic fields across most of the disk surface could play a very important role.”

However, other processes are also responsible for shaping protoplanetary disks. These include “X-wind,” where the star’s magnetic field pushes material outward at the inner edge of the disk. There are also “thermal winds,” which blow at much slower velocities and are caused by intense starlight eroding its outer edge. The high sensitivity and resolution of the JWST were ideally suited to distinguish between the magnetic field-driven wind, the X-wind, and the thermal wind. These observations revealed a nested structure of the various wind components that had never been seen before.

Observed gas jet and wind structure of the HH 30 protostar, with offsets given in astronomical units (au), the mean distance between the Sun and Earth. Credit and ©: I. Pascucci et al./MPIA

A crucial distinction between the magnetically driven and the X-winds is how they are located farther out and cover broader regions. These winds cover regions that correspond to the inner rocky planets of our solar system, roughly between Earth and Mars. They also extend farther above the disk than thermal winds, reaching hundreds of times the distance between Earth and the Sun. While astronomers previously found observational evidence of these winds based on interferometric observations at radio wavelengths, they could not image the full disk in detail to determine the winds’ morphology.

In contrast, the new JWST observations revealed a nested structure and morphology that matched what astronomers anticipated for magnetically driven disk wind. Looking ahead, Pascucci’s and her team hope to expand these observations to more protoplanetary disks to see how common the observed disk wind structures are and how they evolve.

“Our observations strongly suggest that we have obtained the first detailed images of the winds that can remove angular momentum and solve the longstanding problem of how stars and planetary systems form,” she said. “We believe they could be common, but with four objects, it’s a bit difficult to say. We want to get a larger sample with JWST and then also see if we can detect changes in these winds as stars assemble and planets form.”

Further Reading: MPIA, Nature Astronomy

The post The JWST Reveals New Things About How Planetary Systems Form appeared first on Universe Today.

Categories: Science

China Unveils its Lunar Spacesuit

Universe Today Feed - Mon, 10/07/2024 - 3:12pm

China have a roadmap to sent astronauts to the Moon in 2030 and when they do, they are going with a very definite nod to the Chinese origins to the rocket! Their officials have unveiled the new look Chinese space suit with all the mod cons but with a design that is somewhat reminiscent of Chinese armour. There will some fabulous features like the close and long distance field of view visor, a chest control panel and a protective material to shield against the harmful lunar environment. 

Think of space exploration and it won’t be long before images of astronauts in space suits appears in your mind. The puffy looking outfits are of crucial importance to human space flight for they are the life-support system, enabling an astronaut to stay alive in space! Providing protection against extreme temperatures, the suit is also able to maintain a constant pressure around the astronaut to protect from the vacuum of space. 

Astronaut Samantha Cristoforetti – Image : NASA

They provide oxygen for breathing, a coolant system, toiletry provision and a helmet with a special sun visor to protect their eyes. It’s fair to say, without a spacesuit, space exploration wouldn’t be possible, at least outside the confines of a spaceship. 

Just recently, the China Manned Space Agency (CMSA) revealed their space suit to be used in the first China Moon landing. It was displayed at the third Spacesuit Technology Forum in the southwest Chongqing Municipality and was adorned with red stripes. The stripes on the arms are a nod to the famous ‘flying apsaras’ (the flying celestial beings that accompany Buddhas!) while the stripes on the legs represent rocket flames during launch!

A video has been released  that shows the space suits being put through their paces by astronauts Zhai Zhigang and Wang Yaping. It shows the duo wearing the space suits and performing a range of different movements from walking, bending, kneeling on one knee and squatting. All of which seems to have been performed with ease. 

The two made Chinese history when Zhia became the first Chinese astronaut to conduct a spacewalk and Wang became the first woman who entered the Chinese space station. 

Tiangong Chinese space station Image Credit: China Manned Space Agency.

The new suit began development in 2020 with the aim to produce a lightweight suit for lunar exploration that was compact and reliable. To enable the success, a number of technological breakthroughs was achieved. The first and second generations of the Feitian spacesuits which preceded this new design have enabled 17 astronauts to complete 17 extravehicular activities (activities outside the space craft) helping construct and maintain the Tiangong Space Station. 

With all going to plan, the Chinese lunar mission plan is to land an explorer on the Moon’s surface by 2030. With the launch (pardon the pun) of the new Moon-landing spacesuit, CSMA mark a new era in their shot for the Moon. 

Source : China unveils moon-landing spacesuit for the first time

The post China Unveils its Lunar Spacesuit appeared first on Universe Today.

Categories: Science

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