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Nanoscale 3D transistors made from ultrathin semiconductor materials can operate more efficiently than silicon-based devices, leveraging quantum mechanical properties to potentially enable ultra-low-power AI applications.

Nanoscale 3D transistors made from ultrathin semiconductor materials can operate more efficiently than silicon-based devices, leveraging quantum mechanical properties to potentially enable ultra-low-power AI applications.

Stem cells grown in microgravity aboard the International Space Station (ISS) have unique qualities that could one day help accelerate new biotherapies and heal complex disease, researchers say. The research analysis finds microgravity can strengthen the regenerative potential of cells. Microgravity is weightlessness or near-zero gravity.

The temperature of elementary particles has been observed in the radioactive glow following the collision of two neutron stars and the birth of a black hole. This has, for the first time, made it possible to measure the microscopic, physical properties in these cosmic events. Simultaneously, it reveals how snapshot observations made in an instant represents an object stretched out across time.

Researchers have developed synthetic genes that function like the genes in living cells. The artificial genes can build intracellular structures through a cascading sequence that builds self-assembling structures piece by piece. The discovery offers a path toward using a suite of simple building blocks that can be programmed to make complex biomolecular materials, such as nanoscale tubes from DNA tiles. The same components can also be programmed to break up the design for different materials.

Remote medical interpreting (RMI) may be hindering healthcare communication rather than helping it, according to a new study.

Bio-based thermoplastics are produced from renewable organic materials and can be recycled after use. Their resilience can be improved by blending bio-based thermoplastics with other thermoplastics. However, the interface between the materials in these blends sometimes requires enhancement to achieve optimal properties. A team has now investigated at BESSY II how a new process enables thermoplastic blends with a high interfacial strength to be made from two base materials: Images taken at the new nano station of the IRIS beamline showed that nanocrystalline layers form during the process, which increase material performance.

Bio-based thermoplastics are produced from renewable organic materials and can be recycled after use. Their resilience can be improved by blending bio-based thermoplastics with other thermoplastics. However, the interface between the materials in these blends sometimes requires enhancement to achieve optimal properties. A team has now investigated at BESSY II how a new process enables thermoplastic blends with a high interfacial strength to be made from two base materials: Images taken at the new nano station of the IRIS beamline showed that nanocrystalline layers form during the process, which increase material performance.

Astronomers have discovered a supermassive black hole at the center of a galaxy just 1.5 billion years after the Big Bang that is consuming matter at a phenomenal rate -- over 40 times the theoretical limit. While short lived, this black hole's 'feast' could help astronomers explain how supermassive black holes grew so quickly in the early Universe.

From seed oils to olive oil, we now have an overwhelming choice of what to cook with. Here’s how they all stack up, according to the scientific evidence

The campaigning for President reaches a fever pitch today, and then tomorrow people head for the polls to cast their vote (many of us, including me, have voted by mail already).  This is of course an unscientific poll of readers, so let’s call it the Nate Goldenberg poll.  There are two of them, and of course votes are anonymous.  First, tell us your own choice:

Note: There is a poll embedded within this post, please visit the site to participate in this post's poll.

and then tell us who, in your view, will win:

Note: There is a poll embedded within this post, please visit the site to participate in this post's poll.

I’ve left the second poll unexpired because we have no idea how long the vote-counting will go on!

Of course you are encouraged to leave comments pertaining to both questions.

My friend Andrew Berry, who teaches and advises biology students at Harvard, has long had the bug that infected me when I was younger: the desire to trek in Nepal, where the mountains are impossibly high. This summer he took a long guided trek into little-visited parts of Nepal (guides are required for these places), producing a great 37-minute video (bottom) accompanied by music and sound. (For further mountain adventures, see Andrew’s one-hour video of his 2023 trek to Dolpo and the fabled Kingdom of Mustang, featured in these pages.)  The notes below are his:

Limi Valley Trek, June ’24

Like Jerry, I’ve spent a lot of time over the years in Nepal, most often on a trail, trekking. It’s hard to beat a high altitude encounter with the mightiest mountains on earth.  I’m on an academic schedule, which means that I have plenty of opportunity to go travel over the summer, but unfortunately trekking, Nepal, and the summer don’t really go that well together.  The most pressing of my university responsibilities cease around the beginning of June.  The monsoon typically arrives in Nepal in the middle of that same month, veiling the mountains in banks of cloud, soaking the trekker (and everyone else), and delighting/stimulating/exciting the voracious leeches that inhabit the montane forests.  In short, monsoon trekking is pretty dismal.

There are however some regions of Nepal that are less affected by the monsoon than others.  Specifically, the further west and north you go, the less the impact.  It is, after all, the Bay of Bengal branch of the monsoon that inundates Nepal, so it is coming from the east.  Heading north is to take advantage of the rain shadow imposed by the main cordillera of the Himalaya.  Some regions of Nepal are north of the range — they’re politically Nepal but geographically, culturally, and linguistically Tibetan.  In summer ’23 I went to Dolpa and Mustang, this summer to Simikot, the main town in the NW corner of Nepal.  This kind of trekking is a far remove from the kind of ‘teahouse’ trekking that Jerry and I are accustomed to: you walk from village to village and stay in local accommodations, meaning that you can get away with carrying little more than a sleeping bag.  To visit the more remote areas, you’re required to have expensive permits and to be accompanied by officially recognized guides.  In addition, because these routes take you beyond inhabited areas, it’s necessary to camp and to be self-sufficient in food and other supplies.  The result of these joint requirements is a logistically complex undertaking — thank goodness for the excellent outfitter I work with in Kathmandu, Raj Dhamala of Himalayan Trekkers.

I’ve always wanted to go to Simikot.  After spending six months in Nepal before going to university, I had a map of the country on the wall of my room for all three years of college.  As I stared at it, Simikot came, for me, to symbolize the remote, inaccessible Nepal that had been out of bounds for me the year before (for financial and permitting reasons).  It’s taken a few years actually to convert that fixation into an actual visit (42, if you insist on asking!), but I’m happy to report that Simikot didn’t disappoint.  The town is clustered around a Twin Otter landing strip, a slice of the horizontal — well, a slice of gentle slope — in a world of plunging verticals.  The mighty Karnali river crashes through its gorge far, far below.  Plenty of trekker-tourists come through (for many, it’s a jumping off point for a visit to Buddhism’s holy mountain, Kailash, in Tibet), but Simikot remains primarily an administrative and trading center.  Google Translate’s influence has not apparently extended to Simikot (or at least it hadn’t when this sign was painted)

 

Our route started — initially in a Jeep — and finished in Simikot.  Two weeks.  Its main focus was the Limi Valley, which runs W-E just south of, and parallel to, the Chinese/Tibetan border.  An upside of the timing is that this is the time of year that livestock — cattle, sheep, goats, yak — are moved up to high altitude summer pastures, meaning that we frequently encountered people and their animals undertaking the same seasonal migrations that their ancestors (both human and animal) have done for aeons.  It truly is a privilege to spend time in such spectacular country, and to meet so many people living lives so far removed from ours.  With Raj in Kathmandu, I had discussed the possibility of tacking on a (minor) peak ascent on to the trek, but I ended up wimping out.  Just a hike for me: 5000m (16,400′) over passes is plenty high enough for me.  I think Ang Dawa, one of three wonderful Sherpa guides with me, was a little disappointed by this lack of serious climbing (he’s summited Everest five times, so he’s entitled to his disappointment)

Here’s a video montage from the trip.  I like to take panoramic photos in country like this, and I think a slow pan across images like these is the best way to appreciate the scenery.  Also, I can’t resist shooting plenty of video too.  So much to see!

Be sure to enlarge the video:

I was away last week, first at CSICON and then at a conference in Dubai. I was invited to give a 9 hour seminar on scientific skepticism for the Dubai Future Foundation. That sounds like a lot of time, but it isn’t. It was a good reminder of the vast body of knowledge that is relevant to skepticism, from neuroscience to psychology and philosophy. Just the study of pseudoscience and conspiracy thinking themselves could have filled the time. It was my first time visiting the Middle East and I always find it fascinating to see the differences and similarities between cultures.

What does all this have to do with alternating vs direct current? Nothing, really, except that I found myself in a conversation about the topic with someone deeply involved in the power industry in the UAE. My class was an eclectic and international group of business people – all very smart and accomplished, but also mostly entirely new to the concept of scientific skepticism and without a formal science background. It was a great opportunity to gauge my American perspective against an international group.

I was struck, among other things, by how similar it was. I could have been talking to a similar crowd in the US. Sure, there was a layer of Arabic and Muslim culture on top, but otherwise the thinking and attitudes felt very familiar. Likely this is a result of the fact that Dubai is a wealthy international city. It is a good reminder that the urban-rural divide may be the most deterministic one in the world, and if you get urban and wealthy enough you tend to align with global culture.

Back to my conversation with the power industry exec – the power mix in the UAE is not very different from the US. They have about 20% nuclear (same as the US), 8% solar, and the rest fossil fuel, mostly natural gas. They have almost no wind and no hydropower. Their strategy to shift to low carbon power is all in on solar. They are rapidly increasing their power demand, and solar is the cheapest new energy. I don’t think their plan for the future is aggressive enough, but they are moving in the right direction.

What I did not encounter was any defensiveness about fossil fuels, denial of global warming, or any conspiracy nonsense. The UAE is the world’s 8th biggest oil producer, so I would not have been surprised if I had. At the end of the day, the science and the tradeoffs are pretty much the same. There are regional differences in terms of how much wind, sunshine, and water there is locally, and that affects the calculus, but everyone is dealing with the same technologies. But I still found it fascinating to be in a conversation with someone half-way around the world, from an entirely different culture, and hit all the same talking points that I have been discussing for years. We even discussed net metering (he was in favor) and Germany’s poor decision to shut down their nuclear industry.

And, of course, the conversation turned to the question of AC vs DC (which he brought up). Most nerds and technology history buffs know that there was a big fight between Edison and Tesla about whether or not the electricity infrastructure in the US should be alternating or direct current. Edison favored direct current, while Tesla favored alternating current. AC won out largely because it is more efficient to transmit over long distances and to alter the voltage with transformers.

The question of AC vs DC is raising its head again, however, because technology has changed. I am not an expert in electrical engineering, and I have had enough conversations with experts to know that this topic is very technical and complex. So I am not going to try to explain the technical details, but just discuss some of the main issues. There are essentially two reasons to rethink the AC vs DC choice. The first is that as technology has improved, the advantage of AC over DC had diminished. The transformer advantage still exists, but transmission efficiency is not as big of an issue as it was. AC and DC are not very different over short and medium distance, but AC still has an increasing advantage over longer distances.

But the second reason has to do with solar power and electric vehicles. An increasing number of homes have both, and even battery backup to boot. And, in the opinion of many experts, with whom I agree, it is a reasonable goal to maximize the number of residential homes that have all three – solar, EVs, and battery backup. All three of these technologies are DC. So in such a home the solar panels convert their DC power to AC, which then gets converted back to DC to charge the EV. You can have either DC-coupled or AC-coupled battery systems – in the former the power remains DC, while in the latter it is converted to AC before being stored in the battery. DC-coupled systems are more efficient (97.5% vs 90%).

In a modern home, therefore, there could be an entirely DC system where the power from the panels to the battery to the EV (which is just another batter) is all DC. The car battery can then also more easily be used as additional storage without conversion. Every time you convert AC to DC and back you get about a 3% energy loss, and having an all DC system would avoid that loss.

In terms of appliances, it’s a mix. Many of the bigger appliances, like refrigerators and dishwashers, use AC. While most of the smaller appliances, like computers, light-bulbs, and microwaves, use DC power. In order to have a 100% DC home, therefore, all that is necessary is to convert a few large appliances to DC, or for them to have their own DC to AC converter. DC also makes sense for a distributed power system, rather than distant centralized power production. Microgrids could be all DC. All of this makes some experts advocate for a future with residential DC power grids and all DC homes. We would likely need a hybrid system where we will have AC for long distance transmission. There is also still the advantage that AC is easier to alter voltage, but that is not a deal-breaker for DC if the home system were all at the same voltage.

The largest barrier, of course, is technology inertia. It is difficult to change over entire industries and change standards. At this point it’s difficult to predict what will happen, and the default will be for no change. I suspect, however, that this conversation will increase as the penetration of solar power, home battery backup, and EVs increases. At some point “going DC” for the home may be a thing, with the advantage of knocking 10% or so off of electricity demand (by eliminating multiple conversions).

It may happen first in developing nations and those who are currently building a lot of new infrastructure, like the UAE, leaving older industrialized nations with their crusty technology.

The post AC vs DC and other Power Questions first appeared on NeuroLogica Blog.

If you’re curious to know what my book is about and why it’s called “Waves in an Impossible Sea”, then watching this video is currently the quickest and most direct way to find out from me personally. It’s a public talk that I gave to a general audience at Harvard, part of the Harvard Bookstore science book series.

My intent in writing the book was to illuminate central aspects of the cosmos — and of how we humans fit into it — that are often glossed over by scientists and science writers, at least in the books and videos I’ve come across. So if you watch the lecture, I think there’s a good chance that you’ll learn something about the world that you didn’t know, perhaps about the empty space that forms the fabric of the universe, or perhaps about what “quantum” in “quantum physics” really means and why it matters so much to you and me.

The video contains 35 minutes of me presenting, plus some Q&A at the end. Feel free to ask questions of your own in the comments below, or on my book-questions page; I’ll do my best to answer them.

The focus is on finance at the UN climate summit in Baku, Azerbaijan, this month, but countries are a long way from any kind of consensus

A week ago, Donald Trump said that, if elected, he would let Robert F. Kennedy, Jr. "go wild" on healthcare. RFK Jr. has said that he'd immediately remove fluoride from drinking water, while surrogates say he'd work to prove vaccines unsafe. This is why a Trump Presidency could represent an extinction-level event for science-based federal health policy.

The post RFK Jr. is now an extinction-level threat to federal public health programs and science-based health policy first appeared on Science-Based Medicine.

According to the United Nations, the world produces about 430 million metric tons (267 U.S. tons) of plastic annually, two-thirds of which are only used for a short time and quickly become garbage. What’s more, plastics are the most harmful and persistent fraction of marine litter, accounting for at least 85% of total marine waste. This problem is easily recognizable due to the Great Pacific Garbage Patch and the amount of plastic waste that washes up on beaches and shores every year. Unless measures are taken to address this problem, the annual flow of plastic into the ocean could triple by 2040.

One way to address this problem is to improve the global tracking of plastic waste using Earth observation satellites. In a recent study, a team of Australian researchers developed a new method for spotting plastic rubbish on our beaches, which they successfully field-tested on a remote stretch of coastline. This satellite imagery tool distinguishes between sand, water, and plastics based on how they reflect light differently. It can detect plastics on shorelines from an altitude of more than 600 km (~375 mi) – higher than the International Space Station‘s (ISS) orbit.

The paper that describes their tool, “Beached Plastic Debris Index; a modern index for detecting plastics on beaches,” was recently published by the Marine Pollution Bulletin. The research team was led by Jenna Guffogg, a researcher at the Royal Melbourne Institute of Technology University (RMIT) and the Faculty of Geo-Information Science and Earth Observation (ITC) at the University of Twente. She was joined by multiple colleagues from both institutions. The study was part of Dr. Guffogg’s joint PhD research with the support of an Australian Government Research Training Program (RTP) scholarship.

Dr Jenna Guffogg said plastic on beaches can have severe impacts on wildlife and their habitats, just as it does in open waters. Credit: BPDI

According to current estimates, humans dump well over 10 million metric tons (11 million U.S. tons) of plastic waste into our oceans annually. Since plastic production continues to increase worldwide, these numbers are projected to increase dramatically. What ends up on our beaches can severely impact wildlife and marine habitats, just like the impact it has in open waters. If these plastics are not removed, they will inevitably fragment into micro and nano plastics, another major environmental hazard. Said Dr. Guffogg in a recent RMIT University press release:

“Plastics can be mistaken for food; larger animals become entangled, and smaller ones, like hermit crabs, become trapped inside items such as plastic containers. Remote island beaches have some of the highest recorded densities of plastics in the world, and we’re also seeing increasing volumes of plastics and derelict fishing gear on the remote shorelines of northern Australia.

“While the impacts of these ocean plastics on the environment, fishing and, tourism are well documented, methods for measuring the exact scale of the issue or targeting clean-up operations, sometimes most needed in remote locations, have been held back by technological limitations.”

Satellite technology is already used to track plastic garbage floating around the world’s oceans. This includes relatively small drifts containing thousands of plastic bottles, bags, and fishing nets, but also gigantic floating trash islands like the Great Pacific Garbage Patch. As of 2018, this garbage patch measured about 1.6 million km2 (620,000 mi2) and consisted of 45,000–129,000 metric tons (50,000–142,000 U.S. tons). However, the technology used to locate plastic waste in the ocean is largely ineffective at spotting plastic on beaches.

Geospatial scientists have found a way to detect plastic waste on remote beaches, bringing us closer to global monitoring options. Credit: RMIT

Much of the problem is that plastic can be mistaken for patches of sand when viewed from space. The Beached Plastic Debris Index (BPDI) developed by Dr. Guffogg and her colleagues circumvents this by employing a spectral index – a mathematical formula that analyzes patterns of reflected light. The BPDI is specially designed to map plastic debris in coastal areas using high-definition data from the WorldView-3 satellite, a commercial Earth observation satellite (owned by Maxar Technologies) that has been in operation since 2014.

Thanks to their efforts, scientists now have an effective way to monitor plastic on beaches, which could assist in clean-up operations. As part of the remote sensing team at RMIT, Dr. Guffogg and her colleagues have developed similar tools for monitoring forests and mapping bushfires from space. To validate the BPDI, the team field-tested it by placing 14 plastic targets on a beach in southern Gippsland, about 200 km (125 mi) southeast of Melbourne. Each target was made of a different type of plastic and measured two square meters (21.5 square feet) – smaller than the satellite’s pixel size of about three square meters.

The resulting images were compared to three other indices, two designed for detecting plastics on land and one for detecting plastics in aquatic settings. The BPDI outperformed all three as the others struggled to differentiate between plastics and sand or misclassified shadows and water as plastic. As study author Dr. Mariela Soto-Berelov explained, this makes the BPDI far more useful for environments where water and plastic-contaminated pixels are likely to coexist.  

“This is incredibly exciting, as up to now we have not had a tool for detecting plastics in coastal environments from space. The beauty of satellite imagery is that it can capture large and remote areas at regular intervals. Detection is a key step needed for understanding where plastic debris is accumulating and planning clean-up operations, which aligns with several Sustainable Development Goals, such as Protecting Seas and Oceans.”  

The next step is to test the BPDI tool in real-life scenarios, which will consist of the team partnering with various organizations dedicated to monitoring and addressing the plastic waste problem.

Further Reading: RMIT, Marine Pollution Bulletin

The post Plastic Waste on our Beaches Now Visible from Space, Says New Study appeared first on Universe Today.

Here’s this week’s comedy/news bit on Bill Maher’s “Real Time” show.  His topic is voters who can’t seem to agree on a Presidential candidate, and how they should be voting for Kamala Harris.  Maher avers that if Harris loses, it will because of “progressophobia,” which he calls “Steven Pinker’s term for the liberal fear that of ever admitting when things are actually good.”

Maher’s point is that salaries and the economy are “great”, as he says, and that the perception that they’re not is not a reason to vote for Trump.  The predicted recession didn’t happen (note the very salacious==and somewhat tasteless–joke about Trump’s sexual proficiency, followed by a not-bad imitation of Trump himself. I love the “in this reality, if you can’t get bacon, you’ll die” statement, mocking one recent assertion of Trump.  One statement I don’t get, though, is this one: ” I don’t know if Kamala worked at McDonald’s, but she’s not Flo from Progressive.”  Help me out here.

It’s basically an endorsement of Harris, saying that although she’s not perfect, and is mostly campaigning by dissing Trump rather than advancing her own plans, Maher finishes by saying, “‘I’m not Trump’ is still a really great reason.”

The Stanford health economist turned right-wing pandemic star could help take down
academia and scientific institutions in a second Trump administration

The post Bhattacharya for the CDC? first appeared on Science-Based Medicine.

Space-based telescopes are remarkable. Their view isn’t obscured by the weather in our atmosphere, and so they can capture incredibly detailed images of the heavens. Unfortunately, they are quite limited in mirror size. As amazing as the James Webb Space Telescope is, its primary mirror is only 6.5 meters in diameter. Even then, the mirror had to have foldable components to fit into the launch rocket. In contrast, the Extremely Large Telescope currently under construction in northern Chile will have a mirror more than 39 meters across. If only we could launch such a large mirror into space! A new study looks at how that might be done.

As the study points out, when it comes to telescope mirrors, all you really need is a reflective surface. It doesn’t need to be coated onto a thick piece of glass, nor does it need a big, rigid support structure. All that is just needed to hold the shape of the mirror against its own weight. As far as starlight is concerned, the shiny surface is all that matters. So why not just use a thin sheet of reflective material? You could just roll it up and put it in your launch vehicle. We could, for example, easily launch a 40-meter roll of aluminum foil into space.

Of course, things aren’t quite that simple. You would still need to unroll your membrane telescope back into its proper shape. You would also need a detector to focus the image upon, and you’d need a way to keep that detector in the correct alignment with the broadsheet mirror. In principle, you could do that with a thin support structure, which wouldn’t add an excessive bulk to your telescope. But even if we assume all of those engineering problems could be solved, you’d still have a problem. Even in the vacuum of space, the shape of such a thin mirror would deform over time. Solving this problem is the main focus of this new paper.

Once launched into space and unfurled, the membrane mirror wouldn’t deform significantly. But to capture sharp images, the mirror would have to maintain focus on the order of visible light. When the Hubble was launched, its mirror shape was off by less than the thickness of a human hair, and it took correcting lenses and an entire shuttle mission to fix. Any shifts on that scale would render our membrane telescope useless. So the authors look to a well-used trick of astronomers known as adaptive optics.

How radiative adaptive optics might work. Credit: Rabien, et al

Adaptive optics is used on large ground-based telescopes as a way to correct for atmospheric distortion. Actuators behind the mirror distort the mirror’s shape in real time to counteract the twinkles of the atmosphere. Essentially, it makes the shape of the mirror imperfect to account for our imperfect view of the sky. A similar trick could be used for a membrane telescope, but if we had to launch a complex actuator system for the mirror, we might as well go back to launching rigid telescopes. But what if we simply use laser projection instead?

By shining a laser projection onto the mirror, we could alter its shape through radiative recoil. Since it is simply a thin membrane, the shape would be significant enough to create optical corrections, and it could be modified in real time to maintain the mirror’s focus. The authors call this technique radiative adaptive optics, and through a series of lab experiments have demonstrated that it could work.

Doing this in deep space is much more complicated than doing it in the lab, but the work shows the approach is worth exploring. Perhaps in the coming decades we might build an entire array of such telescopes, which would allow us to see details in the distant heavens we can now only imagine.

Reference: Rabien, S., et al. “Membrane space telescope: active surface control with radiative adaptive optics.” Space Telescopes and Instrumentation 2024: Optical, Infrared, and Millimeter Wave. Vol. 13092. SPIE, 2024.

The post Future Space Telescopes Could be Made From Thin Membranes, Unrolled in Space to Enormous Size appeared first on Universe Today.