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The Skeptics Guide #999 - Aug 31 2024

Skeptics Guide to the Universe Feed - Sat, 08/31/2024 - 5:00am
What's the Word: Bunk; News Items: Starliner Update, Therapeutic Roleplaying, The Search for Gravitons, Dinosaur Footprints, Schools vs Cell Phones; Who's That Noisy; Your Questions and E-mails: Slippery Slope; Science or Fiction
Categories: Skeptic

Saturday: Hili dialogue

Why Evolution is True Feed - Sat, 08/31/2024 - 2:59am

Meanwhile, in Dobrzyn, Hili is peckish:

Hili: I have a feeling that it’s the right time.
A: For what?
Hili: For a little something.

Hili: Mam wrażenie, że to jest właściwa pora.
Ja: Na co?
Hili: Na małe Conieco.

Categories: Science

If Gravitons Exist, this Experiment Might Find Them

Universe Today Feed - Fri, 08/30/2024 - 4:53pm

There are four fundamental forces in the Universe; strong, weak, electromagnetic and gravity. Quantum theory explains three of the four through the interaction of particles but science has yet to discover a corresponding particle for gravity. Known as the ‘graviton’, the hypothetical gravity particle is thought to constitute gravitational waves but it hasn’t been detected in gravity wave detector. A new experiment hopes to change that using an acoustic resonator to identify individual gravitons and confirm their existence. 

The four fundamental forces of nature govern the Universe. Gravity is one that many people are familiar with yet we do not fully understand how it works. Its effects are obvious though as the attraction between objects with mass. It keeps the planets in orbit around the Sun, the Moon in orbit around the Earth and us pinned to the surface of planet Earth. One of the earliest attempts to describe it was  from Isaac Newton who stated that gravity was proportional to the mass of objects and inversely proportional to the square of the distance between them. Even at the largest scale of the cosmos it seems to be essential for the structure of the Universe. 

Portrait of Newton in 1702, painted by Godfrey Kneller. Credit: National Portrait Gallery, London

One of the challenges with gravity is that, unlike the other fundamental forces, it can only be explained in a classical sense. Quantum physics can explain the other three forces by way of particles; the electromagnetic force has the photon, the strong nuclear force has the gluon, the weak nuclear force has the W and Z bosons but gravity has, well nothing yet. Other than the hypothesised graviton. The graviton can be thought of as the building block of gravity much as bricks are the building blocks of a house or atoms the building blocks of matter. 

Detectors like LIGO the Laser Interferometer Gravitational-Wave Observatory, can detect gravity waves from large scale events like mergers of black holes and neutron stars yet to date, a graviton has never been detected. That may soon be about to change though. A team of researchers led by physics professor Igor Pikovski from the Stevens Institute of Technology suggests a new solution. By utilising existing detection technology, which is essentially a heavy cylinder known as an acoustic resonator, the team propose adding improved energy state detection methods known as quantum sensing. 

LIGO Observatory

The proposed solution, explains Pikovski “is similar to the photo-electric effect that led Einstein to the quantum theory of light, just with gravitational waves replacing electromagnetic waves.” The secret is the discrete steps of energy that are exchanged between the material and the waves as single gravitons are absorbed. The team will use LIGO to confirm gravity wave detections and cross reference with their own data. 

The new approach has been inspired by gravity wave data that have been detected on Earth. Waves detected in 2017 came from a collision event between two city-sized super dense neutron stars. The team calculated the parameters that would facilitate the absorption probability for a single graviton. 

The team began thinking through a possible experiment. Using data from gravitational waves that have previously been measured on Earth, such as those that arrived in 2017 from a collision of two Manhattan-sized (but super-dense) faraway neutron stars, they calculated the parameters that would optimise the absorption probability for a single graviton. Their development led to devices similar to the Weber bar (thick, heavy 1 ton cylindrical bars) to allow gravitons to be detected. 

The bars would be suspended in the newly designed quantum detector, cooled to the lowest possible energy state and the passage of a gravity wave would set it vibrating. The team then hope to be able to measure the vibration using super-sensitive energy detectors to see how the vibrations changed in discrete steps, indicating a graviton event. 

It’s an exciting time for gravity based physics and we are most definitely getting closer to unravelling its mysteries. Unfortunately though, the super-sensitive detectors are not available yet but according to Pikovski’s team, they are not far away. Pikovski summed it up “We know that quantum gravity is still unsolved, and it’s too hard to test it in its full glory but we can now take the first steps, just as scientists did over a hundred years ago with quanta of light.”

Source : New research suggests a way to capture physicists’ most wanted particle — the graviton

The post If Gravitons Exist, this Experiment Might Find Them appeared first on Universe Today.

Categories: Science

Study combines data, molecular simulations to accelerate drug discovery

Matter and energy from Science Daily Feed - Fri, 08/30/2024 - 1:41pm
Researchers have found a new method to increase both speed and success rates in drug discovery. The study offers renewed promise when it comes to discovering new drugs.
Categories: Science

How Vegetation Could Impact the Climate of Exoplanets

Universe Today Feed - Fri, 08/30/2024 - 1:27pm

The term ‘habitable zone’ is a broad definition that serves a purpose in our age of exoplanet discovery. But the more we learn about exoplanets, the more we need a more nuanced definition of habitable.

New research shows that vegetation can enlarge the habitable zone on any exoplanets that host plant life.

Every object in a solar system has an albedo. It’s a measurement of how much starlight the object reflects back into space. In our Solar System, Saturn’s moon, Enceladus, has the highest albedo because of its smooth, frozen surface. Its albedo is about 0.99, meaning about 99% of the Sun’s energy that reaches it is reflected back into space.

There are many dark objects in space with low albedoes. Some say that another of Saturn’s moons, Iapetus, has the lowest albedo.

Earth, the only living planet, has an albedo of about 0.30, meaning it reflects 30% of the Sunlight that reaches it back into space. Many factors affect the albedo. Things like the amount of ice cover, clouds in the atmosphere, land cover vs ocean cover, and even vegetation all affect Earth’s albedo.

This image made of satellite data shows the regions of Earth covered by forests with trees at least five meters (16.5 ft.) tall. Image Credit: NASA/LandSat

We live in an age of exoplanet discovery. We now know of more than 5,000 confirmed exoplanets, with many more on the way. Though all planets are interesting scientifically, we’re particularly interested in exoplanets that are potentially habitable.

A team of Italian researchers is examining exoplanet habitability through the lens of vegetation and albedo. Their work is in a paper to be published in the Monthly Notices of the Royal Astronomical Society titled “Impact of vegetation albedo on the habitability of Earth-like exoplanets.” The lead author is Erica Bisesi, a Postdoctoral Researcher at the Italian National Institute for Astrophysics’ Trieste Astronomical Observatory.

“Vegetation can modify the planetary surface albedo via the Charney mechanism, as plants are usually darker than the bare surface of the continents,” the researchers write in their paper. Compared to a dead planet with bare continents, an exoplanet with vegetation cover should be warmer if they’re both the same distance from similar stars.

The Charney mechanism is named after Jule Charney, an American meteorologist who is considered by many to be the father of modern meteorology. It’s a feedback loop between vegetation cover and how it affects rainfall.

In their work, the researchers updated the Earth-like Surface Temperature Model to include two types of dynamically competing vegetation: grasslands and forests, with forests included in the seedling and mature stages.

“With respect to a world with bare granite continents, the effect of vegetation-albedo feedback is to increase the average surface temperature,” the authors explain. “Since grasses and trees exhibit different albedos, they affect temperature to different degrees.”

On Earth, grasslands are found on every continent except Antarctica. They’re one of the largest biomes on Earth. Image Credit: NASA Earth Observatory

Since grasses and trees affect albedo differently, vegetation’s effect on planetary albedo is linked to the outcome of their dynamic competition. “The change in albedo due to vegetation extends the habitable zone and enhances the overall planetary habitability beyond its traditional outer edge,” the authors write.

The researchers considered four situations:

  • Complete tree dominance (forest worlds).
  • Complete grass dominance (grassland worlds).
  • Tree/Grass coexistence.
  • Bi-directional worlds

In a bi-directional world, vegetation converges to grassland or to forest, depending on the initial vegetation fractions. In these worlds, seed propagation across latitudes widens the region where forests and grasslands coexist.

The researchers found that vegetation cover lowers a planet’s albedo and warms the climate, nudging the outer limit of the habitable zone. However, they also arrived at more specific results.

They found that the outcome of dynamic competition between trees and grasses affected how vegetation is distributed across latitudes. “The achieved temperature-vegetation state is not imposed, but it emerges from the dynamics of the vegetation-climate system,” they explain.

This figure from the research shows how Earth’s liquid water habitability index is shifted outward by different vegetation regimes. It’s based on Earth’s modern distribution of continents. Image Credit: Bisesi et al. 2024.

The researchers worked with the idea of a ‘pseudo-Earth.’ The pseudo-Earth has a constant fraction of oceans at all bands of latitude, affecting the distribution of continents and vegetated surfaces relative to the equator, where most of the Sun’s energy strikes the planet.

This figure from the research shows how a pseudo-Earth’s liquid water habitability index is shifted outward by different vegetation regimes. It’s based on an equal distribution of oceans at all bands of latitude. Image Credit: Bisesi et al. 2024.

The researchers also worked with a hypothetical dry pseudo-Earth. On this Earth, ocean cover is limited to 30%, while the Earth and the pseudo-Earth both have 70% ocean cover.

The simulated dry pseudo-Earth has less ocean coverage than Earth, meaning there’s more surface area for vegetation to cover. Image Credit: Bisesi et al. 2024.

The team reached some conclusions about vegetation cover, albedo, and habitability.

The more continents a planet has, the greater the climate warming effect from vegetation. When the simulations resulted in a grass-dominated world, the effect was weaker because grass raises albedo. When the simulations resulted in a forest-dominated world, the effect was greater.

The researchers’ key point is that none of this is static. Outcomes are driven by the competition between grasslands and forests for resources, which in turn is driven by the average temperature in each latitudinal band. “In general, thus, the achieved temperature-vegetation state is not imposed, but it emerges from the dynamics of the vegetation-climate system,” they explain.

This is especially pronounced on the dry pseudo-Earth. Because there is so much land cover, vegetation has an even stronger effect on albedo and climate. “However, the ocean fraction cannot be too small, as
in this case, the whole hydrological cycle could be modified,” the researchers add.

Overall, vegetation’s effect on albedo and climate is small. But we can’t dismiss its effect on habitability. Habitability is determined by a myriad of factors.

This issue is very complex. For instance, on a planet where grasslands and forests coexist, external factors like stellar luminosity and orbital variations can be buffered depending on where the continents are and how much their vegetation affects albedo purely by location.

The authors consider their work as a basic first step in this issue. They only included certain types of grasslands and forests, didn’t include the relative availability of water, and didn’t include atmospheric CO2 concentrations.

“The dynamics explored here are extremely simplified and represent only a first step in the analysis of vegetation habitability interactions.” they write. “Future work will also include a simplified carbon balance model in the study of planetary habitability.”

“This endeavour should be seen as a first step of a research program aimed at including the main climate-vegetation feedbacks known for Earth in exoplanetary habitability assessments,” they write.

The post How Vegetation Could Impact the Climate of Exoplanets appeared first on Universe Today.

Categories: Science

Quantum holograms can send messages that disappear

New Scientist Feed - Fri, 08/30/2024 - 1:12pm
Entangled particles of light can transmit holographic images that can be selectively erased, allowing for secure communications that can also be deleted
Categories: Science

Why is the US military getting ready to launch new spy balloons?

New Scientist Feed - Fri, 08/30/2024 - 1:00pm
The US military has prioritised deploying high-altitude balloons that can carry out surveillance
Categories: Science

Generative AI creates playable version of Doom game with no code

New Scientist Feed - Fri, 08/30/2024 - 12:00pm
A neural network can recreate the classic computer game Doom despite using none of its code or graphics, hinting that generative AI could be used to create games from scratch in future
Categories: Science

A New Test Proves How to Make the Event Horizon Telescope Even Better

Universe Today Feed - Fri, 08/30/2024 - 11:50am

Want a clear view of a supermassive black hole’s environment? It’s an incredible observational challenge. The extreme gravity bends light as it passes through and blurs the details of the event horizon, the region closest to the black hole. Astronomers using the Event Horizon Telescope (EHT) just conducted test observations aimed at “deblurring” that view.

The EHT team collaborated with scientists at the Atacama Large Millimeter/submillimeter Array (ALMA) and other facilities to do the tests. The antennas detected light from the centers of distant galaxies at a radio frequency of 354 GHz, equivalent to a wavelength of 0.87 mm.

A map of the Event Horizon Telescope observatories used in recent test observations at 0.87 mm of distant galaxies, to bump up its resolution. Credit: ESO/M. Kornmesser

This pilot experiment achieved observations with detail as fine as 19 microarcseconds. That’s the highest-ever resolution ever achieved from Earth’s surface. Although there are no images from the tests, the observations “saw” strong light signals from several distant galaxies—and that was only using a few antennas. Once the team focused the full worldwide EHT array on targets, they could see objects at a resolution of 13 microarcseconds. That’s about like looking at a bottle cap on the surface of the Moon—from Earth’s surface!

Sharpening the Event Horizon Telescope

These observational tests are a big breakthrough because it means scientists can make images of black holes that are 50% sharper than previous observations. The EHT’s groundbreaking first observations of M87’s black hole and Sagittarius A* in our galaxy happened just a few years ago, at a wavelength of 1.33 mm. Those images were amazing, but the science teams wanted to do better.

“With the Event Horizon Telescope, we saw the first images of black holes using the 1.3-mm wavelength observations, but the bright ring we saw, formed by light bending in the black hole’s gravity, still looked blurry because we were at the absolute limits of how sharp we could make the images,” said the observation’s co-lead Alexander Raymond of the Jet Propulsion Laboratory. “At 0.87 mm, our images will be sharper and more detailed, which in turn will likely reveal new properties, both those that were previously predicted and maybe some that weren’t.”

The first ever actual image of a black hole, taken in 2019. This shows the black hole at the heart of galaxy M87 Credit: Event Horizon Telescope Collaboration

According to EHT Founding Director Sheperd “Shep” Doeleman, an astrophysicist at the CfA and co-lead on a recent paper about the observations, the recent tests will improve the view of our galaxy’s central supermassive black hole, as well as others. “Looking at changes in the surrounding gas at different wavelengths will help us solve the mystery of how black holes attract and accrete matter, and how they can launch powerful jets that stream over galactic distances,” he said. In addition, the new technique should reveal even more dim, distant black holes than the EHT has already seen.

Creating a Big Radio Eye to Study Black Holes

Think of the Event Horizon Telescope as a giant, Earth-sized virtual radio telescope. Instead of one massive dish the size of our planet, it links together multiple radio dishes across the globe. The technique is called “very long baseline interferometry” with each observatory sending its data to a central processing center. For this test, the array consisted of six facilities, including the Atacama Array. The experiment succeeded in expanding the wavelength range of the EHT. Usually, to get better resolution, astronomers have to build bigger telescopes, but this one’s already Earth-sized. So, goosing the wavelength was the only choice.

The current locations of observatories that make up the full Event Horizon Telescope. (Courtesy EHT)

The test observations at higher resolution mark the first time the VLBI technique was used successfully at a wavelength of 0.87 mm. It’s a challenging measurement to make because water vapor in the atmosphere absorbs more waves at 0.87mm than at 1.3mm. As a result, astronomers worked to improve the EHT’s resolution by increasing the bandwidth of the instrumentation. Then, they had to wait for good observing conditions at all the test sites.

The improvements should allow astronomers to get high-fidelity “movies” of the event horizon around a black hole. Of course, astronomers want more upgrades to the existing EHT arrays. Planned improvements include new antennas, as well as improvements to detectors and other instruments. The result should be some pretty spectacular images and animations of material trapped in the extreme gravitational clutch of a black hole.

Revisiting Old Black Hole Friends

Future observations will include return observations of the supermassive black holes in M87 and the heart of the Milky Way Galaxy. Both are surrounded by accretion disks full of material swirling into the black hole. Once that material crosses the event horizon (the gravitational point of no return), it’s gone forever. So, it’s important to track that kind of action around a black hole. That’s where the EHT comes in handy.

Researchers using the Event Horizon Telescope hope to generate more and better images like this of supermassive black hole Sag. A’s event horizon. Image Credit: EHT.

According to Shep Doeleman, the details should be amazing. “Consider the burst of extra detail you get going from black and white photos to color,” he said. “This new ‘color vision’ allows us to tease apart the effects of Einstein’s gravity from the hot gas and magnetic fields that feed the black holes and launch powerful jets that stream over galactic distances.”

With this in mind, he added that the Collaboration is excited to reimage M87* and Sgr A* at both 1.3mm and 0.87mm and move from detecting black hole “shadows” to more precisely measuring their sizes and shapes, which can help to estimate a black hole’s spin and orientation on the sky.

If all that happens as they hope, the 400-member EHT consortium will certainly be able to fulfill its founding aim. That’s to provide the most detailed radio images of the mysterious beasts that lurk in the hearts of most galaxies.

For More Information

EHT Scientists Make Highest-resolution Observations Yet from the Surface of Earth
Event Horizon Telescope Main Page
First Very Long Baseline Interferometry Detections at 870 µm

The post A New Test Proves How to Make the Event Horizon Telescope Even Better appeared first on Universe Today.

Categories: Science

Does mpox cause lingering symptoms like long covid?

New Scientist Feed - Fri, 08/30/2024 - 11:00am
Amid rising cases of mpox in Central Africa, it is important to uncover whether this virus causes symptoms even after the infection has cleared
Categories: Science

Michael Shermer — Unmasking the Unknown: UFOs, Alien Tech, and Military Secrets?

Skeptic.com feed - Fri, 08/30/2024 - 11:00am
https://traffic.libsyn.com/secure/sciencesalon/mss462_Michael_Shermer_2024_08_30.mp3 Download MP3

Extraordinary claims require extraordinary proof. It’s no different when it comes to UFO frenzy. There is a need to separate fact from fiction in UAP claims.

In this episode, Shermer delves into the growing interest in UAPs (formerly UFOs), especially in light of UFOlogist Lue Elizondo’s book Imminent. Elizondo claims the U.S. government has long been aware of extraterrestrial intelligence, backed by reports of unidentified craft surveilling military sites. The episode explores these bold assertions and the tension between believers and skeptics, including scientists like Avi Loeb and institutions like the Department of Defense, which have disputed such claims.

Listeners interested in extraterrestrial intelligence, UFOs, and government secrecy will find this discussion compelling. Shermer reflects on historical UFO figures like Bob Lazar and Travis Walton, questioning their credibility while exploring the widespread belief in imminent “disclosure” of alien contact. Through interviews with experts and analysis of various UAP phenomena, the episode challenges listeners to discern fact from fiction, offering an intriguing examination of what could be humanity’s most profound discovery.

If you enjoy the podcast, please show your support by making a $5 or $10 monthly donation.

Categories: Critical Thinking, Skeptic

Astronomers puzzled by little red galaxies that seem impossibly dense

New Scientist Feed - Fri, 08/30/2024 - 10:00am
‘Little red dot’ galaxies seen by JWST appear to be much more tightly packed with stars than other galaxies, raising big questions about how they came to be this way
Categories: Science

I am out of the bush!

Why Evolution is True Feed - Fri, 08/30/2024 - 9:09am

Just a note to let you know that, after five fantastic days in the huge (7,600 mi², 19,623 km2) Kruger National Park, driving and watching for animals at least eight hours each day (you aren’t allowed to leave your vehicle between camps or rest stops), I have returned to Hoedspruit for one night, flying on to Cape Town tomorrow.

Every day in Kruger was a new adventure, and we never knew what we’d see. Rosemary and I (kudos to her for organizing most of this trip) were driven around by the best guide ever, Isaack Maboea, full of information, stories, and, best of all, a crack spotter of wildlife. (I’m lousy at it; I can’t even see stuff until several people point it out to me, while Isaack can see an unobtrusive brown bird a hundred yards away.) The spottings included giraffe. lion, leopards, zebra, many species of antelope, Southern ground hornbills, lilac-breasted rollers, warthogs, African buffalo, and so on ad infinitum. All will be shown.

Since each day in Kruger provided a panoply of new stuff, I’ll divide my posts on the park into five separate installments, hopefully one per day after I get settled in Cape Town.

All I can say now, after the rude transition from the bush to the town, is that anybody with eyes who loves nature and wildlife should come to Kruger at least once, stay at least four nights, and hire Isaack to be their guide and driver.

After I’d heard that there were a handful white (leucistic, not albino) lions in the huge park, I kept begging Isaack to show me one. This morning, when we left camp for one final day of animal-watching before leaving the park, he told me that he’d had a dream last night that his ancestors came to him, telling him that he’d find that white lion for me (one of the ones in the park is named Casper).  Sure enough, he turned right after leaving the hut encampment and, about two miles down the road was a tawny (regular) lion along with. . . . CASPER!!! Yes, a leucistic lion, though I’m not sure it’s the one called Casper. It looked like this one taken from Wikipedia. But you’ll have to wait to see my own photo until day five of my own photo posts on Kruger.

Benjamint444, CC BY-SA 3.0 via Wikimedia Commons

It turned out that Isaack belongs to a WhatsApp group of Kruger guides who tell each other where they’ve spotted wildlife, and he heard from it yesterday that a white lion was sighted near our camp. He was just ribbing me about his ancestors’ message, though he does have a form of spiritual belief involving consulting his ancestors.

I’ll be in Cape Town until Sept. 8, making the long flight back to Washington, D.C. and then on to Chicago. Let’s hope for no cancellations this time.

More when I get settled in Cape Town–in a hotel that has internet.

Categories: Science

Ultracold quantum battery could be charged with quantum tunnelling

New Scientist Feed - Fri, 08/30/2024 - 9:00am
Atoms tunnelling through a quantum battery could charge it and also keep it from losing energy, which could give an advantage over conventional batteries
Categories: Science

Topological quantum simulation unlocks new potential in quantum computers

Computers and Math from Science Daily Feed - Fri, 08/30/2024 - 8:09am
Researchers have successfully simulated higher-order topological (HOT) lattices with unprecedented accuracy using digital quantum computers. These complex lattice structures can help us understand advanced quantum materials with robust quantum states that are highly sought after in various technological applications.
Categories: Science

Transparency is often lacking in datasets used to train large language models

Computers and Math from Science Daily Feed - Fri, 08/30/2024 - 8:09am
The Data Provenance Explorer can help machine-learning practitioners make more informed choices about the data they train their models on, which could improve the accuracy of models deployed in the real world.
Categories: Science

Novel chemical tool aims to streamline drug-making process

Matter and energy from Science Daily Feed - Fri, 08/30/2024 - 8:09am
The invention of a tool capable of unlocking previously impossible organic chemical reactions has opened new pathways in the pharmaceutical industry to create effective drugs more quickly.
Categories: Science

Upcycling excess carbon dioxide with tiny microbes

Matter and energy from Science Daily Feed - Fri, 08/30/2024 - 8:09am
While some microbes can make people sick or spoil food, others are critical for survival. These tiny organisms can also be engineered to make specific molecules. Researchers have rewired one such microbe to help tackle greenhouse gases in the atmosphere: It takes in carbon dioxide (CO2) gas and produces mevalonate, a useful building block for pharmaceuticals.
Categories: Science

AI tool maps out cell metabolism with precision

Computers and Math from Science Daily Feed - Fri, 08/30/2024 - 8:07am
Scientists have developed an AI tool that creates detailed models of cellular metabolism, making it easier to understand how cells function.
Categories: Science

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