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I think there’s little doubt that the pro-Palestinian and anti-Israel protests will once again roil colleges campuses this coming academic year.  As protestors vow that they’ll continue their activities, legal or not, and as Israel continues to root Hamas out of Gaza, I fully expect more trouble come this fall.

So do colleges, which are at this moment preparing for such trouble by confecting new regulations and policies. We have two articles on this subject, one in the NYT (first below) and the other in the Times of Israel. Click each headline to read; if the NYT is paywalled, you can find the first article archived here.

Note about what’s below: Daniel Diermeier used to be the Provost of the University of Chicago; now he’s the Chancellor (equivalent to the President) of Vanderbilt University, where he’s still carrying out the Chicago Principles, including free expression and institutional neutrality. Indented text is from the press; text flush left is mine. An excerpt from the NYT about Diermeier’s address to this year’s entering class at Vandy:

Less than 10 minutes had passed before Daniel Diermeier, Vanderbilt University’s chancellor, told hundreds of new students what the school would not do.

The university would not divest from Israel.

It would not banish provocative speakers.

It would not issue statements in support or condemnation of Israeli or Palestinian causes.

Before the hour was up on Monday, he added that Vanderbilt would not tolerate threats, harassment or protests “disrupting the learning environment.”

As you see, Diermeier pulls no punches.

This month, Vanderbilt required all first-year undergraduate students to attend mandatory meetings about the university’s approach to free speech, with the hope that clear expectations — and explanations for them — would help administrators keep order after protests rocked American campuses toward the end of the last academic year.

“The chaos on campuses is because there’s lack of clarity on these principles,” Dr. Diermeier said in an interview.

Well, that’s one reason, and I didn’t hear his talk, but the universal hope in all of the new “solutions” to protests is based on the claim that students simply don’t understand how free speech works on campuses, including private ones like Chicago and Vanderbilt. An important difference between “college” free speech and speech in the public arena is that colleges can more easily create “time, place, and manner” restrictions so that while legal speech is allowed, it mustn’t interfere with the mission of the university: no sit-ins or trespassing, no loud megaphones that disrupt classes, no encampments to block access to parts of campus, no deplatforming of speakers.

The problem I see is that the protestors in many places already know about these restrictions, and are determined to violate them anyway. They regard this as a form of civil disobedience—but one that, unlike classical civil disobedience, does not accept any attendant punishment. Indeed, just a handful of protestors who violated university regulations last year received either civil or University punishment, so there’s no incentive to at least go through the motions of obeying free-speech regulations. From later in the article:

Even as some universities have prepared more rigorous rules and procedures, it remains to be seen how strongly or consistently they will be enforced. The lasting consequences of defiance are also murky. Officials nationwide ultimately dropped many of the criminal charges that protesters faced after the spring demonstrations, and school discipline is still pending for many students. Suspensions have often been lifted in the meantime.

This is why universities’ solution to bring more “clarity” to free-speech rules seems hopeless. The solution, I think, is simply to enforce the rules. 

University presidents used summer break to huddle with police commanders, lawyers, trustees and other administrators to rewrite rules, tighten protest zones, and weigh possible concessions to maintain, or restore, order. Many have studied universities that temporarily defused tensions by striking deals with protesters.

But so far, universities are signaling little overt interest in negotiations.

On Monday, the University of California’s president, Michael V. Drake, told campus chancellors to ensure that their policies included bans on unapproved encampments and “masking to conceal identity.” Columbia University, where contentious protests helped drive Nemat Shafik from her 13-month-old presidency on Aug. 14, is limiting campus access. Northwestern University said that students would receive “mandatory trainings on antisemitism and other forms of hate,” with more policy changes coming.

“The question is how do we get more consistent in the way we respond to these issues — and clearer about what the rules are and what the tiered responses will be,” said Richard K. Lyons, the new chancellor at the University of California, Berkeley, a campus with one of the nation’s most robust records of protest. Dr. Lyons estimated that planning for demonstrations had consumed up to 15 percent of the summer for top administrators at Berkeley.

And there have been legal rulings that can force universities’ hands:

A series of recent court rulings, as well as investigations from Capitol Hill and the Department of Education, have created pressure on universities. A federal judge issued a preliminary injunction this month that said the University of California, Los Angeles, could not allow protesters to block Jewish students from campus facilities. (Although U.C.L.A. initially warned that the ruling threatened to “hamstring our ability to respond to events on the ground,” it decided not to appeal and said it would “abide by the injunction as this case makes its way through the courts.”)

Can you believe that UCLA defended the behavior of protestors to keep Jewish students away from their classrooms? Here’s a video of the blocking I remember at the time:

From an article on the UCLA ruling:

The complaint [by three Jewish students] alleges the protesters created a “Jew Exclusion Zone” where in order to pass “a person had to make a statement pledging their allegiance to the activists’ view.” Those who complied with the protesters’ view were issued wristbands to allow them to pass through, the complaint says, which effectively barred Jewish students who supported Israel and denied them access to the heart of campus.

Wristbands! Oy vey!

Our own University, like Vanderbilt, did not divest nor tolerate the encampments for very long, though it did give the encampers what I consider an overly long grace period.

The University of Chicago’s own experience this year suggests that even those deeply held principles do not always prevent turmoil. In May, the university brought in the police to remove an encampment that violated its policy barring unapproved tents.

At any rate, the divisions on campus are now so deep, and the protestors so sure of their moral compass, that I see no rapprochement, no matter how much universities inculcate students with the First Amendment or campus speech regulations.

The solution, which is Diermeier’s is simple, just follow through with campus speech violations by enforcing the rules. In my view, students will be loath to participate in illegal protests if they know that they’re going to be suspended, expelled, or have a punishment noted on their college transcripts. For even more than the students want divestment and a ceasefire, they want their degrees, an untarnished academic record. and jobs. I’m still baffled why many universities are simply letting the protestors off scot-free.

The Times of Israel simply lets us know that more disruptions of campuses are in store (click to read):

An excerpt:

The Student Intifada, a growing coalition of pro-Palestinian, anti-Zionist student groups, is making clear its intention to disrupt the fall semester on school campuses across the United States.

Across dozens of campuses currently opening their fall semesters, there are already calls for masked vigils in support of “Palestine.” Troublingly, many of the groups have gone from calling for demonstrations and encampments to condoning the use of violence and “the total eradication of Western civilization.”

Note that, as some like Douglas Murray have warned, the protestors are not simply anti-Israel, but anti-West and anti-Enlightenment. The article continues.

The Student Intifada’s roots can be traced to the National Students for Justice in Palestine (SJP), founded in 1993 at the University of California Berkeley. However, it’s picked up followers since the war in Gaza and then again with the media attention on Columbia University following last year’s highly-covered student encampment.

It’s worth noting that not a single Columbia student, despite illegal occupation and trashing of a university building faced legal charges (which the Manhattan DA dropped), and nearly none of them (perhaps none at all) faced severe university charges including permanent suspension (many ‘interim suspensions” were rescinded). More:

With the National SJP [Students for Justice in Palestine] as its guide, the movement isn’t limited to local SJP chapters. But it’s not so much the coalition’s reach that troubles some, but rather its refusal to engage with different perspectives.

“The movement is a belief cascade where those in the group compete with each other for acceptance. As they do that, their opinions become more and more extreme,” said William J. Bernstein, author of “Delusions of Crowds: Why People Go Mad in Groups.”

Excuse my cynicism, but I don’t think introductory units on critical thinking, free speech, and civil discussion required for first-year students are going to solve this problem. More:

Across dozens of campuses currently opening their fall semesters, there are already calls for masked vigils in support of “Palestine.” Troublingly, many of the groups have gone from calling for demonstrations and encampments to condoning the use of violence and “the total eradication of Western civilization.”

Yep, all of Western civilization.

The Student Intifada’s roots can be traced to the National Students for Justice in Palestine (SJP), founded in 1993 at the University of California Berkeley. However, it’s picked up followers since the war in Gaza and then again with the media attention on Columbia University following last year’s highly-covered student encampment.

. . . “Expect to see zero compromise”

With the National SJP as its guide, the movement isn’t limited to local SJP chapters. But it’s not so much the coalition’s reach that troubles some, but rather its refusal to engage with different perspectives.

“The movement is a belief cascade where those in the group compete with each other for acceptance. As they do that, their opinions become more and more extreme,” said William J. Bernstein, author of “Delusions of Crowds: Why People Go Mad in Groups.”

“No matter how high their SAT scores were, they don’t have the critical thinking skills they need. They are incapable of putting themselves in other people’s shoes. They are utterly intolerant of other views,” Bernstein said.

. . . University leaders should expect the students to become more strident in their demands this fall, said Lauren Post, an analyst with the Anti-Defamation League’s Center on Extremism.

“They are going to increase their efforts to drive Zionist institutions off campus. They are going to make the average Jewish and Zionist student increasingly uncomfortable. We can expect to see zero compromise from these groups,” Post said.

. . . . In a July 31 Instagram post, the University of Chapel Hill SJP appeared to back the right to use violence.

“We emphasize our support for the right to resistance, not only in Palestine, but also here in the imperial core. We condone all forms of principled action, including armed rebellion, necessary to stop Israel’s genocide and apartheid, and to dismantle imperialism and capitalism more broadly. The oppressors will never grant full liberty to the oppressed; the oppressed must seize liberty with their own hands,” the post said.

The Times of Israel also emphasizes the lack of sanctions for violators, again mentioning my school:

There were an estimated 3,200 people, not all of them students, arrested at colleges and universities last spring, according to the Associated Press. Most of the charges against students have since been dropped.

Other universities, including the University of Chicago and Harvard, withheld degrees from some pro-Palestinian students facing disciplinary measures for their part in encampments and protests. Many of them have since received their diplomas.

About those “nonstudents” demonstrating at many colleges, which also happened at Chicago, it’s a simple matter to ask for IDs, something that students at the U of C must produce on demand.  Then names can be taken and trespassers in unapproved demonstrations given the boot.

Two caveats. First of all, as always I am an exponent of free speech on all campuses, public and private.  I’m even at the extreme of those free-speechers who think that someone shouting “gas the Jews” on campus in a situation that isn’t likely to provoke violence should not be punished.  What I object to is students, with full knowledge, violating campus regulations and, by so doing, impeding the mission of colleges: access to learning. And I object to universities growling about this but doing absolutely nothing to the violators.

There’s a reason why speed traps work: those who speed do so at their own risk (and the risk of others), knowing that they’ll have to get a ticket and a fine. The result: if you know there are speed traps in an area, you slow down.

As an experiement on what happens when deterrence vanishes, read about Montreal’s Murray-Hill Police Strike in 1969. (This is also an object lesson for those who think that you can solve the problem of crime by getting rid of cops and using patrolling by locals.)

Second, I think students deserve a warning when engaged in illegal demonstrations before they’re disciplined.  The encampers in Chicago got several days of warnings before the cops took down the encampment (without a single person hurt) at 4:30 a.m. last May 7.  Those shouting down speakers or occupying buildings should get, say, ten minutes of warnings before the hammer comes down. Finally, there should be no illegal encampments: not a single tent stake should be driven into prohibited college ground without University officials saying, “Sorry, you can’t do that.”

By all means have introductions to free speech and moderated discussions of first-year students to teach them how free speech works, and why we have it. But that’s not enough. I’m stymied by the failure of universities to realize a simple principle of human behavior: if you give people meaningful punishment for doing something that’s prohibited, they will stop doing it. 

A regulation that’s no enforced is a regulation without teeth.

The James Webb Space Telescope (JWST) keeps finding supermassive black holes (SMBH) in the early Universe. They’re in active galactic nuclei seen only 500,000 years after the Big Bang. This was long before astronomers thought they could exist. What’s going on?

Monster black holes like the ones at the hearts of galaxies take a really long time to grow so massive. They could start as smaller ones that gobble up nearby stars and gases, or they can grow by merging with other supermassive black holes. That typically takes billions of years and a lot of material to build up to something as massive as the four-million-solar-mass one in the heart of our Milky Way Galaxy. It’s even longer for the really big ones that contain tens of millions of stellar masses.

A James Webb Telescope image shows the J0148 quasar circled in red. Two insets show, on top, the central supermassive black hole, and on bottom, the stellar emission from the host galaxy.

JWST has spotted many SMBH that already appear “old” and massive less than a billion years after the Big Bang. It’s not an observational fluke—they’re really there.

“How surprising it has been to find a supermassive black hole with a billion-solar-mass when the universe itself is only half a billion years old,” said astrophysicist Alexander Kusenko, a professor of physics and astronomy at UCLA. “It’s like finding a modern car among dinosaur bones and wondering who built that car in the prehistoric times.”

Building Supermassive Black Holes in Ancient Times

So, what built SMBH so early in cosmic history? One obvious process is the death of the first Population III stars that began forming as soon as the infant Universe cooled enough for them to coalesce. These were massive, metal-poor (meaning they had no elements heavier than helium), and short-lived. When they died as supernovae, they formed stellar-mass black holes. It’s possible those early ones merged and got bigger.

Another suggestion is a so-called “gravo-thermal” collapse of self-interacting dark matter halos. That basically means a negative heat transfer inside a system. That can lead to the collapse of a black hole, and from there, it could have grown.

Astronomers have also considered the participation of primordial black holes created in the moments after the Big Bang. These theoretical low-mass black holes could have formed under special conditions when dense areas of space collapsed quickly. How SMBH formed from primordial black holes isn’t understood at the moment. So, is there another formation theory?

Primordial black holes, if they exist, could have formed by the collapse of overdense regions in the very early universe. Some theories suggest these played a role in forming supermassive black holes. Credit M. Kawasaki, T.T. Yanagida.

This is where dark matter comes into play. Kusenko and his colleagues dug into the idea of dark matter-influenced collapse. They found that if dark matter decays, it plays a role in “corraling” a hydrogen gas cloud. It would not fragment (as clouds usually do). Eventually, that could lead to the relatively rapid formation of an SMBH. Since there is evidence of dark matter’s influence in the early Universe, this could explain the monster black holes in the earliest epochs of cosmic history.

From Cloud to Black Hole Formation via Dark Matter?

Of course, the conditions have to be just right for this to happen. “How quickly the gas cools has a lot to do with the amount of molecular hydrogen,” said doctoral student Yifan Lu, the first author on a paper describing the dark matter idea. “Hydrogen atoms bonded together in a molecule dissipate energy when they encounter a loose hydrogen atom. The hydrogen molecules become cooling agents as they absorb thermal energy and radiate it away. Hydrogen clouds in the early universe had too much molecular hydrogen, and the gas cooled quickly and formed small halos instead of large clouds.”

Certain radiation can destroy molecular hydrogen. That creates conditions that prevent cloud fragmentation. The radiation could be from somewhere, and Lu and others suggest an interesting idea in their paper. They state that there’s a possible “parameter space” where relic decaying particles could emit radiation that would spur the collapse. Among other things, they propose an “axion-like” dark matter particle decaying and spurring the eventual coalescence of a cloud of hydrogen into an SMBH.

Mysteries of Dark Matter and SMBH Need Answers

Dark matter itself is a mysterious “stuff” that makes up a very large part of the “stuff” of the Universe. We know about it from its gravitational effects on the objects we can see (called baryonic matter). The form that dark matter takes isn’t understood at all, however. It could be made of particles that slowly decay, or it could be made of more than one particle species. Some could be stable, others could decay at early times. In either case, the product of decay could be radiation in the form of photons, which break up molecular hydrogen and prevent hydrogen clouds from cooling too quickly. Even very mild decay of dark matter yielded enough radiation to prevent cooling, forming large clouds and, eventually, supermassive black holes.

Of course, this idea hasn’t been proven. However, the team points out that the decay of such particles of dark matter can emit light in both the optical and ultraviolet spectrum. That might explain the very precise measurements of the “cosmic optical background” (COB) seen by the New Horizons LORRI instrument. The COB is a visible light background roughly analogous to the cosmic microwave background. Think of it as the sum of all emissions from objects beyond the Milky Way Galaxy. Its presence allows astronomers to diagnose and understand the emissions from all astrophysical objects. There’s still a lot to study and understand about these possible axions (if they make up dark matter).

For More Information

Dark Matter Could Have Helped Make Supermassive Black Holes in the Early Universe
Direct Collapse Supermassive Black Holes from Relic Particle Decay
Pre-print of Paper

The post Dark Matter Could Have Driven the Growth of Early Supermassive Black Holes appeared first on Universe Today.

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

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.

I trust you'll have the intellectual integrity to play videos of these speakers. Anything less, would be misinformation and censorship.

The post An Open Letter to the President of Stanford, Jonathan Levin: Don’t Censor Drs. Scott Atlas, John Ioannidis, Sunetra Gupta, Marty Marky, Monica Gandhi, Jay Bhattacharya, and Vinay Prasad. Amplify Their Voices. first appeared on Science-Based Medicine.

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.

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.

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.

Entangled particles of light can transmit holographic images that can be selectively erased, allowing for secure communications that can also be deleted

The US military has prioritised deploying high-altitude balloons that can carry out surveillance

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

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.

Amid rising cases of mpox in Central Africa, it is important to uncover whether this virus causes symptoms even after the infection has cleared

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.

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‘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

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.

Atoms tunnelling through a quantum battery could charge it and also keep it from losing energy, which could give an advantage over conventional batteries

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.

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.

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.