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A noninvasive colorectal cancer screening test that can be done at home could reduce the risk of colorectal cancer death by 33%, according to a new study.

Artificial intelligence (AI) is hot right now. Also hot: the data centers that power the technology. And keeping those centers cool requires a tremendous amount of energy. The problem is only going to grow as high-powered AI-based computers and devices become commonplace. That's why researchers are devising a new type of cooling system that promises to dramatically reduce energy demands.

Artificial intelligence (AI) is hot right now. Also hot: the data centers that power the technology. And keeping those centers cool requires a tremendous amount of energy. The problem is only going to grow as high-powered AI-based computers and devices become commonplace. That's why researchers are devising a new type of cooling system that promises to dramatically reduce energy demands.

Researchers have developed a material that shows a remarkable ability to convert sunlight and water into clean energy.

Tackling a long-time mystery, scientists have found that the turbulent movements of air in clouds play a key role in the growth of water droplets and the initiation of rain. The research can improve computer model simulations of weather and climate and ultimately lead to better forecasts.

Researchers are proposing a new way to curb industrial emissions, by tapping into the 'atomic intelligence' of liquid metals to deliver greener and more sustainable chemical reactions.

Machine learning models can reliably inform clinicians about the disability progression of multiple sclerosis, according to a new study published this week in the open-access journal PLOS Digital Health by Edward De Brouwer of KU Leuven, Belgium, and colleagues.

Researchers have developed somersaulting spin qubits for universal quantum logic. This achievement may enable efficient control of large semiconductor qubit arrays. The research group recently published their demonstration of hopping spins and somersaulting spins.

Researchers have developed somersaulting spin qubits for universal quantum logic. This achievement may enable efficient control of large semiconductor qubit arrays. The research group recently published their demonstration of hopping spins and somersaulting spins.

Mouse pups have increased activity in certain neurons in the centre of their brains when they interact with their mothers, which is linked to them showing fewer signs of distress

The gamma ray burst known as GRB221009A is the biggest explosion astronomers have ever glimpsed and we might finally know what caused the blast

Being immunised against shingles has been linked to a reduced dementia risk before and now a study suggests that the newer vaccine wards off the condition more effectively than an older one

AlphaProof, an AI from Google DeepMind, came close to matching the top participants in a prestigious competition for young mathematicians

Our CO2 emissions are warming the planet and making life uncomfortable and even unbearable in some regions. In July, the planet set consecutive records for the hottest day.

NASA is mapping our emissions, and while what they show us isn’t uplifting, it is visually appealing in a ghoulish way. Maybe the combination of visual appeal and ghoulishness will build momentum in the fight against climate change.

NASA’s Scientific Visualization Studio has released a video showing how wind and air currents pushed CO2 emissions around Earth’s atmosphere from January to March 2020. The video’s high-resolution zooms in and sees individual sources of CO2, including power plants and forest fires.

“As policymakers and as scientists, we’re trying to account for where carbon comes from and how that impacts the planet,” said climate scientist Lesley Ott at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “You see here how everything is interconnected by these different weather patterns.”

Credit: NASA’s Goddard Space Flight Center

The video starkly shows that it doesn’t matter where CO2 emissions come from; we all deal with the outcomes. Yet there are some interesting global differences.

Above the USA, South Asia, and China, most of the carbon comes from industry, power plants, and transportation. But over Africa and South America, most of the emissions come from burning, including forest fires, agricultural burning, and land clearing. Emissions also come from fossil fuels like oil and coal.

via GIPHY

The image pulses for a couple of reasons. Forest fires tend to flare during the day and then slow down at night. Also, trees and plants photosynthesize during the day, releasing oxygen and absorbing CO2. The land masses and the oceans act as carbon sinks.

There’s more pulsing in South America and the tropics because the data was collected during their growing season.

In this version, the video zooms in on the USA, showing individual CO2 sources.

via GIPHY

These visualizations are based on GEOS, the Goddard Earth Observing System. GEOS is an integrated system for modelling Earth’s coupled atmosphere, ocean, and land systems. NASA calls it a “high-resolution weather analysis model,” and it uses supercomputers to show what’s happening in the atmosphere. GEOS is based on billions of data points, including data from the Terra satellite’s MODIS and the Suomi-NPP satellite’s VIIRS instruments. GEOS has a resolution that’s more than 100 times greater than typical weather models.

Interested users can download the visualizations at the Scientific Visualization Studio.

Image Credit for all videos, images, and clips: NASA’s Goddard Space Flight Center

The post Our Carbon Dioxide Emissions Have a Mesmerizing Side appeared first on Universe Today.

Muscle cells that spent a week on the International Space Station revealed changes in gene expression that suggest microgravity can speed up ageing

Do I need to explain once more the principle of institutional neutrality in academia, whereby a university is prohibited from making official statements about politics, morality, or ideology in its announcements or on its website—except in rare situations when such statements are made to further the mission of the University? This principle was originally devised at the University of Chicago, codified in 1967 as the Kalven Report.

The reason for the principle is to avoid chilling or impeding free speech (we have a separate Principle of Free Expression) by making people fearful of angering authorities and endangering their own status at a university. If a department’s website opposed Israel’s war on Hamas, for example, such opinion (or its opposite) would have to be removed here, for it has nothing to do with the mission of the University. (Of course, there are always Pecksniffs who, by judicious word-twisting, can make any position seem relevant to the mission of a university. But really, our mission is teaching, doing research, and promulgating debate and searches for truth.)

While our Principles of Free Expression were published in 2015, they’ve already been adopted by 110 schools, which adhere to them in varying degrees. However, the Kalven Principle, published 48 years earlier, has been adopted by only a handful of other schools, including the University of North Carolina at Chapel Hill and Vanderbilt University.  Some other schools are contemplating adopting institutional neutrality, but haven’t seemed to push it through.  I’m not sure why, given that freedom of speech and institutional neutrality are mutually supportive, but I suppose schools (and departments, also included in our Kalven Principles) simply can’t resist weighing in on the issues of the day. In fact, even departments at the University of Chicago sometimes can’t resist making statements that seem to violate Kalven, and the administration polices and adjudicates putative violations.

Now the University of California system, as reported by the L.A. Times, is considering adopting institutional neutrality, too, but has gutted the meaning of that principle by watering it down. Click the link below to read, or, if it’s paywalled, find it archived here

Here’s an excerpt from the July 17 article showing how the UC system’s “neutrality” works:

University of California regents voted Thursday to ban political opinion from main campus homepages, a policy initially rooted in concern about anti-Israel views being construed as official UC opinion.

Political opinions may still be posted on other pages of an academic unit’s website, according to the policy approved at the regents meeting in San Francisco. It will take effect immediately.

The main homepage of a campus department, division or other academic unit will be reserved for news about courses, events, faculty research, mission statements or other general information.

Opinion must be published on other pages specifically labeled as commentary, with a disclaimer that they don’t reflect the entire university or campus. Those who want to post statements on their department websites must follow specific procedures and allow faculty members to weigh in through an anonymous vote.

Regent Jay Sures, vice chairman at United Talent Agency, has pushed for such action for the last few years, previously saying he has been troubled by “abuse” and “misuse” of departmental websites featuring anti-Israel sentiment and other opinions that do not reflect official university views.

After initially proposing a more restrictive policy, Sures said the final draft reflects a better balance between free speech and acknowledging both those who want to make statements and those who oppose them.

“This reflects that we value academic freedom, and it provides a very inclusive environment for the individual departments to put out statements and reflecting minority opinions within those departments,” he said.

Sorry, but I find this deeply misguided.  What purpose is served by institutional neutrality on a departmental or division homepage that is violated if you simply click a link on that page?  After all, in California a department or a division can always weigh in on the war, affirmative action, gun control, politics, and so on, on other pages. Suppose the chairman of a sociology department puts up a post condemning Israel for its conduct of the war against Hamas. Even if it’s labeled as “commentary”, who would be foolish enough to think that this will have no effect on the speech of that department? Grad students, junior faculty, and others who are vulnerable will be inhibited from speaking otherwise, even at faculty meetings or in public. After all, your counterspeech could anger the chair, who could then exact retribution, damage your tenure and promotion, and so on.

There are other venues for expressing your opinions as private individuals: they are called “social media.” Or you can write letters to the editor, publish papers, write books, and so on. There is no need to bawl out your political or ideological views on a university website. (As for chairmen and University presidents and provosts, the line is blurred between their private speech and official unviersity speech, and in my view they’d best keep their views on nonacademic stuff to themselves. This is indeed the case at Chicago).

The best course of action is simply to tell people not to use any parts of university websites opinions other than those very relevant to a university’s or a department’s mission. Let us have none of this mishigass about taking votes or putting up disclaimers. That stuff can still chill speech.

A bit more from the article:

Sean Malloy, a UC Merced associate professor of history and critical race and ethnic studies, asserted that regents were trying to “gag faculty speech” and that the proposed policy reflected efforts to repress the growing movement for Palestinian solidarity across UC campuses.

He noted that regents never tried to intervene in faculty statements on the Black Lives Matter movement after George Floyd’s killing, on climate change or in defense of immigrant students.

“It is only when faculty speech threatened to upset support for Israel and Zionism that the Regents saw fit to enact such a policy,” Malloy said in a statement to The Times. “It must be seen along with the dispatch of police against UC students, faculty and staff, as well as the newly adopted measures aimed against encampments as part of an effort by a group of Regents to hold the UC hostage to their own commitment to Zionism in the midst of a genocide against Palestine.”

No, the purpose of such statements is not to “gag faculty speech”, and should certainly not be to profess commitment to Zionism! The principle is meant, again, to allow faculty and everyone else to speak freely without being nervous about revenge from the university.  You just can’t put your speech on official university web pages.

Now Dr. Malloy is right in saying that if there is such a policy, it has to be applied fairly and uniformly: statements not affecting a university’s mission should all be banned from official websites and statements. You simply can’t allow university members to approve of Black Lives Matter or weigh in on George Floyd on one hand, but then then prevent others from writing about Israel on the other. The fair and just solution is simply to tell people to publish all their personal opinions in other places.  After all, there are plenty of such places! This website is one of them: it’s private and not at all connected to or supported by my university. My opinions are, of course, my own, and not that of my school.

Sadly, the regents of the University of California don’t seem to understand either the meaning or the import of institutional neutrality.

Every now and then, I get a question from a reader that I suspect many other readers share. When possible, I try to reply to such questions here, so that the answer can be widely read.

Here’s the question for today:

I do have one question that I couldn’t find the answer to in your book. Maybe I missed it, but here it is:

You explained what the strong force does (encapsulate the quarks and gluons within the proton), but what is the source of the strong force’s agency? I know it has energy used to hold the protons and neutrons together, but where does that force originate? It seems counter-intuitive, given the electromagnetic forces that pull particles apart due to equal charges — but how and why did the strong force come about? — Jeff Cox

Below I give a qualitative answer, and then go on to present a few more details. Let me know in the comments if this didn’t satisfactorily address the question!

First, A Qualitiative Overview

Let me first address this question for other forces:  for instance, “what is the source of gravity’s agency?” Then I’ll turn to electromagnetism, and then to the strong nuclear force. [The explanations given here are based on the ones used in the book.]

The Gravitational Force

What makes gravity happen? There are two answers to this question, both given in the book (chapters 13-14).  

The first answer is from a field-centric perspective: the source of gravity’s effects is the gravitational field.  Object # 1 changes the gravitational field in its general neighborhood.  If object #2 wanders into that neighborhood, it will respond to the changed gravitational field that it encounters by changing its direction and speed of motion.  Watching this happen, we will say: the gravitational effect of object #1 pulled on and altered the motion of object #2.  But really, it was all done through the intermediary of the gravitational field: object #1 affected the gravitational field, which in turn affected object #2.  (The reverse is also true: object #2 affects the field around it and this in turn impacts object #1.)

The second, more complete answer is from the medium-centric perspective.  It was given by Einstein: space should be understood as a medium [albeit a very strange one, as described in the book], and the gravitational field is secretly revealing the warping of space itself (and of time, too).  In other words, what is “really” happening, from this perspective, is that object #1 warps the space around it, and when object #2 comes by, it encounters this warped space, which causes its path to bend.

Both answers are correct — they are two viewpoints on the same thing. But the second answer is more conceptually satisfying to most humans. It gives us a way of understanding gravity as a manifestation of the universe in action. The field-centric viewpoint is more abstract, and less grounded in intuition.

The Electromagnetic Force

For electric forces, we have a field-centric answer: the source of electrical effects (and magnetic ones too) is the electromagnetic field (whose ripples are photons, the particles of light.)  The story of how object #1 affects the electromagnetic field, which in turn affects object #2, has different details but the same outline as for gravity. (Object 1 affects the electric field around it; object 2 wanders by, and its motion is changed when it counters the altered electric field caused by object 1.)

What about the medium-centric answer?  Sorry — we don’t have one yet.  In contrast to the gravitational field, which describes the warping of space, we don’t know what the electromagnetic field really “is” — assuming that’s a question with an answer.   Perhaps it is a property of a medium, as is the case for the gravitational field, but we just don’t know.

This situation might seem unsatisfying. But that’s the limited extent of our current knowledge. Someday physicists may make progress on this question, but there hasn’t been any up to now.

There is a line of thinking (described in the book, chapter 14) in which the universe has more dimensions of space than are obvious to us, and electromagnetism is due to the warping of space along the dimensions that we are unaware of. This is called “Kaluza-Klein theory” and goes back to the 1920s; Einstein was quite enamoured of this idea, and it arises in string theory, too. But at this point, it’s all just speculation; there’s no experimental evidence in its favor.

The Strong Nuclear Force

The field-centric answer: the source of strong nuclear effects is the gluon field (whose ripples are gluons.)  Quark 1 affects the gluon field, which in turn may affect particle #2, which might be a gluon, an anti-quark, or another quark.  And in the proton, all the particles affect all the others, through very complicated processes involving the gluon field.

The medium-centric answer?  Again, we don’t have one yet. Kaluza-Klein theory might or might not play a role here too.

What the Forces Have in Common

Let’s go a little deeper now.

You can’t take a first-year course in physics without wondering why gravity and electromagnetism both satisfy an “inverse square law”. If the distance between two objects is , the gravitational force between them is

where represents an object’s mass and is a constant of nature, known as Newton’s constant; the minus sign means the force is attractive. Meanwhile the electric force between them is

where represents an object’s charge and is a constant of nature, known as Coulomb’s constant. Note there is no minus sign: if the product of the charges is positive, the force is repulsive, while if it is negative, the objects attract each other. (Like charges repel, opposite charges attract.)

Neither of these laws, which were discovered before the nineteenth century, are the full story for gravitation or for electromagnetism; they were heavily revised in the last two hundred years. Nevertheless, the similar behavior is striking.

Remarkably, in the right settings, the strong nuclear force, the weak nuclear force, and the Higgs force also exhibit inverse square laws. Every single one. Again, there are differences of detail — minus signs, the constant in front, and what appears in the numerator — but always a . What’s behind this?!

The answer? Geometry. The fact that a sphere in three spatial dimensions has area is behind the inverse square laws in all the five elementary forces of nature (and some less elementary ones, too.) The reasoning is known as Gauss’s law, which I explained here (see Figure 1 and surrounding discussion). If we lived in four spatial dimensions, the force laws would instead behave as ; in two spatial dimensions they would show ; and in one spatial dimension, the force between two electrically charged objects would be a constant.

However, although each of the forces exhibits an inverse-square law sometimes, none of them does always. And each one deviates from inverse-square in its own way.

How the Forces Differ Attraction and Repulsion

First, about attraction and repulsion. Gravity and the Higgs force between two objects are inevitably attractive forces, but electromagnetism and the nuclear forces (which all come from “spin-one” fields) can be either attractive or repulsive. [The reasons aren’t hard to show using math; I don’t know of a completely intuitive argument, though I suspect there is one.]

In electromagnetism it is simple: as I mentioned, like charges repel, opposite charges attract. But in the strong nuclear force, it is more complicated, because the strong nuclear force has three types of charges (referred to, metaphorically, as “colors”.) Quarks attract anti-quarks, but whether they repel other quarks depend on what charges they are carrying. Three quarks of different colors actually attract each other, and that’s what’s happening in a proton. [See here for some details.]

Distance Dependence

Next, what about the distance-dependence? Electromagnetism exhibits the only force that is always close to , deviating from it only by slow drifts (in math, by logarithms of ). All the other forces show dramatic differences.

The Weak Nuclear and Higgs Forces

At distances greater than meters, 1/1000 of the radius of a proton, the weak nuclear force dies off with distance very rapidly — exponentially, in fact:

where is the mass of the W boson (the wavicle of the W field), and where I am just showing the distance-dependence and am dropping various constants and other details. The same is true of the Higgs force, except in that case is the mass of the Higgs boson. Essentially, in the language of the book, the mass of the W and Higgs bosons represent a stiffening of the W and Higgs fields, and stiff fields cannot generate forces that remain powerful out to very long distances. This is in contrast to the electromagnetic field, which is not stiff and can maintain an inverse-square law out to any .

The Strong Nuclear Force

The strong nuclear force could not be more different. A distances approaching meters, approximately the radius of a proton, the strong nuclear force dies off more slowly than the inverse square law, and eventually, for distances of greater than meters, it becomes constant. One can again understand this in terms of Gauss’s law, but applied to a new physical situation that does not occur in electromagnetism (at least, not in empty space.)

This effect derives from the way that the gluon field interacts with itself, although it is far from obvious. I do give a glimpse of this story in the book’s chapter 24, where I briefly mention the feedback effect of the gluon field on itself. The full story is very subtle, eluded physicists for a number of years, and won a Nobel prize for David Politzer and for David Gross and Frank Wilczek. Today the effect is well-understood conceptually, and computer simulations confirm that it is true. But no one has completely proven it just using mathematics.

The effect is also responsible for why a proton has a larger mass than the objects (quarks, anti-quarks and gluons) than it contans, as I recently explained here.

Gravity

Gravity is different in the opposite sense: instead of deviating from the inverse square law at long distance, as the nuclear forces do, it does so at short distance. Somewhat as the long-distance effects in the strong nuclear force are caused by the gluon field interacting with itself, the complexity of gravity at short distance is caused by the gravitational field interacting with itself… though the former is caused by quantum physics, while the latter is not.

For elementary particles, the distances where gravity deviates from are far too short for us to observe experimentally. But fortunately, large objects such as stars magnify these effects at distances long enough for us to observe them.

The fact that the gravity of the Sun is not quite inverse-square, but has a small component, is what causes the orbit of Mercury to deviate very slightly from the prediction of Newton’s laws. This shift was calculated correctly by Einstein, using the new theory of gravity that he was then developing, and gave him confidence that he was on the right track.

Much more dramatic are the effects near black holes, where force laws are much stronger than the Newtonian inverse square law. These are now observed in considerable detail.

Summing Up

Remarkably, despite all the diversity in the behavior of the five known forces, each one arises in the same way: from a field that serves as an intermediary between objects (which themselves are made from wavicles in these and other fields). This leads naturally, in three spatial dimensions, to laws that are inverse-square, modified by details that make the forces all appear very different. In this way, the huge range of behavior of all known processes in nature can be addressed using a single mathematical and conceptual language: that of quantum field theory. [This is a point I wrote about recently in New Scientist.]

I sent this email to Matthew last night:

Tuesday night I read something about J D. Bernal in Hitchens’s “God is Not Great,” which I was rereading, and I remembered that everybody called Bernal by a nickname that testified to his wisdom.  I turned out the light and unsuccessfully tried to remember it for a while, then fell asleep. “I’ll think of it tonight,” I told myself.

Sure enough, I woke up at about 3 a.m. and the first thing that popped into my mind was “SAGE”. That was, of course, his nickname.  Clearly my cranial neurons had been turning it over while I slept.  And of course this happens to all of us: we can’t think of something and much later it suddenly comes to us.  Clearly the brain was working on it in the interim.

The brain is truly a wondrous organ!

J. D. Bernal was a polymath who pioneered the study of molecular shape using X-ray crystallography. I should add that to me this is evidence for determinism. Seeing that name activated a program in my brain to dig out his nickname (which had been stored there for several decades since I read his biography), and the program kept running while I was sleeping.

I’m sure readers have similar or even weirder stories. (Matthew says that this happens to him all the time when he can’t think of a word for a crossword puzzle, but then it comes to him after he takes a break for a while and goes away.

Well, except for singletons and some videos from Tara Tanaka, this is the very end of the queue. I hope it will be remedied soon.

Today’s photos come from UC Davis ecologist Susan Harrison, whose captions are indented. You can enlarge her pictures by clicking on them.

More from Finland:  mammals and songbirds

Here are yet more pictures from a May trip to Finland and Norway that was previously featured in posts on Arctic seabirds, other Arctic creatures, and birds of the northeastern Finnish forests.

Today’s post begins with mammals….

My first-ever Hedgehog (Erinaceus europaeus), in the half-light of 4:00 am in Oulu:

An unbearably adorable Red Squirrel (Sciurus vulgaris) defending a prize pine cone:

A Mountain Hare (Lepus timidus) in its summertime brown coat, and a far more nervous-looking one still wearing its conspicuous winter white coat; this species is found only in tundra, taiga, and moorlands of northern Eurasia:

A diminutive Roe Deer (Capreolus capreolus), belonging to a genus found only in Eurasia:

A young Eurasian Elk (Alces alces), closely related to our Moose (Alces americanus) rather than to what we call Elk in North America (genus Cervus, which in Europe are called Red Deer):

Next, some colorful songbirds:

Greenfinch (Chloris chloris):

Robin (Erithacus rubecula):

Bullfinch (Pyrrhula pyrrhula):

Siskin (Carduelis spinus):

And finally, some songbirds more remarkable for their elaborate music than for their plumages:

Thrush Nightingale (Luscinia luscinia):

Blyth’s Reed Warbler (Acrocephalus dumetorum):

Wood Warbler (Phylloscopus sibilatrix):

Forests and other land ecosystems emitted almost as much carbon dioxide as they absorbed in 2023 – it will be much harder to restrict global warming to agreed targets