News Feeds

Researchers reveal a new pathway for designing optical materials using the degree of atomic disorder. The researchers anticipate developing crystals that enable advanced infrared imaging in low light conditions, or to enhance medical imaging devices.

In the ever-expanding search for energy resources, a new study has emerged from Mozambique's Maniamba Basin. Mozambique's Maniamba Basin could be a big source of natural gas.

Researchers have invented a breakthrough technique for manufacturing highly purified silicon that brings powerful quantum computers a big step closer.

Discharge from ships with so-called scrubbers cause great damage to the Baltic Sea. A new study shows that these emissions caused pollution corresponding to socio-economic costs of more than EUR 680 million between 2014 and 2022. At the same time, the researchers note that the shipping companies' investments in the much-discussed technology, where exhaust gases are 'washed' and discharged into the sea, have already been recouped for most of the ships. This means that the industry is now making billions of euros by running its ships on cheap heavy fuel oil instead of cleaner fuel.

The natural vein structure found within leaves -- which has inspired the structural design of porous materials that can maximize mass transfer -- could unlock improvements in energy storage, catalysis, and sensing thanks to a new twist on a century-old biophysical law.

A new type of surgically implanted pump that can support a child's failing heart has passed the first stage of human testing in a recent trial.

Researchers used commercially available tabletop lasers to create tiny, atomically sharp nanostructures in samples of a layered 2D material called hexagonal Boron Nitride (hBN). The new nanopatterning technique is a simple way to modify materials with light--and it doesn't involve an expensive and resource-intensive clean room.

Engineers have developed two new graph-based computational tools for tracking genomic variation within microbiomes.

Researchers have harnessed the technology behind foundation models, which power tools like ChatGPT, to discover new cancer imaging biomarkers that could transform how patterns are identified from radiological images. Improved identification of such patterns can greatly impact the early detection and treatment of cancer.

Researchers have debunked a 75-year-old theory about how humans determine where sounds are coming from, and it could unlock the secret to creating a next generation of more adaptable and efficient hearing devices ranging from hearing aids to smartphones.

Researchers have debunked a 75-year-old theory about how humans determine where sounds are coming from, and it could unlock the secret to creating a next generation of more adaptable and efficient hearing devices ranging from hearing aids to smartphones.

Analysis of thousands of exchanges between the intelligent cetaceans suggests they combine short click patterns – similar to letters of the alphabet - into longer sequences

A practical superconductor would transform the efficiency of electronics. After decades of hunting, several key breakthroughs are inching us very close to this coveted prize

Software that has been blocked from connecting to the internet should be secure from hacking attempts, but now researchers have found a way to sneak data out by varying the speed of the computer's processor

Yesterday the Encampment was fairly quiet, but after the President stopped negotiations with the protestors, an air of doom hung over the pro-Palestinian enclave. In this post I’ll put up some photos, videos, and remarks about the final day of the encampment, and then show what happened this morning.

Here are some photos from yesterday afternoon, the last day (hopefully) of the encampment. The afternoon photos are mine, but the video below is credited to another person.

A panorama of the area. Click to enlarge. The encampment is inside the fence to the right, and there were more than 100 tents there.

A press conference held yesterday on the steps of the administration building by the pro-demonstrator professors. They argued strenuously that we should leave up the encampment. After all, they argued, it’s free speech. Well, it’s also a violation of campus speech codes.  250 of these people signed a petition to the President defending the encampment. They lost.

Photos of the last day of the encampment:

I don’t think the University of Chicago Police Department would like this “Fuck UCPD” sign:

Here are three people being kicked out of the encampment yesterday, apparently for no reason except they “intruded”.  Two of them were harassed by the protesters and given the bum’s rush, while the father of Jonathan (the student who took the film) went in to help them. All three were then hustled out with cries of “Fascists! Go home!”, as you can hear.   Video by Jonathan Zeevi.

But the police left the Jewish banners and flags alone, as they were placed legally. Am Yisrael Chai!

The dismantling was already beginning when I walked to work about 5 a.m. There were campus cops all over the place, chanting and screaming by the Encampers, and loud shouts by the police clearing the area. Two cop cars were parked on the quad. I’ll let the Chicago Maroon give the details:

At approximately 4:25 a.m. on Tuesday morning, less than an hour after encampment organizers concluded their final rally of the evening, several dozen UCPD officers arrived at the main quad to remove the pro-Palestine encampment. The officers’ arrival came on the ninth day of the encampment, after UChicago United for Palestine (UCUP) launched an encampment on the quad outside of Swift Hall at 10 a.m. on Monday, following in the steps of pro-Palestinian groups at numerous other universities that have set up encampments in recent weeks.

Shortly before UCPD officers sweeped [sic] the encampment, two UCPD cars arrived on the main quad. Protesters were informed over a speaker that “the University of Chicago [did] not permit their assembly in this area,” and that they were “hereby notified that [they were] committing criminal trespass by remaining on… private property without permission.”

“Anyone who fails to comply will be criminally charged,” the speaker announced. “Students who fail to comply with this order will be subject to University discipline and immediately placed on leave of absence.”

Protesters, as they had largely returned to their tents to sleep for the night following the rally, had only minutes to comply with orders before UCPD officers entered the encampment. As UCPD officers overturned the encampment’s tents and barriers, protesters chanted in unison, repeating the phrases they had used during their daily rallies over the past week of the encampment. The Cook County Sheriff’s Office was also observed on the scene amidst the raid.

“More than 40,000 dead! You’re arresting kids instead!” Encampment members chanted in a video reviewed and verified by The Maroon from a protester inside the encampment during the sweep.

In an interview shared with The Maroon, an encampment member asserted that “[UCPD] did not give [encampment members] a clear plan for leaving.

“They came in maybe two minutes after the warning,” the encampment member said. “It’s clear that they waited until after the rally was over. We were at our most vulnerable.”

JAC: Isn’t that the best time to clear the encampment? We don’t want protestors fighting the cops, which is a recipe for violence and injury. The Maroon continues:

Protesters could be heard screaming by Maroon staff as the raid went on. At 4:55 a.m., UCPD ordered press, including Maroon staff, to leave the quad. It is currently unclear how many arrests may have been made, or if there were any injuries.

In a Telegram message, UCUP encouraged protesters who had not been at the encampment at the time of the raid to return to campus to demonstrate outside of the quad. Protesters gathered near the S. Ellis Ave entrance to the quad and chanted at the line of police donned in riot gear, who set up yellow barricades to separate themselves from the protesters.

Officers then handed out slips of paper with instructions on departing the encampment to the protesters who had gathered. The slips were entitled “Final Notice to Students Participating in Encampment on Main Quad,” and were not handed to protesters inside of the encampment in advance of the raid.

“The Deans on Call and University of Chicago Police Department (UCPD) have informed you multiple times that your tents and other items are unauthorized. This is your final warning to leave the encampment.

If you fail to immediately leave, you will be arrested by law enforcement for criminal trespass under the Illinois Criminal Code.

Additionally, failure to immediately leave will result in disciplinary action as outlined in the Student Manual. You will also be immediately placed on emergency interim leave of absence from the University. A student who has been placed on emergency interim leave of absence must promptly vacate University housing, leave campus, cannot participate in student and academic program activities, or use any University facilities, and may not return until the student has been authorized to return from the leave and reenroll.”

The University could not be reached for comment.

Here’s a video taken by illegal encamper and posted on SJP Twitter; you’ll have to watch it on YouTube (click on “Watch on YouTube”):

This statement by the President was issued shortly after the Quad was cleared, explaining why the Encampment had to go.

 

A similar statement from our Dean of Students and the VP for Safety and Security:

These next photos and videos were taken by several readers of this site.

The protestors after they’d been pushed out of the quad onto Ellis Avenue. They tried to push back into the Quad, but the cops blocked their entry.

The throughway to the Quad that runs beneath the Administration Building, Levi Hall:

The peeved protestors, deprived of their tents and billboards, shouting at the cops blocking their re-entry into the quad:

More: protestors demanding that the cops answer, “Why are you here?” But of course we know whey they’re here: to enforce campus regulations.

“We love you,” they’re crying, though it’s very strange. They’re trying to push back into the quad, but the cops push back using a yellow plastic fence.

Protestors on one side of the fence; cops on the other.

Here, I’m told, are the infamous Weatherpeople, Bill Ayers and Bernadine Dohrn (circled), who were leaders of the Weather Underground (Ayers was a cofounder). They were arrested years ago, but only Dohrn served a bit of time, They got jobs in Chicago, and lately have been hanging around the Encampment to support its members.

The end, a cleared Quad:

Bye, bye, tents!:

I guess not all the protestors took their tents with them, even though they were allowed to.

And here’s a local report from ABC7 News, mentioning punishment of students (but only those who fail to leave).

What’s next? I doubt that these protesters, who are angry and persistent, will give up.  But they won’t be allowed to camp on the campus any longer, and for a while we may have to show University ID cards to get onto campus.

We’re all wondering if there will be punishments for students and “outsiders.”  The cops didn’t apparently ask for IDs as they expelled the Encampers, so I’m not sure how the University will identify those Encampers for punishment. As the President said above, “Where appropriate disciplinary action will proceed.” I’m not convinced, given the history of these protests, that this will occur. But certainly Students for Justice in Palestine, which was a big part of the Encampment and which was already on a warning from the University, should have its status as a Recognized Student Organization revoked.

Student protests will undoubtedly continue, the Jewish students will try to hold their own in the face of the antisemitism that was part of the Encampment, and that’s one form of division that seems irreparable, especially if Israel eliminates Hamas. (Our students should not suffer because of anything Israel does!)

With the faculty divided as well, will things ever get back to normal here? I’m not sure, as antipathy is rife. And our University has certainly had its brand tarnished.

The Jinx Press site has a bunch of tweets, apparently taken by Encampers. Here are a couple (Jinx is clearly pro-Encampment):

Trashing the camp, shouting, tossing debris at press and bystanders pic.twitter.com/cJYaSL1r3I

— Jinx Press (@JinxPress) May 7, 2024

8am on Tuesday and every trace of the encampment has been cleared. pic.twitter.com/f1AQi2Yfnu

— Jinx Press (@JinxPress) May 7, 2024

It took just three hours from when the UCPD started taking down the camp until the quad was cleared. Kudos to the cops for handling this well and avoiding injury, and also to those workers who had to clean up the mess the protesters left behind.

The Sun is increasing its intensity on schedule, continuing its approach to solar maximum. In just over a 24-hour period on May 5 and May 6, 2024, the Sun released three X-class solar flares measuring at X1.3, X1.2, and X4.5. Solar flares can impact radio communications and electric power grids here on Earth, and they also pose a risk to spacecraft and astronauts in space.

NASA released an animation that shows the solar flares blasting off the surface of the rotating Sun, below.

NASA’s Solar Dynamics Observatory captured these images of the solar flares — as seen in the bright flashes in the upper right — on May 5 and May 6, 2024. The image shows a subset of extreme ultraviolet light that highlights the extremely hot material in flares and which is colorized in teal. Credit: NASA/SDO

Predicting when solar maximum will occur is not easy and the timing of it can only be confirmed after it happens. But NOAA’s Space Weather Prediction Center (SWPC) currently estimates that solar maximum will likely occur between May 2024 and early 2026. The Sun goes through a cycle of high and low activity approximately every 11 years, driven by the Sun’s magnetic field and indicated by the frequency and intensity of sunspots and other activity on the surface. The SWPC has been working hard to have a better handle on predicting solar cycles and activity. Find out more about that here.  

Solar flares are explosions on the Sun that release powerful bursts of energy and radiation coming from the magnetic energy associated with the sunspots. The more sunspots, the greater potential for flares.

Flares are classified based on a system similar to the Richter scale for earthquakes, which divides solar flares according to their strength. X-class is the most intense category of flares, while the smallest ones are A-class, followed by B, C, M and then X. Each letter represents a 10-fold increase in energy output. So an X is ten times an M and 100 times a C. The number that follows the letter provides more information about its strength. The higher the number, the stronger the flare.

Flares are our solar system’s largest explosive events. They are seen as bright areas on the Sun and can last from minutes to hours. We typically see a solar flare by the photons (or light) it releases, occurring in various wavelengths.

Sometimes, but not always, solar flares can be accompanied by a coronal mass ejection (CME), where giant clouds of particles from the Sun are hurled out into space.  If we’re lucky, these charged particles will provide a stunning show of auroras here on Earth while not impacting power grids or satellites.

Thankfully, missions like the Solar Dynamics Observatory, Solar Orbiter, the Parker Solar Probe are providing amazing views and new details about the Sun, helping astronomers to learn more about the dynamic ball of gas that powers our entire Solar System.

The post Solar Max is Coming. The Sun Just Released Three X-Class Flares appeared first on Universe Today.

[This is a follow-up to Monday’s post, going more into depth.]

Among the known elementary particles are three cousins: the electron, the muon and the tau. The three are identical in all known experiments — they have all the same electromagnetic and weak nuclear interactions, and no strong nuclear interactions — except that they have different rest masses:

• electron rest mass: 0.000511 GeV/c2
• muon rest mass: 0.105658 GeV/c2
• tau rest mass: 1.777 GeV/c2

[These differences arise from their different interactions with the Higgs field; to learn more about this, see Chapter 22 of my book.]

Question: How sure are we that these three cousins aren’t actually the same object, seen in three different quantum states?

Quantum States

This is a serious possibility, at first glance. After all, individual atoms have many states, in which they look roughly the same but have different energies — which means, because E=mc2, that they have different rest masses. In Fig. 1 are some of a hydrogen atom’s many possible states; the one of lowest energy is called the “ground state”, and ones with more energy are referred to as “excited states”.

Figure 1: Energy levels of quantum states of a hydrogen atom. The lowest-energy state, at far left, is the ground state; all others are excited states. (The energy, measured in electron-volts and negative, is expressed relative to the amount of energy stored in a proton and an electron when the two are fully separated.) Might the electron, muon and tau similarly be three states of the same object?

In a number of ways, hydrogen atoms in these different states are almost the same; each has zero electric charge, and each contains an electron and a proton. They differ in what the electron is doing, as sketched in Figure 2.

Figure 2: How the electron in hydrogen spreads out in different states. Upper left is the ground state; the other five are examples of excited states. Image from https://en.wikipedia.org/wiki/File:HAtomOrbitals.png

From the outside, though, they seem almost the same; the most obvious difference is that they have different amounts of energy. Might the electron, similarly, be the ground state of a complex object, with the muon and tau being that object’s most easily accessible excited states?

I’ve already mentioned one of the facts in favor of this hypothesis: the three particles’ identical interactions with all fields (except the Higgs field). Another hint that might support the hypothesis is this: when a muon or tau “decays” (i.e. when it transitions, via dissipation, to more stable particles), the outcome always includes an electron. For instance, the muon decays to an electron, a neutrino and an anti-neutrino. Tau decays are more complex, but in the end, an electron is always found among its decay products.

Nevertheless, the hypothesis is definitely wrong, as we can see by carefully comparing atoms, electrons, and protons. I’ll do this in two stages:

• Today I’ll describe what we learn from collisions of these particles.
• Soon I’ll describe what we learn from “spin” — angular momentum carried by a particle.

How to Excite an Atom

Let’s look at two typical ways to excite an atom; there are many others, but these two will do for today.

Shining Light

First, we could shine ultraviolet light (an invisible form of light at slightly higher frequency than visible light) on an atom. If so, we might observe processes such as those sketched in Figure 3: a photon of light strikes the atom in its ground state, and what emerges from the collision is the atom in one of its excited states (possibly plus one or more photons). The simplest possible process involves

• photon + atom in ground state → atom in excited state

The excited atom then reveals itself when, at a later time, short on human scales but often long on atomic scales, it decays back to the ground state,

• atom (excited state) → atom (ground state) + one or more photons

Figure 3: A photon strikes an atom; the atom, absorbing its energy, is kicked it into one of its excited states. The excited state will soon “decay”, emitting one or more photons and dropping back down into the ground state.

If there’s just one photon in the excited state’s decay, that photon has always the same frequency , which is determined in terms of the energy of the excited state minus the energy of the ground state

where h is Planck’s constant. [A nitpick: this formula applies when the excited atom is stationary, and has a small correction from the fact that the atom will be moving slowly after the decay.]

Atomic Collisions

Second, we could slam two atoms in the ground state together. If the speed is high enough, one of the two atoms could come out in an excited state, as sketched in Figure 4.

atom (ground state) + atom (ground state) → atom (ground state) + atom (excited state)

Or both atoms could come out in excited states, though not necessarily the same ones. Again, we would learn which excited states were created by looking at the photons emitted when the atoms transition back down to the ground state.

Figure 4: Two atoms collide, and some of the energy of the collision kicks one of them into an excited state. The excited state subsequently decays just as in Figure 3. Could We Excite an Electron?

Let’s imagine trying similar tricks just like this on the electron. We could shine high-energy light on the electron, or we could slam electrons together, seeing if we could turn an electron into a muon or a tau.

Shining Light

If a muon is an electron’s excited state, we could shine light waves — gamma-rays this time, as ultraviolet light would not be enough — at electrons, hoping to turn an electron into a muon. Using the notation

• for electron (the minus-sign reflecting its negative electric charge)
• for muon
• for a photon (and for a second photon)

we could try to look for the processes

• ,

possibly plus one or more photons, as shown in Figure 5.

Figure 5: If the electron is the ground state of an object and a muon is an excited state of the same object, then striking an electron with a high-energy photon ought to be able to turn it into a muon (possibly plus additional photons), in analogy to Figure 3.

Direct searches for processes like this have been done, and none has ever been seen. Even more significantly, if they were possible, then the following related process (shown in Figure 6) would also be possible

This has been searched for with great effort. Experiments show that no more than one in 2 trillion muons decay this way. The analogous processes for tau’s have never been seen, either.

Figure 6: The decay of a muon to an electron plus a photon has never been observed, despite considerable effort to do so. At best, it is exceedingly rare.

So what? Even though we can’t excite electrons this way, does that really prove that electrons can’t be excited in some other way?

Essentially, it does. The problem is that electrons are electrically charged, and so, if they are made from other, even more elementary objects, then one or more of these objects must also be electrically charged. By its very definition, “having non-zero electric charge” means “able to interact with photons.” It’s virtually impossible to imagine how an electrically charged interior would be unable to absorb photons. So this is an extremely strong mark against the idea.

But just to be sure, let’s try another approach.

Electron-Electron Collisions

We could also try aiming electrons at each other and seeing what happens when they collide. Just as atomic collisions cause atoms to be excited, we would expect that sufficiently powerful collisions would excite electrons to be muons and taus, and so we should observe processes similar to those in Fig. 4, such as

But again, none of these processes has ever been observed.

Electron-Positron Collisions

It’s interesting to compare this to what happens in collisions of electrons with the antiparticles of electrons, which are known as positrons and are denoted . In such collisions, we do regularly observe muons and taus appear, as follows

However, we never observe

or anything similar. Only a muon and an anti-muon, or a tau and an anti-tau, are ever created.

Meanwhile, another thing we observe

But clearly photons cannot be excited states of electrons, as photons have zero electric charge and smaller rest mass. So this process has nothing to do with creating an excited state.

Similarly, the processes that create and pairs have a simple interpretation that has nothing to do with electrons having internal structure and excited states. In the process , the electrons are not being kicked into excited states. Instead, the electron and positron are “annihilating” — they are transformed into a disturbance in the electromagnetic field (often called a “virtual photon” — but it is not a particle) — and this disturbance spontaneously transforms into two new particles that are “created” in their stead.

Each of the two new particles is an antiparticle of the other: the muon and the anti-muon , as particle types, are each other’s antiparticles, while photons are their own antiparticles. That’s why electron-positron collisions are just as likely to make photon pairs as to make or . Such annihilation/creation processes occur even for elementary particles, and so their presence gives no evidence supporting the idea of a muon as an excited electron.

We can consider other forms of scattering too, and in none of them do we ever see any of the processes that would be consistent with muons or taus being excited states of electrons. Moreover, all experiments on these particles agree with the math of the Standard Model of particle physics, which is based on the assumption that muons and taus are independent particles from electrons, and are not excited states of the latter.

We can conclude that this excited-electron hypothesis is completely dead. It has been for some decades.

What About Protons?

Protons, meanwhile, do have a size. Do the processes mentioned above work for them?

Yes. The first excited state of the proton is called the Delta ; the second is called the . The process

is observed. (In fact this process has a major role to play in the features of cosmic rays, where it causes what is known as the GZK cutoff.) [More easily observed is , which involves a virtual photon and therefore has a similar character.] Also observed is the decay

Scattering processes also create the excited states:

So we see, in experiments, many processes that we would expect to see if the proton is a composite object made of more elementary objects, for which the usual proton is the ground state and the and are excited states.

From these excited states, the size of a proton can be roughly inferred, as explained here.

What About All Those Photons?

But what about the fact that even electron-electron collisions often generate photons? Might that be an indication that electrons have excited states?

In other words, even in processes as simple as two electrons that scatter and remain electrons, photons generally appear

• etc.

Why aren’t these indications that electrons are composite? Because, as with the electron-positron annihilation processes discussed earlier, processes like these are expected even for elementary electrons; and predictions for those processes, based on the assumption that electrons are elementary, agree perfectly with data.

So does this mean that electrons definitely are elementary, point-like objects? Not definitely, no. It simply means that if electrons are the ground states of something complex (such as a string, as would potentially be true in string theory), the excited states of that object have far too much rest mass for us to produce them using today’s technology. Someday, collisions may produce them. But for now, all we can say is that in every experiment we can currently perform, electrons appear elementary. So do muons and taus; so do the neutrinos; and so do all six quarks of the Standard Model.

The strategy for tracking bird flu in US dairy cattle falls worryingly short of what is needed to prevent the outbreak from widening and potentially spreading to humans

At 5 a.m., the encampment was being taken down by the University of Chicago Police (I didn’t see anybody but University Police and Allied Security). Here is a short video of the action on the quad, with lots of chanting, police shouting, and cop-car lights flashing.

It doesn’t look as if anybody’s being arrested, but keffiyeh-clad and mask-clad protestors are fleeing the encampment. If they don’t take names or punish the encampers, they’ll just come back again. But I have no idea what information the University has.  The press, too, are being expelled from the Quad.

. . . and the Maroon’s report:

May 7, 5:09 a.m.

The raid came as most of the encampment had returned to their tents for the night. Two UCPD cars drove onto the quad and used their lamps to light up the encampment. Over a loudspeaker, UCUP ordered the demonstrators to leave the quad. Then, shortly after their announcements, several dozen officers in riot gear surrounded the encampment to prepare to enter.

— Peter Maheras, News Editor

May 7, 5:06 a.m.

The UCUP organizer said that they were not sure whether people were arrested. They believe that the goal was to push people out of the quad.

— Maroon Staff

May 7, 5:03 a.m.

A UCUP organizer described the raid in an interview with the Maroon.

“They pushed me. One person was on the ground. They’ve been pushing people out,” the organizer said.

“They did not give us a clear plan for leaving. They came in maybe two minutes after the warning. It’s clear that they waited until after the rally was over. We were at our most vulnerable,” the organizer added. “I believe we got everybody safely out of [their tents].”

— Maroon Staff

May 7, 4:59 a.m.

Police in riot gear are blocking access to the quad as many people arrive at the quad hoping to enter.

— Peter Maheras, News Editor; Emma Janssen, Deputy News Editor

An implantable heart pump could help children with heart failure awaiting transplants forego bulky devices that require long hospital stays