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Science News Sep 12
🕑 Added 2023-09-12 14:00:06 +0000 UTC[This is a transcript with links to reference.]
Welcome back everyone to our weekly science news. Today we’ll talk about a bubble of galaxies, a climate scientist who made his own paper worse, double magic oxygen, a chemical reaction slowed down 100 billion times, Maxwell’s demon in biology, intelligent life on earth, the launch of a new X-ray space mission, drone racing, and of course the telephone will ring.
Astronomers in Hawaii have spotted a massive bubble of galaxies. It’s approximately 8 hundred and twenty million light years from Earth and one billion light years wide. They called it Hoʻoleilana, Hawaiian for “murmurs of awakening,” because they believe it’s a direct remnant of murmurs from the time our universe awoke.
The astronomers weren’t specifically looking for this galactic bubble, but at that size, it was kind of hard to miss. That it’s a bubble means the galaxies seem to be more likely to be located on a giant sphere.
This observation fits neatly within our current model for the early universe, which you probably know has it that the early universe was filled with hot plasma which then rapidly expanded. According to this model, there were density waves in this hot plasma. They’re kind of like ripples in a pond but in three dimensions. They are known as baryon acoustic oscillations. Acoustic because they are like sound waves and baryons are a type of subatomic particles that include neutrons and protons, the constituents of atomic nuclei.
When the universe expands, the plasma cools and begins to clump, and forms stars and galaxies. In the places where the plasma density was higher, there’ll later be more galaxies. This should give rise to bubble-like structures, exactly like what they observed.
You see it’s not just kids who like making bubbles, the young universe was like that too, though with a bubble of 1 billion light years in size, maybe somewhat of an overachiever.
The bubble is like a mega-structure of mega-structures, and contains previously known giant conglomerates of matter like the Coma Cluster, the Hercules Cluster, and the Sloan Great Wall.
This bubble is so big it’s hard to wrap your head around it, unless possibly your head is a billion light years wide in which case I think you could do better things with it than watching YouTube.
The most depressing story of the week is a climate scientist who single-handedly damaged the reputation of his entire discipline. Here’s what happened.
The climate scientist Patrick Brown recently published a paper about extreme wildfires and their link to climate change in the journal Nature. Now that the paper’s live, he explained on X-formerly-known-as-twitter, that while his paper considered climate change as one driver of wildfire risk, it did not properly account for other factors, such as changes in land use, vegetation, and human behaviour. And he did this deliberately because he believed it would improve his chances to get published.
He claims that there is a “formula” to getting published in high impact journals that requires focusing on the impact of only one variable. It’s not like he falsified any data, but he left out relevant context that he full well knew about.
Brown defended his action by saying that while considering other factors would have made for a more realistic and useful analysis, he didn’t want to “muddy the waters of an otherwise clean story.” However, the peer review file for Brown’s paper is public, and even the reviewers argued against him. Editors from Nature have denied that leaving out relevant variables reduces the chances of getting published. The episode is fuel to the fire of climate change deniers.
Who needs enemies with friends like this?
Hi Rishi,
Iceland resumes whaling? Oh well.
Sure you can do it too, you just say it’s an experiment looking for dark matter. Because you never know, could be the whales have been eating the stuff.
Don’t worry, some theoretical physicist will come up with a theory for it.
You’re welcome.
A group of experimentalists at the Japanese RIKEN facility has for the first time managed to produce a heavy isotope of the oxygen nucleus and found a few surprises.
The oxygen in the air around us is Oxygen 16, it has 8 protons and 8 neutrons in the atomic core and is stable. Atomic nuclei are subject to quantum mechanics, and they have shells and excitations just like the electrons around them. And like the electrons around the nucleus, the nucleus itself has shells that can be more or less full.
If you remember, the structure of the periodic table comes from filling up the electron shells. How full the electron shells are determines much of the chemical properties of the elements. Noble gases for example have their electron shells full, that’s Helium, Neon, Argon and so on. Since the shells are full, they are slow to react. It’s why they’re called noble! Noble people don’t explode!
The same is the case for nuclei, some are more, others less explosive, so to speak. When it comes to atomic nuclei, the full shells are called “magic numbers”. But since atomic nuclei have two different constituents, protons and neutrons, there are two numbers. A nucleus who has a magic number of both neutrons and protons is called “doubly magic”. The common oxygen, oxygen-16 is “doubly magic” and it’s stable.
That a nucleus is doubly magic doesn’t necessarily mean its stable though, it’s more complicated than that. It should however at least be strongly bound and hold together reasonably well.
After Oxygen 16 you expect the next doubly magic oxygen to be oxygen 28, that has 8 protons and 20 neutrons. It’s difficult to produce nuclei with that many neutrons. And not only do you need to produce them, you then also need to measure them, but that’s what they did in this new experiment.
The researchers started by firing calcium forty-eight at a beryllium target. This results in a lot of lighter atoms, including fluorine-29. They isolated out the fluorine and then dumped that into liquid hydrogen to remove one of the protons. This process generates the oxygen-28. But contrary to expectations, the oxygen 28 turned out to be not double magic! The oxygen 28 decayed readily by spitting out four neutrons, leaving behind oxygen 24. This is really interesting because clearly there is something about nuclear structure which we don’t fully understand.
By the way, don’t do this at home. Free neutrons are really not healthy.
An international group of physicists and chemists has simulated an essential property of chemical reactions. This allowed them to look at the process 100 billion times slower than it occurs in nature, and confirmed an essential prediction of quantum chemistry.
Chemistry is all about electron energy levels and how the electron wave-functions reshape when two atoms approach each other. One particularly essential feature of wave-functions is that, well, they’re waves, so they can interfere. In particular, they can interfere with themselves.
This can lead to very interesting effects if you have a particle whose wave-function goes around an obstacle on both sides. Because then what happens on the other side of the obstacle depends on how the wave-function overlaps on the other side. They might cancel out, or they might add up.
This self-interference around an obstacle is a really famous quantum effect and it’s believed to play a role in chemical reactions, such as those contributing to photosynthesis. Problem is, in an actual chemical reaction, this all happens in a matter of femtoseconds. A femtosecond is 10 to the minus 15 seconds, and to give you some context, that’s the approximate duration of summer in the UK.
In the new experiment, they simulated this process with an ion trap. In such a trap, a charged atom is held in an electromagnetic field. In this case they did this with a configuration of four lasers. These electromagnetic fields generate an energy potential around one axis. The wave-function of the ion can’t go through this axis, so it goes around it and then wobbles back. The observations agree with theoretical predictions amazingly well. This is an example of a direct quantum simulation that needs no quantum computer.
Okay so you might say but if it agrees with prediction that’s kind of boring. Down the line this could become a useful method to better understand the quantum effects in chemical reaction.
I wish to apologize to all chemists in the audience, but this is more proof that chemistry is really just applied quantum mechanics.
A group of biologists in Switzerland have found a Maxwell demon in cells.
Maxwell’s demon is a thought experiment for beating the second law of thermodynamics, that’s the one which says that entropy cannot decrease. The thought experiment goes like this.
If you have two boxes of gas at different temperature and combine them, then the second law says the gases will mix and reach equilibrium at a temperature somewhere in the middle. In that process, entropy increases. Maxwell said, let’s supposed we enter a wall to separate the boxes again and we add a little person, that’s the demon, which lets fast gas atoms through to the right and keeps slow ones on the left, then that would decrease entropy and shouldn’t be possible.
That confused people greatly at the time, but we now understand that this only works if the demon itself has information about the system, which requires low entropy. And the entropy of the demon increases while that of the gas decreases, so the second law remains intact. Still, this has been a very interesting thought experiment because it’s lead to some ideas how one can convert information to low entropy.
The biologists now found that nature was well ahead of Maxwell. They say that there are certain proteins known as ATP-Binding Cassette transporters –ABC for short—that work pretty much the same way. These proteins control the movement of molecules and help cells regulate energy flow tiny just like Maxwell’s demon.
Of course they don’t violate the second law either, they use energy from the ATP molecules which is a low entropy reservoir. So, physics wins again.
Mr President,
A study has found that seafood tastes better by the seaside? That is most interesting.
Yes, you’re entirely correct, this must mean that junk food tastes better next to the rubbish bin. You’re welcome.
NASA, together with the Japan Aerospace Exploration Agency, and the European Space Agency have finally launched their shared X-Ray Imaging and Spectroscopy Mission, XRISM. Now that it’s in orbit, it can get to work capturing the dynamics between galaxy clusters, helping us understand the chemical makeup of the universe, and measuring the way black holes affect star formation.
The X-ray Imaging and Spectroscopy Mission contains two main instruments. One, called Xtend, consists of four detector arrays that pick up on ultraviolet, visible, and near-infrared light. The other, called Resolve, is an X-ray calorimeter. When photons hit this detector, they’ll warm it up, changing the conductive properties of the instrument from which the energy of photons can be inferred.
Resolve requires helium to stay cool enough to operate, and because the satellite can only hold enough helium for three years, that’s about how long we can expect to obtain data from this mission.
So the universe is getting an X-ray. Let’s hope nothing’s broken.
Astrophysicists say that the James Webb Space Telescope has found that there’s intelligent life on Earth.
Whew, that’s some relief.
In a new pre-print that just appeared on the arXiv, a group of astrophysicists shows that if the Webb telescope were to look at Earth, it could confirm both the potential for and the presence of intelligent life. They arrive at this conclusion by looking at a bunch of molecules in the atmosphere that the telescope can detect, this includes water, carbon dioxide, nitrogen, and methane, but also more complex substances like CFCs.
They say that these not only do they make life possible, but they also imply the presence of technologies that might be created by intelligent civilizations. Combined with contextual data like temperature, pressure, altitude, and so on, the presence of these gasses signal that life forms like our own might be nearby. They conclude that the Webb Telescope would be able to confirm the presence of intelligent life on Earth with 88% accuracy.
This study is proof that the Webb Telescope isn’t just for taking pretty pictures of the cosmos. Indeed, the telescope’s potential is much wider in scope, and might even help us locate those aliens American officials have been blabbing on about.
Engineers at Intel and the University of Zurich have used artificial intelligence to build a super-fast, self-flying drone. It’s so good at finding optimal routes and making quick turns that it’s capable of beating even the most experienced human drone racers.
The drone is based on an AI system called Swift. It collects data through a camera and integrated inertial measurement unit, which monitor the drone’s environment and acceleration. This data feeds into Swift’s deep neural network. It works in real time and decides the best route forward and the most efficient manoeuvres to make. The system beat three of the world’s best human drone racers in multiple 100-kilometer-per-hour races.
But speed isn’t everything. Intel and the University of Zurich found that human drone operators were more adaptable than Swift, meaning they were able to handle changing conditions and unpredictable challenges more easily. If there was too much light in the room, for example, Swift’s lack of adaptability slowed it down. Human racers were also better at adjusting their flight strategies to reduce their odds of crashing.
But if all goes well, soon enough we’ll all be completely unnecessary and can leave the world to self-flying intelligent drones.
Comments
Rad Antonov
Gotcha. My point was that when it comes to understanding how these elementary particles (quarks and gluons specifically) come together to form nucleons, our models seem clumsy or incomplete. I don’t know if that’s a feature of the way the world is or a bug in our understanding of the transition from the micro to the macroscopic.
No, my considerations refer to the elementary particle, not to the nucleus or the atom. And there are so many open points about elementary particles that I intend to finalize this as a first step. Please see my explanation of inertial mass in my reply to Tracey DeLaney. The classical derivation of mass is so much more powerful than the QM-related one (e.g., Higgs) that I think it is worthwhile to continue this work for other particle properties.
Rad Antonov
So, can you calculate the form factor? Can you predict the lifetime of the first excited state that lives above the binding energy?
It is a different case. The electric charge in a nucleus is basically a monopole, with some changes due to the superposition of several charges. But all charges have the same sign. In contrast, the multipolar field of "strong" charges is formed by charges of different sign.
Rad Antonov
In that case, what’s the monopole form factor as a function of Q^2 for the helium nucleus?
The forces inside of hadrons and between hadrons are basically the strong force. These forces are realized in the particles as multipoles. This explains their behaviour with respect to distance.
Rad Antonov
Yes, good for deep inelastic scattering cross sections but not at the confinement scale.
Asymptotic freedom is a property of the inner of Hadrons?
Rad Antonov
What I find puzzling is that despite having an extremely accurate theory at high energies, we still struggle to predict nuclear properties at low to intermediate energies. We can’t even calculate nucleon properties from their constituents. Asymptotic freedom is kinda useless at the scale of ordinary matter. Are we missing something or this is just the way it’s gonna be? Messy problem with a messy solution?
Hm, three days after uploading this video, I register a lot of climate change deniers in the YT comment section, who are pissed off to be climate change deniers - Great.
"Hmm, it seems to me that this theory "works" because of the ad-hoc adjustment of lots and lots of parameters that define the density of Dark Matter over vast regions of space that is the supposed cause of those rotation curves." Yes, this is a known fact for most theories. But as I wrote above, this approach I refer to does *not use* any single free parameter that has been adjusted. It uses only facts like the speed of light, its known dependence on the field strength and the known masses of the elementary particles. In addition, of course, the measured astronomical facts like the number of stars in a galaxy and the luminosity of the stars; and the measurements of dark matter by e.g. the CLASH cooperation. Any further question?
There's a big confusion about the nature of dark matter among physicists at the moment, think that's part of the joke. Hopefully you are right
Hmm, it seems to me that this theory "works" because of the ad-hoc adjustment of lots and lots of parameters that define the density of Dark Matter over vast regions of space that is the supposed cause of those rotation curves. At least until the day, if ever, when someone finally figures out how to calculate this density distribution based on a theory of the actual origin (new particles beyond the Standard Model, flaws in space-time such as cosmic strings ...?) of this dark gravitation, if that is what this is, and test this experimentally, and consistently get decent results that way. In the mean time: yes it "works", but why? There is more than plain curiosity behind the spending of zillions of hard currency units in setting up and conducting large underground experiments, trying to catch a whiff of the things that cause this dark gravitation. And, so far, without success.
Sabine says to Rishi: “Sure you can do it too, you just say it’s an experiment looking for dark matter. Because you never know, could be the whales have been eating the stuff. Don’t worry, some theoretical physicist will come up with a theory for it.” Sorry, there is not such arbitrariness to the theory of dark matter. Because there is only one theory, which agrees with all observations, and even better, which gives quantitative results in the case of rotation curves, without the need to adjust any free parameters.
Hi Oscar, the structures, that are supposed to form the great attractor, are much smaller than that bubble as far as I know, so it´s perhaps a part of that thing. About chemistry, I heard a physicist say some years ago: "For physicists, chemistry is just the physics of the outer electron shells." Coming from reading Sabine´s new book this year, learning a lot by that, I can express it now more philosophically: Chemistry is a weak emergent property of physics. - Ha!
As to those bubbles of galaxies that are bigger than the bigger structures known until now, maybe looking for them, may not astronomers finally find the Great Attractor that is supposed to be causing our galaxy and the rest of its local group move more or less together and in the same direction as if towards some huge and distant thing gravitationally attracting them to itself? About chemists being offended by Sabine's opinion that chemistry is applied quantum mechanics, chemists have been aware of this since early last century. A prominent and effective promoter of the quantum physical foundations of chemistry was Linus Pauling, who won the 1954 Nobel Prize for his work on how atoms bond to form molecules. The discipline studying chemical reactions and properties of substances in the light of modern physics, Physical Chemistry, includes not just concepts of Quantum Theory, but also of Special Relativity (e.g. why is gold a golden color?). https://www.nobelprize.org/prizes/chemistry/1954/pauling/facts/ As to the paper on the influence of climate change on the hundreds of forest fires across Canada, that have been sending smoke down south all the way to where I live in the US Mid-Atlantic region, making it hazardous going out and breathing (the later not considered optional)? Well, I would not regard the paper controversial per se, because the author now making waves with a post-publication mix of some remorseful and some provocative opinions on his own work, on scientific publishing, etc.(that, as Sabine regrets, deniers of everything that needs urgent, expensive and to them inconvenient action are starting to wave around like a big red flag), this author, as I was saying, made very sober and atendible statements in his now self-criticized paper, about the difficulty of separating the signature of climate change on the fires from other factors, such as arson, lightning, etc. He wrote that, although climate change was a good candidate for explaining much about those fires, those other factors should also be looked into, with more time and in greater detail that were available for the study. So those were topics for further research (and more papers). All of which was very appropriate to mention in a scientific article. Finally, it is not wrong to criticize, in the right context, how work on trendy stuff is more likely to be published than other, less sexy, and climate change is sexy right now (and rightly so). As is Dark Matter. All this about the paper and its author's about-face, are detailed in this article I found in "Nautilus" today: https://heatmap.news/climate/patrick-brown-nature-climate-scientist
Prof. Alan Sokal and Patrick Brown? But that´s another story.
Hi Allan, I'm thinking that paper is sort of a 'reverse Sokal'. Oversimplified possibly to make a point but also blatantly problematic.
ALLAN LEES
Surely Patrick Brown has demonstrated something of importance? He seems to have been correct in his assertion that simplification (at the expense of scientific rigor) does increase one's chances of getting published in a prestigious journal. Nature went ahead and published his paper even though reviewers called out and criticized the omission of other factors. Which means Nature's editors seem truly to have been interested more in a simple story than in a complex but more correct one. QED, Brown's contention seems to have been validated and this is surely a problem for science.
