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Physicists Investigate Why Matter and Antimatter Are Not Mirror Images (economist.com)
An anonymous reader shares a report: As mismatches go, it's a big one. When physicists bring the Standard Model of particle physics and Einstein's general theory of relativity together they get a clear prediction. In the very early universe, equal amounts of matter and antimatter should have come into being. Since the one famously annihilates the other, the result should be a universe full of radiation, but without the stars, planets and nebulae that make up galaxies. Yet stars, planets and nebulae do exist. The inference is that matter and antimatter are not quite as equal and opposite as the models predict.
This problem has troubled physics for the past half-century, but it may now be approaching resolution. At CERN, a particle-physics laboratory near Geneva, three teams of researchers are applying different methods to answer the same question: does antimatter fall down, or up? Relativity predicts "down", just like matter. If it falls up, that could hint at a difference between the two that allowed a matter-dominated universe to form.
This problem has troubled physics for the past half-century, but it may now be approaching resolution. At CERN, a particle-physics laboratory near Geneva, three teams of researchers are applying different methods to answer the same question: does antimatter fall down, or up? Relativity predicts "down", just like matter. If it falls up, that could hint at a difference between the two that allowed a matter-dominated universe to form.
Various ways of creating antimatter have been used in physics. One is to get a photon (particle of light) to convert into an electron and positron (antimatter equivalent of an electron). Another is to smash a proton into a necleus and create various particles of matter and antimatter and filter them by charge and momentum. If you want learn about antimatter in general, Don Lincoln has some introductory videos on YouTube.
What I got from multiple college level courses on quantum physics was.... maybe.
This problem has troubled physics for the past half-century...
This "problem" is why we are here. How about not calling the existence of the universe a "problem"?
Different kind of problem. (from Google):
Physics : Mathematics
- an inquiry starting from given conditions to investigate or demonstrate a fact, result, or law.
It must have been something you assimilated. . . .
What's wrong with asking how the universe works?
There is a retired scientist called Jean-Pierre Petit that has some ideas about this question (spoil: this antimater will fall down). This is the Janus cosmological model
. I do not know if he is right or wrong, but the videos are worth a look
Quantum physics is ultimately very unsatisfying, no matter how well it works. You always have the feeling that it's a working kludge, but has to the results of us just not understanding something very basic.
“In the beginning the Universe was created. This had made many people very angry and has been widely regarded as a bad move.” Douglas Adams, The Restaurant at the End of the Universe
Inheritance is the sincerest form of nepotism.
Very, very carefully.
We used to have a Bill of Rights. Now, with the rights gone, all we have left is the bill.
Quantum physics is ultimately very unsatisfying, no matter how well it works. You always have the feeling that it's a working kludge, ...
I agree with the first part of this. But, when I was studying quantum mechanics, I can’t say I felt it was a “kludge”. I felt like it was this completely non-intuitive, abstract mathematical model which had no reason to work... but somehow did, every freaking time it was tested against something as-yet unknown.
It was a real problem for me since I tend to be an intuitive learner. I learned the equations, but never really could wrap my mind around the science as a whole.
#DeleteChrome
We've never observed Hawking radiation from a black hole. An analog of Hawking radiation has been observed from model experiments, e.g. where a medium has an area that is supersonic so sound waves can't propagate back out of that region.
That was effectively my point, there's no question that you can mathematically predict what will happen, most of the time. But this thread is about one of the examples where it doesn't appear to work, along with the various other examples mystery coefficients or mystery energy or mass being kludged in to patch things up.
I think that this apparently "statistical" nature is a function of something very fundamental that we don't yet understand, and some day, somebody will find the reality with a slap to the forehead and a loud "D'OH!"
Note that this has *always* been the case in physics and science in general. Phlogiston theory predicted a lot of things correctly for a long time, for a lot of people who were not morons. Then the edges started fraying, people tried various fixes to try to patch it back together, until someone came along with a conceptual advance, then the old way seems ridiculous and obviously wrong. We are in the "fraying edges" point of the cycle (like the late 1800s).
The goatee that antimatter seems to have of course its not an exact mirror image
Your'e all thinking it, I just said it for you
Very, very carefully.
If all the antimatter ever made by humans were annihilated at once, the energy produced would be just about enough to make a cup of tea.
We observe hawking radiation
No we don't. Hawking Radiation is conjecture at this point. The closest known black hole is 2800 LY away, has 11 solar masses, and emits about one particle of hawking radiation every 10 Billion years. That is roughly a googoleth of a watt.
CERN experiments to test the free-fall of antiatoms
https://cerncourier.com/does-a...
Wouldn't "falling up" mean that the anti-matter somehow breaks out of the curvature of the space and lays waste of Newton and Einstein?
Yes. If anti-matter "falls up", then that blows a major hole in General Relativity. It is extremely unlikely that "falls up" will be the outcome of these experiments.
Look at it this way: Matter falls down, so if anti-matter falls up, and matter and anti-matter annihilate to form a photon (which is its own anti-particle), then the photon should be neutral in a gravitational field. But it isn't. Photons "fall down", which was measured during a solar eclipse in 1919, as the first experimental confirmation of General Relativity.
Accelerator Physicists have factored Gravitational effects into Storage Rings and TOF lines for decades. The assumption has been that Gravity is universally Attractive, and among other things, even Electrons and Positrons having Mass have Gravitational Fields of their own. Since the first TOF measurements of the Antiproton at the Bevatron nearly six decades back, no evidence of any anomalies have been detected. The research here is still ongoing for ever more precise bounds, largely from inferences rather than direct measurements; from 2016:
https://www.nature.com/articles/srep30461
"Gravitational mass of positron from LEP synchrotron losses"
Verdict: Falls down.
Captcha: cheers
The question is not about why did matter win, but why there is a winner at all.
The quantum butterfly could explain why we are in a pocket of matter, as opposed to a pocket of antimatter, but I think the hypothesis of matter and antimatter co-existing has been disproven. There really seems to be only matter, antimatter is nowhere to be found in significant quantities, and as a result, that matter is fundamentally different from antimatter.
The main problem with pilot wave theory is that it requires faster-than-light transfer of information, which implies that causality can be violated (an effect can precede a cause).
The most popular way to save pilot wave theory is to introduce the concept of implicate order, a bizarre concept that frankly makes the Copenhagen interpretation look like child's play in comparison.
It really doesn't matter how chaotic it is at the microscopic level, quantum physics is at heart a statistical beast and the macro level the picture should be consistent. And yet there's more matter than antimatter.
I should note , if antimatter DOES function inversely to matter re gravity , it opens a whole boatload of extremely fun physics implications , the least of which would be the identifying a candidate for the prized unobtanium needed for a warp drive
Excuse the Unicode crap in my posts. That's an apostrophe, and slashdot is busted.
Very sure. If distant clusters were anti-matter, at some point there would be a boundary. Annihilation at the boundary would be crazy obvious, like "outshines entire galactic clusters at x-ray wavelengths" obvious.
God uses Intel floating point numbers.
Table-ized A.I.
No it is not!
Why the funk would it?
https://en.wikipedia.org/wiki/...
Cost free eBook I read (by iBook/Kobo/Amazon/ObookO/Gutenberg etc.): "The Green Odyssey" by Philip Jose Farmer.
No; the photon is its own antiparticle, as are a few other neutral force carriers (like the Z-boson, and gluons). But the antiparticle of a neutron is different: as per an AC posting above, it's composed of antiquarks. Read all about it in the Wikipedia.
if antimatter DOES function inversely to matter re gravity , it opens a whole boatload of extremely fun physics implications , the least of which would be the identifying a candidate for the prized unobtanium needed for a warp drive
And to lift your flying car. You would need a ton or two of antimatter. Collide with another flying car and the explosion would be how big? Enough to create a second moon?
When all you have is a hammer, every problem starts to look like a thumb.
I have long since believed that the matter that we have in the universe is just the statistically insignificant remainder from an unfathomably larger amount of matter and antimatter that annihilated each other after the big bang..
File under 'M' for 'Manic ranting'
I don't really know why people get hung up on the fact that QM is non-intuitive. There are many macroscopic physical phenomena that also defy intuition.
I see the Sun move across the sky every day, but I don't feel the Earth move at all. Intuitively the Sun must orbit the Earth, right? Except that overwhelming evidence beyond my own measly human observation has shown that in fact, the Earth orbits the Sun.*
QM is exactly the same. It defies intuition, but the evidence backs it up. There is no reason to expect the laws of nature to be intuitive.
*inb4 all the smart-asses who want to point out that they both orbit a common center of mass :P
Only crack the nuts that crack. You don't put the ones that don't crack in the sack.
Anti-neutrons are definitely different from neutrons. Neutrons are made up of 3 quarks, two down and one up whereas anti-neutrons are made of three anti-quarks, two anti-down and one anti-up.
This is because neutrons are made of fermions which have different particle and antiparticle states. Only bosons, like the photon, have the same particle and antiparticle states.
This is almost duplicate since I remember a similar article which talked about some experiment by Italian scientists a few years ago.
But again, our current understanding is that gravity is the curvature of space and time. The anti-matter has no choice but to follow that curvature. It cannot pretend that curvature does not exist.
So, if anti-matter were actually fallen up you can throw general relativity out of the window. I do not expect that will happen.
Government cannot make man richer, but it can make him poorer. - Ludwig von Mises
Couldn't this be a case of a butterfly flapped its wings...
Short answer: no, assuming you mean some random fluctuation in the early Universe. For the excess of matter over anti-matter in the early universe to be due to such a random fluctuation, there would have to be some process that allows more matter than anti-matter to be created and we have not seen anything that does this yet.
However, we have seen a bias between matter and antimatter in decays of certain types of particles made of quarks and anti-quarks bound together. While this is not enough to create more matter than anti-matter if the same effect exists in the oscillations of neutrinos then there may just be enough to explain the excess of matter over antimatter. However, this would still not be a random fluctuation but rather that the universe has an inbuilt bias in the laws of physics which favours matter over antimatter.
As an interesting aside this difference, called CP violation, is also the only physics we know of that requires three generations of quarks and leptons to exist. If there were only two generations we could not have a difference at least via this mechanism.
Your right. I think I was thinking of a photon.
My bad. Posting before morning coffee.
Excuse the Unicode crap in my posts. That's an apostrophe, and slashdot is busted.
Making a cup of tea from energy requires quite a lot of energy!
We used to have a Bill of Rights. Now, with the rights gone, all we have left is the bill.
That sounds very improbable.
http://michaelsmith.id.au
Very, very carefully.
If all the antimatter ever made by humans were annihilated at once, the energy produced would be just about enough to make a cup of tea.
Or, at the very least, something almost, but not quite entirely unlike tea.
It must have been something you assimilated. . . .
In your frame of reference, the sun does orbit the earth. It's intuitive because it's literally true in the frame you're in. If we take a more natural frame to use for studying the solar system, one in which its barycentre is stationary, then we get the more familiar result of the earth going round the sun. This does not mean that a geocentric frame is never appropriate. The speedometer in a car is measuring the car's speed in this frame, for example. If it was instead measuring the speed at which it orbited the sun, then every car would be breaking the speed limit all the time. Saying the sun orbits the earth is no more ridiculous than saying a parked car is stationary, yet people are ridiculed for one and not the other. The ones to ridicule are the ones claiming the only valid viewpoint is geocentric.
But this has always been the question. The question has never actually been why, out of the two, that the one we call matter won. If what we now call antimatter had won, then in that universe we would still have called that matter and its opposite antimatter. So "why did matter win" is how it's spoken of, but really no one has ever really cared why the winner was what we call "matter". The question has only ever been why was there an imbalance and "why did matter win" is just the way a lot of people articulate that question.
CP violation is a current favourite to explain this and is being investigated. I personally think antimatter falling "up" is so unlikely as to be a waste of money to look at. The quantum butterfly idea is actually quite true, I suspect. Where something like the already known CP violations set a process into motion that continued to favour one over the other.
Schrödinger did not wish to promote the idea of dead-and-alive cats as a serious possibility; on the contrary, he intended the example to illustrate the absurdity of the existing view of quantum mechanics.
Read some context... literally the next line from your quoted article: "However, since Schrödinger's time, other interpretations of the mathematics of quantum mechanics have been advanced by physicists, some of which regard the "alive and dead" cat superposition as quite real."
Schrödinger was very much trying to show that QM theory, which was in its infancy at the time, was absurd and therefore must have been incomplete or flawed . Just as Einstein was trying to do with EPR and when he questioned if the moon was there when nobody looks. They were trying to falsify their own theories by showing how fundamentally ridiculous they were. Of course a cat cannot be alive and dead at the same time. Of course things must continue to exist when nobody is looking at them.
However, they failed in falsifying the theory - instead, they just created excellent examples of how utterly bonkers QM really is. That QM theory (and later experimental evidence) shows that these absurd rules are in fact the ones that govern our reality.
In the words of Niels Bohr: "Anyone who is not shocked by quantum theory has not understood a single word."