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Physicists Test Symmetry Principle With an Antimatter Beam
Hugh Pickens DOT Com writes "Jon Butterworth has an interesting article at The Guardian about the idea of standpoint-independence in physics and the absence of 'privileged observers.' The ASACUSA experiment at CERN plans to make a beam of antimatter, and measure the energy levels as the beam travels in a vacuum, away from the magnetic fields and away from any annihilating matter. The purpose of the experiment is to test CPT (Charge/Parity/Time) inversion to determine if the universe would look the same if we simultaneously swapped all matter for antimatter, left for right, and backwards in time for forwards in time. In string theory for example it is possible to violate this principle so the ASACUSA people plan to measure those antihydrogen energy levels very precisely. Any difference would mean a violation of CPT inversion symmetry. Physicist Ofer Lahav has some interesting observations in the article about how difficult it is these days for physicists to develop independent points of view on cosmology. 'Having been surrounded by a culture in which communication is seen as generally a good thing, this came as a surprise to me, but it is a very good point,' writes Butterworth. 'We gain confidence in the correctness of ideas if they are arrived at independently from different points of view.'
A good example is the independent, almost simultaneous development of quantum electrodynamics by Richard Feynman, Julian Schwinger and Sin-Itiro Tomonaga. They all three had very different approaches, and Tomonaga in particular was working in wartime Japan, completely cut off from the others. Yet Freeman Dyson was able to prove that the theories each had provided for the quantum behavior of electrons and photons were not only all equally good at describing nature, but were all mathematically equivalent — that is, the same physics, seen from different points of view. Whether we are using thought experiments, antimatter beams, sophisticated instrumentation, or sending spaceships to the outer solar system, Butterworth says the ability for scientists to loosen the constraints of our own point of view is hugely important. 'It is also, I think, closely related to the ability to put ourselves into the place of other people in society and to perceive ourselves as seen by them — to check our privilege, if you like. Imperfect and difficult, but a leap away from a childish self-centeredness and into adulthood.'"
A good example is the independent, almost simultaneous development of quantum electrodynamics by Richard Feynman, Julian Schwinger and Sin-Itiro Tomonaga. They all three had very different approaches, and Tomonaga in particular was working in wartime Japan, completely cut off from the others. Yet Freeman Dyson was able to prove that the theories each had provided for the quantum behavior of electrons and photons were not only all equally good at describing nature, but were all mathematically equivalent — that is, the same physics, seen from different points of view. Whether we are using thought experiments, antimatter beams, sophisticated instrumentation, or sending spaceships to the outer solar system, Butterworth says the ability for scientists to loosen the constraints of our own point of view is hugely important. 'It is also, I think, closely related to the ability to put ourselves into the place of other people in society and to perceive ourselves as seen by them — to check our privilege, if you like. Imperfect and difficult, but a leap away from a childish self-centeredness and into adulthood.'"
What's this icky nerd stuff doing on a political web site like Slashdot?
(-1: Post disagrees with my already-settled worldview) is not a valid mod option.
The purpose of the experiment is to test CPT (Charge/Parity/Time) inversion to determine if the universe would look the same if we simultaneously swapped all matter for antimatter, left for right, and backwards in time for forwards in time.
Uh...last post, anyone?
Ezekiel 23:20
At first I understood quantum mechanics well enough to get good grades on my problem sets and exams, but I regarded it as delusional because I was heavily into the deterministic Newtonian idea of The Clockwork Universe.
He was able to give me a deep insight into QM without ever once doing a derivation or even simple arithmetic. For the most part it was purely conceptual discussions of the two-slit experiment.
What convinced me of quantum indeterminism in the end was Feynman pointing out that the two-slit also works for electrons, not just photons, and that one can use Shot Noise to determine when individual electrons are leaving the hot wire filament used to produce them.
Even if you send over just one electron at a time, you still get the rippled interference pattern at the detector.
It turns out that an antiparticle going back in time is exactly the same as a regular particle going forward in time. Just by watching an individual particle, or only a few of them, you cannot determine which direction time is going on.
It's only when you have enough particles for their measure of entropy to make sense that you can determine which direction time is going in. Entropy ALWAYS increases with time, so if you watch a system of particles, and their entropy is steadily decreasing, they are going backwards.
I've never heard anyone mention it, but what about smaller systems of particles, where entropy can be measured, but whose entropy fluctuates? Does time go back and forth? I don't know.
"MAYBE THERE'S JUST ONE ELECTRON!" Feynman once shouted.
We don't think that's the case - that just one electron goes from the beginning of the Universe to the end, then returns as a positron - because if there were significant amounts of antimatter in the Universe, we would expect there to be lots of 0.511 MeV gamma rays in the cosmic radiation but there is not.
I am STILL stymied by a question he asked once:
"Why does a mirror reverse left-and-right but not up-and-down?"
Please mail me URLs of software employers.
> For instance, the belief that the world began in flames is a religious ideology that is thousands of years old, yet persists to this day veiled beneath the Big Bang theory.
Correlation does not imply causation.
Whoah. Are you even remotely aware of what is being done in cosmology these days?
Planck Sloan Digital Sky Survey
Square Kilometer Array
Ice Cube
Large Synoptic Survey Telescope
Euclid
Hardly "ideologically/branding driven pseudoscience". Who the hell modded you up?
Except that's not really true. Our current Big Bang cosmological theory rose into the forefront (despite being derisively named the "Big Bang" by the proponents of the earlier reigning cosmological theory of the steady-state universe) when the cosmic microwave background was discovered. Quantum mechanics is the reigning theory for explaining particle behavior at very small scales, despite Einstein's well-known dislike for the theory. The fact is: you don't have to convince your opponents, you have to convince everyone else. It doesn't matter if you have a bunch of scientists unwilling to give up their "sacred cows", because you have a bunch of other scientists who have no stake in one theory or the other but are perfectly capable of judging between the evidence. Thats really the key: scientific progress is made by the community testing and accepting theories. Of course, some people (like Hawking) have a significant influence, but it's not like Hawking is never willing to admit he's wrong either: he has famously made several bets with John Preskill/Kip Thorne about singularities and black holes, which he has lost (and admitted to losing).
"None can love freedom heartily, but good men; the rest love not freedom, but license." --John Milton
What I found most interesting is what the head researcher found interesting:
In other words: Cambridge (Hawking) Dogma
Ofer Lahav didn't say anything of the sort. What Lahev said was the reason for non-independent viewpoints was "...these days we communicate continuously and too much. Developing independent points of view on cosmology, or indeed other matters, is therefore very difficult." - which has nothing to do with "Cambridge (Hawking) Dogma" (or anybody else's dogma for that matter).
Perhaps you didn't read TFA and simply decided you "knew" what Lahev was referring to just by reading the summary. In other words: you put words in Lahev's mouth to validate your fear of pervasive "ideologically/branding driven pseudo-science". In any case it looks like you have some ax to grind - and given the mods, you're not alone.
I think you'd be surprised by just how much "religion" is actually just made up shit.
Let me take a stab at that: All of it?
The purpose of the experiment is to test CPT (Charge/Parity/Time) inversion to determine if the universe would look the same if we simultaneously swapped all matter for antimatter, left for right, and backwards in time for forwards in time.
"As long as no red flags are raised in the experiment, we plan to move forward with the project in November," said top engineer Fedwick McGillicutty. "Our hope is that, by reversing time itself, we can do away with the whole debacle that is 'daylight savings time.'"
Any sufficiently simple magic can be passed off as mere advanced technology.
I think that says more about your misconceptions regarding "check your privilege": the idea is that you become aware of your own observer biases and account for them. It's an idea that's practically created for scientists.
No kidding!!! What do you say at this point?
Another "science" critic that doesn't understand what science is.
If you take a fuzzy creation story or prophecy you can make it fit anything you want. The myths that survive ARE the fuzzy ones that can be made to fit anything. It IS kind of like science actually: the scientific theories that survive are the ones that fit. Except science has the additional criteria that they have to also be as simple as possible and make specific predictions.
Your example defeats you nicely. Most scientists of the early 20th century (including Einstein and Eddington) had a strong belief in a basically static universe that was infinite in time, because that was the elegant solution with philosophical appeal. It took the indisputable evidence of the red shift to convince them that there was in fact a big bang which was the beginning of the current order, against their natural inclinations.
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