Slashdot Mirror
10-Year Study Reveals Electron Shape
lee1 writes "In a 10 year long experiment, scientists at Imperial College have made the most precise measurement so far of the shape of the electron. It's round. So round, in fact, that if the electron were enlarged to the size of the solar system, its shape would diverge from a perfect sphere less than the width of a human hair. The experiment continues in the search for even greater precision. There are implications for understanding processes in the early universe, namely the mysterious fate of the antimatter."
Maybe its shape is indeed a perfect sphere and the "width of a human hair" is just a measurement error. How more precise they want to get, until its shape diverges a human hair from a perfect sphere when enlarged to the size of the galaxy? Is there an end to measurement errors? Am i making any sense? I think not, its late at night :x
Sig? Heil
Your head exploding is a perfectly normal reaction to trying to comprehend modern physics. Carry on.
'Sensible' is a curse word.
First I studied they were particles, then I studied they are actually mixture of waves and particles. Then I studied you cannot actually pinpoint it at all, and all you can know is probability density of its existence in space. Now, I read that they are extremely round.
My mind is full of fuck.
These virtual particles are tiny compared to atomic matter and exist for short amount of time, such a short amount of time thier very existence is below the uncertainty thresholds. They are a consequence of the fundamental uncertainty in position and momentum. They are created out of the vacuum.
So the question the experiment attempts to answer is does the electron behave like an object that reacts symmetrically in all dimensions, or is there so aberration, that is, is it not a perfect sphere. To a very high accuracy the paper claims that it is a sphere.
However that is not the full story. The paper is based on the idea that the aspherical shape would be larger than the standard model predicts. Adjusted models predicts a larger aspherical aberration. Since this experiment did not detect large aberrations, these other models, extensions of the Standard Model seem to be less than accurate. Form what I read, the standard model predictions are orders of magnitude lower than current sensitivity so it remains unclear if the electron acts like a sphere or something that is almost like a sphere.
What this experiment does is provide a novel and fascinating method to probe subatomic particles, as well as establish an upper limit on how big the abberation could be. Good science.
"She's a scientist and a lesbian. She's not going to let it slide." Orphan Black
This is simplified, don't take this completely literally, but get this first. I'll use a car analogy.
You and several other clowns are in a clown and some of them are juggling. You are driving so you can't look at them. You can't look because you are doing a precision maneuver with several other clown cars. As part of the act they are also exchanging juggling objects with other cars. Even though you can't look at the jugglers you can sense what they are doing due to the fact that their motions and transfer of momentum are throwing you off course. It is important that you stay on course to make the jump. God help you if you hit the ramp like like the last guy did, but the kids like to see this act up close.
If the jugglers are throwing around tennis balls your course will be effected differently than if they were throwing juggling pins.
Now, back in the world of the article you've got the same thing. Atoms with electrons flying around and shared by chemical bonds. The shape of the electrons effects the shape of the molecule. More specifically the shape of the charge around the electron effects the shape.
Don't try to watch the objects being juggled, watch the clown cars try to stay in formation on their way to the jump over lion pen.
It took a long time because the measurements are so delicately precise and spurious data had to be discounted and filtered from the signal. The measurements weren't averaged but they were mercilessly filtered and subjected to analysis to take the "noise floor" down this low.
I am not a physicist. Someone correct me or clarify if I was dead wrong. Thanks!
md5sum
d41d8cd98f00b204e9800998ecf8427e
Is it always round, even when it's tunnelling through a potential wall?
I think that the way they are translating the physics into English is awful. I'm not sure I fully understand their method, but I'll try to restate. What they actually found was that they electric dipole moment of the electron was very small. It it were not that small, they would have seen changes in the wave function. From there they go to stating that if the electron can be modelled as a charge distribution or a charged object, that object would be spherically symmetric with dipolar radial deviations of less than that very small number. But more precisely, the wave function of an electron behaves as if it represents a particle that has a electric dipole moment less than 1.05E-27 ecm.
If course you couldn't actually make measurements to determine whether that dipole moment is a property of a physical shape of the electron or is an intrinsic property. Nothing we have can probe those size scales, and if you could you'd have particle antiparticle pairs popping up everywhere from the energy of the collisions. You might even create a new universe at those energies. Everything we've done so far suggests that the electron has no structure, but that's on much larger scales/lower energies.
Support SETI@home
They were hoping electrons were shaped like Pac-man. This would where the antimatter went.
You and several other clowns are in a clown
Sup dawg, I heard you like quantum physics, so I put a clown in your clown so you can juggle while you drive
No it's not. Your head exploding is a perfectly normal reaction to trying to comprehend the piece of shit that passes as scientific journalism nowadays. I'm a physicist and after reading the article I still had no idea about what the researches discovered. At least Science Daily had the original reference so I could look up. Even more appalling is BBC's coverage: http://www.bbc.co.uk/news/science-environment-13545453
They both only said "lasers" about what the group actually measured. As if the measurement technique were as relevant as what they were actually measuring. Even laymen like OP see that there's something weird about saying the electron has a shape and is a sphere. Of course, this makes absolutely no sense. This talk about sphere is a semiclassical analogue that someone in the 20's once thought that could be true and was quickly disproved. What they measured was the electron's electric dipole moment. What is that?
Imagine a small bar magnet, with south and north poles. This is what we call a magnetic dipole. The strength of the magnet (measured in a standard way) is what we call magnetic dipole moment. Now imagine that instead of south and north poles, we have negative and positive electric charges. This is an electrical dipole, and it's strength is likewise the electrical dipole moment.
Now the beauty of the electron is that despite not being a small bar magnet, it still displays a strong magnetic dipole moment, which we call spin. Originally people thought that it could be explained by postulating a structure on the electron (an electric charged spinning sphere gives rise to a magnetic dipole moment, hence the name spin), but quickly we found out that it couldn't be so. We have no explanation for it, it is what it is, just a property of the electron.
But what the electric dipole moment? The electron is a single charge, so it can't be an actual electrical dipole. But despite this, the Standard Model predicts that it has a very small electric dipole moment, too small to be measurable. But Supersymmetry predicts that it is quite larger, and even measurable, and these folks' measurement showed that Supersymmetry's prediction is probably wrong.
Ok, but why did they call it measuring the roundness? Analogously with the spinning sphere model for the magnetic dipole moment, a distorted sphere gives rise to an electric dipole moment. But calling it measuring the roundness makes as much sense as saying that when we measure the magnetic dipole moment (spin) we are measuring the speed with which the electron spins about itself.
So, makes more sense now?
entropy happens