Slashdot Mirror
"Perfect" Electron Roundness Bruises Supersymmetry
astroengine writes "New measurements of the electron have confirmed, to the smallest precision attainable, that it has a perfect roundness. This may sounds nice for the little electron, but to one of the big physics theories beyond the standard model, it's very bad news. 'We know the Standard Model does not encompass everything,' said physicist David DeMille, of Yale University and the ACME collaboration, in a press release. 'Like our LHC colleagues, we're trying to see something in the lab that's different from what the Standard Model predicts.' Should supersymmetrical particles exist, they should have a measurable effect on the electron's dipole moment. But as ACME's precise measurements show, the electron still has zero dipole moment (as predicted by the standard model) and is likely very close to being perfectly round. Unfortunately for the theory of supersymmetry, this is yet another blow."
"ACME collaboration"?
Then just bang the electron on the head with an ACME anvil, and it will grow lumps.
Table-ized A.I.
If you measure it, an electron is perfectly round. The rest of the time it's kind of oval.
http://www.youtube.com/watch?v=hhbqIJZ8wCM
I have been on the edge of my seat waiting for something genuinely new. Something like when people were discovering that atoms were made up of even tinier bits. Or that quantum was not just a mathematical nicety but way cooler. Each of these fairly "academic" discoveries then opened up whole new trains of thought that led to lasers, solid state electronics, nuclear reactors, etc.
So what wonderful physics is hiding out there waiting to be discovered and open up a whole new world to us?
Personally my biggest recent letdown were the FTL neutrinos that turned out to be bogus. I was genuinely hoping that something cool revealing itself. But alas. My favorite today is that entanglement and wormholes might have some relationship. Minimally that will result in some cool sci-fi if not actual science.
Personally I don't mind if ultraspherical electrons shut down a bunch of pet theories. They didn't seem to be making much progress and thus the door has been opened to explore something new. Maybe there is some guy trying to get his doctorate showing that supersymmetry is a load of rubbish but hasn't been able to get much traction because the entire panel got their doctorates in supersymmetrical related ideas and in order to defend his thesis he has to first set fire to theirs.
Science is going to be really screwed when they discover frictionless planes also exist.
Every time I see a news item about supersymmetry, it always seems to be disproving it. Seems like the only thing the hypothesis has going for it is the universe would make a lot more elegantly designed if it was true. It seems like mostly wishful thinking to me.
I'm trying to teach myself to set people on fire with my mind... Is it hot in here?
radius: 2.8179403267e-15 m
surface: 9.9786881e-29 m^2
volume: 9.3731159e-44 m^3
above in fuzzy logic: very tiny
... of models involving perfectly spherical atoms, nanoparticles, cows, planets, stars, etc, there is something ironic about an electron being too round.
The deviations they are talking about aren't things like mountains or bumps, but a systematic non-spherical bias.
For example, the earth isn't spherical either, it's basically a bit fatter around the equator pretty close to an oblate spheroid (e.g., an M&M is a more exaggerated oblate spheroid). Like a baseball, if the electron isn't totally spherical, you can detect a systematic bias as it's being thrown around (you can think of the LHC as throwing an electron spit-ball or a knuckle-ball).
Although even in the standard model, the electron at some energy level probably has a detectable dipole moment (e.g., the charge wouldn't be uniformly spherically distributed in the electron), it is my understanding that it is predicted to be too small to be validated by current experiments. However, some versions of super-symmetry apparently would predict that the electron at some energy levels would have a larger detectable dipole moment . I guess these super-symmetry predictions didn't pan out.
radius: 2.8179403267e-15 m
That is the classical answer. It is generally considered to be a point particle today.
How can anything have a shape that turns into an electromagnetic wave when you're not watching...
bickerdyke
Must have some rough edges.
Faster! Faster! Faster would be better!
Isn't that a rather pointless conjecture?
Faster! Faster! Faster would be better!
I assume they mean the force created by the electron is perfectly round, rather than the particle itself. Perhaps someone can confirm.
Why OpalCalc is the best Windows calc
http://en.wikipedia.org/wiki/Supersymmetry
A whole lot of PhD dissertations, physics publications, and academic careers are on the line over this. String theory is the current favorite and loop quantum gravity the underdog. The direction of theoretical particle physics could be radically altered if the LHC doesn't find evidence of supersymmetry.
Why is Snark Required?
Yeah, but the summary nor the article explain why supersymmetry is a question or an issue in the first place, just that the evidence doesn't support the theory. What does the theory it disproves mean/change?
I do not fail; I succeed at finding out what does not work.
Yes in a way you are correct.
"Thus, at non-relativistic energies the EDM [electric dipole moment] corresponds to a shift of energy levels of the electron in an external electric field E that depends on the direction of electron's spin Se. "
More details:
http://resonaances.blogspot.com.au/2013/11/electric-dipole-moments-and-new-physics.html
An aspect of science is applied math as the AC below mentioned. More particularly, we should be somewhat cautious in treating math as physics. Physics is describable in math, but it isn't math. And the mathematics of a physical situation functions more like an analogy. It says "that works like this"...and usually it does that to some epsilon because we can only measure up to a certain energy. One can think of a physical theory described in mathematics as an idealization. The math is very precise, the real world is not necessarily.
What I'm not interested in is smug assholes claiming "it's in the summary" when it's not.
I do not fail; I succeed at finding out what does not work.
Uhm, haven't you heard? Size doesn't matter.
Everything and its opposite is true. Get used to it.
This is a good question. There are a number of theoretical and empirical motivations for supersymmetry, including the existence of dark matter, the matter-antimatter asymmetry in the universe, and the hierarchy problem in particle physics. I don't fully understand all of these myself. However, this short video released by my collaboration tries to explain some of them at a basic level: http://www.youtube.com/watch?v=UIflReRmynk.
It says that supersymmertry predicts a larger dipole moment, that's why it would be in question.
If you want to know why supersymmetry makes that prediction then you aren't going to get that in a new article or a slashdot post. There are lots of resources available for learning SUSY, or jump in the deep end with something random like http://www.springer.com/physics/particle+and+nuclear+physics/book/978-4-431-54543-9
The trouble is that Mathematics can describe ANY universe, not just the one we happen to be able to perceive.
Math is great at describing perfect theories that fail to pan out in real life, but that are perfectly self consistent in the theory and equations. Just look at all of the great, and completely wrong, models offered in super-symmetry, string, and all the other Grand Unified Theories that mathematically are perfectly sound, but are disproved by actual experiment.
This is why Physics, e.g. "science" > Math.
"Unheard of means only it's undreamed of yet,
Impossible means not yet done." ~~ Julia Ecklar
You seem to be implying that somehow mathematics are not sufficient for describing the "real" world, and that is simply not the case.
Mathematics are the language of the universe, as far as we can tell.
Speaking as a person who does mathematical modeling for a living, I can tell you that a mathematical model is definitely only an approximation for the real world. There is no such thing as a perfect model due to the limitations of our knowledge and our inherent inability to model every single detail in the world. There are huge stochastic effects that we can only approximate statistically (a deterministic model would require a near infinite number of parameters, and even it would be an overfit because we cannot measure or determine the all underlying phenomena).
Mathematics cannot be the language of the universe as the vast majority of the universe does not communicate any ideas. The parts of it that do is an insignificant, tiny portion that includes us and whatever other self-aware/reasoning beings that may be out there.
What mathematics is are a set of insanely great tools that we use to create models helping us to describe the universe. One thing we've learned from math is that self-referential systems tend to have issues that can crop up in spots. And it's hard to get more self-referential than a subset of the universe trying to understand the whole thing.
Saying that mathematics is sufficient to describe the real world, no matter how successful it has been at it so far, is awfully presumptuous.
Happy people make bad consumers.
It's a bit complex to squeeze into a slashdot summary. Here's what has to say about it. This article, written by Theoretical Physicist Matt Strassler, does a better job of explaining it in layman's terms, I found it to be an excellent article. I'd had only the vaguest idea what it was about before reading it.
Now I have a much less vague idea, but reading an article by a physicist doesn't magically turn you into one.
Free Martian Whores!
Supersymmetry solves an enormous number of problems in particle physics, except for experimental facts.
To defend Mathematics a bit, it does tend to advance much more quickly than Physics since it isn't hampered by the restrictions of the real world.
Just think of General Relativity and non-Euclidean Geometry. Often times when a new scientific concept is created/discovered and a model is required to flesh it out, all you need to do is look around existing mathematics and, oh look, there's an app for that.
Happy people make bad consumers.