Supersymmetry

[Yamialpha]

Do you believe that supersymmetry exists? Do you believe that supersymmetric particles will ever be discovered?

 

[Whistler]

I'm thinking it probably won't be true. Experiment already puts severe constraints on the masses and couplings of supersymmertric partners. Too severe for my taste. Also, the simplest SUSY models involve over 100 adjustable parameters compared to our current standard model, which has around twenty (depending on wether you include neutrino masses). All this seems to needless complicate things.

But from a mathematical standpoint it's a fascinating subject and it does give us some insight on how to connect quantum mechanics and gravity and how inflation and the higgs mechanism come about. I guess we'll start to see how right the theorists are when the LHC at CERN goes online in 2007.

can't wait for that

 

[Iron Sun 254]

The trick is that not finding any does not necessarily prove they don't or can't exist. You can only prove they exist by finding them or prove they don't exist by finding evidence that and alternate theory which excludes their existance is true.

 

[Yamialpha]

The thing I find most intriguing about supersymmetry is the fact that without it, the nongravitational forces at the extreme beginning of the universe
(10^-29 of a second if I remember correctly) have strengths almost but not quite equal, but with supersymmetry they are precisely equal. To me it seems that it is more satisfying that a universe governed by precise parameters (in other words, the anthropic principle) would be exact instead of just almost exact.

 

[Glass*Soul]

I don't suppose any of you would attempt to explain supersymetry to a layperson? I'm reading The Elegant Universe and having trouble following the discussion of supersymetry. Really having trouble.

 

[Yamialpha]

I don't suppose any of you would attempt to explain supersymetry to a layperson? I'm reading The Elegant Universe and having trouble following the discussion of supersymetry. Really having trouble.

I'll give it a shot. Basically it is just a type of symmetry that states that for every boson there is a fermion partner and vice versa. In other words, for every particle there is a superparticle that differs in spin by 1/2. There hasn't been any direct experimental proof, although those of us who believe that supersymmetry has promise are waiting to see what the Large Hadron Collider finds when it's completed (maybe even the Tevatron at Fermilab ). Supersymmetry seems to be especially welcoming since it unites the three nongravitational forces in the circumstances I mentioned above. That's an extremely rough definition, and if I have time I'll try to Google it and see if I can find any websites with better explanations.

 

[Glass*Soul]

That's a good start. I could follow that.

Am I right in thinking that gravity consists of bosons? What does supersymetry do with gravity?

 

[Illuminatus]

Am I right in thinking that gravity consists of bosons?

Not really. To simplify, a boson is just a class of elementary particle. Gravity is a force, the cause of which we have no clue. There are a lot of theories for the basis of gravity, including string theory and loop quantum gravity.

 

[Glass*Soul]

I phrased that question badly.

My understanding is that the graviton is a messenger particle of the force of gravity and that it is an example of a boson. Is that even remotely correct?

Why do a particle whose spin is a whole number and a particle whose spin differs by 1/2 cancel each other out?

 

[Yamialpha]

My understanding is that the graviton is a messenger particle of the force of gravity and that it is an example of a boson. Is that even remotely correct?

The graviton is a theoretical boson that has yet to be observed.

Why do a particle whose spin is a whole number and a particle whose spin differs by 1/2 cancel each other out?

My take on it is that bosonic and fermionic quantum-mechanical vibrations are opposite (i.e. when bosonic vibrations are positive, the fermionic vibrations are negative). Since in supersymmetry they occur in pairs, they cancel each other out.

 

[Glass*Soul]

The graviton is a theoretical boson that has yet to be observed.

I want to believe.

My take on it is that bosonic and fermionic quantum-mechanical vibrations are opposite (i.e. when bosonic vibrations are positive, the fermionic vibrations are negative). Since in supersymmetry they occur in pairs, they cancel each other out.

So, am I on the right track to be picturing two waves in which the trough of one corresponds to the crest of the other so they are cancelling each other out?

 

[Yamialpha]

I want to believe.

I think that most of us who want to see a theory of quantum gravity to come into existence want to believe .

So, am I on the right track to be picturing two waves in which the trough of one corresponds to the crest of the other so they are cancelling each other out?

I guess you could. I've never heard of destructive interference being used as an analogus, but I can see your point.

 

[Glass*Soul]

And, I understand, supersymetry smooths out some of the crazy quantum weirdness you get at supermicroscopic levels.

 

[Yamialpha]

And, I understand, supersymetry smooths out some of the crazy quantum weirdness you get at supermicroscopic levels.

Yes it does, which is another reason why many physicists find it so attractive.

 

[Glass*Soul]

Thank you for letting me in on your rarified discussion.

 

[Yamialpha]

No problem. Always glad to have other members in the discussion.

 

[Yamialpha]

I'm attempting to get an H-Bar armory item in.

http://www.christianforums.com/t1645741-h-bar.html

If you support the idea, then your input at the thread will be appreciated.