string theory?

Question

please explain the link between the following:

supersymmetric(SUSY) particles
fermions & bosons (what are these paticles??)
string theory
SUPER string particles
Theory of everything (TOE)

Answer 1

In particle physics, supersymmetry (often abbreviated SUSY) is a symmetry that interchanges bosons and fermions. In supersymmetric theories, every fundamental fermion has a bosonic superpartner and vice versa.

Now I had already explained bosons and fermions in another question. They're basically the two broad and distinct class of elementary particles in nature. So if supersymmetry exists in our Universe, there are many many more elementary particles that are superpartners of particles that we already know.

The difference between String Theory and Superstring Theory is basically the incorporation of supersymmetry into the String. We already know that without supersummetry, String Theory doesn't work. So that's why, String Theory later became Superstring Theory.

It just happens that supersymmetry is key in developing a Theory of Everything (TOE), which really is just a physical theory that can explain all the fundamental forces and particles of nature. Right now, one promising TOE candidate is Superstring Theory.

Now, why is supersymmetry needed? This has to do with what's called the "Hierarchy Problem". It's a deep rooted problem that currently exists in our Standard Model of quantum theories. Hierarchy problem occurs when the fundamental parameters (couplings or masses) of some Lagrangian are vastly different (usually larger) than the parameters measured by experiment. This can happen because measured parameters are related to the fundamental parameters by a prescription known as renormalization. Typically the renormalized parameters are closely related to the fundamental parameters, but in some cases, it appears that there has been a delicate cancellation between the fundamental quantity and the quantum corrections to it. In other words, the Hierarchy problems has to do with the fact that we need to manually "fine-tune" (i.e. make up numbers) so that we don't get infinities in our calculations. This of course is very "Un-natural", and "Dis-satifying" to all physicists.

What the Hierarchy Problem tells us is that our current theories are NOT complete, and they are crude approximations to the real physical quantum theories of nature (or TOE).

Answer 2

Read the Wikipedia articles on these. Read any of the many popular general science books on physics. Go to a library and browse some general physics texts. Several brilliant people have taken the trouble to present these concepts in relatively simple prose requiring minimal mathematics.

Answer 3

tricky factor. seek onto search engines like google. that will will help!