What is the difference between social theory and sociological theory?

What is the difference between Quantum Theory and String Theory?

• What is the difference between Quantum Theory and String Theory? And what is the Theory of everything and why do we need it? Please answer in simple English because it's my second language.

• Answer:

  Quantum Theory deals with the very small (atomic sizes). General Relativity deals with the very large (planets, galaxies and cosmology). Quantum effects don't scale to the large and gravity is unbelievably weak in the small scales. Both theories have been proven over and over and are extremely robust. The problem is when you have a small size *and* large gravity (black holes and the big bang are the common problem areas) the two theories don't work together - at all. Enter string theory which purports to solve for both Quantum Theory and Gravity but to do so requires 11 dimensions. It postulates that at the smallest scale, energy is *string like* with oscillations and vibrations forming the properties of what we see as point particles. Since the strings are not points with no size they smooth out the rough Quantum Foam and allow for gravity to have effect. The biggest issue the theory faces is at the energies required and the scale of the effect there doesn't seem to be any way to test this theory at our current level of technology. That's where the study is. There are other candidates for unification of Quantum Theory and General Relativity but few have captured the public imagination as string theory has.