“Unified field theory” (and the String Theory later): who tries to unify the quantum mechanics theory(describes: strong nuclear forces, weak nuclear forces, electromagnetic forces) and the general relativity theory(describes the gravity); to unite the world of the small and the world of the large. General relativity describes the force of gravity and hence is usually applied to the largest and most massive structures including stars, galaxies, black holes and even, in cosmology, the universe itself. Quantum mechanics is most relevant in describing the smallest structures in the universe such as electrons and quarks.

Why is so difficult to find the “Unified field theory”?

Because at quantum level space and time are so twisted and distorted, that the conventional ideas of left and right, up and down, even before and after break down. If I am at this level I can’t say I’m here or there or both places at once; or maybe I’m right here before I’m right here!

In quantum theory, a field is not just something associated with waves, but is also related to particles by virtue of the well-known wave-particle duality.

The rules at small world don’t behave at same way like the smooth way of the general relativity(Einstein didn’t understand it and was far away to find the UNIFICATION, his dream)

The Standard Model is a highly successful and experimentally tested theory of “three-fourth of everything” (since it incorporates three of the four fundamental interactions) and does not include the graviton and its interactions. The reason why the Standard Model is useful despite the absence of gravity is that the strength of gravitational interactions depends on the masses of the gravitating bodies involved. For elementary particles, the gravitational force between them is so small that one cannot even conceive of observing it directly.

General relativity and quantum mechanics are mutually incompatible: any calculation which simultaneously uses both of these tools yields nonsensical answers.

The String Theory: based on the concept of elementary particles, tiny vibrating loops of energy called strings. The unification: all the fundamental particles we know can be described by one object, a string!

The theory started from the Euler equations.

Superstring theory did the Unification!

No experiment can prove the strings exist,because of course are so small. The size of a string is somewhere near the length scale of quantum gravity, called the Planck length, which is about a millionth of a billionth of a billionth of a billionth of a centimeter.

The strings have certain vibrational modes which can be characterized by various quantum numbers such as mass, spin, etc.

Compose of an enormous number of oscillating strings, the universe is like an elegant symphony.

Are five different Superstring theories, but not in harmony.

The M-Theory explain the origin of strings, why we have five superstring theories. Is a 10 dimensional theory.

The F-Theory is a 12 dimensional theory, has two time co-ordinates.

Imagine you live in a world with two times.

I consider too that a true theory may be independent of any dimensionality of space-time.

I see in The String Theory a EQUIVALENCE between Strings and Prana in Yoga and Qi in Qigong. This EQUIVALENCE it’s a huge step in understanding the Universe.