QUANTUM GRAVITY (UNSOLVED FORCE)
# Currently gravity is based on “Albert Einstein’s general theory of relativity” which is formulated with the Classical Physics.
# Quantum Gravity is generally used to describe the gravitational field and unite all forces in a single force.
# In Quantum Theory, it gives rise to a String Theory.
# String Theory however on the other side try to unify gravity with other fundamental forces such as quantum loop.
# In above diagram, various fields have their won meaning but when come to end “Quantum Gravity” stuck the mind of everyone.
# Standard Model of Physics yet is unable to find the GUT ( Grand Unified Theory) and still facing a problem of “Gravitons” (that is 2-spin massless particles).
# In Kaluza-Klein Theory, five dimensional theory combined with the gravitation and electromagnetism as it generally appears in String Theory.
# There are many ways to define Quantum Gravity such as ‘”Quantum Loop Gravity”, “Time”, String Theory” , Nonrenormalizability of Gravity and many others ways.
# Quantum Gravity is no the end of the ultimate reality as this is still a smaller beginning.