
Kaku also explains the intense controversy swirling around this theory, with Nobel laureates taking opposite sides on this vital question. This would be the crowning achievement of science, a profound merging of all the forces of nature into one beautiful, magnificent equation to unlock the deepest mysteries in science: What happened before the Big Bang? What lies on the other side of a black hole? Are there other universes and dimensions? Is time travel possible? Why are we here? But perhaps the ultimate challenge is achieving a monumental synthesis of the two remaining theories-relativity and the quantum theory.

Since then, physicists have been placing new forces into ever-grander theories.

When Newton discovered the law of gravity, he unified the rules governing the heavens and the Earth.
