The Theory of Everything is the attempt to describe all four fundamental forces as aspects of a single unified force. The force that has proved to be the MOST difficult to incorporate into such a theory is
A) gravity.
B) electromagnetism.
C) the weak nuclear force.
D) the strong nuclear force.

Question

Quizplus · Accepted Answer

Gravity has been the most challenging force to incorporate into a unified theory, primarily because it is so weak compared to the other forces and because the quantum mechanics that successfully describe the other forces do not easily apply to gravity.

The Theory of Everything Is the Attempt to Describe All