Albert Einstein spent the last three decades of his life pursuing a unified field theory that would unify gravity with electromagnetism and the other fundamental forces into a single theoretical framework. However, he was ultimately unsuccessful in this endeavor. This article reviews the major issues and challenges that Einstein encountered in his attempts to formulate a viable unified field theory:

Incompatibility of General Relativity and Quantum Mechanics

The central problem is the fundamental incompatibility between Einstein’s general theory of relativity, which describes gravity, and quantum mechanics, which governs the behavior of matter and energy at the subatomic scale. General relativity treats spacetime as smooth and continuous, while quantum theory is based on quantized, discrete values. The two theories are mathematically inconsistent when naively combined…