The Quest for the God Equation: Unification of Physics through String Theory

Michio Kaku, a renowned theoretical physicist, and author of "The God Equation: The Quest for the Theory of Everything," discusses the pursuit of the "God Equation," a unifying theory of physics that would explain all four fundamental forces of nature. Albert Einstein spent the last thirty years of his life searching for this equation, which would unify gravity, electromagnetic force, and the two nuclear forces. In the pursuit of this goal, many scientists have proposed theories, but so far, only one theory has survived every challenge: string theory.

String theory proposes that subatomic particles are not point-like dots but instead tiny vibrating strings, similar to guitar strings. These strings have an infinite number of vibrations, which correspond to different subatomic particles. The vibrations of the strings can rotate particles into each other, which means that electrons could turn into neutrinos, and neutrinos could turn into quarks without changing the theory. The symmetry of the string is what makes it powerful and allows it to encapsulate the entire universe.

String theory allows for the possibility of time machines, wormholes, the universe before the Big Bang, parallel universes, and the multiverse, among other phenomena. Although objections to the theory exist, including the inability to test it, Kaku argues that string theory is the only mathematically consistent theory of everything proposed thus far.

The pursuit of the God Equation has historical significance, as each time a fundamental force has been unraveled, it has led to significant changes in human history. For example, Newton's mechanics of moving objects and gravity laid the groundwork for the Industrial Revolution, while Maxwell and Faraday's unification of electricity and magnetism gave us the electromagnetic force, which led to the electric revolution of dynamos, generators, and light bulbs. Similarly, Einstein's e=mc^2 paved the way for the nuclear force.

The unification of relativity and quantum theory is a significant challenge, as the quantum theory is based on chopping things up into particles, whereas relativity is based on smooth curves representing space-time. However, Kaku argues that string theory provides a possible solution to this problem.

The search for the God Equation remains an ongoing endeavor, with string theory being the most promising candidate so far. The pursuit of this theory has not only the potential to transform our understanding of the universe but also to bring significant changes in human history.


Kaku, M. (2021). The God Equation: The Quest for a Theory of Everything. Doubleday.

Smolin, L. (2006). The trouble with physics: The rise of string theory, the fall of a science, and what comes next. Houghton Mifflin.

Witten, E. (1995). String theory dynamics in various dimensions. Nuclear Physics B, 443(1-2), 85-126.