In 1919, Theodor Kaluza introduced a five-dimensional spacetime. In 1995 Edward Witten extended this to 11 dimensions. Was this necessary? Why?
A)No, this was not really necessary. Witten was attempting to recast the theory to make its connections with general relativity more apparent.
B)Yes, this was necessary. Mistakes had been found in the earlier theory, and additional dimensions seemed the easiest way to fix these.
C)Yes, this was necessary. Between Kaluza and Witten, two additional forces had been discovered, and the natural solution was to add more dimensions to the theory.
D)Yes, this was necessary. Witten's extra dimensions were specifically an attempt to account for dark matter.

Question

Quizplus · Accepted Answer

Between the time of Kaluza and Witten, the strong and weak nuclear forces were understood in addition to electromagnetism and gravity. The introduction of extra dimensions in string theory, which Witten contributed to, was part of an effort to unify all known forces in a single theoretical framework, suggesting that additional dimensions could provide a natural explanation for the characteristics of these forces.

In 1919, Theodor Kaluza Introduced a Five-Dimensional Spacetime