What is multidimensional space-time?
To ordinary people, talking about multidimensional space might feel very sci-fi, or they might think of traveling through time and space, and so on. If they continue to ponder, they reach the realm of deities, where, by developing their imagination, they can come up with many more things.
However, in the eyes of top mathematicians and theoretical physicists, multidimensional space-time is nothing more than a bunch of data, explanations, equations, and analyses.
Edward Witten could easily discuss multidimensional space-time and even explain it using mathematics because he often researched string theory and M Theory, the core support of which was the existence of multidimensional space-time.
M Theory is a further development of string theory, proposed in the hope of achieving a grand unification of physical laws.