The idea of living creatures existing in higher dimensions, as theorized by string theory and M-theory, is a concept that goes beyond the current understanding of the physical world. While these theories propose the existence of additional dimensions beyond the three spatial dimensions we are familiar with, there is no direct scientific evidence specifically supporting the existence of living creatures in those dimensions. It is important to note that these theories are still areas of active research and subject to ongoing scientific investigation and refinement.
String theory and M-theory aim to unify our understanding of the fundamental forces of nature, including gravity, and provide a framework to describe the fundamental constituents of the universe. These theories propose that the fundamental building blocks of matter are not point-like particles but rather tiny, vibrating strings or higher-dimensional objects called branes. The mathematics of these theories require additional dimensions, typically ranging from 10 to 11 dimensions, for the consistency of the equations.
However, the extra dimensions in string theory and M-theory are usually considered to be compactified or curled up at extremely small scales, making them effectively unobservable with current experimental techniques. Therefore, any speculation about the existence of living creatures or any specific entities in these dimensions remains highly speculative and falls outside the realm of empirical scientific evidence.
It is worth mentioning that the lack of direct evidence for higher-dimensional life does not disprove its existence. Science often explores and discovers new phenomena that were previously unimagined. Nevertheless, as of now, the notion of living creatures in higher dimensions remains a speculative concept within the realm of theoretical physics and mathematics, with no direct scientific evidence supporting or refuting it.