In our current understanding of physics, the number of dimensions is a topic of debate. In classical physics, we typically work with three spatial dimensions (length, width, and height) and one time dimension, making a total of four dimensions. However, certain theories propose additional dimensions beyond these four.
In the context of string theory, which is a theoretical framework attempting to unify all fundamental forces and particles, it suggests that there may be extra spatial dimensions—typically six or seven in total. These extra dimensions are believed to be curled up or compactified at extremely small scales, making them imperceptible to our everyday experiences.
Regarding the concept of traveling through dimensions to change reality or travel through time, it's important to note that this idea mostly belongs to science fiction rather than current scientific understanding. While theoretical physics explores the possibilities of additional dimensions, the practical implications and abilities associated with traversing these dimensions are largely speculative and not supported by empirical evidence.
Time travel, specifically, is an intriguing concept that has been explored in various scientific and fictional contexts. In conventional physics, time is treated as the fourth dimension, and traveling through it in a manner similar to spatial dimensions remains purely theoretical at this point. No scientific evidence or established mechanism exists to suggest that time travel is possible.
It's essential to distinguish between the fascinating concepts presented in science fiction and the current scientific understanding, as they often diverge significantly.