https://www.vice.com/en_us/article/7kbwme/scientists-are-creating-synthetic-dimensions-to-probe-limits-of-4d-reality

We humans experience spacetime in four familiar dimensions: Three spatial (depth, width, and length), plus time. While most models of the universe assume that all matter exists within these parameters, many theories speculate there could be all sorts of lurking higher dimensions that are hidden beyond our comprehension.

While we have not been able to break free of our 4D experience, scientists are getting pretty good at simulating extra dimensions through the creation of so-called “synthetic dimensions.” These trippy experimental concepts provide a way to mimic the kinds of higher-dimensional concepts explored in some far-out models of nature using lower-dimensional materials that exist in the real world.