If we knew how to create world simulation, and how to make it working 4D, then humans would be able to plug themselves in, and experience 4D space. Alternatively there could simulated 4D beings, whose sentience could be transferred to robot body in our real 3D space.
*A fourth dimension can be time.
Time is a very convenient choice for a fourth dimension, but “fourth” is purely namesake. There’s no reason we couldn’t describe our world in our three familiar spatial coordinates with an additional coordinate for temperature, for example. We just don’t easily conceptualize it that way because it feels less contiguous according to how we currently frame our model of reality.
Disclaimer: my sources include internet research and far too much time to think. I’m absolutely open to discussion and new ideas in whatever form.
Edit: Temperature is kind of a bad example at face value, but good conceptually. Hopefully I’m communicating my point at least we’ll enough to be comprehended.