Does the universe have extra dimensions hiding in plain sight?

A dark dot sits in the middle of a blue and black starry folded cloth with grid lines over it.

In 1919, physicist Theodor Kaluza hypothesized that extra dimensions might solve some outstanding problems in physics. And while we haven't found any evidence yet for anything outside our normal four-dimensional space-time, there are still plenty of intriguing options worth exploring.

One of the biggest puzzles facing modern physics is the "hierarchy problem." Basically, the force of gravity is way too weak. It's billions upon billions of times weaker than any of the other fundamental forces, and we have no idea why.