For the past 100 years, physicists have been working to unify the theories of relativity and quantum mechanics, and establish gravity as a force arising from quantum interactions at tiny scales.

Thomas Hartman, professor of Physics at Cornell University, studies the quantum theory of gravity, focusing on a promising approach called emergent spacetime.

Introduced by Albert Einstein, spacetime is the notion that space and time form a continuous four-dimensional fabric.

This fabric can bend and warp, resulting in the force of gravity.

Hartman and his colleagues argue that spacetime is not a fundamental property of the universe, and instead emerges from matter interacting at the microscopic level, a sort of quantum soup permeating the universe.

However, these interactions are so complicated that the normal mathematical tools used by physicists break down, making study difficult.

To tackle this problem, Hartman and his colleagues have devised thought experiments involving black holes, where particles entering or passing close by a black hole can reveal how quantum matter behaves in general.

These theoretical scenarios have been confirmed by numerical simulation, providing new insight into strongly interacting quantum matter which could help resolve one of the deepest mysteries of modern physics.