Energy always has an upper limit
Currently, scientists believe that energy can, in theory, be released at infinitely high levels. This makes some equations in quantum gravity impossible to solve.
Now imagine space and time were not smooth but made of tiny, indivisible building blocks—like pixels on a screen — similar to how energy and momentum in quantum mechanics come in small, indivisible packets called quanta.
In such a world, you wouldn’t be able to move an object by just any distance. Instead, it would jump in fixed steps. Similarly, time wouldn’t flow continuously but would tick forward in tiny increments, like the ticking of a clock.
These steps are so incredibly small that we don’t notice them in everyday life. According to general relativity, gravity comes from the curvature of spacetime. If spacetime itself is not smooth but made of small chunks, then this curvature must also follow a step-like, quantized pattern.