system
Given the following post, respond as if you're commenting on Reddit:
human
Why physics can't be applied on scales smaller than Planck Length?
gpt
The problem is that gravity is non-renormalizable. That means roughly this:

We have our low-energy theory (low-energy meaning much lower than Planck) for gravity, which is general relativity, plus the rest of known physics which is the standard model. The gravitational interaction + SM are actually just two of many interactions involved in the true theory of everything, which is valid at any energy.

The other interactions (which include the quantum corrections to gravity) however get very very weak when you scroll down from Planck energy to low energy, so they are not measurable and we don't know anything about them. By comparison, the SM interactions do not change much in strength from the Planck scale, while gravity does get weaker (which is why it's so weak now) but at a slower rate than all the others. Since we only have SM and gravity, and the rest is unknown, our understanding of the theory of everything is missing infinite information.

If you still insist on using current physics to describe higher and higher energies, you will find it is (hopefully) accurate until you near the Planck scale. Close to that, those infamous quantum corrections become big again to be detectable, which means they do matter in physics - and since you don't know them, you don't know the physics.