Because we cannot experiment with items that are so small.
However...
Science has thrown math at the theories of strings and the math tends to work out. The models we've built tend to confirm it.
At one time mankind didn't believe in unseen 'creatures' that made one sick. At one time mankind didn't believe in anything we cannot see, and yet we have infrared detectors, xray detectors, photon detectors, etc...
No proof doesn't mean shit in science, it only means we haven't been looking long enough or hard enough, or we don't have the right tools /at the moment/ but perhaps in the near future.
Science is full of ideas that work out mathematically but were supplanted by a better model (epicycles) or refined when their predictions didn’t match reality (ethers).
String theory could easily be that; we didn’t find super-symmetric pairs at the LHC.
> Science is full of ideas that work out mathematically but were supplanted by a better model (epicycles) or refined when their predictions didn’t match reality (ethers).
Honestly I think this is even true of much of our current understanding of physics. People take it for granted that we've discovered some irrefutable facts, but there is so much we don't know and understand.
It's entirely possible while the math checks out currently for our theories, they could be way off in many ways.
String theory hasn't been able to reproduce either the Standard Model or General Relativity. They have lots of arguments for why they should, but they can't even come up with existing physics, let alone predict anything that can be tested.
This after around 40 years of work.
We have no real evidence because it can't even make a prediction that could be tested.
Because we cannot experiment with items that are so small.
However...
Science has thrown math at the theories of strings and the math tends to work out. The models we've built tend to confirm it.
At one time mankind didn't believe in unseen 'creatures' that made one sick. At one time mankind didn't believe in anything we cannot see, and yet we have infrared detectors, xray detectors, photon detectors, etc...
No proof doesn't mean shit in science, it only means we haven't been looking long enough or hard enough, or we don't have the right tools /at the moment/ but perhaps in the near future.
Here's a bit of a primer:
> https://www.space.com/17594-string-theory.html#:~:text=Has%2....