The problem is that the two theories conflict, so they both can't be right. Physicists are trying new experiments using ultra precise atomic clocks to probe ever smaller scales to find the spot at which they start to conflict. This will reveal lots of fascinating information that will help them to figure this out.
www.inverse.com
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Physicists are finally ready to test a key Einstein theory
In February 2022, physicists made two critical advances in atomic clocks — bringing them closer than ever before to testing a key Einstein theory.
@PhysicsGuy this one's right up your street. Check it out.