Without a doubt, quantum mechanics is weird as it allows multiple particles to interact non-locally through phenomena including entanglement. This ability to have two spatially separated particles share information with each other is not something easy to accept when armed with the theories of relativity. For this reason researchers have constantly been trying to test quantum mechanics against relativity, and now those at the Center for Quantum Technologies have devised a new way to perform this test.
The premise is simple enough in that for quantum mechanics to make sense from a relativistic point of view; either the information between the particles had to be set in advance of their separation, or there is some hidden influence that can travel at superluminal speeds to connect them. Previous research has rejected the former idea, but has not proven the latter. That is what the researchers hope to do thanks to their recent analysis of systems of four entangled particles. The constraints on this system form an 80 dimensional object and to test for hidden influences, its shadow in a 44-dimensional space has to be examined. If the examination comes up with a value within the shadow, then quantum mechanics stands as it is. If the value is outside of the shadow though, then potentially weirder things are true. Either these hidden influences can become visible, which means superluminal communication is possible, or they travel at infinite speed.
Believe it or not but if the hidden influences are proven to exist, the infinite speed possibility is the preferred one. Generally superluminal communication is dismissed because it violates relativity, but something moving at infinite speed may skirt around that issue. Of course, the results of this test could be that quantum mechanics stands as we know it today.