The only theoretical hard limit that makes sense is a limit on information. If you can't transmit information from A to B faster than C, then yes you've got a h

The only theoretical hard limit that makes sense is a limit on information. If you can't transmit information from A to B faster than C, then yes you've got a hard limit. Every other natural phenomenon that doesn't obscure infromation that way can be figured out. There may of course be soft limits like it taking a billion years to figure out.