Why don’t we have a theory of quantum gravity yet? I explore why it has been so difficult.
Our best theories of physics are incomplete, quantum mechanics and general relativity don’t work when we try and put them together so physicists have been looking for a grand unifying theory of quantum gravity for decades, and so far have failed.
This is because it is virtually impossible to make an experiment where the large and small scales meet, so we look to the places in our universe where this happens naturally: black holes and the big bang via the cosmic microwave background.
In this video I explain what our best theories are and how we are trying to get to a theory of quantum gravity.