I guess he meant general, not special, relativity.

General, not special.

>VERY deep, highly irrelevant to our lives.

1. What a foolish comment. The ability to understand, and one day control, the strong force of matter, is extremely relevant to our lives. Indestructible building materials, space elevators, economic boom from harvesting the asteroid belt, etc. Use your imagination.

2. For the purposes of this comment thread, it's irrelevant whether it's relevant to our lives our not. The assertion was physics is still far from figuring everything out. Nothing to do with our everyday lives.

I wonder sometimes if this suspension of critical thinking about what physics will be able to give us is due to science fiction. SF from the beginning has been promising far more than science could ever deliver. We're now at the point in history all those fantasies have to be put down.

But I bet during the time quantum theory was first being developed it was hard to see how or whether it might be used in actual technology. I'm sure some even dismissed such possibilities. But here we are now using it to inform radio telecommunications tech, and experimenting with quantum entanglement communications and quantum computers.

A hundred of years of having the correct theoretical foundations + hacking and tinkering on them may make possible things that seem exotic or impossible now.

The is point is - finding the correct theory sets off a process of hacking and tinkering that results in useful new technologies at some future time, some of which may not have been foreseeable at the time the theory was discovered. But we have to invest in finding the correct theory, anticipating eventually useful things will come of it, some we can foresee and some we can't.