When is theoretical computer science useful?

Question

In class, we learned about the halting problem, Turing machines, reductions, etc. A lot of classmates are saying these are all abstract and useless concepts, and there's no real point in knowing them (i.e., you can forget them once the course is over and not lose anything).Why is theory useful?

Answer 1

I'm not a computer scientist, but do computational physics. In general, increasing the speed of computers is in general useful. A calculation that would take me years 10 years ago would only take me hours now. National laboratories continue to build large supercomputers to support this work.