The most important application of quantum computing in the future is likely to be a computer simulation of quantum systems, because that's an application where we know for sure that quantum systems in general cannot be efficiently simulated on a classical computer.
It is often stated that of all the theories proposed in this century, the silliest is quantum theory. In fact, some say that the only thing that quantum theory has going for it is that it is unquestionably correct.
Quantum field theory was originally developed for the treatment of electrodynamics, immediately after the completion of quantum mechanics and the discovery of the Dirac equation.
In relativity, movement is continuous, causally determinate and well defined, while in quantum mechanics it is discontinuous, not causally determinate and not well defined.
Quantum mechanics broke the mold of the previous framework, classical mechanics, by establishing that the predictions of science are necessarily probabilistic.
The math of quantum mechanics and the math of general relativity, when they confront one another, they are ferocious antagonists and the equations don't work.
Einstein's theory of relativity does a fantastic job for explaining big things. Quantum mechanics is fantastic for the other end of the spectrum - for small things.
The development of quantum mechanics early in the twentieth century obliged physicists to change radically the concepts they used to describe the world.
We talk about quantum weirdness and things being in two places at once, but it all involves atoms and molecules, stuff we don't normally interact with.
