Theory of interactions, theory of collisions?

[jostpuur]

Can QFT be used to anything else but particle collisions? Particle collisions seem to be the major application of the theory, but it hasn't become clear to me if it works for anything else.

 

[ZapperZ]

QFT is used in everything from nuclear physics to condensed matter theory. That semiconductor in your modern electronics has a complete description using QFT.

Zz.