Solo et pensoso, quantizzava campi
Quantum Field Theory took us by surprise.
Back in the day, we praised Schroedinger's might:
with utmost joy and cerebral delight
slow-moving systems we could analyse.
Alas! Yet, toughest issues were to arise:
Energy is mass - Herr Einstein got it right! —
So, if things are moving nearly as fast as light,
when they collide, more things materialise!
But QFT will fix for us the plight:
the existence of the fields we can surmise,
and using operators, then outright
our old QM we can second-quantise.
And if you find infinities, no fright:
stick to your guns, and just renormalise.
Stefano De-Nicola, 2013