I Never Tire of Learning

So today I've learned so many interesting things. Like what goes into a recording session in a studio ("creating" background vocals? news to me..) or the "rope trick effect" seen within a few milliseconds after detonation of some nuclear tests in the early 60's. And by the way...how thick is a shock wave? (I don't know the answer to that, and I don't know if the answer would make any sense even if it was given to me.)