The answer is "God knows!"

Monty Python imitated Britain first.

Well, yes, and art did life, more generally.

"In 1944, while at a railway station he started chatting with a stranger who turned out to be an engineer who worked on ENIAC." I thought this was precisely the kind of careless talk people were told to avoid during wartime.

That doesn't sound quite like the Balboa I was taught, where the contact is at the top of the chest (and along the arms and hands of course) and the partners are slightly offset to the side to avoid shin kicking and toe trampling. As you say, the footwork is very rapid and the hold is close - perfect for fast tunes and crowded dancefloors - but no hip mashing that I recall.

We were slightly offset, yes; her foot fell between mine, and vice versa.

Agreed, I had learned it as basically a continuous hug, still really close chest to chest and not something that everyone was comfortable with.

I thought the catch was going to be people who cannot stand upright.

As far as I recall, QCD gives you a nice simple formula - a path integral over quantum operators - for any quantity you want. Lattice QCD works out the answer with great big Monte-Carlo integration. The tricky bit is defining a field theory on a finite discrete space-time lattice that is provably equivalent to the continuum theory after controlled extrapolations to the continuum. And you have to show that you can define the correct operators in the lattice theory that really do give the quantities you want. Then you need to implement this in code that runs blazingly fast over huge data sets. These considerations, and the fact that there are all sorts of solutions to these problems which might supported by a code base, tend to make code implementations complicated.

Goodness me, that's a blast from my very distant past! The venerable MILC code is still available: https://web.physics.utah.edu/~detar/milc/milc_qcd.html

And since you had asked for the difference and not the ratio, the candidate immediately failed, right?

Funny :) I would have hired the candidate who would have told me the difference is 7 bits!

Still a failure because the ratio is actually 0.125, but I kept going for a few questions, I stopped when they could not explain the difference between a thread and a process...

A London taxi driver explained to me back in the 1980's how he liked fares from clubs where boys wore make-up because anyone who has spent three hours crimping and back-combing and spraying their hair is unlikely to want to risk damaging it by having a fight.