Weirdly enough that conclusion reminds me of a scene I once saw in a nature documentary. It involved a species of birds where the males showed off their "fitness" to the females by doing dangerous things. One remarkable thing was that in one particular area near a highway, a group had adapted to show off by diving in front of a car without being hit (I guess that that species already used to do that with snakes and other predators before).

Anyway, in a general sense that's a particular type of sexual selection[0] that's been observed more often: showing that you are a healthy individual with good genes by taking risks. It probably has name. I suspect that with humans it's also an instinctual way of showing off who is the strongest in your peer group, without the sexual selection connotations.

EDIT: turns out the wikipedia article was one click removed from what I had in mind: signaling theory! (the evolutionary biology version)

[0] https://en.wikipedia.org/wiki/Sexual_selection

[1] https://en.wikipedia.org/wiki/Signalling_theory

I think it does, that’s the normalisation of deviance, slotin had stopped respecting the danger because he’d worked with it so much it had become mundane, innocuous. Doing party tricks with barely sub-critical masses absolutely qualifies for me.

There is Slotin and his motivations and then there is the visual vocabulary of musume art and how it represents emotions. The quickest way to get schooled on the latter is to watch the anime for

https://en.wikipedia.org/wiki/Azumanga_Daioh

which has a mad scientist character that I can easily picture screwing around with plutonium half-sphere and a screwdriver.

That makes this even more funny. Next you'll be telling me it was his daughter's birthday.