Persona 3 Reload: What’s it called when the bubbles in a whirlpool bath make your body vibrate?

Mr. Takenozuka has a weird, difficult question for you in his June 25 (6/25) physics class in Persona 3 Reload. For some reason he asks Junpei the correct term for something that happens in a whirlpool bath, and Junpei asks you for help.

Unfortunately, I have no recollection of the context in which Mr. Takenozuka came up with this question, but I do remember Googling it and finding nothing. I did get the answer right, though. But it was a bit of a lucky guess.

What’s it called when the bubbles in a whirlpool bath hit you and make your body vibrate?

First of all, I don’t think I’ve ever experienced this phenomenon first-hand. I have, many times, created my own bubbles in an ordinary bath, and that can make the bath vibrate pretty hard. But I think that’s more my body making the bath vibrate and not the other way around.

Maybe the three possible answers will offer some kind of clue:

• The anchor effect.
• The flutter effect.
• The bubble jet phenomenon.

So, I Googled all three of these answers, and not one of them is a commonly used term in the field of luxurious bathroom fittings. The “flutter effect”, however, shows up a lot in articles and videos about electronic music and machinery, aircraft in particular. It seems to have something to do with things vibrating when jets of air hit them, so I went for that as my guess.

And it was correct. The flutter effect is what it’s called when the air bubbles in a whirlpool bath hit you and make your body vibrate, so the answer is “The flutter effect.” Why Mr. Takenozuka used whirlpool baths and vibrating bodies as an example, and not something more sensible, like vibrating machinery, is a bit of a mystery. If you ask me, he chose that context because Mr. Takenozuka, like a lot of things in Persona 3 Reload, is more than a little bit creepy

We had a teacher like that at my school; Mr. [redacted]. He was the [redacted] teacher, and he used to walk around with a big [redacted] in his hand.

Anyway, there are no questions about bathtubs or about the flutter effect in the final exams, so you can forget all about the subject as soon as you’ve answered correctly and earned your Charm points. And, better still, you can forget all about Mr. [redacted]. I wish I could.