For fun, I'd say.
Apparently they wanted to see if constant vertical vibrations could prevent the light air from coming back on top of the fluid.
And then a guy went like "hey guys I got a lil plastic boat, what if we put it in? How do you think it would float?"
This is probably a perfect example of human scientific progress. Scientists: This has interesting applications and could help further our understanding of the universe and what we're capable of doing. That one weird scientists in the back: I've got little boats lets add them for fun. Results: Well look at that. Not only did we learn what we thought we were going to learn but the fact the boat floats raises even more interesting questions.
Apparently they wanted to see if constant vertical vibrations could prevent the light air from coming back on top of the fluid.
And then a guy went like "hey guys I got a lil plastic boat, what if we put it in? How do you think it would float?"