Swimming on the Moon

Have you seen the What If? segment of XKCD? This week he has a great article up on the question of Lunar Swimming. About once a week there is an article that explores some strange maths/physics/science/whatever question that is explored to see what the results are. If you enjoy them there is a compiled collection of them in What If?: Serious Scientific Answers to Absurd Hypothetical Questions that is well worth the read as well as plenty of them on the website itself.


Each segment starts with a question, this week was What if there was a lake on the Moon? What would it be like to swim in it? Presuming that it is sheltered in a regular atmosphere, in some giant dome or something. and then a discussion of the results.

This would be so cool.
In fact, I honestly think it’s cool enough that it gives us a pretty good reason to go to the Moon in the first place. At the very least, it’s better than the one Kennedy gave.


‘You know, I hear the Soviets are already a third of the way through their bag of pinec–‘ ::grabs bag:: ‘HOMF NOMF HOMF GRROFMPH’
Floating would feel about the same on the Moon as on Earth, since how high in the water you float depends only on your body’s density compared to the water’s, not the strength of gravity.
Swimming underwater would also feel pretty similar. The inertia of the water is the main source of drag when swimming, and inertia is a property of matter[1] independent of gravity. The top speed of a submerged swimmer would be about the same on the Moon as here—about 2 meters/second.
Everything else would be different and way cooler. The waves would be bigger, the splash fights more intense, and swimmers would be able to jump out of the water like dolphins.

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