Can you swim in space?

Question

My wife shared this picture with me today:

picture of a cartoon corgi doing the doggie paddle in space and moving forward

Adorable, but it got me thinking about that trope - swimming in space.

I've seen it before, mostly in cartoons and not live-action shows, the latter of which tend to have either more realistic space stations that astronauts pull themselves along on rails to get around in, or fictional artificial gravity.

My question then is three-part:

Can a person actually 'swim' to get around in a real spacecraft?
Could they do this in the vacuum of space? (Assuming they have proper space protection)
Could a Pembroke Welsh Corgi on the ISS do a doggie paddle to get around?

Related question: http://space.stackexchange.com/questions/5232/is-there-an-upper-limit-for-the-internal-size-of-space-stations — Nickolai, Feb 09 '15 at 18:50
Related: How to escape the center of a room without gravity? on [physics.se]. — user, Aug 23 '16 at 10:55

score 13 · Accepted Answer · answered Feb 09 '15 at 13:07

13

You can sort of swim, but it would be very slow. The viscosity of air vs water is very low. Therefore the 'scoop' your hands or feet can get of the fluid, to propel it, and thus move you around would need to be much higher.

If you had fans (or 'wings') on your arms you would be more effective.

As for the corgi? Not likely, or at least very, very slowly.

You might be more effective inhaling with a wide open mouth slowly, then quickly exhaling through a small mouth in the direction opposite you wish to go.

answered Feb 09 '15 at 13:07

geoffc

79,523
12
227
419

2

Astronaut Dan Barry tried "swimming" in the ISS. It did not work. https://space.stackexchange.com/questions/18386/tiny-emergency-propulsive-device-if-stuck-floating-in-a-large-volume-in-microgra/18485#18485 – Organic Marble Mar 30 '18 at 18:34
2

@OrganicMarble: Nowhere in the text in the linked answer does Barry actually mention "swimming" - reading that text, it sounds more like he was trying to move by thrashing his limbs, which doesn't work even in water. Additionally, swimming through air would be quite slow, to the point where it would take quite a while to realise that you were, in fact, moving. – Vikki Aug 16 '20 at 19:38
@Sean I guess it depends on your definition of "swimming". I am not as confident about how swimming in air would actually work as you seem to be. – Organic Marble Aug 16 '20 at 19:48
@OrganicMarble I think that Dan Barry story is some sort of joke. – Matthew Christopher Bartsh Apr 22 '21 at 20:55
@MatthewChristopherBartsh Why would you think that? – Organic Marble Apr 22 '21 at 21:23
@OrganicMarble Are you kidding me? – Matthew Christopher Bartsh Apr 22 '21 at 21:37
@MatthewChristopherBartsh No. – Organic Marble Apr 22 '21 at 21:38
1
'Sneezing and spitting didn't do much good either.' That implies that he sneezed and spat. Sneezing is an involuntary act, so how did he try it as a way to get to a wall. Sneezing in a space station or the like is highly frowned on, because it is unhygienic in the extreme, and disrespectful to everyone else, because whatever particles you sneeze out will float on the air rather than falling to the ground, and can easily be inhaled, a major health hazard. Deliberately spitting would be even worse. No astronaut would admit to having done that deliberately. 2. How would an astronaut not...

Matthew Christopher Bartsh

Apr 22 '21 at 21:48

@OrganicMarble ...know that there is a law of conservation of momentum that has no exceptions (not even in relativity and quantum mechanics, by the way), and it not only allows rocket propulsion, but also propeller propulsion and so by causing air to move one way, by blowing or fanning the air with his hands in one direction he can move his body in the opposite direction. It's clearly a joke. A useful lesson in physics made into a humorous untrue anecdote. A joke. – Matthew Christopher Bartsh Apr 22 '21 at 21:55

1

@MatthewChristopherBartsh I hate to tell that I know Barry personally (here's a picture of he and I in a tank together) and I know for a fact that this happened. Theorize all you like. https://science.ksc.nasa.gov/shuttle/missions/sts-105/images/high/KSC-01PP-1305.jpg – Organic Marble Apr 22 '21 at 21:56

@OrganicMarble My theory is that you never asked him whether he was being serious. – Matthew Christopher Bartsh Apr 22 '21 at 21:58

@MatthewChristopherBartsh I should have said I knew him personally. Haven't talked to him since he left NASA. Anyway, I'm gonna believe him over you. – Organic Marble Apr 22 '21 at 22:08

@OrganicMarble I made it into a question just now. https://space.stackexchange.com/q/51610/40252 – Matthew Christopher Bartsh Apr 22 '21 at 22:22

@MatthewChristopherBartsh I can't answer because it's hearsay. Best wishes. – Organic Marble Apr 22 '21 at 22:24

Let us continue this discussion in chat. – Matthew Christopher Bartsh Apr 22 '21 at 22:26

2

@MatthewChristopherBartsh - actually doesn't "conservation of momentum" only apply to the system as a whole and might not apply to an object subject to a small or large impulse in a liquid/gas with viscosity? In other words, if, while floating in air, you breath in slowly, that might not change your momentum much in the space you're floating in, but then you exhale quickly it could? Check your assumptions. The facile answer isn't always right. – davidbak May 05 '21 at 21:14

@davidbak MatthewChristopherBartsh said that momentum conservation means that it is possible to propel yourself "by blowing or fanning the air", i.e. the same thing you said, not the opposite claim that you seem to be rebutting. – benrg May 06 '21 at 18:50

score 5 · Answer 2 · answered Feb 09 '15 at 18:29

5

A person could swim. But that would take many, many effort to generate even a little of velocity. The viscosity of air is much lower than the viscosity of water. When you swim in water you are practically pushing the water away, creating a force that makes you go the direction you're swimming to.

Imagine this with air. You could simulate this yourself too: Standing on the bottom of a swimming pool and make a swimming movement with your arms and feel the effect of you pushing forward. Then try it in normal air, almost nothing would happen. Then again with a propeller it's a different story.

In the vacuum of space you can't do this of course. Since there's no mass to push away, nothing to swim in, nothing can make you push forward.

The Corgi in the ISS could theoretically do that. But, that would be more of an disappointment if you compare that with the moving picture. It would take a long time a little, so I don't think the dog will use that to move itself around.

answered Feb 09 '15 at 18:29

joppiesaus

473
1
5
10

2

In fact, you can "swim" in a vacuum, taking advantage of relativity: http://www.science20.com/hammock_physicist/swimming_through_empty_space . However, this is a very subtle effect, and takes hours to move a foot or two. – Skyler Feb 20 '18 at 16:45
1

Astronaut Dan Barry tried "swimming" in the ISS. It did not work. https://space.stackexchange.com/questions/18386/tiny-emergency-propulsive-device-if-stuck-floating-in-a-large-volume-in-microgra/18485#18485 – Organic Marble Mar 30 '18 at 18:33
@OrganicMarble Perhaps this could be an answer to the question? – joppiesaus Aug 20 '20 at 09:34
@Skyler Are you being serious? – Matthew Christopher Bartsh Apr 23 '21 at 20:19
@OrganicMarble I don't think that really happened. Do you? – Matthew Christopher Bartsh May 01 '21 at 20:48
1

@MatthewChristopherBartsh are you as tired of having this discussion as I am? Didn't you ask a question about it? And write a whole bunch of comments about it on the other answer? For the record: it happened. I'm not responding to any more comments, chats, or questions on this matter. – Organic Marble May 01 '21 at 20:49
Update: https://www.universetoday.com/14967/space-station-astronauts-could-get-stranded-in-kibo/ has this comment by Vernon Balbert dated June 10, 2008 at 3:18 PM:
"Robert Heinlein already covered this in one of his stories. It seems that the individual who was stuck in the middle of a large space simply took off his shorts and threw them in one direction. Newton made sure he went in the opposite direction and eventually he got to where he wanted to be. (Never mind that just as he got to where he could grab onto something the space station manager’s wife came in and saw him in the buff.)"
– Matthew Christopher Bartsh May 01 '21 at 21:11

score -2 · Answer 3 · answered Jun 17 '21 at 15:35

-2

No you can't. There is no air in space. Basically you need some things to push backward to move forward. In water we push water backward to move forward. Space is void. Same case, for helicopter and aeroplane cannot fly in moon.(Don't get confuse: remember the first law of motion by sir Isaac Newton)

answered Jun 17 '21 at 15:35

Abhishek Nayak

1

Welcome to Stack Exchange! I didn't down vote and usually people leave comments why they do. I would guess that here it's because your answer doesn't seem to add anything new that's not covered by other answers already, and because the question has three parts and they are not all asking about a vacuum; the first one mentions being inside a crewed spacecraft where there is presumably an atmosphere and so something to push against. Just a suggestion: It might be better to delete your answer to avoid further down votes. – uhoh Jun 18 '21 at 05:51

Can you swim in space?

3 Answers3

Linked