# Can a human body change direction when floating in a space without gravity?

Suppose I am in the center of a hypothetical 4mx4m room and there is no gravity. I am wearing a spacesuit with no means of propulsion (e.g. venting, ejecting, etc..).

Would I be able to reach "the door", i.e. start movement in a certain direction, by body movements of some kind, or would I float in the center of the room forever?

• Possible duplicate: Can you swim in space? Dec 13, 2016 at 12:29
• Dec 13, 2016 at 12:31
• – user
Dec 13, 2016 at 12:43
• @YazaFatutu it's a really interesting question, but it's so interesting that several people have asked many variants already. In stackexchange sites duplicates or near-duplicates of existing questions are usually marked as duplicates, if it happens here don't let it bother you. If you can look at all of those questions and answers mentioned in the comments above and find something meaningfully unique or new in your question, then edit your question accordingly. In the mean time keep thinking of new questions!
– uhoh
Dec 13, 2016 at 13:08
• Not only on this site. Your entire question with answers is here
– user10509
Dec 13, 2016 at 14:58

## 3 Answers

You haven't specified if you're in vacuum or not (though the spacesuit is suggestive).

If you're in vacuum, you're stuck, unless you started with some motion relative to the room, or something accelerates the room itself.

If you're in a fluid medium, even air, you can "swim", pushing the medium around you preferentially in one direction to accelerate yourself in the opposite direction. This would be slow going in air -- each stroke produces very little momentum -- but you could escape.

• That's a good point - the space suit is a not-so-subtle clue. However there are alternative explanations for the suit - my hypothetical ammonia leak or a prank.
– uhoh
Dec 14, 2016 at 16:01

You haven't mentioned your initial velocity in respect to the door. It is probably not perfectly zero, so after some time you will be able to touch a wall, floor or ceilling. Then you can push yourself towards the door.

I would say, the chances your initial velocity is really 0 is almost non existing.

You cannot change the location of your center of mass without some form of propulsion. You can, however change your attitude by wiggling around like a falling cat.

• So is your answer "No"? Don't you want to find out if the room has an atmosphere first? Or do you think "swimming" is excluded by the "no means of propulsion? I can't really decide what it means.
– uhoh
Dec 13, 2016 at 21:31
• I would argue that "swimming" is some form of propulsion. Even if you admit the possibility, it would be remarkably ineffective, especially in a spacesuit that restricts mobility. Dec 14, 2016 at 16:01
• Ya I think you are right about that. btw I really like that video clip! Here's an alternate video involving a rotating cat and a rocket scientist.
– uhoh
Dec 14, 2016 at 16:13