I was reading a different thread the other night and i had the idea for this post.
What if you could have a swimming pool in space, what effect would space have on a human body swimming under water? Is it possible to be weightless within a weightless environment, IE under water in space?

not weird at all.. you brought up the question.. am also waiting for the answer.. thanks..

Interesting idea, belial.

Well, you really can't have a "pool" in space, since there's no way for the water to "pool". You'd just have a mass of water floating about in a room in various sized spheres and undulating masses. You'd float about with the water, and would find oneself alternately in the water, and out of it depending on where you went.

All of it would be weightless. Personally, if there was a substantial amount of water in the chamber, you might be in a dangerous situation. You could find yourself inside a substantial mass of water (submerged, as-it-were), and with no up or down, wouldn't know where to go to find some air. You have to thrash about at random to get into an air pocket. Of course, propelling oneself into an air pocket wouldn result in a continuation of your movement, unless you happened to find yourself next to a bulkhead or a hand rail where you could stop your motion.

But even then, your movement in the water would result in all sorts of random motion of the water as well, and you could find your air area suddenly a water area again, necessitating your thrashing about to find another air pocket amidst the moving water. The water itself would provide some resistance to your intent to go in a certain direction, and you'd have to swim in some direction with some force.


I think such an experiment would quickly convert itself from being fun for a minute, to annoying in the next, to exhausting in the next, and posossibly to very dangerous in short order!

One could drown in a zero g "pool" and not know where to go to find air, since there's no up!

ok... that was freakishly scary.. although I had this crazy idea while reading your post. when in a sphere of water so to speak. wouldn't you move into / beside a wall and push with your legs to get out of the sphere.

Drat!

I guess I had best scratch this off my things to do before I die list

Sure.
Provided you knew where the wall was, you could swim over to it and push off. However, In a weightless environment, with spheres of water that could be huge...you need to know where the air is. It is probably all over the place, in spaces of various sizes. You've got to get to one, and be able to stay in one. Once you're moving, you're gonna continue to move until another wall stops you, and, you're going to drag water with you, which could congeal into another undulating mass right on your head...it's complicated motion, to be sure.

This is really an interesting concept to explore.

In thinking about a "zero g swimming pool", I'm trying to visualize a chamber where you could have a whole lot of water inside. You'd never have a "pool", so to speak, just a bunch of various sized globules of water floating about, some connecting to make large masses, others separating into smaller spheres and banging off walls...a pretty wild dynamic, which would get more wild when some folks floated into it and started jostling it around.


Personally, I visualize an area where no more than 25% of the volume was water. That way, one has a much better chance of getting into, and remaining in air.

All-in-all, however, I see a dangerous environment.

Might be a good idea!

However, it might be the thing to do IF you wanna die!

I Would also like to experiment on it, although I don't have hands on a zero g environment. an interesting topic.

Weird question 2:

Could a balloon filled with helium float up and away from the moons surface, like it does here on earth?

Probably,


But belial, you do have alot of questions about space, anything to relate it to?
I want to make a rocket and be the REAL first person to get on the moon...
Alive? Well see...

I think not.. I think it will just drop? Helium is lighter than oxygen ( ok everybody knows that ) although. There is no present oxygen in the moon. so you would rather get a result where the balloon might not "float" at all.

I do believe you are correct, the wieght of the balloon it's self would make it fall. However I do believe the balloon would explode as soon as it was exposed to the moons enviroment or lack of.

okay to the pool in space thing...put on a respirator. then a big space filled with water wouldn't be that scary. it would be weightlessness

opps.. sorry.. regardless of course the harsh environment of space. hmm.. Belial has many interesting questions that I too would like to hear.

Yea, you guys are right.

The helium balloon rises on Earth because of the low weight of the gas in relation to the air. Up it goes.

On the Moon, in a vacuum, there's no air, just the mass of the balloon (and the tiny mass of the gas in it) so, it would drop to the ground.

But...Silver's right,...it's a futile experiment, as the balloon would expand rapidly and pop encountering no pressure outside of it.

You have the solution. Strap on an air tank, and you're free to have some fun in the micro-gravity pool!

In response to the original question and MIDs reply, imagine you are in a pocket of water, bigger than you are, at a stand still. In other words neither mass is moving, you nor the water. Someone would have to move you in to place and stablize you with no force to move/push you in any direction, ie just floating there. In that situation, wouldnt you have to "push" the water away? In zero gravity I would think that the force of one pushing the water would be greater than the resistance of the water, so you wouldnt move much but youd be flinging the water everywhere.

An interesting idea, Classic.

I am often heartened at the level of thinking that people exhibit here in certain places.

As I said, this is an interesting topic. Let me see if I understand this position:

Since were talking about microgravity, I visualize a large sphere of water with a fellow inside it. Both are of course essentiually zero g. You're talking about someone having to move you in the water, since you're just floating there, right (you, and the water)?

Let's think about the same scenario on Earth. You're floating in the water. Both of you are under the force of gravity (and of course the neutral buoyancy of you being in the water tends to remove alot of your mass property...and you float, essentially).

How do you move?
You swim...using coordinated movements of your arms and legs, you create a thrust, as-it-were, which propels you through the mass of water. A matter of fluid dynamics. You can move in a given direction, like a fish can, by propelling yourself through the mass of the water.

The same thing would happen were you to be suspended in a sphere of water in zero g. You could propel yourself through that water in a given direction just the same as you would on Earth...you don't need anyone to move you. However, you're right about the flinging of water everywhere.

You could execute a breast stroke, say, and start moving in a given direction. The water, however, being not all too stabilized by a gravity vector (it's surface tension being the thing holding it together in the utterly logical ball shape) would respond unrestricted by that to your movements within it.

The net result would probably be a certain directional movement on your part, and a bunch of movement reactions in the water. From an outside observer's perspective, you'd probably see the sphere of water with you in in begin to undulate in various directions, some of which might indeed impede your directional movement to a degree, and that mass of water would probably look pretty funny, parts of it breaking off and forming individual undulating spheres of water.


All in all, I'd say you'd move in your intended direction, but the water would move in reaction to your impulses, and some of it might stick with you.


The more I think about this, the more I'd love to see some experiments done on the idea!!

Could probably be pulled off with a big enough area and enough water. Hook somebody up with emergency bungee line or something and it could be done.

So if you were in a giant spherical pool of water in zero-g, would you kinda "drift" to the outskirts of the pool due to you being less dense than the water itself? Or drift to the center.... Its quite a concept.

You would move in whatever direction that you propelled yourself. A small impulse would produce motion. If you were perfectly still, and there was no movement of the water mass...you'd just float where you were.

If we was to float in space with rocket packs pointing away from our bodies in all possible directions, and they all started at the same time which way would you go? (Without getting burned...small error. lol)

...


Assuming "all possible directions"...you'd go no place, as the thrust from all the jets would net zero impulse in any specific direction. You have to have a "vector" in some direction that's dominant in order to actual translate anywhere. All directions at the same time (and assuming the same thrust) is a net zero (and a waste of fuel!!!).

Thanks.
What if we did have the power and knowledge to have a succesfully working 'anti gravity' system, how would it work in a space environment? (if this is to startrek - i understand, lol)

Would a cheese sandwich decay in space?

Good thread belial.

I gotta question; Can you actually hear sound in deep space.

NASA: Sounds in Space

Saw the re-run of the movie Alien the other night ''In space no one can hear you scream'' lol!

Well, it probably is too Star-Trek, but the idea does prompt a curiosity!
An "anti-gravity" system is only necessary where you need to defeat gravity.
Generally speaking, in the space environment, you don't have to do that...!

...we actually do have anti-gravity systems. They may not be "Star-Trek", but they do result in airplanes flying and spacecraft getting into space...!






...out in the vacuum? Probably not!

REBEL:

Good question!

It needs some qualification, however.
If you were in deep space, or any old space for that matter, you can only hear what the atmosphere around you can transmit. Inside a spacecraft, you can hear sounds internally generated, or even some sounds caused by external things like engines firing, since their vibrations are transmitted through the spacecraft structure and then through the spacecraft atmosphere. In a spacesuit, "outside", as-it-were, you could hear the sounds made in your suit...you could hear yourself tapping on your helmet...things like that, because there's an atmosphere inside your suit.

But, if you're out there in the vacuum, without a suit...and you could stay alive for a minute...you'd hear no sound, since there's no transmission media.

In these sound recordings you're hearing, you're actually hearing a conversion of energy picked up by sensing instruments into a sound wave generated by other instruments which produce a wave that you can hear through the air you're in.


It's kinda like types of astronomy using instruments that pick up light that the human eye can't see. For instance, infra-red, ultra-violet, or radio astronomy. We can't see any of this radiation, yet, our instrumentation can convert them into visible images that we can look at, and see things that our eyes cannot see no matter how hard we might try.

In like manner, these "sounds" in this recording are converted electron impacts on sensing instruments. They're converted to sound waves so we can get an impression of their character and frequency. You couldn't hear them with your ears out in deep space, but you can hear them once they're converted to a wave that can be put out of a speaker in an atmosphere.

I hope that was a little clearer than mud!

Those are produced by energy and magnetic waves.

Thanx for the clarifications MID. I follow ya, err in most parts anyway. lol!
So your basically saying in order to hear sound say for eg, someone shouting at you from a distance you have to have atmosphere? But as you said not that we'll never survive without a space suit anyway...


Yea Alex, i realized the NASA site was energy, magnetic & sonar/radar waves sounds etc, was actually looking for answers to my original question when i came across it, i thought it was a cool site to post anyway lol!


BTW MID, if true about that sandwich in space theory, you realize it would be an awesome place to 'preserve' things?

Would that mean that metal would never rust in space? <-- great place to keep your 66 Mustang in mint condition eh!




later.

Ask yourself this question.

Would the water stay liquid

You're welcome, REBEL!

That's it, in a nutshell.
Sound is a wave that can only transmit through a medium. For us humans and our ears, that medium is air (although water can transmit certain audibles as well).




Yea, I think if you could get that 66 Mustang into orbit, and stick it there someplace, you wouldn't be getting any rust. Rust is the product of oxidation on metal surfaces. You need air and water content for that. In the vacuum, no way to rust!

However, with continual exposure to solar light and heat, and then cycles of cooling on back-side passes, I think the upholstery (those leather seats and stuff like that) would probably deteriorate over time. Of course, you could send it up in a garage...into a fairly high orbit that wasn't going to decay for while...but that's a hell of a bill to pay for storing your vinatge Mustang!

Probably best just to keep the paint job clean, keep her waxed, undercoated, and garaged right here on Earth!