# How would a little bit of air react in a vacuum?

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• This topic has 72 replies, 1 voice, and was last updated 8 months ago by Anonymous.
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• #76348
Anonymous
Guest

If I have a container that has nothing in it like space hypothetically and I were to put just a little bit of air in it would the air sit at the bottom of the container due to gravity or fill the container?

• #76349
Anonymous
Guest

according the interuniversal quantum teichmuller theory the air would teleport to each other by sppoky acction at a distancě so yes they woulpd sit at the bottom container

• #76350
Anonymous
Guest

The air would fill the container.

Obviously.

• #76351
Anonymous
Guest

So gas is unaffected by gravity?

• #76360
Anonymous
Guest

is a baseball being hit out of the park unaffected by gravity?
air molecules move really fast

• #76362
Anonymous
Guest

No but if you put a baseball in an empty container it will sit at the bottom and it also will fall after you hit it and then stick to the ground.
But I have to make the baseball move, it doesn’t do that by itself. If the baseball moves by itself it implies that it’s not subject to gravity.

• #76365
Anonymous
Guest

imagine if the walls of the box did not absorb any energy from the baseball, similar to how if the walls were the same temperature as gas in the box.
Then it would just bounce around like an air molecule.

• #76367
Anonymous
Guest

I think we can take this metaphor a bit farther

• #76366
Anonymous
Guest

what if your walls are made out of constantly swinging baseball bats

• #76368
Anonymous
Guest

I would be hurt

• #76369
Anonymous
Guest

don’t be inside the box, there’s no air in there
also the air might be made out of baseballs

• #76363
Anonymous
Guest

If you put one molecule in a box, is it just gonna keep bouncing around forever, with an equal probability of being found at any point of the box regardless of how strong gravity is? Come on. Even soience fans should be able to grasp the difference between reality and statistical models in cases like this.

• #76364
Anonymous
Guest

yeah, because the speed it’s moving at is its temperature
that’s how much energy it picks up by contact with the warm walls

• #76370
Anonymous
Guest

>yeah

• #76371
Anonymous
Guest

lol scrotebrain

• #76373
Anonymous
Guest

you could maybe try to argue that it’s slightly less likely to be found at the top of the box due to gravity, but it really depends on how big your box is

• #76375
Anonymous
Guest

>you could maybe try to argue that it’s slightly less likely to be found at the top of the box due to gravity
Yes, I’m pretty sure you could.

>it really depends on how big your box is
It obviously also depends on how strong gravity is. Either way, the premise of the model where molecules bounce around uniformly, is that you have loads of molecures, and I think OP is asking about what happens when you have so few of them that the premise breaks down and pressure becomes undefined.

• #76376
Anonymous
Guest

yeah but I didn’t feel like getting into the weeds like that

• #76417
Anonymous
Guest

It is affected but to a minimal degree. The speeds at the top of the container will be lower than at the bottom.

• #76418
Anonymous
Guest

>Why does earth have an atmosphere
The real answer is a mix of both 1 and 2. Air particles everywhere but densest at the bottom.

• #76352
Anonymous
Guest

The container would be completely filled with air, just at a really low pressure.

https://en.wikipedia.org/wiki/Boyle%27s_law

• #76353
Anonymous
Guest

So gas is unaffected by gravity?

How does air on Earth stay here if it would fill a ‘space container’ regardless of the gravity pulling on it?

• #76355
Anonymous
Guest

The concentration/pressure is a bit higher at the bottom. That’s why air pressure decreases with altitute. But it’s neglegible unless your container is really large – or the amount of air is absolutely miniscule.

• #76356
Anonymous
Guest

This doesn’t make sense to me.
So gravity can pull my entire body down, but can’t keep some air at the bottom of the container?

• #76357
Anonymous
Guest

No, sir. You put one air molecule in — it falls down. Put two and they start to float and bump against the edges of the surface. It’s science. Trust the model.

• #76359
Anonymous
Guest

>You put one air molecule in — it falls down. Put two and they start to float and bump against the edges of the surface.
I don’t get it.
So if I have a little air it will go around the whole container, but if I have too little air it just acts different?

• #76361
Anonymous
Guest

the relevant term and number here is "scale height" go punch that into google

• #76358
Anonymous
Guest

it can if the amount and the temperature are sufficiently low.

• #76372
Anonymous
Guest

F=m*g

Your body has a lot more mass (m) than some air particles, so the force (F) to pull you down is higher.

Air particles repulse each other – that works against gravity.

• #76377
Anonymous
Guest

at room temperature gas molecules move at hundreds of meters per second. Gravity is only 9.81m/s2. A single molecule of gas would be able to make it quite high before falling back down.

• #76378
Anonymous
Guest

>at room temperature gas molecules move at hundreds of meters per second
Hmmmmm… if you pump more gas into a container, do the molecules move faster?

• #76379
Anonymous
Guest

I don’t think so, speed is related to temperature.

• #76380
Anonymous
Guest

Is temperature related to pressure? Is pressure related to the amount of gas in the container?

• #76381
Anonymous
Guest

no
yes
rapidly increasing the pressure causes an increase in temperature, but it’s complicated and simply adding more mols of gas is not going to cause an increase in temperature (unless the gas was hot I guess) (because that gas is going to be cooling as it expands out of the container you opened up into your box)

• #76383
Anonymous
Guest

https://en.wikipedia.org/wiki/Gas_laws

>for a given mass and constant volume of an ideal gas, the pressure exerted on the sides of its container is directly proportional to its absolute temperature.

• #76384
Anonymous
Guest

correct
I will now copy the text of an earlier post, you may recognize it
>Hmmmmm… if you pump more gas into a container, do the molecules move faster?
you may see that the question being posed here would increase the mass of the gas inside the container, thus rendering your quote nonapplicable to this situation

• #76385
Anonymous
Guest

If I shrink the volume, what happens to the temperature?

• #76386
Anonymous
Guest

it depends on how quickly you do it but only in degree, the temperature will increase
also I’m done doing your homework

• #76387
Anonymous
Guest

Does compressing a gas take some energy? Where does that energy go, anon?

• #76388
Anonymous
Guest

• #76389
Anonymous
Guest

I’m genuinely trying to help you here. Where does that energy go? What type of energy does it get converted into?

• #76390
Anonymous
Guest

you are confusing me for somebody else

• #76391
Anonymous
Guest

Where does the energy go, anon? You’re compressing gas. You’re pushing those molecules together. They’re colliding, they’re pushing back.

• #76392
Anonymous
Guest

quit being smug and tell me what you think I got wrong

• #76393
Anonymous
Guest

Where does the energy go? Maybe it gets converted into kinetic energy?

• #76394
Anonymous
Guest

yeah no shit, I said that earlier
compressing a gas will heat it up

• #76395
Anonymous
Guest

>yeah no shit
But you said that if I pump more molecures into a container, they don’t move any faster.

• #76397
Anonymous
Guest

yes, you are confused because pumps typically heat up gas as they compress it (thus you’re putting hot gas in), but the mere act of putting more gas into a container does not increase the temperature, these are unrelated
I could contrive a situation where putting more gas into a container would decrease the temperature of the gas

• #76398
Anonymous
Guest

Does the mere act of pumping more gas into a container increase kinetic energy?

• #76399
Anonymous
Guest

dunno, I’m no physicist
also I think it’s unrelated to OP’s original question
increasing the amount of gas in a container would increase the potential energy of the system
I’m going to bed now

• #76400
Anonymous
Guest

>dunno
But you said that compressing gas increases kinetic energy. Does pumping more gas into a container nor involve compressing gas?

• #76401
Anonymous
Guest

not necessarily, especially when most of this thread was talking about very good vacuums indeed

• #76402
Anonymous
Guest

>not necessarily
Where does the space for the extra gas come from, if not from making the gas inside the container denser?

• #76403
Anonymous
Guest

>not necessarily
Where does the space for the extra gas come from, if not from making the gas inside the container denser?

absolutely freaking not because gas only moves from high pressure to low pressure, so adding gas will always involve decompressing gas

• #76404
Anonymous
Guest

>gas only moves from high pressure to low pressure
But we’re expending energy to pump more of it into a container.

• #76382
Anonymous
Guest
• #76414
Anonymous
Guest

no
yes
rapidly increasing the pressure causes an increase in temperature, but it’s complicated and simply adding more mols of gas is not going to cause an increase in temperature (unless the gas was hot I guess) (because that gas is going to be cooling as it expands out of the container you opened up into your box)

Pressure is measured as an amount of force per unit area, and the actual source of this force is fluid particles constantly hitting anything suspended in that fluid, with each little particle impact causing the particle to bounce back but also causing whatever was hit to experience an equal and opposite impact. The force conferred to a unit of area embodies what pressure actually is: the total net force of a series of impacts conferred from the particles of a fluid to a unit area of whatever is suspended in that fluid.

Temperature is measured as its own macroscopic quantity but is basically the amount of energy associated with particle movements that aren’t in bulk motion, just with the energy adjusted as a proportion of the material’s heat capacity. It’s important to note here that temperature doesn’t exist at any single point since it’s due to the motion of multiple particles, so when we say that something has a particular temperature at a particular point, it’s an energy measurement of particles NEAR that point.

To put it another way, pressure is associated with how hard & often fluid particles hit things, and temperature is associated with how much total particle speed is contained near a point in a material. That’s to say, they’re both associated with kinetic energy.

Now,
>expand the container
You get the same amount of particles available to hit the sides of a larger container, ergo less impacts per unit area, so less pressure. You also get the same amount of particle kinetic energy contained in a larger space, ergo less particles are moving near any point you select, ergo less temperature.
You get more particles available to hit the sides of the container, ergo more impacts per unit area, ergo more pressure. You also get the kinetic energy associated with those fluid particles added to the energy associated with the particles in the container, ergo more particles moving near any point you select, ergo more temperature.

• #76415
Anonymous
Guest

sorry, i’m just not convinced

• #76354
Anonymous
Guest

A small amount would all fall to the bottom.
There would be a certain minimum amount of air to fill it completely.
It all depends on the energy of the particles and the strength of the gravity though.

• #76374
Anonymous
Guest

first result for speed of air molecules
https://pages.mtu.edu/~suits/SpeedofSound.html
they’re moving at about a thousand miles an hour just from temperature

• #76396
Anonymous
Guest

Air will usually fill the container because of electromagnetic repulsive forces between the particles combined with the kinetic energy of the particles already setting them in motion at very high speeds. That’s to say, the particles ARE affected by gravity, but they’re already moving so quickly that gravitational acceleration is negligible in most cases.

Theoretically, air near absolute zero temperature would allow for air particles to move upward so lazily that they fall back down, but if you have this near-absolute-zero air to put into the box, it’s probably going to be a chunk of solid air. What this will do is sublimate until the vapor pressure of the container is conformant to the temperature of the solid air, after which point you’ll have a chunk of solid air inside a container full of gaseous air.

• #76405
Anonymous
Guest

This is one of the funniest threads on the board. Why do these people think keeps the planet’s atmosphere from drifting into space?

• #76406
Anonymous
Guest

It’s already been lampshaded multiple times: the air is just moving really quickly, so within the scope of the box, gravitational acceleration is negligible. The implication here is that the box isn’t so huge that the air would be able to reach its maximum height before it falls back down.

• #76407
Anonymous
Guest

>the air is just moving really quickly, so within the scope of the box, gravitational acceleration is negligible.
I don’t see that specified anywhere.

• #76408
Anonymous
Guest

You can see it specified from the relative scale of the box and air molecules in the picture.

• #76411
• #76412
Anonymous
Guest

>0.99… != 1 schizo

• #76409
Anonymous
Guest

>I don’t see that specified anywhere.
>literal brainlet can’t make appropriate hypothesis woke af on the situation

• #76410
• #76413
Anonymous
Guest

My intuition is that the gas still fills it uniformly, if that gravitational force is uniform. Because of collisions.

• #76416
Anonymous
Guest

No because it has a temperature and therefore kinetic energy therefore its moving at high speed.
You may ask why doesnt solid matter do?
Because the atoms are bounded to each other. Chained. They rattle but cant move too much.

• #76419
Anonymous
Guest

How

• #76420
Anonymous
Guest

i want to think of gases(well all phases really) as a field…

i dont know much about fields but it seems it makes more sense to me.

the "small balls" theory of science seems like something a simpleton would come up with…

i know it has predictive power and i know it is useful in a wide array of cases but it doesnt feel very complete.

it’s not beautiful either. and simple.

feels much more likely that everything is simply different configurations of the ether. field pertubations.

isnt this what all the europeans came to too before the gnomishization of academia, einstein and his ilk?

doesnt the gas theory of colliding balls not losing energy(now suddenly they are not balls anymore but elastic balls LOL) suddenly now need you to believe in perpeetum mobile(which i do but no hate please. Because i know I LOVE SCIENCE types and stuffy academics without imagination love to seethe about it).