ArmandoAlvarez wrote:

I don't think I will engage much further on this topic.  This feels like debating a flat earther or a new atheist saying, "But then doesn't God need a cause?"

That's fine. Thank you for providing the video of Neil de Grasse pointing out the very problems I said are real.

ArmandoAlvarez wrote:

Vacuums are not "powerful" or "intense".  The "power" of a vacuum comes from the pressure differential.

Correct, the intensity of a vacuum is actually the force of other things trying to fill or negate or pressurize that vacuum. But vacuums are real and have real, physical consequences - except, apparently, in and for post-Einstein physics, where they magically become nothing of consequence and things aren't moved to fill or pressurize them.

The low pressure air is still higher than the vacuum surrounding it; and if the vacuum is real, then that air will be evacuated into it. But this doesn't happen. Perhaps this is so because there just isn't a vacuum.

ArmandoAlvarez wrote:

Down here there is 14.7 psi of pressure. As Poe notes, in the upper atmosphere, there is barely any pressure.

Let's test this logic. If the air pressure is extremely high in a submarine, is that going to spare the submarine from the pressure of the deep as it goes deeper and deeper? At some point it wont matter anymore and the hull will just be crushed. The "air" in the upper atmosphere just has to eventually meet a real vacuum, and it will try to fill that vacuum, regardless of how meek the pressure differential is. Space is supposed to be an enormous vacuum. There is just no way the ever increasing feeble strength of earth's gravity could prevent the atmosphere from being sucked into that vacuum: and whether we like it or not, a real vacuum does have the effect of sucking things into it.

ArmandoAlvarez wrote:

So there's not much of a differential between space and the upper atompshere.
Imagine a human pyramid.  The folks at the bottom of the pyramid feel a lot of pressure.  The people in the middle of the pyramid feel less, and the person at the top feels none.
Imagine rational animals inhabiting the bottom of the Mariana Trench.  They need 15K psi to survive.  They send Terranauts to the land to explore it.  They must do so in landships that  can create 15K pressure inside the ship and are perfectly sealed against the atmosphere or they will explode and our Terranauts will die.  The air seems like a vacuum to these creatures because of the pressure differential.  Even a depth of 100 meters below the surface of the ocean will seem like a vacuum to them.  The question "Why doesn't the ocean get sucked into the atmosphere?" makes as much sense to them as the question "Why doesn't the atmosphere get sucked into space?" makes to you.  The 14.7 psi of air pressure doesn't seem like a lot to them because they think of ocean pressure as 15K psi

All of this is just effectively denying the vacuum of space even exists. The ever decreasing air pressure is no different. At some point you have a vacuum surrounding an area that is not contained or sealed. That vacuum will be filled if it is real; that, or there just is no actual vacuum.

Last edited by Timocrates (7/13/2016 11:46 pm)

Sorry for the disorganized answer but I hope it helps you.

For our case, it is safe to assume that vacuum is actually nothing and as we know nothing can do nothing ( nihil fit ex nihilo). Now why does it seem like that vacuum can suck out gas molecules?
Basically gas molecules are moving randomly in all direction. Now if you expose these molecules to vacuum, they will start to fill the vacuum (the vacuum is doing nothing). Why does that happens? because the gas molecules are moving in all direction, one of the direction leads to vacuum so they when move toward this direction, they start to fill the vacuum.
So as it can be seen actually vacuum is not doing anything. It does not have any power or so of its own.

just one small note, the air pressure in a container comes from the collision of the gas molecules with the wall of container and thus the higher the velocity of gas molecules the higher the pressure.

Now let us move to the case of earth atmosphere and let us look at it from a different perspective. The atmosphere of the earth is exposed to vacuum, but why then does it not start to fill the vacuum. Well, for the gas molecules to fill the vacuum, they have to have velocity. However, in order for gas molecules to go space, they have to gain gravitational potential energy by sacrificing their kinetic energy (velocity). Since the gas molecules do not have enough velocity they cannot leave the earth. (this is very similar to the fact whatever you throw toward the sky does not leave the earth and again comes back to you)

ArmandoAlvarez wrote:

You keep on saying "gravity cannot defeat a vacuum."  That's not true.  Take an ordinary home vacuum with a nozzle of one square inch in area. The air pressure inside the tube is 2 psi.  Apply the nozzle to the top of a  piece of cardboard that is 1'x1' and weighs less than an ounce.  Will the vacuum lift the cardboard?  Yes.  The net force on the piece of cardboard by air pressure is (14.7psi upward - 2 psi downward)x 1 square inch= 12.7 pounds upward.  This "defeats" the weight of the piece of cardboard and the cardboard goes upward.
Now attach the same vacuum cleaner to a block of metal that weighs 20 lbs.  The vacuum cleaner will not lift the block because the net force of air pressure is still 12.7 pounds upward (because it's the same vacuum cleaner so the calculation is the same).  So gravity will "defeat" that "vacuum."
Now you say, "But the vacuum cleaner is not a perfect vacuum".  Correct.  Neither is space.

The vacuum of space per Neil Tysson is much more powerful than anything we can reproduce on earth. That is a sufficiently powerful vacuum to negate the force of gravity on air molecules, especially as gravity weakens the further one gets from the earth.

I never said that a vacuum would suck out heavy, dense, solid objects. I only said that it would suck out air/atmosphere; indeed, I suspect that if the vacuum were real, it would probably also cause the oceans to be simultaneously sucked out into outer space as the air was evacuated. Remember, there is literally supposed to be just nothing to resist such movement in space. Consequently, your own argument and logic is actually working against you here: it's the exact nothingness of the void/vacuum that causes the physical problems: there is literally supposed to be nothing stopping molecules from filling or pressurizing the vacuum of space, which is radically more intense than any vacuum we can even artificially generate here on earth, even with all of our modern power over the material world.  

ArmandoAlvarez wrote:

There is a very small pressure from ambient particles anywhere in the universe.

Yes this is of course true per physical necessity, which is actually my point. There just is pressure in outer space and there obviously has to be.

ArmandoAlvarez wrote:

Let's make our vacuum cleaner as close to a perfect vacuum as the vacuum of space, but keep the nozzle the same size.  The pressure inside the tube is so close to zero that I will treat it as zero.  Apply the vacuum to the piece of cardboard.  The upward force on the cardboard is now (14.7psi-0)x1 square inch=14.7 pounds.  So the vacuum cleaner lifts the cardboard.
Now apply the vacuum cleaner to the block that weighs twenty pounds.  Does it lift the block?   No.

True but it is still exerting pressure on the block. I am not claiming that the vacuum of space would cause the earth itself to explode.

ArmandoAlvarez wrote:

The upward force on the block is 14.7 pounds.  The downward force is 20 pounds.  So "gravity defeats the vacuum."
Now try our second vacuum on Mars. The atmospheric pressure on the surface of Mars is 0.09 psi.  No matter how good of a vacuum you have, no matter how close you get to a perfect vacuum, a vacuum tube with a nozzle of one square inch will not lift any object that weighs more than .09 pounds on Mars.  "Gravity will defeat the vacuum" for any greater weight.
Let's return to the atmosphere.   The further up in the atmosphere you go, the lower the pressure is.  The reason the atmosphere doesn't get sucked into space is because the pressure differential decreases gradually enough that, for the most part, the difference in pressure between position X and position Y is not high enough to overcome the weight of the air molecules (for most air molecules).  Some molecules do, of course, escape into space, but the net movement between our atmosphere and space is approximately zero.
If you just mean "space isn't a perfect vacuum," that's true.  Nobody said it was.
EDIT:
This gets quite good after you read down a bit.  http://boards.straightdope.com/sdmb/showthread.php?t=328607
Also good http://earthscience.stackexchange.com/questions/736/does-earths-air-leak-into-space-over-time

Thank you for the links, I will also read these posts as your earlier ones.

Last edited by Timocrates (7/19/2016 5:43 pm)

iwpoe wrote:

The vaccume of space has no special suction power of its own apart from pressure. A perfect vaccum permits depressurization at exactly the pressure of the gas down to a minimal point determined by the gas and tempature (there is a pressure at which the internal effect of the particles in a cloud on one another is so trivial as to be insignificant).

If you have a spaceship pressurized at 14psi and a hole forms it will exit the ship starting at 14psi and declining as gas is lost down to a minimal pressure at which the gas particles don't push on one another at any significant way. Of you start with 100psi it leaves at 100psi. If you start with 1 psi it leaves at 1 psi. I think your entire problem comes from supposing that gas in the presence of space tries to spread *infinitely* coupled with some idea about the independent "power" of space's vacuum, which just isn't so.

Even in this case we are granting that things would be moved and forces/pressures would exist.

Again, in my mind, all we are doing here is negating the alleged near perfect vacuum of space. Indeed, I believe that given the demonstrable and measurable strength of the earth's gravity, I do not believe it is even plausible to conclude that the earth ever would have attracted or kept an atmosphere at all, because at some point you had to have a situation where the earth was like the moon is supposed to be (devoid of atmosphere), but then the pressure differential would have been absolute between any atmospheric molecules, which then would have been in direct contact with the void/vacuum of space. But we know gravity is not a strong enough force to resist such a vacuum. So how did we acquire an atmosphere in the first place?

Again, we have to entertain "spaceship earth" for this theory to work. At best, this necessitates creation and a Creator.

Last edited by Timocrates (7/19/2016 6:07 pm)

Timocrates wrote:

Even in this case we are granting that things would be moved and forces/pressures would exist.

Again, in my mind, all we are doing here is negating the alleged near perfect vacuum of space. Indeed, I believe that given the demonstrable and measurable strength of the earth's gravity, I do not believe it is even plausible to conclude that the earth ever would have attracted or kept an atmosphere at all, because at some point you had to have a situation where the earth was like the moon is supposed to be (devoid of atmosphere), but then the pressure differential would have been absolute between any atmospheric molecules, which then would have been in direct contact with the void/vacuum of space. But we know gravity is not a strong enough force to resist such a vacuum. So how did we acquire an atmosphere in the first place?

Again, we have to entertain "spaceship earth" for this theory to work. At best, this necessitates creation and a Creator.

Well this is an interesting part of natural history, but it is far different from the idea you previously articulated of gravity being unable to retain the atmosphere.

Vaccums don't work like you think they do and you are confused- probably because you model them on Dysons and not conceptually.