Upbeat music plays
Alright everyone, welcome back to Cody'sLab.
So I just watched some awesome video of the astronauts on the space station
passing a football. And apparently the pass was something like 500,000 yards;
that's because the space station is of course moving very quickly around the earth.
But it got me thinking; What would happen if the astronauts would have actually done it in the vacuum of space?
Now this is something of course that NASA would never try, but
I've got my 40 liter budget space vessel here
I could give it a shot.
So I got the ball inflated to the recommended 9 pounds per square inch.
Now that, of course, is relative to the outside air pressure.
The absolute pressure, because the air around it is about 12 PSI,
therefore, is about 21 PSI.
You see you've got 12 pounds pushing in, and 21 pushing out
But if we remove that 12 that is pushing in,
what happens to the ball? Let's turn on the vacuum pump, and find out.
You can see the balloon back there is inflating, that's because the pressure forcing in on the balloon is dropping,
and so now the gas that was trapped in there is allowed to expand.
Now the balloon can of course increase its volume because it's so stretchy.
The, uh, ball however cannot.
So it'll be interesting to see what happens when it finally can't hold any more pressure.
So it's been roughly 5 minutes worth of pumping and the ball is still intact.
You can see the balloon has expanded quite a lot
but, uh, the ball has not ruptured.
It looks like the seams might be a little bit stressed
but so far it's been able to handle the pressure.
Let's turn the pump off.
And let's see what happens when Iet the pressure back in.
The balloon definitely shrank.
But the ball...yeah the ball definitely shrank a little bit.
I'm not...It's not like super noticeable or anything, though.
So this ball probably can actually survive the vacuum of space.
But now, let's, uh, take this, and let's add a little more pressure to it.
Let's, uh, pump it up to around 20 psi
'cause we've shown that it can handle that, and let's put it in here, and vacuum out the air again.
So the ball has been inflated to 20 psi relative to atmospheric pressure
which is what it was, back when it was inside the chamber.
Now, it's a lot stiffer. You know, I'd hate to play with it in this state,
but it is still holding together.
But let's see what happens when we remove the 12 psi that's holding it together.
Now, see if it can handle 30.
Let's—heh, it makes a different noise when you hit it on things.
We're back under vacuum and the ball is yet to explode.
That's actually relatively impressive, because the pressure differential now is about the same as you'd have inside of a car tire.
So,
this ball's a little tougher than I thought it would be.
'Couse, I guess it does have to be rather tough to handle being played with on a field.
And, uh, one thing I'd like to note is that the balloon over there,
that will never pop, even if I put it in a perfect vacuum.
You see, the little tiny bit of gas that was there has now expanded so much,
you know, the ideal gas law,
that the amount of pressure that the gas is forcing on the sides of the balloon
is now so little
that it can no longer stretch the rubber.
So even if the pressure is zero on the outside of the balloon, it still is not going to expand any more.
But, uh, yeah.
Let's try pressurize this ball a little bit more, and let's try it again.
So I've now inflated the football to 35 pounds per square inch, and it is rock hard.
Like, I can't imagine why anyone would it inflate one this much.
In fact, I don't really like being around it, 'cause it just feels like it might explode.
Perhaps someone might accidentally inflate one this much, if they were thinking they were inflating a car tire, or something.
Or perhaps, trying to make the opposing team have more difficulty.
But... I'm going to say this is probably one of the worst-case scenarios, uh, pressure-wise, and let's, uh, try it out.
Let's see if it can handle the vacuum now.
That kind of makes me nervous.
he he
It's definitely deforming the ball enough to make it roll around.
I wonder if I should, like, try to push it back before it gets under total vacuum.
Oh, it blew up!
ha ha ha!
It actually, it actually blew up.
Let's turn that off.
Whew! Ha ha ha
So over-inflating your ball and then throwing it into space is a bad idea.
And look at this: so you've got the rubber inner bladder,
and then this fabric covering.
My guess is that the fabric covering was doing most of the, you know, support, holding the ball together.
There you go.
So what must have happened is that the stitching was giving way; that's what made it kind of roll around in there.
And then, the stitching just finally unzipped and the whole thing exploded.
The ball wasn't actually in a total vacuum when it exploded.
If you look at the balloon, the balloon was still only kind of rather small.
That sort of tells me that the pressure in there was about one-third of what it is at normal atmospheric pressure.
So that means this ball exploded at just over 40 psi.
Kind of gives you an idea of what kind of pressure you could put into the ball and have it explode.
You know, this was actually a very dangerous experiment, because if this would have went off out here in the atmosphere,
it probably would have hurt me.
Or certainly would have hurt my ears, made a loud noise.
Inside the chamber, the gas that was in here was able to expand and occupy the space that was, uh, vacuumed,
and it never reached a point where the pressure was high enough to burst to the outside.
So I'm going to put the video of this exploding at fifteen-hundred frames per second towards the end of this video.
I hope you enjoy; I'll see you next time.