Thursday, April 17, 2008

Bullets and baseballs

So, I read yesterday that some astronaut on the space station was gonna throw out the first pitch from space for the Yankees-Bosox game. How does that work, exactly? Is he really gonna throw it from space into Yankee stadium? It seems unlikely. I missed the beginning of the game because of soccer practice (which got snowed out, another strange story, but I digress), so I never got to see the pitch thrown. I assume he lobbed a throw inside the space station, it got shown on the jumbo-tron at Yankee stadium, the umpire said "plsy ball," life goes on. But I don't know. All the press releases and coverage of the game just said he threw out the first pitch from space. No more explanation. You'd think somebody in the newsroom would have enough intellectual curiosity to find out exactly what that means. And then tell us.

But no.



Again, I digress.

My main point is, I don't think you can throw a baseball from the space station to Earth. If I remember my high school physics, all actions produce equal and opposite reactions. So, if you tried to throw a baseball from space, the ball would go toward Earth a little, the space station would go away from Earth a little, they'd both end up in orbit. Because the baseball is already falling. That what orbits are: objects in freefall around other, larger objects. Caught in the sweet spot where centrifugal force balances out gravity. That's what Newton really figured out when that apple fell on his head. Not that gravity caused the apple to fall. But that the falling apple and the orbiting moon are both exhibiting the exact same behavior. Both are in freefall.

But something tells me my logic regarding the baseball is wrong. Because if you fired a gun toward Earth, surely the bullet would hit. It wouldn't go in a straight line, it'd travel in a spiral, but ultimately it would hit. The bullet would have enough energy to cancel out the centrifugal force. I think.



So maybe the deciding factor is how hard you throw the baseball. I don't know.

Anybody out there know? Anybody out there care? Anybody out there spend inordinate amounts of time thinking about useless minutia like this?

Probably.




Since I don't have an end to that thought (it's basically just an extended question), I'll post a wonderful picture I stole from Primordial Slack. She stole it from someone else. So I can't give credit. But it sure is cool.

6 comments:

Eric Shonkwiler said...

There's nothing to stop the baseball from falling. What little relative momentum is generated by the throw is not canceled by the roughly perpendicular movement of orbit. Even the space station would continue moving, wouldn't it? Just at a rate that we can consider nil.

This is all high school physics, though. I could be very, very wrong.

Also, I had that same Godzilla as a child. I love how half of them seem to be cackling with glee at the coming raid on Tokyo.

Dianne said...

love the image of the bullet.

I didn't even hear about the first pitch being thrown from space and I was watching the game! Oh well!

Victoria Gothic said...

Well I'm in high school physics and the answer is: yes, the ball would, theoretically, hit earth. Gravity though small, exists in space, and this is why satellites and the International Space Station for that matter just readjust their decaying orbits, else they would tumble back to earth, thus, without a doubt the baseball would head to earth almost regardless of how minor the force applied to it was, but here is the catch.

It would completely disintegrate in the atmosphere during reentry. Did anyone else see Apollo 13? That space capsule survived only because of the immense shielding; the same concept has been applied to the space shuttle, and unless the baseball was shielded, it would not reach earth at all.

Unless a shield was designed to protect the baseball with a duration equal to the amount of time it would take for the baseball to pass into the lower atmosphere and be of a much lower velocity, thus allowing the baseball to be protected during reentry but not be surrounded by a large steel shell when it lands at the baseball field.

But then there is the issue of aiming it. The Apollo capsules were landed in the ocean because such falling objects have a very wide area of landing possibilities. The only reason space shuttles can land at predetermined sites is because they have the ability to guide their landing with glider like qualities once in the lower atmosphere.

Therefore I have come to the conclusion that your assessment is correct. “I assume he lobbed a throw inside the space station(without it leaving the oxygen interior of the station), it got shown on the jumbo-tron at Yankee stadium, the umpire said ‘play ball,’ life goes on.”

That was strange. I’ve never been any good at physics. Besides, my physics teacher is more interested in environmental science; we’ve had an ongoing discussion of the Geia theory, or living earth theory, which proposes that the earth is in fact a living organism, and in the same way a single cell as parts within it that allow it to function, plants and animals (including humans) are a part of the living organism, Geia.

Well, I’ll be off to look at the “Daisy Experiments,” possible proof of the Geia theory.

Clowncar said...

Eric, centrifugal force keeps it from falling. Throwing it toward Earth would do nothing; it's still in orbit at the same speed. So it'll stay in orbit. And that same Godzilla is on our TV set at this very second. He's so dreamy!

Thanks for stopping by, D. The bullet is indeed very cool. And the game was quite a bit more exciting than the first pitch, I'm guessing.

Vicky G, I love the Geia theory. Not sure I believe it, but like many things, it's fun to think about. And you're right about the baseball burning up in orbit. But the baseball wouldn't leave its orbit unless it slows down, and throwing it toward Earth wouldn't slow it. It'd eventually slow due to friction with the air (which is what decays the orbits of satelites), but that'd take a long time. I'm sticking to my guns: even with a heat shield, you can't throw a baseball to earth from space.

Nancy Dancehall said...

Dude. Pedro could do it.

Eric Shonkwiler said...

So, rather than aim themselves towards the Earth and fire up rockets, shuttles and etc. slow down to kill the centrifugal force?