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Psh! Do not count on earth's gravity to bring it back for you, that is weak! Be a man! Go out to the middle of space where your OWN gravity will RULE and throw that damn ball! It will come back to YOU! Not earth! >=D

Won't work. A person isn't massive enough to have his gravitational pull retrieve thrown objects.

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I don't think this needs to be complicated as people are trying to make it. I promise you nobody reading this can throw it hard enough straight up for the rotation of the earth to come into play.

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How bout you just throw it straight in the air as hard as you can? Wouldn't it just fall back to you barring it hitting a plane, bird or the tornado you didn't notice when you threw it?

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I know! I'll say what everyone else has said along with the solution!!!!! That will make me sound smart!

Come on guys! seriously

no need to post something someone else has already said 300 more times!

it's starting to get ridiculous!


My solution (which may or may not have been said, I apologize if it has)

would be to throw it inside of an air tunnel so that it comes back to you.

I also like the magnet idea.

Especially if you're wearing metal underwear.

That would make the magnet a hole lot more fun!

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This is not as elegant a solution, but...

If you were on a planet with just the right mass and diameter, you're hardest throw in the right direction would allow the ball to orbit the planet once (or twice, etc. depending on the constants just mentioned).

here's why that's a problem. the earth's diameter is about 7900 miles. when the ball is thrown it will not only be traveling around the world but also falling. what that means is that the ball has to travel 7900 miles before it falls 6 feet. with some physics (or a stop watch) we find that an object falls to the earth from 6 feet in about 0.61 seconds. convert 7900 miles per 0.61 seconds to mph and you get 46,622,951 mph!! earth's escape velocity is 25000 mph. so once you threw the ball at 47,000,000 mph it would just keep going out into space instead of curving around the earth.



Anything travelling that speed through our upper atmosphere (mesosphere) will instantly incinerate due to friction. Anything travelling that speed near the surface, where the density of the air is tremendous (compared to outer space), will never reach that speed. But IF it did it would explode like a bolide (<!-- m --><a href="http://en.wikipedia.org/wiki/Meteor#Bolide" target="_blank">http://en.wikipedia.org/wiki/Meteor#Bolide</a><!-- m -->), IF it didn't incinerate first, because infinite acceleration (which is necessary to bypass these effects) doesn't exist, but IF it did, the Earth would probably be destroyed in the process since F = ma (Newton's Second Law) would generate infinite force which would tear a chunk out of the particular hemisphere of the earth where the infinite acceleration experiment is being conducted. This is a conservative guess. Well, this chunk would seperate and decrease the overall mass of the Earth by perhaps 30% and the resulting pieces would spiral in towards the Sun over the course of several decades. So, our oceans would evaporate, then we would evaporate, then the earth would melt as its being sucked in to provide more fuel for the unrelenting sun. We'll ONLY live to see this if we don't all get ejected from the surface of the planet and flung out into space due to the unavoidable whiplash/shockwave of the earth-shattering explosion. Or, all of the molten rock in the core would spill out (of this huge hole the size of the Pacific) and cover what's left of the earth. Either way, we're toast.

So, kids, don't try this at home.

Of course, the obvious solution is to throw it straight up..

My best solution is to take it very literally and say that you travel to the intergalactic void discovered recently in the headlines, and only there will the ball not hit anything. "Outer space" isn't good enough... solar winds and dust particles litter our solar system (<!-- m --><a href="http://en.wikipedia.org/wiki/Interplanetary_dust_cloud" target="_blank">http://en.wikipedia.org/wiki/Interplanetary_dust_cloud</a><!-- m -->), especially along the ecliptic plane, and very much so within a few thousand miles of earth (tons of rocket debris). Interstellar space could suffice, if it weren't for the average value of a million particles per cubic meter. Intergalactic space (at least 1 million light years aways, to be sure) will do just fine for this experiment. Since there is only about 10 to 100 hydrogen atoms per cubic meter, so the statistical probability of actually hitting one of these atoms can be greatly reduced by throwing a very tiny ball... but the ball must be very massive in order for its gravity to interact with the spaceship's which you used to travel the million light years. Since it took so long to get out there, you can wait the few extra years for the weak gravitational interaction to pull it back towards you after you threw it as hard as you could, which was very hard, since it weighs a ton or so. But, now its more than several cubic meters in diameter, so we know for sure that it's going to hit at least a few of those hydrogen atoms. So we must ask, 1)How few atoms constitute a negligible collision? 2)If one atom is too many, then will the trade off of travelling to the intergalactic void, allow us to have a large enough ball, which will then hit "nothing" yet be sufficiently large enough to get pulled back in by our spaceship all while resisting our strongest throw and not flying completely free of our ship's weak grasp? Oh yeah, the void is about 10 billion light years away. Much further.

It's too much!!! Ahh!!

yeah, let me know what you think!!


Well, to start with, kudos to you. I extremely like the fact that you took your time to explain everything. I must say, I didn't read the last 8 pages of "throw it up" and "you're overcomplicating it". So, if someone else already pointed this out, sorry. But, his (the person you quoted) said if you were on a planet with the......blah, blah, blah. That means, without a doubt, you're not on Earth anymore. Assuming you MUST stay on Earth, then yes, you're right. But, that's not one of the requirements/restrictions. But, still. Everything other than that detail is great. Except that the molten iron would come seeping out. That wouldn't necissarily happen. Maybe as volcanoes, but the pressure would be relieved from the molten iron when all of the land on top of it (in one area0 was ripped away, wouldn't it? At least enough that it wouldn't need to seep out since it is more dense than the land on top of it. Think of it as a centrifuge. Even if you only have a little bit of molten iron, it will still go to the bottom of te centrifuge because it is more dense than the dirt, rock, minerals, and other things on top of it. Right? But, like i said, good post. Please, pardon any mispellings or grammatical errors in this. it's around 4 A.M.

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well, just throw the ball vertically upward as hard as you can and i assume you can't throw it as hard that it escape the gravitational force, so naturally the ball will come down by itself to you .

neat, isnt it

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