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DTMark

Space Travel Question

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Can't work this one out for myself, so I need the collective genius.

If a space ship is travelling at high speed - far too high for it to detect a piece of solid debris the size of, say, a coke can in front of it, far less avoid it..

And that space ship is heavily reinforced, but even so:

Does the piece of debris cut through it and smash it to pieces like a knife through butter, or

Does the ship simply bat it away like a train hitting a fly?

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I shall say (like a contestant in 'Who Wants to be a Millionaire' after given the answer by the audience) that I thought the latter would be the correct answer, though wondered about the differences in the speeds and the resulting terminal velocity (say the ship is going at 50,000kph and the object is coming towards it) and if that made any difference.

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If you hit the can while doing 20 in your car, or doing 120, isn't it the same end result? Albeit at a different speed. What brought this question on? :)

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The former.

A fly hitting you at the speed of light? Well you don't wipe that away with a wet wipe.

Having said that, space is so big and a fly is so small. You will never hit it anyway.

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If you hit the can while doing 20 in your car, or doing 120, isn't it the same end result? Albeit at a different speed. What brought this question on? :)

The can is practically weightless if empty. "A big stone" might have been a better example. A rock the same size as a coke can.

Then I got confused with weight and mass and the effects in zero gravity.

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Can't work this one out for myself, so I need the collective genius.If a space ship is travelling at high speed - far too high for it to detect a piece of solid debris the size of, say, a coke can in front of it, far less avoid it..And that space ship is heavily reinforced, but even so:Does the piece of debris cut through it and smash it to pieces like a knife through butter, orDoes the ship simply bat it away like a train hitting a fly?

Neither

The impact will hurt both

http://en.m.wikipedia.org/wiki/Micrometeoroid#Effect_on_spacecraft_operations

http://en.m.wikipedia.org/wiki/Whipple_shield

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If you hit the can while doing 20 in your car, or doing 120, isn't it the same end result? Albeit at a different speed. What brought this question on? :)

It's not the same. Hitting a can doing 20 towards you, while you are travelling at 120 = standing still and having a can thrown at you at 140!

If you're in a train and you pick up a brick off the table, it's doing 125 mile an hour, but you don't get your arm ripped off and a window smashed.

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Impacts by small objects with extremely high velocity (10 kilometers per second) are a current area of research in terminal ballistics. (.. The risk is especially high for objects in space for long periods of time, such as satellites.

The idea of a small piece of random debris destroying the satellite that Sky use to broadcast from is coming close to to arousing me.

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Both enties will be damaged but in terms of the space craft it could result in anything from loss of atmosphere to its total destruction.

Hence why, in Star Trek, the navigational deflector / deflector shield plays an important part on the Enterprise as such a shield will be needed if Humanity is going to travel at high speeds through interstellar space. A minute particle can cause serious damage to a spaceship when it is traveling at superluminal velocities. Scientists have been working on how to develop such a deflector for decades.

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A speck of interstellar dust travelling *at* the speed of light would have infinite mass and hence be unstoppable.

Would a speck of dust travelling at 1/2 the speed of light hitting a space ship travelling at 1/2 the speed of light in the opposite direction be the same?

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I liked the blue planet, so I live here now! :blink:

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My understanding is that the relative density between the colliding objects is key in dictating potential depth of impact

http://en.m.wikipedia.org/wiki/Impact_depth

Which is why armies use tank shells with uranium or tungsten, rather than marshmallow, cores.

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Not in space.

Without wind resistance you don't need pure mass for energy storage only speed. You can't have high speed on earth, because of the atmosphere.

Your not wrong. but your not right.

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In answer to the question posed earlier, this is something I had pondered before in random moments, though it was brought on by watching 2010 this evening. The slingshot around Jupiter. And I thought "at that speed even the tiniest particles in near-orbit around the planet are going to slice through that ship like airgun pellets through jelly".

There's something similar in another sci-fi film where the craft hits a shower of tiny meteors and ends up riddled with holes.

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Not in space.

Without wind resistance you don't need pure mass for energy storage only speed. You can't have high speed on earth, because of the atmosphere.

Your not wrong. but your not right.

I believe that some of the alleged attacker satellites - to attack other satellites - merely hurl loads of ball bearings at speed at the target.

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In answer to the question posed earlier, this is something I had pondered before in random moments, though it was brought on by watching 2010 this evening. The slingshot around Jupiter. And I thought "at that speed even the tiniest particles in near-orbit around the planet are going to slice through that ship like airgun pellets through jelly".

There's something similar in another sci-fi film where the craft hits a shower of tiny meteors and ends up riddled with holes.

Mission to Mars.

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As far as speed is concerned, what matters is the relative speeds of the colliding objects.

You say the spaceship is 'reinforced' but that is rather arbitrary. How well 'reinforced'?

Collisions between orbiting objects can easily involve relative speeds of 50,000kph.

Compared with a 'lightweight' object such as a bullet travelling at a mere 1,000 kph, and you realise your coke can could do an immense amount of damage.

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In answer to the question posed earlier, this is something I had pondered before in random moments, though it was brought on by watching 2010 this evening.

In the book, they had an inflatable shield at the front of the ship to absorb impacts and heat as they used the atmosphere to slow down. Not sure whether that was shown in the movie.

The other movie was probably Pitch Black. IMHO, a ship that delicate probably wouldn't be going anywhere.

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just to help you, a 5.56mm US rifle bullet weighs 62 grain or about 4 grams.

An empty coke can weighs about 15 grams.

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Some special circumstances might ensue here.

A - coke can - a thinly skinned cylindrical object largely full of air, very similar to a plane.

B - spaceship - most like a government funded large scale project, call it a government building.

When A hits B, A disappears without trace, nothing recongisable as a plane left. Some damage is done to B.

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