BF2S Forums An Asteroid will destroy us all

Commie Killer wrote:

Kmarion wrote:

Commie Killer wrote:

Yeah, but the force above ground is shown by the air that is being pushed. If the air isnt there to be pushed on, what is there to move or use a debris?

What do you think the shuttles thrusters push against when it gets into space? Newtons third law (maybe the first law of inertia). It applies in space as well, "air" is not needed. Rockets are able to accelerate due to the fact that they burn fuel and push the exhaust gases in a direction opposite the direction which they wish to accelerate. If an explosion were to occur in space side (a) will cause side (b) to exert force also, therefor displacing mass on side (b).

Meh sorry, I've been trying to understand that, but, I just dont really understand it....but isn't it true that rockets lose a large majority of their effectiveness once they leave the atmosphere?

Yes, it's absolutely true that rockets loose alot of their effectiveness in space. One of the reasons that rockets are effective is they produce a very high density of gas behind them, much higher than the density of gas than at the front of the rocket. This pressure difference pushes the rocket along. In space, the gasses produced can very quickly disperse and so don't form anywhere near as large a pressure gradient as they do in the atmosphere (dispite the low pressre at the front of the rocket). It's the same reason that guns use a barrel. It stops the high pressure differential from dispersing quickly and hence propels the bullet alto faster than if it were fired without being in a barrel. Similarly nukes won't work very well as it's the pressure wave that does the most damage. In space this pressure wave will dispurse extremely rapidly and therefore will have a much weaker effect.

Another thing worth noting is that most asteroids are not in fact big rocks, they are a loose amalgamation of millions of small rocks, and hence they are actually much more difficult to blast appart as they tend to absorb impacts alot better than a solid object.