Nuclear explosion question
 

*Spoilers for Call of Duty Modern Warfare 2*



My question is, you see the nuke go off from the view of an astronaut, over DC. If you look directly down, you appear to be over Florida.

Could a nuke really explode in space, and a thousand miles away, you are hit with the shockwave, but just some hundred miles down, the ground is only hit with the EMP, and none of the shockwave?

I know its a game and all so its part of the story, but Im just curious if that would happen in real life. Would the atmosphere have a hand in dissipating the shock wave, yet the EMP can get thru? And can a shock wave from 1 nuke really travel a thousand miles in space?

Re: Nuclear explosion question
 

Even in low earth orbit there probably isn't enough atmosphere to carry a shock wave very far at all. Remember that a shock wave is energy being transmitted through the air itself. It needs a fluid (like our atmosphere) to be transmitted. Shock waves don't work in space.

So no, it probably wouldn't happen like it did in MW2 at all.

Edit: Okay it's not true that shock waves don't work at all in space, but a nuke wouldn't cause one. Shit like a supernova going off can use the interstellar medium as a... well... medium. We have people on the board who actually know physics much better, so they can probably comment more.

Re: Nuclear explosion question
 

I think it'd have to be a pretty big bomb to cause a shockwave to go all the way to Florida. The shockwave would most likely go downwards with more intensity, becuase of the increased density of the atmosphere. I think you just put that down to artistic license.

Re: Nuclear explosion question
 

It was my understanding that the nuke would have to be closer to Earth to cause an EMP, like the mid-lower stratosphere (If I'm mistaken, then please say so, cause I probably am ;)). From what I saw in the video, it looks like the nuke detonated a good distance out in space; too far to cause an EMP.

Re: Nuclear explosion question
 

There's very little matter in space, and although at the altitude you're talking about there's a bit more than you'd find in deep space, it's still not very much. Shockwaves of that sort travel through matter, using the same sort of mechanism to do so as sound does, and will have trouble getting about in space.

An EMP, on the other hand, is just electromagnetic radiation, and will travel happily through a vacuum. The sun manages to shoot enough of the stuff in our direction without needing an atmosphere to do so, after all.

I've never seen any film or video game treat a nuclear detonation in space with any sort of accuracy, so it's not much of a surprise that CoD (despite its claims to be 'realistic') has failed to do so as well.

Cheers for the spoilers, by the way!

Re: Nuclear explosion question
 

Before I start, that missile went in the opposite direction than it should have. It's a longer trip west to the Eastern US coast from eastern Russian than east. But this was a game.

Supernova shockwaves propagate through the stellar material (or the star's own self) and pushes everything out at a very rapid speed. This is the explosion you see. Supernovas are not nuclear, but mechanical. It comes from a the star's inner core rebounding from it's first collapse (collapsing faster than the rest of the star) and running into the rest of the star that trying to follow the core inward. The result is a massive crash and an outbound mechanical shockwave.

If a nuke goes off in space, the only thing that would propagate from it would be energy (light, etc.), and that could have some force out to a small radius. There isn't enough air in the upper atmosphere for the mechanical part of the explosion to propagate like it does on the ground (The destructive force of a nuke is from a massive air displacement).

So, no, a shockwave from a nuke cannot travel 1,000 miles in space to hit you because there is no mechanical shockwave, only the radiation "shockwave" which would probably emanate out at the same radius as it would have it if was detonated on the ground.

And, no, the people below a nuclear explosion in space wouldn't feel a shockwave because of same fact stated above. If no mechanical shockwave is created at the explosion epicenter, then you won't have to worry about any shockwave riding down the atmosphere.

@Afterburner: Energy actually doesn't need a medium to propagate through, but I know what you are referring to (the mechanical shockwave, which is kinetic energy).

EDIT: Also, nite, we have spoiler tags for spoilers.

Re: Nuclear explosion question
 

I know its a Micheal Bay-style game, so it just looks cool, but being over Florida and the explosion supposedly occures over DC, thats a far as hell distance.

So....myth busted?

Re: Nuclear explosion question
 

The only true effects would be a wave of radiation and the EMP. No shockwave.

Re: Nuclear explosion question
 

The EMP into the vicinity below is plausible?

Re: Nuclear explosion question
 

You get an EMP like that when the gamma rays from the nuke going off result in Compton electrons in air molecules; the electrons then interact with the Earth's magnetic field to make the EMP. So it really depends what you mean by, 'in space,' if it's in a thin atmosphere and a strong magnetic field you'll get a High Altitude EMP (HEMP.) The electrons I mentioned are trapped in the Earth’s magnetic field and set up an oscillating – generally asymmetric - current, and thus you get a brief pulse of very intense electromagnetism radiating out. That can travel just fine through a vacuum once it has been generated. A suitably powerful device at about 400 kilometers up you’re looking at the signal going out to the visual horizon, from the perspective of the device.

If on the other hand you set a nuke off in space proper, away from the Earth, you won't get very much at all; because there’s no atmosphere and no magnetic field. You won’t get a shockwave either, at least not as anything other than a secondary effect of heating if you’re really close to it, because there’s no fluid to transmit it.

From the perspective of an astronaut, assuming his eyes were suitably protected and his spaceship was far enough away - say a kilometre, kilometre and a half - a powerful nuke would just look like a flash bulb going off and that'd be pretty much the end of it.

Re: Nuclear explosion question
 

I thought it detonated over the Mid-Atlantic. It may have been a little south, but not down to Florida. I could watch that segment again to make sure, but I wouldn't be to picky where it blows up.

Also, good answer Nem.

Re: Nuclear explosion question
 

From the view of the game, you are in orbit over Florida, but the nuke explodes washington DC-ish.