Originally posted by StratComm
Actually, by definition shockwaves cannot propogate through a vaccuum, if you want to get literal with it. There'd be no shock, as there's no medium to move. What can happen is that a wave of high-energy matter can expand rapidly enough to form a shell of outward-moving particles, which in turn create the "shockwave" effect we're so used to seeing as it is their collisions with an object that would effect it. Given that the surface of the shockwave is particulate matter, and not pure energy, it would by definition not be able to travel at the speed of light.
That depends on what do you want to call a shockwave.
Practically, in interstellar nebulaes there simply are not enough matter to convey mechanical energy via wave movemet. Still we can see shockwaves created by supernovae. These larg-scale shockwaves are nothing more but simply gas emitting the energy of electromagnetic pulse from the supernova (and later, of course, particle radiation including expanding gas, protons, neutrons, electrons, positrons, helium4 nuclei and such staff). The emitting zone moves outwards from the explosion, creating a shockwave-like effect.
However, both this c-speed part and slower particles pack quite a punch. Actually this latter phenomenon is strong enough to create more dense concentrations of gas in the previously homogenous gas cloud. These concentrations can then form whole new stars, so this phenomenon is really a great-scale one. The initial electromagnetic radiation is responsible of the initial brightness of the supernovae, and it fades away rather fast, while the later matter-based slower "shockwaves" last longer.
On FS2 or any other space simulation, this would only be useful in nebula missions. The emitting energy from the explosion would make the surrounding nebula glow for a brief moment, then the glow would move away at c. That's what I meant with a "flashlight-effect".
Originally posted by CaptJosh
The part of the explosion that does move at cee has already passed through you or been absorbed by your radiation shielding by the time the debris from the explosion hits you.
Yes, but the part moving at can last a bit of time, and you'd still see the fotons emitted by surrounding gas, creating a short-timed overall (or ambient) lighting boost. You would certainly have no time to see the radiation zone, moving at c, but you could see it's consequences. It would increase the temperature of the gas around it, and hot gas would start to emit fotons... creating a visible glow, for a brief moment of time.
Supernova can overcome it's mother galaxy in brightness during first few days. While the ship's energy source cannot be nearly as energetic, it should still create a visible glow on surrounding gas in nebula for some time. If there is no nebula in the mission, there would not be this glow. Simple.
Then come the particles (electrons, positrons, helium4 nuclei, neutrons, protons and stuff like that) and then comes the debris aka pieces of molecular matter hitting you.
Depending of the power source of the ship, it would certainly create different type of explosions. For example, fusion reactors would actually have severe problems trying to explode. The density needed for a hydrogen bomb to detonate can only be achieved by putting fusion materia (primarily tritium and deuterium) inside a fission bomb, which compresses the hydrogen enough so that it can fuse into helium and release energy. Reactor technology is somewhat different; the fusion must actively be fed to make it continue. Fission reactor could actually reach critical mass more easily, but there are few space ships using this primitive technology, eh?
Anti-matter and subspace/hyperspace energy sources create explosions more like these described. Anti-matter fuel must be kept away from matter actively. If this system suffers damage and becomes unable to do this, the resulting energy burst has the energy of 2mc^2, where m is the mass of anti-matter released.
Even small amounts of anti-matter annihilated with matter release *significant* amounts of energy, as you probably know... This would be in the form of gamma radiation, which could create a glow effect very much like mentioned before. Then the glow would die away, revealing some debris of the ship. Subspace/hyperspace tap energy sources could behave similarly; when the tapping mechanism becomes damaged, it could create a local energy overflow, released in explosion.
Btw,
here are some images of shockwaves created by radiation zone travelling through space and making the gas glow. As I said, the initial superior brightness of the supernova becomes from the electromagnetic radiation making nearby gas glow, while the later particle radiation travels slower and creates a much similar phenomenon in a smaller scale, and the slowest and latest, but not least, comes the high-speed gas colliding other gas molecules and creating the longest visible effects in space.
All these are results of the explosion, but I don't know if you like to call them all "shockwaves". They can all cause damage to your ship... but practically none of these would even be seen as shockwaves we see on FS2. Alla of them would have such speed that in small range such explosion would only produce the bright glow, and parctically a *very* small time interval would be between that and gas and other particles hitting you.
The only way for such shock waves to be seen in FS2 would be wighting on an athmosphere. But as I said, I don't really care of that while I'm playing FS2 - the flight model is not newtonean and thus has no resemblance to real life physics, so why would the rest of the game have?
It's more important that it looks good and is fun to play in this occasion.