LogFAQs > #973544851

slacker03150 posted...

If you could hypothetically develop a supersonic torpedo, what kind of effect would that have on the ocean? Would there be a sonic boom? Would that hurt marine life? Would the water displacement cause a tidal wave? Or would it not have any noticeable affect?

Would there be a sonic boom? Yes. A sonic boom is just a pressure wave generated by something moving, and when it is close to or at the speed of sound, the waves overlap and merge, as they are also travelling at the speed of sound. An object moving at supersonic speeds underwater would result in the same effect - however, because water is largely incompressible, the pressure wave would be more damaging than the over-air equivalent.

Would it be harmful to marine life? Yes - potentially fatally so, if they're close enough. Again, it's a pressure wave, so it will behave like any other pressure wave in an incompressible medium.

Would the water displacement cause a tidal wave? No - not unless you were somehow launching this from very, very deep underwater (and generating enough energy to have a supersonic missile under that much pressure is well beyond what our technology is capable of - honestly, something that can go supersonic speeds underwater is already beyond our tech level, but doing so that deep underwater adds an even greater level of difficulty). Tidal waves are largely based on the volume of water displaced, not the speed at which it is displaced, so the fact that your torpedo is moving really, really fast isn't any more likely to result in a tidal wave than a speedboat doing the same thing.