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You're mixing apples and oranges. Air and water are matter, sound is not. Any sound-producing plane generates sound waves, not just a plane that goes faster th

You're mixing apples and oranges. Air and water are matter, sound is not. Any sound-producing plane generates sound waves, not just a plane that goes faster than sound.

freeone3000 1y ago
Sound is the vibration of matter. Waves do not move matter! Like, look at a leaf on a lake. The leaf moves up and down with the ripples, but does not move back and forth. The water isn’t moving, the wavefront is. Sonic booms are nothing more than a collapsed wavefront of that wavefront. The speed of sound, definitionally, is the maximal speed at which any physical wavefront can propagate through a medium. (We hear it in air as sound, but no wave can be propagated through the medium any faster than this. You cannot move air any faster than the speed of sound in air.) This causes all of the disturbances from the aircraft moving through the air to be compressed into a single, maximal wave that itself moves at the speed of sound, since it can’t move any faster. Thus the boom. (You can see a similar cool thing with Cherenkov radiation, where neutrons moving faster than light in water produce a bright blue glow — or, waves of light!)
- zigzag312 1y ago
  I was referring to your explanation "When a plane goes faster than air, it makes air-waves. When a plane goes faster than sound, it makes sound-waves." In physics, an air wave typically refers to a sound wave. While both of your statements are true (plane makes sound-waves at both speeds), they didn't explain the sonic boom, like you did now. > You cannot move air any faster than the speed of sound in air. Minor nitpick, doesn't a plane traveling above Mach 1 displace (i.e. move) air faster than the speed of sound in air? :)
  - freeone3000 1y ago
    Right, sorry. The wave can't propagate any faster than the speed of sound -- the air itself be moved faster, but you have to do so by physically displacing it.

You're mixing apples and oranges. Air and water are matter, sound is not. Any sound-producing plane generates sound waves, not just a plane that goes faster than sound.

freeone3000 1y ago

Sound is the vibration of matter. Waves do not move matter! Like, look at a leaf on a lake. The leaf moves up and down with the ripples, but does not move back and forth. The water isn’t moving, the wavefront is. Sonic booms are nothing more than a collapsed wavefront of that wavefront. The speed of sound, definitionally, is the maximal speed at which any physical wavefront can propagate through a medium. (We hear it in air as sound, but no wave can be propagated through the medium any faster than this. You cannot move air any faster than the speed of sound in air.) This causes all of the disturbances from the aircraft moving through the air to be compressed into a single, maximal wave that itself moves at the speed of sound, since it can’t move any faster. Thus the boom. (You can see a similar cool thing with Cherenkov radiation, where neutrons moving faster than light in water produce a bright blue glow — or, waves of light!)

zigzag312 1y ago
I was referring to your explanation "When a plane goes faster than air, it makes air-waves. When a plane goes faster than sound, it makes sound-waves." In physics, an air wave typically refers to a sound wave. While both of your statements are true (plane makes sound-waves at both speeds), they didn't explain the sonic boom, like you did now. > You cannot move air any faster than the speed of sound in air. Minor nitpick, doesn't a plane traveling above Mach 1 displace (i.e. move) air faster than the speed of sound in air? :)
- freeone3000 1y ago
  Right, sorry. The wave can't propagate any faster than the speed of sound -- the air itself be moved faster, but you have to do so by physically displacing it.