3 ms·

Is the sound faster than the shockwave or same speed? I think same speed. Might have been a previous explosion that triggered the look before the main one.

gpm 6y ago
I think you're hearing/seeing the difference between the speed of sound through the ground, and through the air.
- jhrmnn 6y ago
  Sound moves 4-times faster in water than in air, I assume even faster in ground surface, so let’s just assume it arrives instantly via ground. This would mean a delay like in lightning/thunder, which is what one can see in the video (2–3 seconds ~ 0.5–1 km). (This is the restaurant https://goo.gl/maps/td5K1vxUDBN4i1CA8 https://goo.gl/maps/td5K1vxUDBN4i1CA8) But I could equally imagine it’s some lesser explosion before the main blast.
numpad0 6y ago
Object moves -> air goes back and forth -> your eardrum moves -> pressure pattern over time registers as sound as a 20-20kHz ish spectrum captured at 0.1s ish timesteps Supersonic airplanes move past the speed of sound(280-340m/s in air) and generate wavefront at its interfaces with air but the resulting disjoint tsunami wave expands at the speed of sound and heard as single ‘bang’ when it reaches ears or microphones So there’s no way one could hear the bang through air before visual bang hits However the speed of sound is about 10x faster on solid mediums such as ground or seawater so could be those
- m0zg 6y ago
  It's actually two "bangs" for a plane. Tum-dum. Source: grew up about 100km away from a military air base in Russia at which at least a couple planes went supersonic almost every day for years. You can hear several sonic booms in this video, although they're from low-flying planes: https://www.youtube.com/watch?v=jmhU7SEo4gg https://www.youtube.com/watch?v=jmhU7SEo4gg. The higher the plane, the more distinct and "bassy" the "booms". Here's another example, a bit higher, a bit more distinct: https://www.youtube.com/watch?v=M_KbZON5sW0 https://www.youtube.com/watch?v=M_KbZON5sW0
MaxBarraclough 6y ago
> Is the sound faster than the shockwave or same speed? I think same speed. Shockwaves propagate faster than sound by definition. The speed of sound depends on the medium, as a few replies have mentioned.
ignoramous 6y ago
TFA says shock-waves travel much faster than sound's speed in air (343 m/s) whilst pressure-waves (as in the explosion in Beirut at 200+ m/s) travel relatively slower.

gpm 6y ago

I think you're hearing/seeing the difference between the speed of sound through the ground, and through the air.

jhrmnn 6y ago
Sound moves 4-times faster in water than in air, I assume even faster in ground surface, so let’s just assume it arrives instantly via ground. This would mean a delay like in lightning/thunder, which is what one can see in the video (2–3 seconds ~ 0.5–1 km). (This is the restaurant https://goo.gl/maps/td5K1vxUDBN4i1CA8 https://goo.gl/maps/td5K1vxUDBN4i1CA8) But I could equally imagine it’s some lesser explosion before the main blast.

numpad0 6y ago

Object moves -> air goes back and forth -> your eardrum moves -> pressure pattern over time registers as sound as a 20-20kHz ish spectrum captured at 0.1s ish timesteps Supersonic airplanes move past the speed of sound(280-340m/s in air) and generate wavefront at its interfaces with air but the resulting disjoint tsunami wave expands at the speed of sound and heard as single ‘bang’ when it reaches ears or microphones So there’s no way one could hear the bang through air before visual bang hits However the speed of sound is about 10x faster on solid mediums such as ground or seawater so could be those

m0zg 6y ago
It's actually two "bangs" for a plane. Tum-dum. Source: grew up about 100km away from a military air base in Russia at which at least a couple planes went supersonic almost every day for years. You can hear several sonic booms in this video, although they're from low-flying planes: https://www.youtube.com/watch?v=jmhU7SEo4gg https://www.youtube.com/watch?v=jmhU7SEo4gg. The higher the plane, the more distinct and "bassy" the "booms". Here's another example, a bit higher, a bit more distinct: https://www.youtube.com/watch?v=M_KbZON5sW0 https://www.youtube.com/watch?v=M_KbZON5sW0

MaxBarraclough 6y ago

> Is the sound faster than the shockwave or same speed? I think same speed. Shockwaves propagate faster than sound by definition. The speed of sound depends on the medium, as a few replies have mentioned.

ignoramous 6y ago

TFA says shock-waves travel much faster than sound's speed in air (343 m/s) whilst pressure-waves (as in the explosion in Beirut at 200+ m/s) travel relatively slower.