Could a fish swim faster than sound?

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SUMMARY

Fish and birds cannot swim or fly faster than the speed of sound using only their natural propulsion methods, such as fins or wings. The speed of sound in water is approximately 4.5 times faster than in air, making it theoretically possible for aquatic creatures to exceed this speed under specific conditions, such as riding the wake of a moving ship. However, no known animal can achieve this speed unaided. The Pistol Shrimp is an exception, as its claw can close faster than the speed of sound, creating a cavitation bubble for hunting purposes.

PREREQUISITES
  • Understanding of fluid dynamics and propulsion methods
  • Knowledge of sound propagation in different mediums
  • Familiarity with marine biology, specifically dolphin and shrimp behavior
  • Basic principles of cavitation and its effects
NEXT STEPS
  • Research the mechanics of sound propagation in water versus air
  • Study the Pistol Shrimp's hunting techniques and cavitation effects
  • Explore the potential applications of cavitation in fusion technology
  • Investigate the limitations of animal propulsion in achieving high speeds
USEFUL FOR

This discussion is beneficial for marine biologists, physicists studying fluid dynamics, and anyone interested in the biomechanics of animal movement and sound propagation in different environments.

haael
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Is it possible for a fish or a bird to swim/fly faster than sound? I mean: no rockets, no free fall, no cheating by tying a string to the ground and using it to violate the conservation of momentum.

Is it possible to accelerate over the speed of sound using only fins, wings or screws?
 
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haael said:
Is it possible for a fish or a bird to swim/fly faster than sound? I mean: no rockets, no free fall, no cheating by tying a string to the ground and using it to violate the conservation of momentum.

Is it possible to accelerate over the speed of sound using only fins, wings or screws?

Not possible, the speed of sound is around the speed a bullet is ejected from a gun.
 
Another thing to consider...the speed of sound is much much faster in water, isn't it?

Edit: looked it up. Approximately 4.5x faster in water.
 
Last edited:
well actually a dolphin can't swim that fast, but put it behind a cruise liner or another ship and they can go pretty darn fast. Faster then they're supposed to, by riding on the wake, as there is less drag due to the ship doing the work for the dolphin. So i wouldn't be surprised if they could do it if they were behind a ship that traveled sufficiently faster than the speed of sound. Assuming, that the terminal velocity of water, like that of air, isn't lower than the speed of sound itself.
 
no there's no animal that can break the sound barrier without attaching rockets to it and that would be pretty cool/cruel. I wonder if we could genetically engineer one some day to do that though, maybe convert food into rocket fuel or instead of flapping wings eject streams of air out the back. I was watching a documentary based on possible animals that could exist on alien planets, they had an animation of a bird firing streams of air behind it to propel itself but I don't think they said it was possible for it to break the sound barrier.
 
Of course it's possible in theory to go faster than the speed of sound under water, but in practice its nowhere near possible for an animal to get going that fast.

Simon Malzard, but then the water would be traveling, so the dolphin would just be inside water which is traveling faster than the speed of sound.
 
Well, this guy wants to break the sound barrier with no motors...

http://dnainfo.com/20100122/manhattan/skydiver-will-attempt-break-speed-of-sound-with-freefall-from-space
 
I think the point of the question is can you theoretically swim faster than the speed of sound in the medium.
If swimming involves pushing against a fluid can you do this faster than a 'push' can travel through the fluid?
 
cstoos said:
Another thing to consider...the speed of sound is much much faster in water, isn't it?

Edit: looked it up. Approximately 4.5x faster in water.

Yes, the molecules are closer together in water, so disturbance travels faster.

Simon Malzard said:
well actually a dolphin can't swim that fast, but put it behind a cruise liner or another ship and they can go pretty darn fast. Faster then they're supposed to, by riding on the wake, as there is less drag due to the ship doing the work for the dolphin. So i wouldn't be surprised if they could do it if they were behind a ship that traveled sufficiently faster than the speed of sound. Assuming, that the terminal velocity of water, like that of air, isn't lower than the speed of sound itself.

The ship would have to be traveling at 720 Knots to surpass the speed of sound.
 
  • #10
Maybe not swim faster than sound, but the 'Pistol Shrimp' can move faster than the speed of sound. Its claw closing travels faster than the speed of sound, taking the local pressure to below the vapour pressure of water, causing a cavitation bubble, which it uses to hunt prey.

Actually, people think this kind of thing could have applications in future fusion technology, the temperatures created as the cavitation bubble collapses are pretty impressive.

Perhaps not what you were looking for, but quite interesting I think.

,Simon
 
  • #11
SimonRoberts said:
Maybe not swim faster than sound, but the 'Pistol Shrimp' can move faster than the speed of sound. Its claw closing travels faster than the speed of sound, taking the local pressure to below the vapour pressure of water, causing a cavitation bubble, which it uses to hunt prey.

Actually, people think this kind of thing could have applications in future fusion technology, the temperatures created as the cavitation bubble collapses are pretty impressive.

Perhaps not what you were looking for, but quite interesting I think.

,Simon

I don't think it moves faster than sound because of this action. The entire mass of the shrimp would need to be accelerated to this velocity and the force of the action is not enough to do this.
 
  • #12
I meant that its claw travels faster than the speed of sound. The cavitation bubble is somewhat similar to a sonic boom in air. The shrimp remains stationary.
 
  • #13
I think the point of the question is can you theoretically swim faster than the speed of sound in the medium.
If swimming involves pushing against a fluid can you do this faster than a 'push' can travel through the fluid?
Yes, that's exactly my point. Does anyone know the answer?
 
  • #14
cstoos said:
Another thing to consider...the speed of sound is much much faster in water, isn't it?

Edit: looked it up. Approximately 4.5x faster in water.


Which must explain why thinks sound different underwater?

I remember what it sound like but it does sound different.

Or maybe it is because you can't hear the low frequencies because they are reflected away?
 

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