Why ripple effect doesn't happen on air as it does on water?

  • Thread starter Thread starter tsean88
  • Start date Start date
  • Tags Tags
    Air Ripple Water
AI Thread Summary
A single disturbance creates visible ripples on water due to surface tension, while sound waves in air produce pressure waves that are not visually perceptible. Sound waves consist of multiple pulses that our ears interpret as different pitches, but these do not manifest as ripples like in water. The propagation of sound is three-dimensional and involves longitudinal waves, contrasting with the two-dimensional surface waves of water. Human perception plays a significant role, as our ears can detect a wider range of sound energy levels than our eyes can see ripples. Ultimately, both phenomena follow similar mathematical principles, but their visibility and perception differ due to the medium and wave type.
tsean88
Messages
3
Reaction score
0
Hi everyone,
I am wondering why a single disturbance can cause ripple on water surface but the same is not true when sound wave is made. When air is disturbed, only one pulse is made in one time. What set the difference?
Thanks in advance.
 
Physics news on Phys.org
There are multiple pulses in air as well, but our ears don't pick up individual pulses. If the pulses are close together, we perceive them as a high-pitched sound; if they're a bit farther apart we hear them as a lower-pitched sound.
 
Sound is transmitted by pressure waves - the air is slightly compressed by the "speaker", then relaxes - and the pressure waves move outward from the source, decreasing in intensity as they move outwards.

You may not see these "ripples" in the air, but you can hear them - and the ear is a complex device which can pick up quite faint sounds, though bats and owls have better hearing.

The ripples you see for water are a surface effect - but we are immersed in the air, so for us there is no surface ripple for sound. But you can indeed see it for very strong sound waves - both on a water surface, a drum head, or worst of all - in the after effects of an earthquake.
 
Thanks for your reply, PED.
Now I think of that it's true when immersed in a body of water, one can only produce one pulse a time. I think ripples can only exist on surfaces or boundaries between different medium.
 
tsean88 said:
Thanks for your reply, PED.
Now I think of that it's true when immersed in a body of water, one can only produce one pulse a time. I think ripples can only exist on surfaces or boundaries between different medium.

You can think whatever you want. That doesn't make it true. It's possible to produce a single ripple wave on either surface or bulk waves, but that's usually not what happens.
 
dauto said:
You can think whatever you want. That doesn't make it true. It's possible to produce a single ripple wave on either surface or bulk waves, but that's usually not what happens.

Hi dauto, thanks for replying.
Can you show me how to produce a single ripple water wave on the surface? Why do we usually have it like it is then? I'd appreciate it if you can tell me more details.

256bits said:
Here is a video describing ripples in a pond of water.
More interesting than you thought, I bet.
http://wn.com/capillary_wave

That's cool. Thanks man. Then how about other waves, do they act the same?
 
What other waves do you refer to?
 
tsean88 said:
Hi everyone,
I am wondering why a single disturbance can cause ripple on water surface but the same is not true when sound wave is made. When air is disturbed, only one pulse is made in one time. What set the difference?
Thanks in advance.
Bottom line is that exactly the same Maths describes all of these phenomena. A disturbance spreads out in all directions, whether it's a stone or a 'bang'.
Imo, the relative difference between the two things is a matter of Human Perception and the timescales involved. 'Ripples' spread out from any sound source and they bounce off walls and obstacles. That's all in three Dimensions, rather than the two Dimensions of a water surface. The waves are longitudinal, rather than surface waves but a single pulse in both cases behaves pretty much the same (once you scale the times appropriately).
Aamof, sound tends to propagate better than most surface waves, which is easily shown by clapping your hands together in a large cave or stone building - you can identify the reverberation for many seconds in some cases. Our hearing can detect a vast range of sound energy levels whereas our eyes will not actually see ripples of less than, say 5% of the original amplitude.
 
Back
Top