When sound collides

[coregazer]

i was just wondering, despite sound not being matter, what happens when two similer sounds or identical sounds hit each other? and how would this inpact the sound?

[Klaynos]

They interfere....

 

http://en.wikipedia.org/wiki/Interference

 

What happens depends where on the wave you are when you look...

 

http://en.wikipedia.org/wiki/Interference#Constructive_and_destructive_interference

[ecoli]

superposition, baby

[coregazer]

i know this is like... kind of stupid... but is there any two waveleanghs of sound could create pressure? either on an object or on each other?

[swansont]

Sound waves are pressure waves.

[iNow]

And, since sound waves are, by definition, pressure waves, the answer to coregazer's question is that any sound will create pressure on objects (and/or other sound waves).

 

Put a song with a fair amount of bass into your player, and get a tower speaker... hold a piece of paper in front of it, play the song. You will see the paper move as if being held in the wind.

[coregazer]

oooh, cool. So... does this mean they would be able to lift an object? if so, how bigger speaker would you need/how mutch sound?

[insane_alien]

you do realise that sound is cyclical. in other words, half a cycle round you'll have a partial vacuum pulling the object towards the speaker again.

[coregazer]

you do realise that sound is cyclical. in other words, half a cycle round you'll have a partial vacuum pulling the object towards the speaker again.

 

lol. sounds like a good idea for a whole new generation of trampolining XD. lol. im not that mad. dont worry.

 

but a little more on the insane side, would a circle of inverted sound be able to hold an object in place? once more, if so, what would be required.

[garshmuda]

ever seen the howard stern movie 'private parts'? there's a great scene in which he uses sound pressure to, well, go see for yourself

[John Cuthber]

Perhaps watching this would be at least as scientific.

and a not brilliant wiki article.

http://en.wikipedia.org/wiki/Acoustic_levitation

[coregazer]

Perhaps watching this would be at least as scientific.

and a not brilliant wiki article.

http://en.wikipedia.org/wiki/Acoustic_levitation

 

okay, so hes using ultrasonic sound to levitate droplets of water... cool, is that because he thinks it looks cool or he cant levitate anything else without amplyfying the sound tenfold?... o_O... ie. what would be required to lift... i dont know... a.... glass?

[Zephir]

... what happens when two similer sounds or identical sounds hit each other? and how would this inpact the sound?..

 

Some trivial simulation of such situation (developed & tested just for MSIE 6.0 browser only, sorry).

[CaptainPanic]

There's a research about Thermo-acoustic heat pumps... these devices convert heat into acoustics (a step which I actually don't understand)... these acoustic waves (at some massive 170 dB or more) are transported through a pipe and generate a significant pressure fluctuation at the other end. Because compression and expansion of gases go together with warming up and cooling down, a temperature difference is created... result: a heat pump.

 

About the company that is doing research:

http://www.ecn.nl/en/eei/r-d-programme/industrial-heat-technology/process-heat/thermoacoustic-heat-pump/

 

A website which shows how it works (click "principle", and then "start"):

http://www.aster-thermoacoustics.com/indexeng.html

 

I think it's mad, and I think it's diabolically cool... and that's why I posted it.

[Klaynos]

It's quite a well known effect, you can supposedly cool stuff down from that as well...

 

One of my friends did a third year project on it...

[zeig]

you do realise that sound is cyclical. in other words, half a cycle round you'll have a partial vacuum pulling the object towards the speaker again.

 

even tho sound levetaion devices have been made