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General Discussion => Science & Nature => Topic started by: GillE on January 14, 2010, 14:16

Title: An Idle Thought
Post by: GillE on January 14, 2010, 14:16
When I was at school, we were told that things like sound and light travel in waves, a bit like a sine wave.  Yet sound is three dimensional so wouldn't it be more accurate to say it travels in bubbles?  I wonder how whatever the bubble displaces remembers its original form when the bubble has passed.  And I wonder if it's an important consideration when firing a particle gun at parallel slots to establish principles of particle physics.  A bubble only bursts when it comes into contact with an outside body, and where it bursts depends on the position of the outside body, a bit like how particle physics depends on the position of the observer.

I'm delaying washing up after lunch.
Title: Re: An Idle Thought
Post by: Rik on January 14, 2010, 15:36
I don't understand your logic, Gill, as that would imply that once one person had burst the bubble, no-one else would hear the sound, surely? I'm not even sure that sound can be considered three-dimensional. Essentially every track on a 5.1 soundtrack is a one dimensional sound from a specific position. The brain re-assembles the various channels to create the 3D effect, just as the brain interprets the two monocular 'signals' from the eyes to produce three-dimensional vision.
Title: Re: An Idle Thought
Post by: Simon on January 14, 2010, 16:30
Done the washing up yet, Gill?  ;D
Title: Re: An Idle Thought
Post by: Rik on January 14, 2010, 16:35
If she has, she's using Fairy Liquid. ;)
Title: Re: An Idle Thought
Post by: Rodders on January 14, 2010, 16:57
Gill, since the term "bubble" is merely analogous to the form you're describing, I would suggest that it's incapable of actually "bursting".

Is it not more likely that Sound has a somewhat more ephemeral effect on the medium carrying it -- not perhaps displacing it, but temporarily acting as a factor upon the medium, until the energy contained in the sound is attenuated to the point of dissipation?

...or something.
Title: Re: An Idle Thought
Post by: Simon on January 14, 2010, 17:49
:stars:
Title: Re: An Idle Thought
Post by: GillE on January 14, 2010, 19:46
I don't understand your logic, Gill, as that would imply that once one person had burst the bubble, no-one else would hear the sound, surely? I'm not even sure that sound can be considered three-dimensional. Essentially every track on a 5.1 soundtrack is a one dimensional sound from a specific position. The brain re-assembles the various channels to create the 3D effect, just as the brain interprets the two monocular 'signals' from the eyes to produce three-dimensional vision.

Must the bubble burst?  We perceive bubbles as being held together by surface tension.  Would 'bubbles' of energy be dissipated entirely upon contact or would just the energy at the point of contact be subsumed?  After all, when a wave makes contact its form changes around the point of contact and some energy is consumed, distorting the shape of the wave, but the rest of the wave continues.
Title: Re: An Idle Thought
Post by: sam on January 15, 2010, 00:44
Sound is a compression wave that starts at a point of original. Sound waves are longitudinal waves (if you consider the movement of the material you get a sinusoidal amplitude changes), not transverse (well I guess they could be considered to be in solids; the sine wave normally thought of is light, well any electromagnetic radiation) and move via compression and rarefaction of the medium.  I guess the best way to really describe sound leaving a point is a shell. Is a shock wave more than a bubble. I guess you could consider it a bubble around the point of origin.

More about sound on hyperphysics.. http://hyperphysics.phy-astr.gsu.edu/hbase/sound/sprop.html#c1
Title: Re: An Idle Thought
Post by: Sandra on January 15, 2010, 01:04
I think that Gill may be right, I have often seen speach bubbles in cartoons  ;D
Title: Re: An Idle Thought
Post by: sam on January 15, 2010, 01:05
I think that Gill may be right, I have often seen speach bubbles in cartoons  ;D

 :woot:
Title: Re: An Idle Thought
Post by: Sandra on January 16, 2010, 03:19
Heres the proof of Gills thoughts Sam  :)x
(https://www.pc-pals.com/smf/proxy.php?request=http%3A%2F%2Fi.dailymail.co.uk%2Fi%2Fpix%2F2010%2F01%2F15%2Farticle-0-07DFCF87000005DC-652_468x275.jpg&hash=2cb4b4d007368c8b9075da5b95a3c93f668a2fcb)
Title: Re: An Idle Thought
Post by: sam on January 16, 2010, 04:02
Heres the proof of Gills thoughts Sam  :)x
(https://www.pc-pals.com/smf/proxy.php?request=http%3A%2F%2Fi.dailymail.co.uk%2Fi%2Fpix%2F2010%2F01%2F15%2Farticle-0-07DFCF87000005DC-652_468x275.jpg&hash=2cb4b4d007368c8b9075da5b95a3c93f668a2fcb)

proof, eh  8-)