Why can't sound produce light?

[tomasro]

Alright. I was sitting in physics class, as the professor was explaining light operates at certain ocilations per second (frequency), and then later he talked about sound in Hz (a frequency). Now, I've noticed that light produces sound when I listen to those UV lights, you hear the humm. So why can't it be the other way around? Why can't sound produce light? I've heard that it creates heat within an enclosure when the air is compressed, so why can't it make light?

Maybe I just need to stop thinking....

[Ren]

Just a couple of points.

I think you've observed two phenomena in conjuction w\ one another (light & hum from a fluorescent light) and assumed there is cause & effect. There isn't. The hum is from the power supply for the light fixture, not directly from the light.

Secondly, there is a fairly rare effect called triboluminscence whereby mechanical energy is directly converted to light. This is the effect you see (the flash of light observed in a very dark room) when you bite down on a wintergreen Lifesaver candy.

I suppose if your subwoofers were loud enough...

[MRehorst]

It can! Look up sonoluminescense.

There is quite a bit of research into the phenomena going on now.

MR

[phishead8]

Another couple of points.

The frequencies of audible sound would reside in the radio end of the spectrum for light. For example 1khz light would be a 300,000 meter radio wave. Very long wavelength, as you can see. Even if sound to light were possbile it would require some very large antennae's to detect the "light". Likewise it would be difficult to create it.

The US Navy uses ELF (Extra Low Frequency) to talk with submarines around the world. The antenna is located in landlocked Michigan, as the waves travel well through the earth and oceans. I don't think they produce waves that would be audible, though (assuming we had a crazy device that would convert).

Don't stop coming up with crazy ideas, though. That is what this world needs more of.

-Dan

[MRehorst]

here's a link for you...

http://www.newton.dep.anl.gov:70/ask...0/phy00261.htm

Ignore the "Philadelphia Experiment" search results.

MR

[tomasro]

Thank you guys very much. My quest for the light continues...

[gromanswe]

Originally posted by tomasro
Thank you guys very much. My quest for the light continues...

Light is a higher energy form than SOUND
Energy goes from higher forms to lower.
Energy it remains
but not as useful as before.
This degradation is called "something"
Study the principals of Energy!

And study elementary PHYSICS

[Peter Daniel]

Originally posted by gromanswe


This degradation is called "something"

Isn't it called entropy?

[Ren]

Originally posted by gromanswe

Light is a higher energy form than SOUND
Energy goes from higher forms to lower.
Energy it remains
but not as useful as before.
This degradation is called "something"
Study the principals of Energy!

And study elementary PHYSICS

I think perhaps we could all use to review elementary physics... light and sound are fundamentally different things. What we call sound is the transmission of a vibration (in the range of 20 Hz to 20,000 Hz) THROUGH A MEDIUM (like air, water, or a railroad track) which excites our eardrum into vibration. Light is electromagnetic radiation, having both an electronic and a magnetic vector of equal frequency at 90 degrees to one another along the axis of propagation, 180 degrees out of phase. Electromagnetic radiation does not need a supporting medium to travel, unlike sound. Different beasts entirely.

[Keld]

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This degradation is called "something"


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Isn't it called entropy?


The "degradation" is mesuared with entropy.
Where higher number is more degradation.
Read more here: http://www.entropylaw.com

Its actually about a problem most DIY amp builders run into when trying to the maximum energy trough a minimum heatsink