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sonarluminescence

Posted: Thu Jun 04, 2009 6:54 pm
by Robthebob
http://www.youtube.com/watch?v=LWO93G-zLZ0

Star in a jar? Are you kidding me?

Posted: Thu Jun 04, 2009 8:39 pm
by Skipjack
Instead of wondering to much, I would rather not believe it.
But, I am willing to be surprised.

Posted: Thu Jun 04, 2009 9:55 pm
by jgarry
I've heard of this in the past. It's a naturally occurring phenomenon. Shrimp in the ocean, for instance, are far noisier than they should be. Like cold fusion, whatever's happening is interesting in its own right, whether or not fusion is actually occurring.

Posted: Fri Jun 05, 2009 11:14 am
by D Tibbets
Nothing acutely new here. Sono fusion- Bubble fusion has been speculated on for years and one researcher at least has claimed succes. I don't think his results have been reproduced though, and he has suffured negative repercusions that (to me at least) seem more political and personal, rather than mearly an appropiate disclaimer that his results are not supported by other researchers/ labs.

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

Dan Tibbets

Posted: Fri Jun 05, 2009 11:36 am
by Skipjack
Now, I dont know what "liquid" this is. It might be one with a very high boiling point (must be a pretty interesting fluid indeed). Yet I am still surprised, that at "tens of thousands of degrees" that this "star" supposedly has, the surrounding fluid does not start to boil?

Posted: Fri Jun 05, 2009 3:08 pm
by MSimon
Skipjack wrote:Now, I dont know what "liquid" this is. It might be one with a very high boiling point (must be a pretty interesting fluid indeed). Yet I am still surprised, that at "tens of thousands of degrees" that this "star" supposedly has, the surrounding fluid does not start to boil?
There is a laser experiment - zapping light bulbs with terrawatt pulses to improve efficiency - big laser huh? You can plug it into the wall socket.

Posted: Fri Jun 05, 2009 4:06 pm
by pfrit
Skipjack wrote:Now, I dont know what "liquid" this is. It might be one with a very high boiling point (must be a pretty interesting fluid indeed). Yet I am still surprised, that at "tens of thousands of degrees" that this "star" supposedly has, the surrounding fluid does not start to boil?
The issue there is temperature, not heat. Very, Very, Very tiny bit of really, really hot matter.

Posted: Fri Jun 05, 2009 5:50 pm
by Skipjack
There is a laser experiment - zapping light bulbs with terrawatt pulses to improve efficiency - big laser huh? You can plug it into the wall socket.
I read about that one. Sounded pretty interesting at the time. I am a sceptic regarding the new laws they made in the EU (basically banning the old lightbulbs in favor of the supposedly better neon bulbs). This law is as always favoring two big companies and will make my chandelier in the living room a lot uglier. Thanks EU. So any development in that regard is welcome.
The issue there is temperature, not heat. Very, Very, Very tiny bit of really, really hot matter.
I dont quite understand how that answers my question. I have something that is supposedly very hot in a fluid. Unless there is some sort of insulation that heat will somehow radiate, or conduct into the fluid. At tens of thousands of degrees it should not take long for the surrounding fluid to boil, even if this tiny bit of matter is very small. Unless it I did not judge the size correctly. The video was rather sparce with real facts and instead showed some rather meaningless "pretty pictures".
E.g. it would be nice to know what fluid. How big is that bubble, etc.

Posted: Fri Jun 05, 2009 9:13 pm
by pfrit
Skipjack wrote:
The issue there is temperature, not heat. Very, Very, Very tiny bit of really, really hot matter.
I dont quite understand how that answers my question. I have something that is supposedly very hot in a fluid. Unless there is some sort of insulation that heat will somehow radiate, or conduct into the fluid. At tens of thousands of degrees it should not take long for the surrounding fluid to boil, even if this tiny bit of matter is very small. Unless it I did not judge the size correctly. The video was rather sparce with real facts and instead showed some rather meaningless "pretty pictures".
E.g. it would be nice to know what fluid. How big is that bubble, etc.
From http://en.wikipedia.org/wiki/Sonoluminescence
The bubbles are very small when they emit the light—about 1 micrometre in diameter—depending on the ambient fluid (e.g., water) and the gas content of the bubble (e.g., atmospheric air).

The amount of heat in these bubbles is small. It is just very concentrated.

Posted: Fri Jun 05, 2009 10:35 pm
by D Tibbets
The effect is due to the collapse of bubbles that are first formed by some means- like sound waves. As the bubble collapses the energy that was stored in the surface tension of the liquid is concentrated into a very small volume in a very short amount of time. It is like a acellerater, the molecules in the collapsing bubble are acellerated to very high speeds at a central focus, speeds equivalent to thousands of electron volts.

Remember that speed and temperature are related but can be misleading. Putting some stress on a crystal can generate sparks with 'temperatures' of millions of degrees (better described as charged particles with thousands of electron volts of kinetic energy). The same for shuffling your feet on a carpet. The energies per particle are large, but thay are existant for only brief periods of time and involve small amounts of matter.
Eg: a billion joules sounds like alot of energy, but if it is contained in a laser pulse that lasts for only one nanosecond, it amounts to only one Watt of power.


Dan Tibbets

Posted: Fri Jun 05, 2009 10:58 pm
by Skipjack
Ohhh, ok.
Now that is a lot smaller than what we saw in the video...
I understand now.
Also, it looked a lot more continuous in the video also.

Posted: Sat Jun 06, 2009 12:02 am
by KitemanSA
D Tibbets wrote:Eg: a billion joules sounds like alot of energy, but if it is contained in a laser pulse that lasts for only one nanosecond, it amounts to only one Watt of power.
Sorry Dan, you got that backward. Easy to do. A billion Joules IS a large amount of energy. It is a billion watt seconds. A million kilowatt seconds. 278 kilowatt hours.

I think what you met to say was that a billion Watts sounds like a lot of power, but if it lasts for a nano second it is only one Joule.

Posted: Sat Jun 06, 2009 1:39 am
by KitemanSA
Skipjack wrote:Now, I dont know what "liquid" this is. It might be one with a very high boiling point (must be a pretty interesting fluid indeed). Yet I am still surprised, that at "tens of thousands of degrees" that this "star" supposedly has, the surrounding fluid does not start to boil?
Usually clean water.
One thing to remember about bubbles oscillating in a liquid due to sonic excitation is that the fluid tends to evaporate into the bubble as it grows, cooling the liquid, and part of the vapor gets injected deep into the liquid as the bubble collapses. This tends to transfer heat that would normally accumulate near the bubble more broadly. And, of course, some of the remaining energy goes to creating the glow. None-the-less, eventually it will heat, perhaps to the point where the oscillation frequency changes and the excitation drops so much that the phenomenon stops.
Obviously, it is still being studied with interest in some quarters.

Posted: Sat Jun 06, 2009 3:19 am
by pfrit
KitemanSA wrote:
Skipjack wrote:Now, I dont know what "liquid" this is. It might be one with a very high boiling point (must be a pretty interesting fluid indeed). Yet I am still surprised, that at "tens of thousands of degrees" that this "star" supposedly has, the surrounding fluid does not start to boil?
Usually clean water.
One thing to remember about bubbles oscillating in a liquid due to sonic excitation is that the fluid tends to evaporate into the bubble as it grows, cooling the liquid, and part of the vapor gets injected deep into the liquid as the bubble collapses. This tends to transfer heat that would normally accumulate near the bubble more broadly. And, of course, some of the remaining energy goes to creating the glow. None-the-less, eventually it will heat, perhaps to the point where the oscillation frequency changes and the excitation drops so much that the phenomenon stops.
Obviously, it is still being studied with interest in some quarters.
Either clean water with low levels of dissolved noble gassses (they make the light significantly brighter) or, in the case of fusion experiments, deuterated acetone. The reason you can see it so well, is that millions of bubbles form and burst in the same spot a second. It looks like a continuous light source. They learned how to do that in the 80's. It is a standing pressure wave. Neat stuff, but I doubt it is a path to fusion. I would, however, be happy to be wrong on that.

Posted: Sat Jun 06, 2009 2:07 pm
by D Tibbets
KitemanSA wrote:
D Tibbets wrote:Eg: a billion joules sounds like alot of energy, but if it is contained in a laser pulse that lasts for only one nanosecond, it amounts to only one Watt of power.
Sorry Dan, you got that backward. Easy to do. A billion Joules IS a large amount of energy. It is a billion watt seconds. A million kilowatt seconds. 278 kilowatt hours.

I think what you met to say was that a billion Watts sounds like a lot of power, but if it lasts for a nano second it is only one Joule.
Err... I hate it when I have to think. Once prodded by Kitemen , I realized that I was indeed reversing the relationship. Oh well, consider what I meant, but ignor what I said... :oops:


Dan Tibbets