Underwater Bubbles Create Light and No-one Knows Why.

#1




Sonoluminescence - Wikipedia, the free encyclopedia


From left to right: apparition of bubble, slow expansion, quick and sudden contraction, emission of light


Sonoluminescence is the emission of short bursts of light from imploding bubbles in a liquid when excited by sound.

The Royal Navy employed the services of physicist Lord Rayleigh in the early 20th century to understand the degradation of ship propellers. Lord Rayleigh concluded that collapsing air bubbles were the cause.[1]

The sonoluminescence effect was first discovered at the University of Cologne in 1934 as a result of work on sonar. H. Frenzel and H. Schultes put an ultrasound transducer in a tank of photographic developer fluid. They hoped to speed up the development process. Instead, they noticed tiny dots on the film after developing and realized that the bubbles in the fluid were emitting light with the ultrasound turned on. It was too difficult to analyze the effect in early experiments because of the complex environment of a large number of short-lived bubbles. (This experiment is also ascribed to N. Marinesco and J.J. Trillat in 1933, which also credits them with independent discovery). This phenomenon is now referred to as multi-bubble sonoluminescence (MBSL).


Single-bubble sonoluminescence - A single, cavitating bubble.

In 1989 a major experimental advance was introduced by Felipe Gaitan and Lawrence Crum, who produced stable single-bubble sonoluminescence (SBSL). In SBSL, a single bubble trapped in an acoustic standing wave, emits a pulse of light with each compression of the bubble within the standing wave. This technique allowed a more systematic study of the phenomenon, because it isolated the complex effects into one stable, predictable bubble. It was realized that the temperature inside the bubble was hot enough to melt steel. Interest in sonoluminescence was renewed when an inner temperature of such a bubble well above one million kelvins was postulated. This temperature is thus far not conclusively proven, though recent experiments conducted by the University of Illinois at Urbana–Champaign indicate temperatures around 20,000 K. Research has also been carried out by Dr. Klaus Fritsch of John Carroll University, University Heights, Ohio.


Long exposure image of multi-bubble sonoluminescence created by a high-intensity ultrasonic horn immersed in a beaker of liquid.

Only just found out about this, naturally the first sweeping conclusion that any layman would jump to is that one of the main theories about the universe' creation is from a bubble, the release of heat and light indicate a mini explosion of some sorts.

So we're all in an immense sea? :)


I wonder where the photon comes from?


Some further info:

In 2002, M. Brenner, S. Hilgenfeldt, and D. Lohse published a 60-page review "Single bubble sonoluminescence" (Reviews of Modern Physics 74, 425) that contains a detailed explanation of the mechanism. An important factor is that the bubble contains mainly inert noble gas such as argon or xenon (air contains about 1% argon, and the amount dissolved in water is too great; for sonoluminescence to occur, the concentration must be reduced to 20–40% of its equilibrium value) and varying amounts of water vapor. Chemical reactions cause nitrogen and oxygen to be removed from the bubble after about one hundred expansion-collapse cycles. The bubble will then begin to emit light "Evidence for Gas Exchange in Single-Bubble Sonoluminescence", Matula and Crum, Phys. Rev. Lett. 80 (1998), 865-868). The light emission of highly compressed noble gas is exploited technologically in the argon flash devices.

During bubble collapse, the inertia of the surrounding water causes high pressure and high temperature, reaching around 10,000 kelvins in the interior of the bubble, causing the ionization of a small fraction of the noble gas present. The amount ionized is small enough for the bubble to remain transparent, allowing volume emission; surface emission would produce more intense light of longer duration, dependent on wavelength, contradicting experimental results. Electrons from ionized atoms interact mainly with neutral atoms, causing thermal bremsstrahlung radiation. As the wave hits a low energy trough, the pressure drops, allowing electrons to recombine with atoms and light emission to cease due to this lack of free electrons. This makes for a 160-picosecond light pulse for argon (even a small drop in temperature causes a large drop in ionization, due to the large ionization energy relative to photon energy). This description is simplified from the literature above, which details various steps of differing duration from 15 microseconds (expansion) to 100 picoseconds (emission).

Computations based on the theory presented in the review produce radiation parameters (intensity and duration time versus wavelength) that match experimental results with errors no larger than expected due to some simplifications (e.g., assuming a uniform temperature in the entire bubble), so it seems the phenomenon of sonoluminescence is at least roughly explained, although some details of the process remain obscure.

Any discussion of sonoluminescence must include a detailed analysis of metastability. Sonoluminescence in this respect is what is physically termed a bounded phenomenon meaning that the sonoluminescence exists in a bounded region of parameter space for the bubble; a coupled magnetic field being one such parameter. The magnetic aspects of sonoluminescence are very well documented.[6]

Also, I wonder if this cavitation effect and tiny bubbles cause any light emission for ships or subs? The Sonar might cause solarwotchacallit from prop bubbles. Tho I imagine the designers are aware of this as the RN discovered it in the first place.
 
#3
DC - while I enjoy the science threads you post, can you for once do one that my tiny mind can comprehend. Every time I read them, I have to sit down with a cup of Horlicks and a damp towel around my head!
 
#4
....
Also, I wonder if this cavitation effect and tiny bubbles cause any light emission for ships or subs? The Sonar might cause solarwotchacallit from prop bubbles. Tho I imagine the designers are aware of this as the RN discovered it in the first place.
Regardless of whether or not cavitation is a source of light, it is definitely a source of sound. For this reason, vessels that wish to minimise their acoustic signal minimise the chance of cavitation. Prairie masker is one way.

Also, if you look at the bow wave of any vessel on a dark night, you will see phosphorescence which I was told was bioluminescence.
 
#5
DC - while I enjoy the science threads you post, can you for once do one that my tiny mind can comprehend. Every time I read them, I have to sit down with a cup of Horlicks and a damp towel around my head!

This one's simple enough, until you get to the second quote of my post which discusses the complex scientific stuff.

As someone who's self taught and didn't even do physics GCSE (my own field being history) I struggle with trying to make sense of it and some of it reads as gibberish, the vague outline suggests the composition of the gas in the bubble has an effect on the intensity of the light and the surrounding water is responsible for the temperature variation. Someone clever will probably come along and explain it in words better than I. I thought it was an interesting topic not for its complexity but moreso for the mystery. Light from bubbles? Whoda thunk it!

It does make me wonder whether the origins of the universe might have had a similar cause, although for this mini explosion and release of light you still need a bubble there to start with.
 
D

Davetheclown

Guest
#6
there was a theory that when a bubble implodes it generates heat hotter than the surface of the sun, problem is it at such a high speed that it cannot radiate, convect the heat created.
 
D

Davetheclown

Guest
#7
This one's simple enough, until you get to the second quote of my post which discusses the complex scientific stuff.

As someone who's self taught and didn't even do physics GCSE (my own field being history) I struggle with trying to make sense of it and some of it reads as gibberish, the vague outline suggests the composition of the gas in the bubble has an effect on the intensity of the light and the surrounding water is responsible for the temperature variation. Someone clever will probably come along and explain it in words better than I. I thought it was an interesting topic not for its complexity but moreso for the mystery. Light from bubbles? Whoda thunk it!

It does make me wonder whether the origins of the universe might have had a similar cause, although for this mini explosion and release of light you still need a bubble there to start with.
get a large sugar crystal, and a pair of stubnose pliers, place the crystal in the jaw and apply high pressure very quickly, you will get a spark. Similar effect is seen in piezo crystals, these however are stronger.
 
#8
Um.........When subjected to sound do the particles vibrate within the bubble, creating friction, and heat and light, upon bursting the heat is disapated due to the surrounding cool liquid, but as energy can neither be created or destroyed it has to take the form of light? Thats my theory anyway, hopefully someone will come along and burst my bubble.
 
#11
light is vibration in a further dimension, what we see as light is the tip of an iceberg , so to speak. Same with forces like gravity.

Imagine you are a 2d bug crawling on a flat sheet of paper, all 2d only,. But then a 3d person crumples up your paper sheet and makes a hump and a trough in the formerly flat surface. The 2d bug crawling along its surface 2d world cannot know it is going "up" or "down"... SO... and this is the biggy.... it describes certain bits of its (now crumpled in 3d) world as "easygoing" when going down the hump and "hardgoing" when going up the hump. In short it experiences an unseen FORCE... when as 3d outsiders, we can explain its force phenomenon in simple terms of geometry .

What we see as light, a 7d creature will see as just a part of the geometry makeup of his 7d universe
 
D

Davetheclown

Guest
#13
light is vibration in a further dimension, what we see as light is the tip of an iceberg , so to speak. Same with forces like gravity.

Imagine you are a 2d bug crawling on a flat sheet of paper, all 2d only,. But then a 3d person crumples up your paper sheet and makes a hump and a trough in the formerly flat surface. The 2d bug crawling along its surface 2d world cannot know it is going "up" or "down"... SO... and this is the biggy.... it describes certain bits of its (now crumpled in 3d) world as "easygoing" when going down the hump and "hardgoing" when going up the hump. In short it experiences an unseen FORCE... when as 3d outsiders, we can explain its force phenomenon in simple terms of geometry .

What we see as light, a 7d creature will see as just a part of the geometry makeup of his 7d universe
your meant to wear the tin foil not eat it!
 
#19
Theres also a short novel about a 2d land.. all the shapes social status is determined by how many sides they have, so circles are the lowest, and dodecagons (12 sides) the highest. Mr square is a normal shape going about his business when he meets Lord Sphere, who appears in front of him as an expanding then contracting circle, as he passes through his 2d world (cos hes 3d, but no one in flatland can see him geddit ?) Mr square gets put into a looney bin when he describes this phenomenon to the other 2d shapes... because its impossible in flatland.
 

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