Physics Help Forum Nuclear fusion in collapsing air bubbles

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 Oct 17th 2018, 03:17 AM #1 Senior Member   Join Date: Apr 2017 Posts: 443 Nuclear fusion in collapsing air bubbles I wonder if members here have come across this ... also called sonoluminescence ... Small collapsing air/vapor bubbles in water , that can easily be created in the laboratory, can collapse so rapidly that fusion temperatures are reached. Ten years ago when I first heard of this it was very fringe science , now universities are investigating it ... This 2 min video is a good introduction ... topsquark likes this.
 Oct 17th 2018, 05:38 AM #2 Senior Member     Join Date: Jun 2016 Location: England Posts: 752 As I remember there was considerable controversy over some experiments that gave some rather ambiguous evidence of this effect. No problem over the ambiguous evidence, as Oz says subsequent investigations have firmed up the evidence. The problem was the rather wild leap made from the initial rather temperamental experiment (no one else could get it to work as advertised) to the prospect of nuclear fusion in a test-tube and consequent clean limitless energy. This was probably down to excessive excitement from the scientific team (possibly with an eye on funding) and inappropriate hype from the press. It almost killed the whole field of investigation. Slow and sober study since has shown that the pressures that occur inside collapsing bubbles can indeed be very large, leading to some very interesting possibilities for unusual chemical reactions (requiring high pressures) to be achieved without the need for expensive pressure vessels. The possibility of the pressures getting high enough for fusion is (I feel) still a bit of a speculation too far. __________________ ~\o/~ Last edited by Woody; Oct 17th 2018 at 08:40 AM.
Oct 17th 2018, 07:25 AM   #3
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 Originally Posted by Woody As I remember there was considerable controversy over some experiments that gave some rather ambiguous evidence of this effect. No problem over the ambiguous evidence, as Oz says subsequent investigations have firmed up the evidence. The problem was the rather wild leap made from the initial rather temperamental experiment (no one else could get it to work as advertised) to the prospect of nuclear fusion in a test-tube and consequent clean limitless energy. This was probably down to excessive excitement from the scientific team (possibly with an eye on funding) and inappropriate hype from the press. It almost killed the whole field of investigation. Slow and sober study since has shown that the pressures that occur inside collapsing bubbles can indeed be very large, leading to some very interesting possibilities for unusual chemical reactions (requiring high pressures) to be achieved without the need to expensive pressure vessels. The possibility of the pressures getting high enough for fusion is (I feel) still a bit of a speculation too far.
I agree. The pp-chain reactions in the Sun require a temperature of approximately 15 MK at pressures ~$\displaystyle 10^{16}$ Pa. Even if you could get reactions to occur at lower temperatures and pressures through some sort of technique (such as using particle accelerators, inertial confinement fusion, etc.), the high energy conditions required for fusion power are a unique and extremely challenging engineering problem with regards to the design of a fusion power generator.

The way I see it, research into fluid physics and materials science is cool and has its own merit, even if the conclusion doesn't lead to anything like fusion power. I mean... just look at the super-fluid helium studies... they're awesome and absolute barmy!

 Oct 17th 2018, 08:31 PM #4 Senior Member   Join Date: Apr 2017 Posts: 443 There were some excellent videos on this a decade ago ....I can't seem to find them now . A very good case was presented to explain the anomalous elemental composition in the oceans ...Too many heavy elements , like gold , these naturally would end up at the core during the earths molten stage... It was postulated that when meteors impact the oceans a great many collapsing bubbles occur, resulting in fusion producing very heavy elements ... It takes some time to get used to this idea ... we are brought up to believe only supernovas can produce heavier than iron elements. This also ties in with HOH ... the seemingly insane idea that feeding the products of electrolysis into an internal combustion engine can result in a net energy gain!!! Moray B King explains how this could be possible .... Last edited by oz93666; Oct 18th 2018 at 01:05 AM.
 Oct 18th 2018, 01:34 AM #5 Senior Member     Join Date: Jun 2016 Location: England Posts: 752 Getting enough pressure in a collapsing bubble to fuse hydrogen (deuterium or tritium) is stretching credence. Getting enough pressure to fuse higher elements is just beyond... The sort of pressures and energies needed to transmute base elements into gold are those found in supernovas. You are not going to get those sorts of pressures in collapsing bubbles. Running an engine on water with helium as your exhaust is a lovely dream, maybe one day, but the engineering required is sill way off. __________________ ~\o/~ Last edited by Woody; Oct 18th 2018 at 01:37 AM.
Oct 18th 2018, 02:10 AM   #6
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 Originally Posted by Woody Getting enough pressure in a collapsing bubble to fuse hydrogen (deuterium or tritium) is stretching credence. Getting enough pressure to fuse higher elements is just beyond... The sort of pressures and energies needed to transmute base elements into gold are those found in supernovas. You are not going to get those sorts of pressures in collapsing bubbles..
You clearly haven't looked at the science ... no doubt you'll believe it when it's on the news ...

Common sense might tell you it shouldn't be possible to get these temperatures from collapsing bubbles , but the light has been analysed from easily reproducible experiments ....

UCLA Experiment

 Originally Posted by Woody Running an engine on water with helium as your exhaust is a lovely dream, maybe one day, but the engineering required is sill way off.
And you haven't watched the second video ... nowhere is that suggested.

It's always best to look into a subject before jumping to conclusions

Last edited by oz93666; Oct 18th 2018 at 02:43 AM.

 Oct 18th 2018, 05:28 AM #7 Senior Member     Join Date: Jun 2016 Location: England Posts: 752 I have to admit that I haven't watched the videos my current computer set-up is refusing to work with them. __________________ ~\o/~

 Tags air, bubbles, collapsing, fusion, nuclear

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