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Desktop Cold Fusion Reconsidered
Armchair Anarchist writes "Nature.com reports on Rusi Taleyarkhan of Purdue University in West Lafayette, Indiana, who is once again claiming to have achieved ultrasound-induced fusion in deuterium-enriched acetone. Other experts are sceptical, but Taleyarkhan is keen to have other scientists check his results."
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From the article:
The idea is simple enough. Blast a liquid with waves of ultrasound and tiny bubbles of gas are created, which release a burst of heat and light when they implode. The core of the bubble reaches 15,000 C, hot enough to wrench molecules apart.
This isn't cold fusion, it's just a sneaky way of achieving hot fusion without huge x-ray lasers and giant magnets and such.
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"Although the neutron count doubles at some points in the experiments, Putterman says that neutrons produced in random showers of cosmic rays, rather than fusion events, could be responsible. But Taleyarkhan points out that the neutron count was smaller in detectors further from the reaction chamber.
To prove that the neutrons are coming from fusion as bubbles burst, Putterman and Suslick suggest that the team closely monitor exactly when the neutrons appear. The current experiment simply counts up the number of neutrons detected over minutes, so correlations with bubble bursts cannot be seen."
They are NOT yet sure whether the neutrons come from bubbles or from cosmic rays.
So let's not start the usual jokes about using car stereos to power cars, sound waves harming swan ears, etc.
"Doing what i can, with what i have." ~ Burt Gummer
A byproduct of this research has led him to create the variable velocity bullet. You can read more here: http://inventors.about.com/od/tstartinventors/a/ve locity_bullet.htm
http://religiousfreaks.com/Here's the most important part of the article: "There is one big problem, however: the experiment doesn't always work, and the group is not sure why." Until they figure out what's going on, the group really hasn't advanced much beyond what is already there.
Also I'm interested in seeing other try to replicate their experiment. That will be the ultimate test as to whether their methods are valid or not.
Cold Fusion should focus on the server where it belongs. The desktop is just a pipe dream.
The real test of whether cold fusion is for real is not scientific. It is economic. When someone opens a cold fusion power plant which sells more power than it consumes, you'll know it's the real deal.
Ceci n'est pas une signature.
Unjustly dismissive. First off, even initially, Taleyarkhan rallied about as much support as he did opposition. Now, even much of his initial opposition considers his work valid. Sonofusion seems to be quite a real phenominon (albeit, currently six orders of magnitude from breakeven).
Here's a very interesting paper by him in Oct. 2005, in which they discuss many of the recent developments, including the potential for nonlinear scaling of efficiency and even the possibility of criticality. It's a very interesting read.
The *special* hell.
So apparently I'm wrong.
Oh, and apparently the new MacBook Pro produces energy too.
Nuclear Fusion is most certainly possible. However, in order for it to be useful (at least for power production purposes) the energy output must surpass the energy input. In the article it looks like (and I'm not sure if it is even true) the "ultrasonic" waves introduce enough energy into the liquid to separate molecules, which in turn fuse together and release energy.
So, the "cool" aspect of this technology is *not* that ultrasound can wrench molecules apart, but that the molecules release energy upon "fusing".
Regardless of however, "cool" this is, it is still quite impractical. Perhaps if the energy released was in the form of heat instead of "light" then a chain reaction could occur. We'll I just hope that humanity invests in the "basic" research necessary to create useful technologies from this. At a minimum, it is very interesting!
Matthew Wong.
The reason their experiment only works "sometimes", is because the US Military Industrial Complex is in cahoots with Big Oil and is using alien technology from the Rosswell crash to constantly alter the laws of physics in close proximity to any attempted Cold Fusion reactions.
--
Don't believe the hype; Tinfoil hats work.
Cold Fusion. And, I quote, "I'll believe that when me shit turns purple and smells of rainbow sherbert."
/dev/random
Undue harshness given the state of the literature. It *has* been reproduced extensively, so those comments are completely incorrect; the main controversy is about the level of radiation emitted. Subsequent experiments in better conditions have reduced much of the criticism.
However, good comments on fusion's radiation. Even prized "pure" fusion reactions, such as B11+p, produce nasty radiation because you get some p-p fusion, you get some of the alpha particles (He4) as fusion reactants, even a tiny B12 or Dt impurity will dramatically increase the radiation levels, and all sorts of other problems.
The good thing about radiation from fusion reactors is that the fusing materials generally aren't "hot". The only problem is that irradiation of the reactor chamber itself can leave it radioactive; however, proper selection of construction materials can ensure that it has a short halflife, making reactor part disposal much less controversial.
The *special* hell.
We've got diesel from algae, electricity from trees, and now Mr. Fusion! We're saved! Woo Hoo!
San Francisco Photographers
Perhaps if the energy released was in the form of heat instead of "light" then a chain reaction could occur.
Incorrect. First off, you get light even when there is no fusion; the light is simply blackbody radiation of very hot material that was heated by the coalescing of shocks from bubble collapse in a very small region. The *fusion* gives off most of its energy as high-energy neutrons.
It's six orders of magnitude from breakeven currently, but has a lot of potential to scale up, including potential for criticality. Will it actually pan out as a valid energy source? Who knows; it's still in its infancy.
The *special* hell.
I hope it was the exploding grapes in a microwave that got modded "Informative" and not the South Park reference. :D
The Chewbacca Defense
(That link is pretty damned cool, by the way.)
DATABASE WOW WOW
"Sceptical" is the British spelling, you wancre.
Let's assume they can increase efficiency enough orders of magnitude they get much more heat out than they put in. Clearly they won't be able to run the "reactor" at super high temperatures, since it depends on the liquid phase of the water to work. So how will they extract enough electricity out of a relatively small temperature gradient to make the whole thing worthwhile?
Even before getting to any goal of practical power generation, the most important thing in a scientific investigation is to structure it to avoid doubts -- meaning either proving or disproving it completely. There's no dishonour in disproving it, if it helps to clarify what the remaining fusion possibilities are. Dr Taleyarkhan should have specifically monitored the neutron outputs to see if they had any cyclicality that coincided with the bubble oscillation cycle. If you get neutron spikes when the bubbles implode, then that's a very helpful sign consistent with acoustic fusion occurring. Why a big scientist like him didn't do such an obvious thing worries me. But the article says that Putterman et all will be working to duplicate his experiments. Duplication is really the essential thing for proving something. After all, if it only works when Taleyarkhan does it, but not for anybody else, then you know something's wrong.
PWRs only work if the water is in a liquid state, too ;) Now, pressure may end up being bad here, but still, it's just an issue of how quickly you can draw off heat from the core. Also, since the neutrons contain most of the energy of the reaction, you could have them tend to be absorbed in a different chamber than the core.
The *special* hell.
... and he's a freakin' genius. He taught us very briefly about his work, but was hesitant when I took the class to go into a lot of details because of the pre-publication nature of the work. The TA for the class, Adam Butt, is also a very quick guy. Although I recognize the possibility of fabrication, all the people I know around the project were hesitant to make claims until they had better proof. They are still hesitant to proclaim victory. All things considered, I think this is the most promising energy work since the Manhattan project.
Guess I don't need to buy the 1kW power supply for this system, or...?
Now, if they also would come up with a laptop cold fusion unit...
During the first cold fusion flap, back in the 1980s, I went to a talk by a physicist at Stanford who was trying to replicate the experiment. He mentioned that when they first started, they had radiation alarms set up around the equipment, but after a while, they moved those back. They measured neutron levels around twice background on occasion, but realized that people around the experiment were acting as neutron reflectors for background radiation and affecting the results. So the whole experiment was moved into a cube of lead bricks, after which no neutron emissions were observed.
Bear in mind that it's not that hard to generate fusion. There have been fusion lab setups since the 1950s. There are many ways to force large amounts of energy into a small volume and thus create the conditions for small-scale fusion. The hard part is getting out more energy than you put in.
The thing I think is interesting is perception of difficulty. I have an idea:
We'll get a multiple-hundred-ton platform, and float it on the open ocean. Despite currents and storms, we'll send a 10-inch drill bit down 1-3 kilometres in to the ground below the ocean. From there we'll drill into a big oil resivoir.
Then we'll pump the oil up - without spilling it. We'll somehow load it onto ships, and distribute it all around the world.
When you think about it, this is bloody amazing. It shows what we can do if we put our minds to it. Granted - the oil industry has a bit of a headstart over cold-fusion, but we must recognise the limitations of oil and pursue other options.
The scientific comunity is more like the Mafia an anything else. The idea of cold fusion is not a theory it is a fact ( this is why helium is minned ). Cold fusion happens every day inside the earth, people just don't know why or how it happens. The real problem is that the scientific community is more like the Mafia, it is not and open minded industry for enlightenment it is more like the Catholic church during Gallileos time. When pons and fleishman published their experiment they essentially threatend all of the very expensive plasma and laser bassed fusion projects and because of this it was shut down, instead of investigating the phenominae of cold fusion it was instantly ostrisized. Plasma and lasers will never work in the arena of fusion and they will just continue to suck up money and resources but the scientific comunity is backing that technowlogy and they will never acknolege any other method of fusion until the money has run dry and they are considered the fools that they are. we should be investigating and trying to replicate what is happening in the earth, but doing so wil kill your carreer.
As long as the fusion is happening within water, you'll deposit some energy inside the core. But let's say you've found a way to minimize that, and you've got a surrounding chamber that can go superhot. A few issues to contend with are
1) Heat flux. How do you ensure that the sono chamber stays cool while right next to a much hotter system?
2) Neutronics/materials. The wall(s) keeping the systems from mixing are going to see a whole lot of fast neutrons, which is a big problem. You have to pick a material that holds up well under fast neutron flux + heat.
These two issues are, ironically/unsurprisingly, two of the issues "conventional" magnetic fusion faces. In such a device, you've got vacuum pumps that run at cryogenic temperatures (1), and a so-called 'first wall' that sees a whole lotta neutrons over its operating lifetime (2). Needless to say, we don't have good solutions to these problems yet.