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."

Defending cold fusion and talkin' about Chewbacca!

Why would a Wookiee, an eight-foot tall Wookiee, want to live on Endor, with a bunch of two-foot tall Ewoks? A microwave can to create a plasma cloud using a grape [barnesos.net]. If Chewbacca lives on Endor, then the popping of tiny bubbles triggers nuclear fusion. The defense rests.

Conjugatin' the emancipation proclomamation...

I hope it was the exploding grapes in a microwave that got modded "Informative" and not the South Park reference. :D

The Chewbacca Defense [wikipedia.org]

(That link is pretty damned cool, by the way.)

Not Cold Fusion

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.

Re:Not Cold Fusion

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.

Bingo. And this is one of 50,000 articles that Slashdot has had on Sonofusion. The long and short of it is, there's lots of light and neutrons when some tiny bubbles pop. Some scientists think it's fusion. If it is fusion (as predicted), there's no current way to make it energy positive. However, it will make a nice desk ornament right next to your Farnsworth-Hirsch Fusor [wikipedia.org]. (Which is also table-top, BTW.)

Re:Not Cold Fusion

There's no current way to make it energy positive

It's currently six orders of magnitude from breakeven.

  * The addition of tritium into the mix should automatically make it three orders of efficiency better. In fact, even starting with deuterated acetone, it would eventually breed enough tritium to make a difference.

  * There is no reason to believe the current starting conditions (the solution used, the temperature and pressure used, the frequency of the ultrasound, etc) are anywhere close to optimal.

  * There is potential for faster than linear scaling. The more efficient it gets, the larger the bubble clusters you have; the shock waves from multiple bubbles in a cluster interact to produce stronger shocks.

  * There is potential for criticality in theory, in which neutrons from one reaction seed bubbles at its acoustic anti-nodes at the time in which they're under maximal tension.

So, no, there is no reason for your fatalistic attitude. *Will* it pan out? Who knows, but it is definitely worth investigation, just like the concept of fission criticality was early this century.

Re:Not Cold Fusion

Not cold fusion because it's at 15,000 degrees? Sure it is.

http://www.foresight.org/Conferences/MNT05/Abstrac ts/Donoabst.html [foresight.org]

In practice, an ignition temperature of 400M K is needed to compensate for lost energy

Even the lower temperature of only77 million degrees makes 15,000 degrees look positively arctic. Being able to do it in a container without magnetic containment in a vacuum ... well, sounds like cold fusion to me.

Before you jump to conclusions...

Before you jump to conclusions like the Robot Lawyers episode, here's a scrap from the article:

"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.

Re:One thing screams "HOAX!"

From their Oct 2005 paper [rpi.edu] ...

It is significant that 2.45 MeV D/D fusion neutrons were measured only when chilled, well-degassed, cavitated D-acetone was used. That is, no neutrons were measured when room temperature D-acetone, or as expected, normal acetone, was used.

So the obvious and cheap control was done after all.

A biproduct of this research...

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 [about.com]

http://religiousfreaks.com/ [religiousfreaks.com]

this has come up again?

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.

My recommendation

Cold Fusion should focus on the server where it belongs. The desktop is just a pipe dream.

how how to tell if its for real

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.

Re:how how to tell if its for real

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.

This is true in a pretty strong sense. If it was possible to extract large amounts of energy by inserting pins into effigies of (say) Britney Spears or Tom Delay, and we didn't know why it worked, that wouldn't erase the basic fact that you could get energy out of torturing dolls.

The infuriating thing about "economic" is that it periodically annoints technologies which all Right Thinking Persons know are blasphemous, such as: Windows (compared to Mac OS or Gnu/Linux), or VHS (vs Betamax), or Infix Notation (vs Postfix), or MKS (vs CGS), or Vi (vs. Emacs), or Visual Basic (vs. Lisp), or the Dallas Cowboys (vs. the Green Bay Packers), or GSM (vs. CDMA), or Complex Numbers (vs. Quaternions), or the Hummer (vs. the Prius), or the body image of Kate Moss (vs. that of Scarlett Johansen), or that of Brad Pitt (vs. that of Jack Black), or ABBA (vs. Silkworm), or Old Coke (vs. New Coke); or George Bush (vs. George McGovern).

For all you nerd-kings and nerd-queens out there: ignore "economics" at your peril. That doesn't mean that you shouldn't ignore economics; it just means that you should ignore it at your peril. Occasionally weird things happen, involving (say) quixotically charismatic Finnish grad students. Some of them become cellists http://www.apocalyptica.com/home/ [apocalyptica.com], or hackers http://en.wikipedia.org/wiki/Linus_Torvalds [wikipedia.org], or radar waveform designers, http://www.eiscat.no/EISCAT/boards/discuss/0081.ht ml [eiscat.no].

You just never know.

light was a form of energy last time I checked...

Caption on the figure:

Imploding bubbles, caught on film emitting light. Are they emitting energy too?

So apparently I'm wrong.

Oh, and apparently the new MacBook Pro produces energy too [apple.com].

...but it wont surpass the "break even" threshold.

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.

Re:...but it wont surpass the "break even" thresho

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.

Conspiracy Theory

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

Cold Fusion. And, I quote, "I'll believe that when me shit turns purple and smells of rainbow sherbert."

What a day!

We've got diesel from algae, electricity from trees, and now Mr. Fusion! We're saved! Woo Hoo!

Experimental Improvement Needed

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.

Had this guy for class...

... 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.

Re:Cold Fusion

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 [rpi.edu] 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.

Re:Cold Fusion

I don't understand why so many people on slashdot are quick to dismiss this. Clearly there's something happening. Here's my question, though:

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?

Re:Glow in the dark scientist

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.

Re:sceptical?!

"Sceptical" is the British spelling, you wancre.