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More Evidence for Tabletop Fusion
heptapod writes "Researchers at Purdue University have statistically significant evidence that their tabletop fusion experiments were successful. Yiban Xu's experiment different from an earlier Oak Ridge experiment using a different and cheaper source of neutrons than Oak Ridge's pulse neutron generator. Surpassing break-even point still eludes the grasp of science."
Will we get it before or after Duke Nukem Forever?
Statistical evidence of fusion at this level is indeed impressive; however, while fusion experiments such as this others remain below the break-even point, they shall yet be little more than a labtable source of neutrons. We await developments from the latest in the field.
Are they counting break-even as getting back more energy than needed to operate the ultrasound source ou they did count also the expense of producing the deuterated acetone and their expendable neutron source?
It reminds me of when people say hydrogen burning cars will solve all emition problems because they produce water. They don't count the emissions that may be needed to produce, compress and ship the hydrogen to the nearest gas station.
http://www.dieblinkenlights.com
So... that Mr. Fusion I ordered off of eBay will actually work?
#define CLUE 0
Breakeven is defined as the point at which the fusion gain factor equals 1. In other words where the ratio of the power output of the fusing plasma is equal to the energy needed to maintain the plasma in a fusing condition. Thermonuclear devices by definition reach breakeven and ignition with high gain.
If you are referring to the energy required to produce the plutonium and to separate the deuterium from water then they still VASTLY exceed in energy output the energy required to produce these things, as a typical fusion bomb is capable of releasing energies in the PETAjoule range (>10^15J).
- "Hear that?! The percolations are imminent! Cease your ingress!"
"When it's time to railroad, you get railroads." Or however the saying goes.
This question is one I've been thinking about for a few years now due to an idea for an invention I've got (not cold fusion, though), plus some stories I know of. The most relevant one is an episode of Outer Limits (the series from the 90s, not the one from the 60s).
In the story, an expelled physics student detonates a small 'cold fusion bomb' in a campus clocktower as proof of the technology, then takes a physics class hostage with another device. He demands that the people who have tormented him in the past be brought to the courtyard and shot in front of him, or he'll detonate the more powerful device he's got with him.
While the military is trying to figure out what the hell it was that detonated (since they don't believe in a cold fusion bomb), the negotiator is trying to figure out what the deal is with the hostagetaker. It comes out that, among other things, he believes there's a reason we've not found any signals from other species. The cold fusion technology is so simple that anyone can make it. When a species gets advanced enough to realize how easy cold fusion is, he says it's inevitable that a species will destroy itself before it can get mature enough to handle its technology. The negotiator then says, well, tell us what led you to the idea, and we can try to steer science around that until we can mature enough to handle it. The guy thinks back to what started him on the path to cold fusion - a physics test with the question, "Demonstrate why cold fusion is impossible."
I'd say it's inevitable that we WILL have this technology. How simple it winds up being is unknown at this point, of course, but hopefully it'll be complex enough that not every nut in a garage can do it.
I think this has some potential for abuse. Do we want this power to get into the wrong hands?
That's the very question currently being asked at the Pentagon. Just what will our government due when a drop on productivity is caused by millions listening to music with an ever-lasting battery in their iPods?
Life is not for the lazy.
It reminds me of when people say hydrogen burning cars will solve all emition problems because they produce water. They don't count the emissions that may be needed to produce, compress and ship the hydrogen to the nearest gas station.
The trick with this one is in the may.
Maybe someday we'll find a technology that's clean-burning and energy-efficient to the point where oil is no longer the most cost-effective way to make energy. Say, maybe nuclear fusion. Or maybe oil will eventually get so expensive that other energy technologies start to look not so bad by comparison. But if we ever reach this point, because of the massive installed base and economies of scale of oil systems, especially the ones in cars, we and our economies will still be dependent on oil. So it won't matter that the newer technology is better, we'll keep using oil anyway. That's bad.
Hydrogen may at first be ultimately dependent on "dirty" oil and coal to make the hydrogen in the first place, but because it decouples energy production from energy use, in the long run it gives us the capacity to move on to better energy sources. It's like a nicotine patch, okay, it technically doesn't address the addiction but the thing is eventually you get to take the nicotine patch off.
On top of this, there are situations where if you can't eliminate emissions, moving the emissions is a desirable second best thing. Like, of course we're not making advances in our contribution to global CO2 levels if all these cars in the city burning oil are replaced with a bunch of cars burning hydrogen [PLUS] one huge smoke-belching oil-burning hydrogen plant. But, well, if the city is Los Angeles, and the city is basically one huge smog-trapping bowl surrounded by mountains, and the smoke-belching hydrogen plant is on the other side of the mountains, then never mind the global CO2 levels, you've still made Los Angeles a significantly more pleasant place to live.
Irritable, left-wing and possibly humorous bumper stickers and t-shirts
Seems pretty easy to me:
Step One: Build a sonoluminescence apperatus using an ocilloscope, a sine generator, audio amplifier, piezo transducers and spherical flask. Details here: http://www.physik3.gwdg.de/~rgeisle/nld/sbsl-howto .html
Step Two: Build a neutron supply source, problalby most easily constructed is a farnsworth-type fusor: http://en.wikipedia.org/wiki/Fusor (makes a great science project too)
Step Three: Get some deuterium and dissolve it in acetone, place in your sonoluminescence apperatus and start tuning it to produce bubbles. Availible at your local scientific supply store.
Step Four: Build your own neutron detector and confirm the bubbles are producing fusion: http://home.earthlink.net/~jimlux/nuc/ncount.htm
Step Five: Become the envy of the neighbourhood as the only guy on your block with a nuclear fusion device in your garage! (to avoid police suspicion call it a magical glowing bubble maker)
Step 6: Profit!
Where's the nuclear powered car we were promised back in the 1950s?
Some genius figured out that providing every man, woman, and child with sufficient nuclear material to create an atomic pile wasn't such a good idea?
From a technology perspective, there were a few other problems as well. Off the top of my head:
- Radiation: You need a lot of shielding to stop the "hard" stuff like Gamma, Neutron, and X-Ray bursts from escaping a functioning pile.
- Weight: All that shielding results in a lot of extra weight.
- Inefficiency: A "simple" atomic pile may be relatively safe (from a runaway reaction perspective), but it's not particularly efficient, nor can it be actively controlled.
In any case, the Ford atom car was never seriously developed. It was just an "Atoms for Peace" idea that was kicked around as a promotional gig.
A far better use for nuclear tech is in Merchant ships. Today's merchies pay extraordinary amounts for diesel fuel, have limited range, and burn fuel at the rate of gallons per feet. Nuclear reactors could provide these ships with more cargo space (no fuel tanks!), greater speed, longer endurance, and better turn-around times.
Unfortunately, the case of the NS Savannah turned off the private sector to the idea of a nuclear merchant ship. There was no real problem with the ship herself, but rather the fact that she was ahead of her time (crude was still VERY cheap back then) and one of a kind (no infrastructure to support her) meant that she couldn't compete in the market.
The equation today is a very different one from the equation back then, but concerns related to the control of reactors and nuclear fuels have placed road-blocks in the way of reviving the idea.
Javascript + Nintendo DSi = DSiCade
5+ standard deviations against the control is interesting. Should be easy to reproduce. (or not).
"A language that doesn't affect the way you think about programming, is not worth knowing" - Alan Perlis
However, as a geek, I know that the Dark Ages were as much caused by the change in the fuel economy from wood to coal as the retreat of the Roman Empire.
However, as a pastry chef, I know that the Krebs cycle causes metal fatigue in steel structural support beams.
However, as a ballerina, I know that the Pythagorean theorem causes the release of neutrons from radioactive material.
However, as a professor of French literature, I know that penicillin causes cost overruns in long-haul LTL shipping.
All employees must wash hands before seeking equitable relief.
So you're worried that this might lead to a technology that could devastate the earth? I guess you've never heard about Nuclear Weapons, some of which are in the hands of some not so wonderful people, such as Kim Jong Il of North Korea. Sorry bud, you're trying to close the barn door after the horse has already left, about 60 years to late I might add. On the other hand, if this were an easy way to make large amounts of U-238 and Plutonium then I might be worried.
Not only that, but fuel for very large diesel engines contains lots of residual oil, and is very high in sulfur. 5000 ppm plus. I understand that England recently traced the source of some acid rain problems to maritime activity. They've practically eliminated their sulfur output from coal power plants, etc, so boats are now the biggest producer.
That heavy diesel fuel is nasty stuff. Basically, its what's left over after they boil off all of the gasses, gasoline, kerosene, road use diesel fuel and the lower grade heating oils. They have to pre-heat it quite a bit to get it to burn in an engine, otherwise it's about as good as filtered crude oil--slightly less viscous.
Nuclear power would be a huge step forward in this area... I can't agree more. Throw in some modern reactor and propulsion designs and you'd have a terribly efficient and manuverable ship. Might even make fuel a bit cheaper for the rest of us if it caught on... Bonus.
Constitutional rights may be respected, repealed, or modified; but they must never be ignored.
You can get tabletop fusion with a TV high voltage supply, a glass bulb, some wire, and deuteriums gas. That's been known for decades and is used as a neutron source commercially. People build those things for science fairs. It's called the "Farnsworth Fusor" (I know, in light of Futurama it sounds like a joke, but the fictional character was named after the real one).
Why don't we all have flying cars, then? Because you can't get a net energy gain with the Farnsworth Fusor--it seems to be impossible in general to do so, the numbers just don't work out.
Of course, even if you do make it efficient, it's not exactly "clean energy": even with so-called aneutronic fusion, a few percent of the fusion reactions will generate neutrons, which, for realistic power generation, results in a neutron flux that causes the power generation to be quite dirty. Not as dirty as fission--disposal should be easier--but don't expect something harmless you can just run in your basement.
So, tabletop fusion isn't really anything impressive: there are probably lots of ways of getting fusion on your tabletop. The question is how you make it efficient enough to useful amounts of energy out of it. And cavitation seems no more promising there than inertial confinement in the Farnsworth Fusor. But maybe if enough people keep playing around with this, someone will get lucky and find something that works.
There was a BBC Horizon documentary on this nuclear fusion sonoluminescence phenomenon that casts strong doubt on the validity of previous work conducted by this researcher. The acid test for the occurence of fusion is the release of a neutron at the exact instant that the flash of light from sonoluminescence occurs. The Horizon team used a detector that can record the neutron releases at the required instant in time. After recreating Taleyarkhan's experiment according to his published journal papers, results were disappointing. None of the neutrons that were detected occurred at the same instant of any of the sonoluminescence flashes. The extra neutrons were explained away as originating from the emitter used to generate bubbles, or from external sources. No doubt rivals will challenge the statistically significant tritium claim. Tritium does occur naturally in significant quantities in any mass of heavy water (deuterium oxide).
About coal being worse than nuclear, I have not the best references, but here are a few:
/ FS-163-97.html / colmain.html
http://geology.cr.usgs.gov/energy/factshts/163-97
http://www.ornl.gov/info/ornlreview/rev26-34/text
http://yarchive.net/nuke/coal_radiation.html
Remember the year 2000? They promised us flying cars. They delivered the PT Cruiser...