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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."
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
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!"
In fact, even the most modern thermonuclear devices have an efficiency ratio of "only" 20% or so. The "Fat Man" bomb dropped on Hiroshima (?) in WWII had a ratio of only 1.4%. It only looks amazing because it's all released at the same instant.
The indiscriminate use of vulgar language is the linguistic crutch of the inarticulate motherfucker
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
Ok, let me ask this. Why is this on AScribe and not on Nature?
I won't belive it until it's published on a peer reviewed journal.
I agree that mainstream fusion work will be important and is probably the right track toward a practical fusion powerplant.
However, remember that Cathode Ray tubes were also once little more than a labtable source of tightly controlled electrons. New sources of materials often lead into practical applications not originally envisioned.
It is impossible to enjoy idling thoroughly unless one has plenty of work to do.
- Jerome Klapka Jerome
Some hints as to the answer to this question can be found in the link you yourself have provided:
- The report of the panel after five months' study was that there was no convincing evidence for cold fusion
- Neither of these strategies has produced conclusive evidence that this cold fusion process exists
You may also note that despite fantastic claimed benefits, governments in general are indifferent to Dianetics. Why do you think that is?New sources of materials often lead into practical applications not originally envisioned.
This is so true. No-one making velcro thought it would be good for strippers. It took their wives to figure that one out.
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.
I would love to see some hard documentary evidence on this point. From my knowledge of history, it was precisely the use of coal as a fuel source that triggered the Industrial Revolution. Almost immediately prior to the widespread use of coal in England, the primary fuel source was wood or hydro power (for running mills and stuff). There was a huge debate in England at the time because the forests were visibly disappearing from all over the British Isles, and doom and gloom were predicted (as supposedly did happen at Easter Island). After coal was used in large quantities, England went from a largly agrarian lifestyle and small villages (London had only about 30,000 people in the year 1400) to a major industrial power. The use of coal had a major impact on that occuring.
When coal was finally excavated in large quantities, there was a need for bulk shipments of the stuff overland to larger concentrations of people who needed it. From this came railroads, steel production, mechanical and civil engineering, and a modern industrial economy.
As far as the Great Depression being caused by a shift from coal to oil, that is incredibly simplistic, and there were many causes for what happened, including a lack of securities oversight (triggering the Wall Street Stock Market Crash of 1929), overproduction of food stocks, preditory pricing companies, and reconstruction issues from WWI where the bill to pay for that awful war finally came due and had to be paid. Conversion from coal to oil may be there as a slight cause, but nearly as significant with those fuel sources was the conversion from passenger rail travel to personal automobiles... which really didn't happen until the 1950's in the USA anyway.
What a fusion energy economy would actually provide is a cheap energy source that would cause a huge expansion of economic resources for just about everybody, even in the most poor parts of the world.
It could be argued that the wealth a person has is determined by the amount of raw power that they have available to do what they want to accomplish. This is actual power, as measured in kilowatt-hours, joules, or whatever. If you want to increase the wealth of a region, you need to provide energy resources that will allow the people in that area to be able to accomplish whatever task they set their mind to accomplish. In this regard control of power is also control of political power, as utility companies are quite aware of.
What project like this tabletop device, a Fusor, or even Cold Fusion offer to provide is the potential that you don't need utility companies to provide this energy for you. If you need the power to run an air-conditioner, you just prime your fusion reactor with a little hydrogen gas and some water (to extract some more hydrogen gas). And not much water at that either. And no need for rolling blackouts or even power surges on the power grid.
Geeks successfully decentralized computing power, so why not power generation itself? I for one look strong with anticipation and excitement for the future this may bring.
BTW, I think it will be 1st world nations that will be able to take advantage of a hydrogen economy first before most 3rd world nations. If you look at China, they are incredibly heavy users of coal right now, with manufacturing plants that are actually producing steam-powered locomotives as new products (and hudreds to thousands of deaths every year in the coal mines from accidents). If anything the Chinese experience is that they have had to go through the entire industrial revolution, but at a greatly accelerated pace compared to most western European countries and North America. Africa is in political turmoil that almost seems to resemble what Europe was like in the early part of the 2nd millenium, and simply won't get much of anywhere (except for a few minor countries who get it) until they resolve their political issues and stop the nearly constant state of warfare in Africa.
I think you're using a different definition of efficiency, where "100%" is defined as converting all the mass of the weapon to energy.
In which case your figures are way high. Fission bombs only convert about 0.001% of their mass to energy, early fusion bombs about 0.007%. The latter figure may be higher for modern weapons, but no where near 20%, or even 2%. I might believe 0.02%.
-- Alastair