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Cold Fusion-Whats the deal

  1. Dec 1, 2003 #1
    So what is the deal with cold fusion these days what is hindering the progress of an ubundace of energy?
    Please Explain
    [?]
     
  2. jcsd
  3. Dec 1, 2003 #2

    HallsofIvy

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    Basically, what's hindering the development of cold fusion reactors that will give us an abundance of energy is that it doesn't work!

    The original experiments were flawed and no one has been able to produce any evidence that cold fusion works.
     
  4. Dec 1, 2003 #3
    Its too greater' theory to live down and cast off i believe, this is just history repeating itself, 'We will never be able to fly' etc.
     
  5. Dec 1, 2003 #4

    jcsd

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    There are two main approaches to cold fusion: electrolytic and muonic.

    The electrolytic approach was the subject of a hoax/poor scientific method whioch generated a lot of hype at the time, it's now generally agreed that it is physically impossible to acheive cold fusion via this method. As far as I know it is possible to acheive cold fusion using the muonic method, but it really isn't pratical due to the very short half-life of muons.
     
  6. Dec 1, 2003 #5

    russ_watters

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    I have argued that the very term "cold fusion" (or how about "chemically catalyzed fusion"?)is a contradiction. I can't remember who now (may even have been in a different forum), but someone argued that though the water bath could be at room temp, some atoms could still reach energies required for fusion. I don't buy that and still consider it an oxymoron. Otherwise you could define your system to as big as you want and at some point, the system as a whole can be considered "cold." In my view, if the individual atoms fusing together are of an energy level associated with fusion, thats "hot" fusion. In "cold" fusion, it appears the goal (current websites are sufficiently vague there is some question here) was to get the individual atoms to fuse at energy levels not normally associated with fusion: a physical impossibility like you said.

    In any case, I haven't heard of the muonic method.

    The sound barrier and flight itself are often touted as examples of science saying something is "impossible" only to be proven wrong. This is NOT the case. Scientists always knew that flight and supersonic flight were theoretically possible, after all, we've seen birds fly and bullets have been supersonic for about as long as we knew of the sound barrier. The problem was always an ENGINEERING one.

    So to be concise:
    -Engineering barrier: we don't know how to do it yet but know it can be done.
    -Physical/theoretical barrier: the laws of physics prevent it.

    Cold fusion falls under the second category.
     
  7. Dec 1, 2003 #6
    My physics is a little rusty compared to some of the others on the board, but I heard about work which involved acetone or some other hydrogen-rich hydrocarbon (IIRC) and collapsing air bubbles within it. Apparently, viscous effects aside, the collapsing bubbles would generate temperatures sufficient to initiate fusion as their radius tends to zero. From what I remember, the scientists who did work on it reported a steady stream of neutrons (apparently a sign of fusion) but it has not been independently corroborated. People are questioning as to whether there was a mistake/malfunction in the original researchers technique/apparatus, or if the others trying to duplicate the results actually did duplicate it exactly.

    Russ, to comment on what you said regarding the superfluous nature of the hot/cold fusion label, I agree in its current state it is a bit ambiguous, but I think the temperature label applies to your supposed reacting fuel. So for a Tokamak it would be the confined hydrogen, for an acetone-based experiment, the acetone sitting in the beaker.

    A lot of scientists also don't want to get involved in that field, because after all the false/misreported results, it has become quite taboo. Personally, I am hedging my bets.
     
  8. Dec 1, 2003 #7
    Getting fusion to occur on a lab bench has been done decades ago. The trick is getting it to break even, and this sonoluminesence experiment you cite never even came close. And to my knowledge this was never duplicated anways.
     
  9. Dec 2, 2003 #8
    Humm, in chemistry there is a phenomenon wherein a proton captures and electron, becoming a neutron, low temps 9If I recall properly) sorta a form of a 'fusion' event, so maybe there are conditions we simply haven't found yet.

    That is part of the problem, don't want to waste funding chasing a dead horse, don't want to 'kill' what might be "in the bag" (hidden) by not having spent the money to look, cause it might just be a really fast racehorse. (so to speak)

    Research sometimes pays off the most by proving itself as un-rewarding, just that that takes time, as it is (sorta)like proving a negative.
     
  10. Dec 2, 2003 #9

    mathman

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    This is not a chemical process! It only happens for very energetic collisions. At ordinary temperatures, you simply get hydrogen.
     
  11. Dec 2, 2003 #10
    An interesting book dealing with this subject is "Bad Science: The Short Life and Weird Times of Cold Fusion," by Gary Taubes.

    Be warned, he's sometimes not so nice to Pons and Fleischmann. Frankly, they deserve all the scorn they get.
     
  12. Dec 2, 2003 #11
    Humm, agressive responce, I said "in Chemistry" as I had learned that little tidbit of knowledge about the proton capturing electrons from My Chemistry Book so you have (sorta) 'shot off' in a (kinda) wrong direction, plus I never said the "cold fusion process" (which does produce hydrogen) in this 'reaction', it was seen as an occurance in a chemical reaction,(? Do I recall that properly?) and I suspect its been known of well before 'Cold Fusion' had ever been heard as words.
     
  13. Dec 3, 2003 #12

    mathman

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    Could you clarify what you mean? Fusion processes start with hydrogen, deuterium, or tritium, and end up with heavier isotopes.
     
  14. Dec 3, 2003 #13
    I haven't specified 'cold' myself, simply looking at fusion, and there is a place wherein protons capture electrons, to become neutrons, NOT at elevated extremes of temp, NOT at elevated extremes of pressure, either (as I recall)....demonstrates that some of the inner nuclear particles do things we haven't yet understood/figured-out.
     
  15. Dec 3, 2003 #14
    so what exactly is MUONIC fusion?
    (thats if I spelt it correctly):wink:
     
  16. Dec 4, 2003 #15

    jcsd

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    Basically it uses a muonic hydrogen atom, where the atom's electron has been replaced by the electrons heavier cousin, the muon. A muonic atom has a smaller radius than an electronic atom, which menas that nuclei can get closer together aiding fusion, it also catalyses itself as more muons are produced when nuclei fuse, but the problem is muons have a very short half-life which greatly reduces the chain reaction.
     
  17. Dec 4, 2003 #16

    drag

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    Greetings !
    But, hot fusion occurs in plasmas. What you're describing
    is then a type of cold fusion ?

    Also, anybody heard of any new advancements in particle accelerator
    based fusion ?
    I read some patents a while back and personally it seems
    promising, of course, I know rather little on the subject.
    I mean it's enough for you to accelerate deutirium at about 4 KeV
    to get 1,000 times more enery from the fusion reaction, that
    is, IF - and that's a big "IF", you can make a linear system in which
    more than one of a phousand electron pairs will fuse - to allow
    you to break even or use a circular accelerator with several
    times lower collision rate and low energy losses.

    Live long and prosper.
     
  18. Dec 4, 2003 #17

    jcsd

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    Yes, muonic cold fusion is cold fusion. As I said before I really don't know the current scientific view on it's viabilty, though it does have the big problm of the muons incredibly short half-life.
     
  19. Dec 4, 2003 #18
    And a link to electron capture *Here*
     
  20. Aug 20, 2008 #19

    gdp

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    True.
    False. The fusion reaction releases many times less energy than is required to create another muon. The muon mass is 105.7 MeV/c2, while the D+T reaction only releases a mere 17.6 MeV --- or only a bit more than 16% of the minimum energy required to produce another muon.

    Moreover, for a collision to actually have a significant probability of producing another muon requires a "beam" energy closer to 1--3 GeV. (Muons are a product of pion decay, and pions are only copiously produced during high-energy collisions.)

    However, the D+T reaction does release enough energy that the muon has a high probability of being freed from the alpha-particle reaction product, which allows it to carry out another cycle --- so in that sense, the reaction is "catalytic:" the muon increases the probability of a fusion reaction, without itself having a high probability of being "used up" during the process.

    Current estimates are that a muon would need on the average to catalyze at least 200--500 reactions to achieve "breakeven" before it decays --- but unfortunately, this is larger than the average number of reactions allowed by the muon "sticking probability" (probability that the muon will not be freed from the alpha particle after the reaction).

    There is a good discussion of muon-catalyzed fusion in the Wikipedia.
     
  21. Aug 21, 2008 #20

    ZapperZ

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    Just so you know that you are replying to a thread that had its last activity (till now) in 2003! I think the ship has left the port a loooooong time ago.

    Zz.
     
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