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  • Paul BakerPaul Baker Posts: 6,351
    edited 2005-03-09 00:26
    I can see some wisea$$ state trooper stopping someone and saying "Son, I clocked you going 40 in a 25mph zone, whats so important that you have to drive faster than light in a bose-einstein condensate?". Granted if the average state trooper knows this tidbit, he is probably underemployed.

    Post Edited (Paul Baker) : 3/9/2005 12:32:38 AM GMT
  • SofalogicSofalogic Posts: 49
    edited 2005-03-09 01:18
    Wow reading this is too much fun. What was the original question? I also have a question relating to particle physics but I cant give anything away. I would truly like this question pondered, it would not be in contest from. Would this be the forum to start the thread?? Would parallax get mad if us true geeks (I mean that in a good way) start exchanging thoughts on life, the universe and everything on their forum??

    _______________________________________
    So long and Thanks for all the fish

    Sofa
  • MacGeek117MacGeek117 Posts: 747
    edited 2005-03-09 17:31
    Dr Evil, I got it from the book, Absolute Zero.
    bugg

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    But I canna change the laws of physics, Captain!
  • NewzedNewzed Posts: 2,503
    edited 2005-03-09 17:43
    Alas, there were no winner[noparse]:([/noparse](

    here are the answers I was looking for.

    What is the difference called:· It is referred to as "the packing fraction".

    What happened to it:· The difference in mass is converted to energy in accordance with the formula E = mc Squared.

    There will be another contest in a few days as soon as I can come up with a good question.· I would like to give this EEPROM to deserving Stampersmile.gif

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Sid Weaver
    NEW! 4 MB EEPROM

    http://hometown.aol.com/newzed/page4.html
    ·
  • MacGeek117MacGeek117 Posts: 747
    edited 2005-03-09 17:45
    Forgot about that.
    bugg

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    But I canna change the laws of physics, Captain!
  • Jim McCorisonJim McCorison Posts: 359
    edited 2005-03-09 17:54
    Sid,

    Nobody got what the difference is called. But Beau and JonB got the energy part right. Maybe you should dig out your bandsaw and give each of them 1/4 of an EEPROM. smile.gif

    Jim
  • Paul BakerPaul Baker Posts: 6,351
    edited 2005-03-09 18:08
    Disintegration of Uranium by Neutrons: a New Type of Nuclear Reaction said...


    Following up an observation of Curie and Savitch3, Hahn and Strassmann4 found that a group of at least three radioactive bodies, formed from uranium under neutron bombardment, were chemically similar to barium and, therefore, presumably isotopic with radium. Further investigation5, however showed that it was impossible to separate those bodies from barium (although mesothorium, an isotope of radium, was readily separated in the same experiment), so that Hahn and Strassmann were forced to conclude that isotopes of barium (Z = 56) are formed as a consequence of the bombardment of uranium (Z = 92) with neutrons.

    At first sight, this result seems very hard to understand. The formation of elements much below uranium has been considered before, but was always rejected for physical reasons, so long as the chemical evidence was not entirely clear cut. The emission, within a short time, of a large number of charged particles may be regarded as excluded by the small penetrability of the 'Coulomb barrier', indicated by Gamov's theory of alpha decay.

    On the basis, however, of present ideas about the behaviour of heavy nuclei6, an entirely different and essentially classical picture of these new disintegration processes suggests itself. On account of their close packing and strong energy exchange, the particles in a heavy nucleus would be expected to move in a collective way which has some resemblance to the movement of a liquid drop. If the movement is made sufficiently violent by adding energy, such a drop may divide itself into two smaller drops.

    In the discussion of the energies involved in the deformation of nuclei, the concept of surface tension has been used7 and its value has been estimated from simple considerations regarding nuclear forces. It must be remembered, however, that the surface tension of a charged droplet is diminished by its charge, and a rough estimate shows that the surface tension of nuclei, decreasing with increasing nuclear charge, may become zero for atomic numbers of the order of 100.

    It seems therefore possible that the uranium nucleus has only small stability of form, and may, after neutron capture, divide itself into two nuclei of roughly equal size (the precise ratio of sizes depending on finer structural features and perhaps partly on chance). These two nuclei will repel each other and should gain a total kinetic energy of c. 200 Mev., as calculated from nuclear radius and charge. This amount of energy may actually be expected to be available from the difference in packing fraction between uranium and the elements in the middle of the periodic system. The whole 'fission' process can thus be described in an essentially classical way, without having to consider quantum-mechanical 'tunnel effects', which would actually be extremely small, on account of the large masses involved.

    After division, the high neutron/proton ratio of uranium will tend to readjust itself by beta decay to the lower value suitable for lighter elements.

    I think I came closest, but I disclosed the process that creates the packing fraction difference rather than the name of the actual difference.
  • Paul BakerPaul Baker Posts: 6,351
    edited 2005-03-09 18:27
    Sid said...

    "An atom of plutonium has an atomic weight of 244.· An atom is split and produces one atom of Palladium and one atom of Tin.· The combined atomic weight of· the Palladium atom and the Tin atom is 224.73 leaving a difference of· 19.27.· What is this difference called?· What happened to it?"

    IUPAC Glossary of terms for Radiochemistry and Nuclear Techniques said...

    PACKING FRACTION· The mass excess· of a nucleus divided by the·mass number; that is, the average mass excess per nucleon.
    These don't mesh, your posed question infers that immediately after fission Palladium and Tin are produced having the combined AU of 224.73 (a number corrected later by Beau). Combining the definition of packing fraction with the previously quoted article, leads one to believe that this excess of energy is imparted to the Palladium and Tin atoms of around 200Mev, this excess energy is shed later through the process of beta decay, and is not an immeadiate by-product of the fission itself.

    Im not trying to buck for the EEPROM, I already explained in the PM I don't think I have much use for a EEPROM designed for a stamp. I just noticed the inconsistancies when I went to research it.

    Paul

    Post Edited (Paul Baker) : 3/9/2005 6:34:14 PM GMT
  • NewzedNewzed Posts: 2,503
    edited 2005-03-09 20:22
    Paul, I am not a nuclear physicist, and it has been forty years since I was involved in this sort of thing.· Fission - and fusion - produce an immediate burst of energy.· The produced fission products do carry away a certain amount of the energy in the form of radioactivity.· How radioactive depends on their half-life.· Some isotopes have half-lives that last a few microseconds, others have half-lives that last for months and even years.

    This has been an interesting discussion.· I wish I still had my Nuclear Physics textbooks.

    Sid
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