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1798 - Henry Cavendish

  1. Nov 7, 2004 #1
    “In 1798 Henry Cavendish published a paper in Philosophical Transactions reporting the results of an experiment. This entailed measuring the attraction between two objects on an apparatus called a torsion balance. Cavendish discovered that when he heated one of the objects the attraction between the objects increased. For over two hundred years the physics establishment has either ignored, or tried to explain away, this result.”

    I found the text above, but in that book it doesn't have details.
    Does anybody of the forum know that experience??
    Which is the best explanation for this phenomenon?

    I thank the collaboration at once.

    Rolf .... http://www.geocities.com/rolfguthmann/
     
  2. jcsd
  3. Nov 7, 2004 #2

    Tide

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    I notice you didn't provide a citation for that quotation nor any substantive details.
     
  4. Nov 7, 2004 #3
    Heat is energy. Energy is mass. In theory, heating an object will increase its mass, so will increase the attraction. But the amount of increase is way too small to be measured by crude apparatus. This post doesn't pass the smell test. Surely, Rolf, you can make it sweeter?

    Thanks,

    nc
     
  5. Nov 7, 2004 #4
    I found that. I don't know if it will be of any use.

    Yes, heat is energy. When adding heat it increases the kinetic energy of the molecules that compose that object. With the theory that mass increases with velocity, your explanation could be right. I've read that many physicists choose to ignore the theory of mass increase due to velocity, so I wouldn't find your explanation that valid.

    If you guys want a source for the quoted information at the top, just PM me.
     
  6. Nov 8, 2004 #5

    Tide

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    If you're referring to Cavendish's gravity experiments isn't it more likely that heating one of the masses would produce thermal convection of the air in the room? He didn't do the experiments in a vacuum. Also, heating in the confined quarters of his experimental chamber would surely have affected the torsional constants.
     
    Last edited: Nov 8, 2004
  7. Nov 8, 2004 #6
    Whom are you questioning?
     
  8. Nov 8, 2004 #7

    Doc Al

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    Sounds like the rantings of Stephen Mooney. :yuck:
     
  9. Nov 8, 2004 #8

    Doc Al

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    convection currents

    Here's an excerpt of an article on gravity from the 1911 edition of Encyclopedia Britannica (found online); it is describing Cavendish's torsion balance experiments:
    (Reference: http://1911encyclopedia.org/G/GR/GRAVITATION.htm)
     
  10. Nov 8, 2004 #9
    How observant Doc Al! Yea, that was from Stephen Mooney. I do have a question though: Why does the experiment involve repulsion? I was wanting to know if there was a site with his whole paper on his experiment, so I could digest it myself. I find it peculiar for an experiment to find a constant for attraction to yield data that involves repulsion. I want to see this for myself.
     
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