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What does all this mean ?

  1. Sep 9, 2003 #1
    I found this in a 1911 Encyclopedia.

    The energy in sunlight per cubic cm. just outside the earth's atmosphere is therefore about 4Xio~5 ergs; applying the law of inverse squares the value near the sun's surface would be 1-8 ergs. Let E be the effective elasticity of the aether; then E = pc2, where p is its density, and c the velocity of light which is 3X10 10 cm./sec. If £=A cosu (t-xlc) is the linear vibration, the stress is E d£/dx; and the total energy, which is twice the kinetic energy Jp(d£/dt)2dx, is fp«2A2 per cm., which is thus equal to 1-8 ergs as above. Now \=2irc/n, so that if A/X=£, we have 5p(2Tc&)2 = i-8, giving p=io~i2/fe~2 and E = lo"1^"2. Lord Kelvin assumed as a superior limit of k, the ratio of amplitude to wave-length, the value lo"2, which is a very safe limit. It follows that the density of the aether must exceed io~18, and its elastic modulus must exceed io3, which is only about io~8 of the modulus of rigidity of glass.

    And i have absolutely no clue what 95% of it means. That math looks alien to me... and math hasn't looked this alien since I was in grade school.

    Any body good at this stuff ?
     
  2. jcsd
  3. Sep 9, 2003 #2
    You just saw a picture of how relativity and quantum mechanics will look a few hundred years from now - meaningless cryptic stuff taken as high knowledge by people who didn't know better.
     
  4. Sep 9, 2003 #3

    selfAdjoint

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    Ah, the famous 1911 edition of the Encyclopedia Brittanica! You know there were some people who would never use a later edition, which they considered inferior to this monument of Edwardian scholarship.

    You want to look at the initials at the end of the article and then check them against the contributors list in the first volume. I am sure that it was written by some famous British scientist of the day.

    What the man is doing is casting cold water on the ether theory. He does all these calculations to show that the ether has to be very tenous, but yet very stiff ("Young's Modulus"). These are contradictory attributes.
     
  5. Sep 9, 2003 #4

    marcus

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    most of whom could, moreover, write a good English sentence on occasion

    the moral tone can be very refreshing in some of the historical articles too.
    the faint shock and raised eyebrow when doings of Roman emperors and Russian Tsars are described


    in that edition I gather the article on "Aether" was written by Sir Joseph Larmor, president of the Royal Socieity, occupant of the Lucasian chair of mathematics at Cambridge (St. John's) and when you
    get an MRI scan IIRC the map of your insides is a map of the variation of the socalled "Larmor frequency" of the protons in the molecules. dont know what article the exerpt comes from but if from Larmor's then indeed was by an eminent Br. scientist of the day
     
    Last edited: Sep 9, 2003
  6. Sep 9, 2003 #5

    russ_watters

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    Doubt it. That EB article was wrong even for 1911.
     
  7. Sep 9, 2003 #6

    selfAdjoint

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    In what way? It may not have specifically dealt with relativity, but it certainly expresses skepticism about the ether! And all while citing the most distinguished authorities of the previous century, like Lord Kelvin.
     
  8. Sep 10, 2003 #7
    Where have all these people gone,
    Marcus?

    Do you know the strange story
    behind the original edition of
    the O.E.D.?
     
  9. Sep 10, 2003 #8

    selfAdjoint

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    From what I hear, the education system in England is as much a shambles as that in California, and from the same causes. Lack of money and left wing ideas about what should and should not be taught, and how. (I am not a right winger myself, proud to call myself a liberal, but facts is facts).
     
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