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  • Re: profound?

    From J. J. Lodder@21:1/5 to RichD on Sun Feb 4 15:22:20 2024
    RichD <[email protected]> wrote:

    The legend of Einstein's revelation of the equivalence
    principle has been repeated, endlessly.

    "A person in free all doesn't feel his body weight!"
    um, wow. Wasn't this obvious to every physicist for
    200 years?

    No.

    Did Newton himself miss this profundity?

    THink so, but I'm open to corrections.

    Color me unimpressed -

    That's because you are the one who is clueless about it.
    This point really wasn't general knowledge,
    or even well understood.
    Gravity was understood as a universal force that acts on everything,
    no matter what.
    You can take Jules Verne's Voyage to the Moon as a typical illustration.

    A generally held misconception was that people
    would still feel their weight inside a space capsule, (aka Cannon ball)
    and that they wouldn't become weightless
    until they had reached the point at which the attractions
    of the Earth and Moon were equally strong, and opposite.

    Einstein really had an original insight,
    (even if others had thought of it too)

    Jan

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  • From J. J. Lodder@21:1/5 to ProkaryoticCaspaseHomolog on Sun Feb 4 15:53:22 2024
    ProkaryoticCaspaseHomolog <[email protected]> wrote:

    RichD wrote:

    "A person in free all doesn't feel his body weight!"
    um, wow. Wasn't this obvious to every physicist for
    200 years? Did Newton himself miss this profundity?

    Color me unimpressed -

    Rather, you should be impressed that it took 200 years
    for a person to realize the profound -consequences- of
    this simple observation.

    It is always simple, a complete triviality even,
    once you have been told the answer,

    Jan

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  • From J. J. Lodder@21:1/5 to RichD on Sun Feb 11 11:57:09 2024
    RichD <[email protected]> wrote:

    On February 4, ProkaryoticCaspaseHomolog wrote:
    "A person in free all doesn't feel his body weight!"
    um, wow. Wasn't this obvious to every physicist for
    200 years? Did Newton himself miss this profundity?
    Color me unimpressed -

    Rather, you should be impressed that it took 200 years
    for a person to realize the profound -consequences- of
    this simple observation.

    That's a reasonable response.

    However, the legend is always represented such that Einstein
    was the first to ever see this, thus stamping him as a Jeenyus.
    This simple fact of weightlessness flew beyond Laplace,
    Hamilton, et alia? Ludicrous.

    Perhaps they would have seen it, if someone had asked them.
    But afaik, nobody asked them,
    and they didn't think of it for themselves.
    Or if they did they never wrote about their insights.

    As for the errors in Jules Verne:
    it is known that they were not his errors in particular,
    and that they were not seen as errors in his times.
    It -is- known the Verne consulted some distinghuised astronomer
    about the orbital mechanics of it all.

    Likewise, between Verne and Einstein there was no one who said:
    Hey, this is all wrong!
    It cannot have been for lack of familiarity. Verne's books were hugely
    popular, and they were tanslated into all major languages.
    Barbicane's lecturing on it was generally taken
    as true descriptions of what would happen in such a situation.

    But if you have a reference to someone before Einstein
    discussing weightlessness in a spacecraft or falling elevator
    I would like to hear about it.

    Failing that I'll continue to believe
    that you are just plain wrong about all this,

    Jan

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