RE: The Star-Trek effect

From: Glenn Morton (
Date: Wed Jan 23 2002 - 09:02:57 EST

  • Next message: Glenn Morton: "RE: The Star-Trek effect"

    George Wrote:
     In 1853 there were proponents of the idea that some of the nebulae were
    galaxies external to our own, but no compelling evidence for this view. At
    that time it wasn't possible to resolve individual stars in M31 (Andromeda)
    or other spirals and there was no way of measuring the distances to these
    objects. Thus it was quite reasonable to argue, as many astronomers did,
    that they were within the Milky Way. This situation continued for some
    time, & there seemed to be strong arguments against the extragalactic
    character of these nebulae. E.g., in ~1889 there was what we now know to be
    a supernova in M31, but since astronomers didn't know about SNs they thought
    it was an ordinary nova & greatly underestimated its distance. The
    extragalactic character of nebulae like M31 wasn't firmly established until
    the early 1920s. So on this point I'm not sure one can be too critical of
    Whewell. >>>

    I had always heard that also, but then I read in Whewell about the Nebula:

    "It was conceived that they were not stars, but Stellar matter in the course
    of formation into stars,; and it was conceived, further, that by the gradual
    concentration of such matter, whirling round its centre while it
    concentrated, not only stars, that is, suns, might be formed, but also
    systems of planets, circling round these suns; and thus this Nebular
    Hypothesis, as it has been termed, gave a ckind of theory of the origin and
    formation of systems such as the solar system. But the great telescope which
    Lord Rosse has constructed, and which is much more powerful than any optical
    instrument yet fabricated[is was 6 feet in diameter], has been directed to
    many of the nebulae, whose apearance had given rise to this theory; and the
    result has been, in a great number of cases, that the nebulare are proved to
    consist entirely of distict stars; and that the diffused nebulous appearance
    is discovered to have been an illusion, resulting from the accumulated
    light of a vast number of small stars near to each other. In this manner, we
    are led to regard every nebulae, not as an imperfectly formed star or system
    but as a vast multitude of stars, and, for aught we can tell, of systesm;
    for the apparent smallness and nearness of these stars are, it is thought,
    mere results of the vast distance at which they are placed from us." p. 12

    I reassert my claim, that knowing of a impressive point of data against the
    view he was advocating, he still advocated it. Indeed, he even talks about
    linear wisps of nebula being resolved into stars. But then he turns around
    and calls them mere dots of light and goes into his comet claim. The point
    is even with today's telescopes most stars are mere points of light and all
    were that way for Whewell yet he treats points of light in the galaxies
    differently than points of light not in the nebula.

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