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Subject: SPACE Digest V12 #7

SPACE Digest                                       Volume 12 : Issue 7

Today's Topics:
        Re: Reflections on (Edwin P.) Hubble and NASA
       Re: RE  Hubble Space Telescope Update - 06/28/90
             Unexplained Circles

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Date: 2 Jul 90 19:26:08 GMT
From: usc!jarthur!bridge2!3comvax![e-mail]  (Michael McNeil)
Subject: Re: Reflections on (Edwin P.) Hubble and NASA

[e-mail] (Ronald Florence) writes:

>[e-mail] writes:
>>Lets draw a lesson from Hubble himself.  He first studied law and
>>passed the bar.  He then enlisted and became an officer.  Later
>>he turned Yerkes,  'a moribund institution', into a major research
>>center and made many famous discoveries.  Pretty good for such a
>>humble start in the wrong direction.
>
>Hubble's autobiography shouldn't be trusted any more
>than his British accent, which was pure affectation.  Yerkes was
>hardly a "moribund" institution before Hubble's arrival.  Under Hales
>it was probably the premier institution for astronomical research in
>the United States.  Hubble dismissed the work of Shapley and his other
>predecessors at Mount Wilson as "of no significance" which is
>remarkably like the NASA press releases which described the Hubble
>Space Telescope as the most important event in astronomy since Galileo.

Edwin Hubble made two outstanding discoveries in his life -- he
discovered that the Milky Way isn't the only galaxy in the universe,
and he discovered that the universe as a whole is expanding.  (For a
while after the former discovery, galaxies like the Milky Way were
termed "island universes," a phrase I always thought quite romantic.)
Most people would be satisfied with one Columbus- or Galileo-caliber
discovery.  Personally, I'm willing to forgive a little "affectation"
and even some personal grandstanding, in return for his discoveries.

--
Michael McNeil            [e-mail] (3comvax.UUCP)
3Com Corporation        ucbvax!hplabs!oliveb!3comvax!michaelm
Santa Clara, California        work telephone: [phone] x 5-208

    Extremely little is known of the nature of nebulae; and no
    classification has yet been suggested....  The agreement
    [between the velocity of escape from a spiral nebula and
    that of our galaxy] is such as to lend some color to the
    hypothesis that the spirals are stellar systems at
    distances to be measured often in millions of light years.
        Edwin P. Hubble, 1920, "Photographic investigations
        of faint nebulae" (Ph.D. thesis), publication
        delayed 3 years by World War I

    Critical tests made with the 100-inch reflector, the
    highest resolving power available, show no difference
    between the photographic images of the so-called
    condensations in Messier 33 and the images of ordinary
    galactic stars....  The period-luminosity relation is
    conspiculus among the thirty-five Cepheids and indicates
    a distance about 8.1 times that of the Small Magellanic
    Cloud.  Using Shapley's value for the latter, the
    distance of the spiral is about 263,000 parsecs.
        Edwin P. Hubble, 1926a, "A spiral nebula as a
        stellar system," *Astrophys. J. 63*, 236-274

    The present investigation [using Cepheid variables for the
    first time as an indicator of distances beyond the Magellanic
    clouds] identifies NGC 6822 as an isolated system of stars
    and nebulae of the same type as the Magellanic clouds,
    although somewhat smaller and much more distant.  A
    consistent structure is thus reared on the foundation of
    the Cepheid criterion, in which the dimensions, luminosities,
    and densities, both of the system [NGC 6822] as a whole and
    its separate members, are of orders of magnitude which are
    thoroughly familiar.  The distance is the only quantity of
    a new order.  The principle of the uniformity of nature thus
    seems to rule undisturbed in this remote region of space.
        Edwin P. Hubble, "NGC 6822, a remote stellar system,"
        *Astrophys. J. 62*, 409-433

    The data ... indicate a linear correlation between distances
    and velocities [for extragalactic nebulae].  Two solutions
    have been made, one using the 24 nebulae individually, the
    other combining them into 9 groups according the proximity
    in direction and distance.  The results are ... 24 objects:
    K = 465 +- 50 km/sec per 10**6 parsecs; 9 groups: K = 513
    +- 60 km/sec per 10**6 parsecs....  The outstanding feature,
    however, is the possibility that the velocity-distance
    relation may represent the de Sitter effect, and hence
    that numerical data may be introduced into discussions
    of the general curvature of space.
        Edwin P. Hubble, 1929, "A relation between distance
        and radial velocity among extragalactic nebulae,"
        *Proc. Nat. Acad. Sci. U.S. 15*, 169-173

    Many ways of producing such effects [redshifts in
    extragalactic nebulae] are known, but of them all, only
    one will produce large redshifts without introducing other
    effects which should be conspicuous but actually are not
    found.  This one known permissible explanation interprets
    redshifts as due to actual motion away from the observer.
        Edwin P. Hubble, 1934a, *Red-shifts in the
        spectra of nebulae* (Halley Lecture)

    We now have a hasty sketch of some of the general features
    of the observable region as a unit.  The next step will be
    to follow the reconnaissance with a survey -- to repeat
    carefully the explorations with an eye to accuracy and
    completeness.  The program, with its emphasis on methods,
    will be a tedious series of successive approximations.
        Edwin P. Hubble, 1934b, "The distribution of
        extra-galactic nebulae," *Astrophys. J. 79*, 8-76

------------------------------

Date: 2 Jul 90 20:41:57 GMT
From: mojo![e-mail]  (Doug Mohney)
Subject: Re: RE  Hubble Space Telescope Update - 06/28/90

In article <[e-mail]>, [e-mail] (Glen Overby) writes:
>In article <[e-mail]> [e-mail] (Doug Mohney) writes:
>>If Hubble was run on a shoe-string budget, instead of big bucks...well...
>>I can't help but think the thing would have A) Gotten off the ground about
>>4 years sooner and B) Given us more than we bargained for.
>
>HST was trundled across the country for launch two previous times, but was
>delayed both times by shuttle problems.  Complaint "A" above isn't the HST
>project's fault (except that they should have chosen a different booster).

If Hubble hadn't been designed as an "oversized payload" (ie: Shuttle bay)
they could have popped it onto a Titan just as easily. Instead, it is an
exceptionally complex piece of machinery in LEO....

What kind of science do you think we could have gotten out of two
"Half-Hubbles" which could have been launched either by Titan or Shuttle?

------------------------------

Date: 29 Jun 90 18:36:02 GMT
From: sdd.hp.com!elroy.jpl.nasa.gov!peregrine!ccicpg!felix!dhw68k!ofa123![e-mail]  (Mark Perew)
Subject: Unexplained Circles

I thought that I had read somewhere that this phenomena of near
perfect circles was caused by the freezing of subsurface water.
A somewhat complex mechanism of expansion and contraction was
(over time) causing the soil to ripple when the water found at
a depth of a few centimeters froze.

I wish I could provide a reference, but I can't recall where I
saw this.


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End of SPACE Digest V12 #7
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