Space & Astronomy/Space and Astronomy (October 1993).iso/pc/text/spacedig/v09_4/v9_438.txt

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Subject: SPACE Digest V9 #438

SPACE Digest                                      Volume 9 : Issue 438

Today's Topics:
            Re: asteroid almost hits earth
         Re: Private funding of space science
         Re: UFOs and other weird stuff on this list.
     Asteroids and Dinosaurs (was Re: asteroid almost hits earth)
            Re: New Orbiter Name Announced
                  Re: memes
                Re: Near miss
          Re: space news from March 27 AW&ST
            Re: asteroid almost hits earth
            Re: NSS Hotline Update
          Re: In-flight liquification of air
        Re: Does anyone know *why* the USAF did this?
----------------------------------------------------------------------

Date: 12 May 89 09:08:30 GMT
From: mcvax!ukc!warwick!nfs4![e-mail]  (Keith Dancey)
Subject: Re: asteroid almost hits earth

In article <[e-mail]> [e-mail] (Mike Ekberg, Sun {GPD-LEGO}) writes:

>
>But even greater menace lurks in the darkness of space.  Scientists have
>speculated that objects as large as several miles across have crashed into the
>Earth, spewing millions of tons of debris into the atmosphere, blotting out the
>Sun for months or years, and causing mass extinctions of life -- including,
>many believe, the dinosaurs.  Of the known larger Earth-crossers, none seem to
>pose a threat in the near future.  But, says Shoemaker, "until we have tracked
>all of them, something could sneak up on us."
>

My understanding is that the demise of the dinosaurs extended over a period
of order of magnitude of a thousand years.  Certainly long enough to place
doubt upon the viability of a single catastrophy such as the one mentioned.

If the palaeontological evidence is not contradicted (and I have understood
it correctly) then a *series* of such catastrophic strikes would be required.

That is not say a single catastrophy is ruled out, but it looks as though
its effects must be longer-lived than a few years.

As for tracking "all" large, earth-crossing asteriods, there is
a danger of conveying the unspoken idea that the number may be fixed and
finite for all time.  I think such a concept is also under question.
There is just the possibility that these bodies are disturbed out of
an otherwise harmless state by the dynamics of the galaxy.  This means
their numbers may be added to at any time unexpectedly.

--
Keith Dancey,                               UUCP:   ..!mcvax!ukc!rlinf!kgd
Rutherford Appleton Laboratory,
Chilton, Didcot, Oxon, England  OX11 0QX
Tel: [phone]   ext 6756                JANET:       [e-mail]

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

Date: 13 May 89 09:28:40 GMT
From: unmvax!polyslo![e-mail]  (Dr. Dereference)
Subject: Re: Private funding of space science

In article <[e-mail]> mordor!rutgers!pnet01.cts.com![e-mail] writes:
>The government is the best source of support for research NOT development
  [a whole lot deleted]

This idea is ok as a general principal but there are many exceptions. The
rest of the posting had some reasonable ideas but was very ideological and
simplified complex situations which have many exceptions.

In order to do a lot of R&D hardware needs to be developed (ie if you want to
explore the planets, you have to develop space probes). While the governemnt
certainly should not do the development itself, it still needs to fund the
development of hardware for R&D that will not be done privately. As for
government involvment in operations, the best people to operate the hardware
built for R&D are usually the scientists doing the R&D, who are usually
government employees (ie JPL). I agree that NASA should stop developing and
operating launch services itself and should buy such services from private
companies.

John L. McKernan.                    Student, Computer Science, Cal Poly S.L.O.
-------------------------------------------------------------------------------
The future is rude and pushy. It won't wait for us to solve today's problems
before it butts in with tomorrow's.

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

Date: 12 May 89 18:35:22 GMT
From: portal!cup.portal.com![e-mail]  (H Keith Henson)
Subject: Re: UFOs and other weird stuff on this list.

[e-mail] (Derek Lee-Wo) posts:
----------
Sometimes I wish I were born a few hundreds years in the future. Could one
just imagine what it would be like to hop a space shuttle to another
planet as easily as we could now jump on a plane to London.

Now if only I could believe in re-incarnation :-)
----------
If you have a background in physics, chemistry, or biology or even computers,
you might look into the emergence of nanotechnology from these disciplines.
Try reading _Engines of Creation_ by Eric Drexler, and if you buy it, consider
cryonics as a way to get you into the future.  Info from the non-profit
Alcor Life Extension Foundation can be obtained by writing them at
12327 Doherty St.
Riverside, CA  92503
or call 800-367-2228 (714-736-1703 in California)  Keith Henson

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

Date: 13 May 89 13:03:55 GMT
From: castor.ucdavis.edu![e-mail]  (Jason)
Subject: Asteroids and Dinosaurs (was Re: asteroid almost hits earth)

In article <[e-mail]> [e-mail] (Keith Dancey) writes:
>>Sun for months or years, and causing mass extinctions of life -- including,
>>many believe, the dinosaurs.
>My understanding is that the demise of the dinosaurs extended over a period
>of order of magnitude of a thousand years.

...etc....

Please correct me if I am wrong, but is this one of the theories (proofs) behind
 the "asteroid theory" of the extinction of the dinosaurs ?:

Layers of Iridium were found deep into the earth's crust ( i.e. in the layers
of the Grand Canyon).  Now, being that Iridium is rare on earth but found
to be relatively more bountiful in asteroids and meteors, it is suggested
that the layer of this element was put on our planet by an extremely large
(or as previously mentioned a few extremely large) asteroid(s) which hit
earth and caused the clouds of dust ...etc., which eventually killed off the
dinosaurs.  This dust, if the theory is accurate, was filled with Iridium and
when settled created a solid layer over years of rain, erosion ...etc...

Is this a widely accepted view? What are the opposing ideas?

   ___    ___   __    ___  )___    __________________________________
  (   |  '__|  (__   /  /  /  /    |       II Corinthians 10:17     |
   \  |  (__)\  __) /__/  /  /     +--------------------------------+
    \_| Internet: jygabler@ucdavis |"Why me?!", Garion said. "Do we |
      | BITNET:   jygabler@ucdavis | we have to go thru that again",|
      | UUCP:     ucdavis!jygabler | the dry voice retorted.        |

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

Date: 13 May 89 00:32:26 GMT
From: portal!cup.portal.com![e-mail]  (Mark Robert Thorson)
Subject: Re: New Orbiter Name Announced

I recall that someone suggested that name on Usenet, shortly after the
Challenger explosion.

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

Date: 12 May 89 19:02:53 GMT
From: portal!cup.portal.com![e-mail]  (H Keith Henson)
Subject: Re: memes

John Roberts ([e-mail]) ends a rather thoughful post with:
>My question is not whether the concept of memes can be used to form a
>model of the spread and application of ideas, but whether such a model
>would be of any actual use, for predicting future events or for some
>other application, which it can handle better than conventional methods.
"Conventional methods" is a term which I do not understand, but as to
predicting future events, I have argued that the mutation/communication
complexity of the memetic ecosystem is subject to chaos, that is long
term projections are *impossible* for the same reason weather is.  Short
term projections, on the order of the popularity of a song or book can
be made (and are by conventional guesses).  As to the use of memetics,
I think its most useful application might be to teach people to be more
thoughtful about which ideas they accept into their minds.  (A 30k byte
article "Memes, Meta-Memes, and Politics" is available by email.)
Keith Henson ([e-mail])

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

Date: 8 May 89 09:01:49 GMT
From: mcvax!ukc!reading!cf-cm!cybaswan![e-mail]  (Steve Hosgood)
Subject: Re: Near miss

In article <[e-mail]> [e-mail] writes:
>> atmosphere (over Colorado, I believe.)  I forget how big it was, but it
>> stayed in the atmosphere for a few minutes, and it didn't burn up.  It
>> just kept going back out into solar orbit.
>
>There is a color picture in a back issue of National Geographic. IT was
>a feature article on meteors and such. Within the last 5 years I
>believe.
>

A thousand people will probably say this same thing, but here's my version:

The Geographic article is in the September '86 Issue, entitled "Meteorites:
Invaders from Space", pages 390-418. The photo mentioned above is on pages 416-
417. Very spectacular it is too.

Looking at it reminds me of a similar sort of picture that was (I think)
taken from a ship off Italy or Greece in about 1944. Similar bright spot with
a tail behind it, though the caption was more along the lines of "UFO sighted
over occupied Europe"....

Does anyone remember this one? I don't have any Geographics back that far, and
anyway, I think it was a newspaper photo.

Steve

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

Date: 13 May 89 00:59:46 GMT
From: att!oucsace!oucs!wright![e-mail]  (Student of Dr. Shock)
Subject: Re: space news from March 27 AW&ST

in article <[e-mail]>, [e-mail] (Robert Casey;6282;3.57;$0201) says:
> Xref: wright sci.space:9941 sci.space.shuttle:3068
> Posted: Wed May 10 11:18:38 1989
>
> I believe I once heard that Enterprise was damaged (bent frame? or something)
> and was not flightworthy.  Any truth to this?

    The Enterprise was never spaceworthy, just a full scale test
bed for reentry/flight dynamics.  (Unless you mean not even able to do
this, anymore)

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

Date: 14 May 89 00:21:08 GMT
From: [e-mail]  (Eugene Miya)
Subject: Re: asteroid almost hits earth

If you are really interested in this. I recommend the work and writings of
Preston Cloud.

Longish signature follows "Type 'n' now"

Another gross generalization from

--eugene miya, NASA Ames Research Center, [e-mail]
  resident cynic at the Rock of Ages Home for Retired Hackers:
  "You trust the `reply' command with all those different mailers out there?"
  "If my mail does not reach you, please accept my apology."
  {ncar,decwrl,hplabs,uunet}!ames!eugene
                  Live free or die.

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

Date: 13 May 89 15:31:33 GMT
From: bfmny0![e-mail]  (Tom Neff)
Subject: Re: NSS Hotline Update

In article <246900024@cdp> [e-mail] writes:
>
>This is the National Space Society's Space Hotline Update:
>Tuesday May 9, 1989.

[ a consistent waste of net bandwidth given the existing contributions
  of Peter Yee, Henry Spencer and (my fave) Jonathan McDowell, however
  since it keeps the NSS acronym in front of peoples' eyes, I suspect
  we are stuck with it, sloganeering and all; so, Rolaids in hand, one
  reads on... ]

>                                      The overall flight of the
>Shuttle Atlantis has gone fairly smooth, with the exception of a
>broken fax machine, and a failed computer.  The crew wanted to fix
>the fax machine themselves but were ordered not to by ground
>control.

Not as trivial a problem as it sounds.  One of the few things they
had room to test given the Magellan weight constraints was a new
Text/Graphics System (TGS was the acronym I saw, if it's different
someone mail me) for uplinking charts and such.  Can someone post
details on the failure mode?  This could mean delays before it's
operational.

[ that's one annoyance about these NSS screeds, they appear to be
  written down to the shoe clerk level.  Mustn't let annoying details
  interfere with the phone tree! ]
--
Tom Neff                UUCP:     ...!uunet!bfmny0!tneff
    "Truisms aren't everything."    Internet: [e-mail]

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

Date: 13 May 89 08:38:34 GMT
From: unmvax!polyslo![e-mail]  (John McKernan)
Subject: Re: In-flight liquification of air

In article <[e-mail]> [e-mail] (Lucius Chiaraviglio) writes:
>    How is liquification of air to be done without the use of horrendously
>heavy equipment and huge energy expenditure?  (It seems that both would be
>needed to liquify air, especially at the rate that would be needed.)
>    Also, since air is only 21% oxygen, storage of liquified air would be
>quite wasteful of weight and space.

Air liquification is an approach the Japanese are taking in their aerospace
plane project. The whole point of such a plane is to drastically increase
performance over a rocket engine by using the oxygen in the air instead of
carrying all your oxydizer with you. So no, the plane would not carry
liquified air. The plane uses liquid hydrogen (its fuel) to liquify the air.
This is necessary because the engine operates at too high a pressure to
practically pump enough normal air into it.

The US aerospace plane project (NASP) is trying to build a scramjet
which uses carefully shaped scoops to bring air into the combustion chamber
without liquifying it. This requires speeds of around 2000 mph before the
engine will operate properly (fuel is liquid hydrogen), so another
engine/rocket must bring the plane up to that speed. The scramjet is
supposed to propel the plane all the way to orbital velocity (17,500 mph).
One major problem is that the hottest parts of the scramjet would be over
5000F (!), and the highest temperature jet engine parts currently built can
only withstand 2800F. I've read that this project is currently using over a
third of all the supercomputer time in the US. It comes as no surprise that
the military is interested in a jet with a top speed of 17500 mph, so the
project is funded by the military at 300 million a year.

The Germans have a somewhat different concept, though I don't know if it's
actually funded at this point. They use an airplane to carry a shuttle to
19 miles and 4500 mph, and then the shuttle separates and uses rockets for
the additional 13000 mph and 80 miles of altitude. This has the advantage
of requiring only current technology. Still, it doesn't seem very cost
effective to build a plane capable of carrying a shuttle to 19 miles and
4500 mph (not an easy plane to build) and then still have 80 miles and
13000 mph to go.

Note: This information is from an artical in the LA Times 5/8/89.

John L. McKernan.                    Student, Computer Science, Cal Poly S.L.O.
-------------------------------------------------------------------------------
The future is rude and pushy. It won't wait for us to solve today's problems
before it butts in with tomorrow's.

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

Date: 13 May 89 15:43:42 GMT
From: portal!cup.portal.com![e-mail]  (Mark Robert Thorson)
Subject: Re: Does anyone know *why* the USAF did this?

I remember seeing a report in the Science and the Citizen column in
Scientific American about a year ago, which said that a paint flake 0.2 mm
long had impacted a window on one of the space shuttles.  It left a crater
about 1 cm in diameter.

Imagine the effect of hitting a clump of copper wires!  Perhaps the proper
successor to smart rocks and brilliant peebles will be "genius dust".
These could be naked IC's powered by the sun and propelled by tiny ion
engines.

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

End of SPACE Digest V9 #438
*******************