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Subject: SPACE Digest V11 #302

SPACE Digest                                     Volume 11 : Issue 302

Today's Topics:
       Re: Drake Equation (was Re: Interstellar travel)
       Re: Drake Equation (was Re: Interstellar travel)
       Re: Drake Equation (was Re: Interstellar travel)
          Re: Teenage Mutant Ninja Tomatoes
        Re: What happened with the Barium drop
         Re: Apollo 13, STS-1, Vostok 1 anniversaries
           Re: The effects of decompression
              Re: Decompression and 2001
         Re: Is the moon upsidedown to NASA?
               Re: voyager images on cd
              Re: Space Tomatoes
----------------------------------------------------------------------

Date: 21 Apr 90 21:57:55 GMT
From: zephyr.ens.tek.com!wrgate!mrloog![e-mail]  (Dan Tilque)
Subject: Re: Drake Equation (was Re: Interstellar travel)

[e-mail] (Steve Nuchia) writes:
>Still, it could easily be the case that the earth's brightest
>spectral lines are at 50 and 60 Hz (remember, not all the
>world is north america -- some places came even closer to
>choosing the optimally fatal frequency than we did).

Is this a figure of speach or is some low frequency actually fatal?


---
Dan Tilque    --    [e-mail]

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

Date: 21 Apr 90 19:51:16 GMT
From: calvin.spp.cornell.edu![e-mail]  (John Sahr)
Subject: Re: Drake Equation (was Re: Interstellar travel)

In article <[e-mail]> [e-mail] (Andrew Pettifer) writes:
>
>What about all those 50Hz power grids?
>They would cause some beat frequencies, and i'm sure that the phase
>relationships are drifting all the time, which would help to make the signal(?)
>seem more random.

To the extent possible, the power grids are "in phase" across the USA.
However, 60 Hz probably isn't such a great place to go looking for
radio sources.

1) 60 Hz is much lower than the "plasma frequency" of the ionosphere
(greater than about 1 MHz everywhere on the Earth).

2) High power lines come in triples for three phase power, and the
separation is much less than the wavelength at 60 Hz, so that the
"radiated" energy field probably falls off faster than inverse square
(inverse cube or maybe even fourth) even in the absence of an
ionosphere.

3) It is very noisey at low frequencies beneath our ionospheric canopy.

4) It is also fairly noisy above, as natural geophysical processes generate
"TMR," or Terrestrial Myriametric Radiation above the ionosphere.

--
John Sahr,                   | Electrical Engineering - Space Plasma Physics
[e-mail] | Cornell University,         Ithaca, NY  14853

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

Date: 20 Apr 90 01:14:58 GMT
From: nuchat![e-mail]  (Steve Nuchia)
Subject: Re: Drake Equation (was Re: Interstellar travel)

In article <[e-mail]> [e-mail] (Phil Nelson) writes:
> I hope this is not one of those often asked questions, what about 3000
>miles of wire sending gigawatts at 60Hz? I don't know if it's all in phase,
>but big chunks of it are. I guess it would be better if all the wire was
>running parallel, maybe a little further from the ground, but it is a lot
>of power. Does anyone know what the propogation of say, 20-200Hz is?

It propagates pretty well, and the overall grid will be phased to
radiate in one direction or another at pretty much any time.  The
problems I can see are:

1) It is very regular.  There is nothing special about the
frequency.  How will the BEMs know it isn't a pulsar?
They could be scratching their ersatz-heads now and churning
out PhD theses proposing models to explain the strange low
frequency emitting, low-mass binary of that otherwise unremarkable
yellow star.  Just imagine how they'd ridicule you for suggesting
it might be a planet.

2) The power companies work very, very hard to balance the
currents in the lines, and the voltages are always well balanced.
The field of a balanced pair (or triple) of point sources
falls off as the _qube_ of distance.  By the time you get to
the far-field, where you can start considering the grid a
point source (say, 1 AU or so) there will be surprisingly
little power left.

Another way to check the last point is to ask youself how
long the power companies would stay in business if they
were radiating a large fraction of the gigawatts they
move around into space.  Engineers make sure most of
it gets where its going, not to the BEMs.  Power costs money.

Still, it could easily be the case that the earth's brightest
spectral lines are at 50 and 60 Hz (remember, not all the
world is north america -- some places came even closer to
choosing the optimally fatal frequency than we did).  Those
lines are certainly among our narrowest.

The most distinctive signals, the easiest to associate with
intelligent life, are probably the ones from the early
warning and ballistic missile defence radars.  Gigahertz
pulse trains, much narrower beams than broadcast entertainment,
steered and deliberately propagated outside the atmosphere.

If they happened to intercept a command sent to a far-off
space craft, like the "wake up" messages occasionally
sent out at very high power levels, that might get their
attention too.

Radio navigation beacons are a candidate too, and will remain
so long after most entertainment broadcasting has gone to cable.
Eventually they will be replaced by satellite systems, whose
transmitters all point down.

Maybe if we all turned on our microwave ovens at the same time ...

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

Date: 21 Apr 90 16:21:09 GMT
From: frooz!cfa250![e-mail]  (Bill Wyatt)
Subject: Re: Teenage Mutant Ninja Tomatoes

<> How about that announcement from NASA backpedalling on the possibility
<> of the tomato seeds having mutated into toxic forms from the extra

< One thing that struck me about this incident was when NASA officials
< said that they wouldn't have any problem with eating a tomato from one
< of these plants.  Excuse my paranoia, but I don't think I would.  It

No. The chances that a mutation would leave a tomato apparently ok -
smells ok, tastes ok, looks ok, but still poisonous are VERY VERY SMALL.
Think about it - the bozo in NASA PR didn't.

--
Bill Wyatt, Smithsonian Astrophysical Observatory  (Cambridge, MA, USA)
    UUCP :  {husc6,cmcl2,mit-eddie}!harvard!cfa!wyatt
 Internet:   [e-mail]
     SPAN:   cfa::wyatt                 BITNET: wyatt@cfa

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

Date: 21 Apr 90 00:48:59 GMT
From: van-bc!ubc-cs!fornax![e-mail]  (Zeke Hoskin)
Subject: Re: What happened with the Barium drop

In article <[e-mail]>, [e-mail] (Glen Overby) writes:
> In article <[e-mail]> [e-mail] (Jack Vinson) writes:
> >What happened with the barium canister that was to be released from
> and I saw what I would normally consider to be Aurora.  Not very exciting.
It went like this:
Friday: I read netnews as usual.
Saturday: Thousands of people in Vancouver see huge glowing ball in the sky.
   The F.O. remained U for a very long time, despite calls to the local
planetarium, astronomy depts, etc
   Sunday: The TV says it was the PEGSAT dump and gives accurate times to`
see more. The sky is at this point normal for Vancouver, i.e. ceiling of
about 100 feet. The clouds remain.
   Monday:I read netnews, which tells me retroactively about the dump.
   Drat. On a typical night, the Galactic Patrol could take on Boskonia
two falls out of three over Vancouver and nobody would see.  The first night
I can ever remember with a clear sky and an interesting space event...
   snd nobody hears about it in time to look.

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

Date: 21 Apr 90 06:58:41 GMT
From: nuchat![e-mail]  (Steve Nuchia)
Subject: Re: Apollo 13, STS-1, Vostok 1 anniversaries

In article <[e-mail]> [e-mail] (John A. Weeks III) writes:
>Duct Tape?  Why on earth did they have duct tape on the Apollo?
>How much did this flight certified duct tape cost?  Did any of the
>LM's that landed on the moon carry duct tape?

This person obviously needs a clue.

Don't tell anyone, but duct tape is The Force.

It has a dark side, and a light side, and it binds the Universe together.



Serisouly, there are two things no mission will leave the ground
without.  Duct tape is one.  Extra self-adhesive velcro is the other.
Drives Liz bananas, but the crew won't go without the velcro, and
the duct tape is astoundingly useful, especially in zero-g where
is it aproximately equivalent to a temporary weld.

If you saw the video of the computer replacement job (I was glued
to the NASA-Select feed for hours) you should have noticed all the
tools and parts duct-taped to the bulkheads and lockers.  Picture
doing the job without it.

Picture doing the job with the whole computer on a 6U card.  But
that's a different story.

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

Date: 20 Apr 90 11:30:02 GMT
From: munnari.oz.au!metro!sunaus.oz!softway!otc![e-mail]  (Greg Wilkins)
Subject: Re: The effects of decompression

In article <[e-mail]> [e-mail] (Henry Spencer) writes:
>In article <[e-mail]> [e-mail] (Mark SOKOLOWSKI) writes:
>>I am wondering wheter or not a human body exposed to void would explode,
>
>Loss of air from the lungs is inevitable, but the rate would normally be
>limited by other factors (e.g. how big the hole in the wall was), and the
>only significant hazard would be rupturing your eardrums if you had a cold
>or otherwise didn't get your ears depressurized properly.  There is some
>cooling effect from evaporation of sweat, much as there is in air, but
>vacuum has no temperature and there is no reason why you would "rapidly
>freeze".  And your skin is a good grade of leather, and does a good job
>(temporarily!) of holding in your body water.
>
>After ten minutes it would undoubtedly be different, but the only problem
>with a brief exposure to vacuum is inability to breathe.
>--

From Scuba diving experience, any time ambient pressure is halved, a person
is in danger of decompression sickness (The bends).  I understand this is
why the shuttle crew must spend some time pre-breathing O2 before suiting
up for a "out-of-vehicle-experience!!!:-)".

Recompression alone will NOT cure the bends.  Bubbles of gas formed in the
blood stream are compressed, but not removed by recompression.  As for
damage to the brain/lungs/etc from stroke type injuries caused by
circulation blockage, biochemical changes in the blood,..... etc etc  (lots
of nasty details deleted).

Recompression therapy for the bends often involves pressures higher than
those experience before the decompression, together with breathing pure
O2 (always dangerous, more so when pressure is involved).

May I suggest reading "Decompression in Depth - proceedings of the Seminar,
PADI, 1243 East Warner Ave, Santa Ana, CA 92705".

Decompression to vacuum is probably survivable -> But I doubt that it would
be so with out medical complications.



-gregw

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

Date: 20 Apr 90 12:55:00 GMT
From: research![e-mail]  (A.C.Beresford)
Subject: Re: Decompression and 2001

People surviving in a vacuum is an old theme of Arthur C. Clark,
I think he wrote an article about it in BIS Journal , many
years ago , and has used it in several stories other than 2001.

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

Date:     Sat, 21 Apr 90 07:04 CST
From: Bill Higgins-- Beam Jockey <[e-mail]>
Subject:  Re: Is the moon upsidedown to NASA?
Original_To:  Orig_To! SPACE,[e-mail]

Some time ago Alan Baxter
( zaphod.mps.ohio-state.edu!samsung!munnari.oz.au!murdu!ucsvc!wehi!baxter_a@tut.
c
 is.ohio-state.edu) explained:

>In Australia, the full moon looks to have an image of a rabbit with
>big ears on the left, with some buckshot passing by its left (right to us)
>ear.

                  XXXXXXX
            XXXXXXXXXXXXXXXXXX
          XX    XXXXXXXXXXXXXXXXX
      XXX         XXXX    XXXXX   XX
    XX XX   mi     XX  ms  XXXX  mc XX
   X   XXX         XX      X  XXXX   XXX
  XX   XXXX        X           XXXXXXXXXX
  X     XX        X       X  mt X      XXX
 XX          \|/       XXXX         mf XXXX
 XX          -O-      XXXXXXXX   XX     XXX
 XX          /|\     XXXXXXXX   XXXXXXXXXXX
 XXX    op          XXXXXXXXXXXXXXXXXXXXXXX
  XXXX                XXXXXXXXXXXXXXXXXXXX
  XXXXX                XXXXXXXXXXXXXXXXX
    XXXX       X    XXXXXXXXXXXXXXXXXXXX
     XXXXX   X     XXXX\|/X/XXXXXXXXXX
      XXXXXXX     XXXXX-O-XXXXXXXXXX
          XXXXX   XXXXX/|\XXXXXXXX
             XXXXXXXXXXXXXXXXXX
                  XXXXXXX


Here is my understanding of lunar geography (all right, "selenography").
My question: Where is the rabbit?

          North
                                Key:
       _____________            OP  Oceanus Procellarum (the big one)
      /             \           MI  Mare Imbrium
     /  MI   MS    MC\          MS  Mare Serenitatis
    /          MT     \         MT  Mare Tranquillitatis
   (  OP         MF    )        MF  Mare Fecunditatis
    \                 /         MC  Mare Crisium (the little one all by itself)
     \               /
      \_____________/
          South


OP is a large dark feature covering much of the western half.  MI is sort of a
bay on this, and straddles the northern center region.  MS, MT, and MF form a
diagonal chain stretching from north central to southeast.  MC is an isolated
circular dark sea surrounded by bright highlands; I use it as the quickest way
to check on the orientation of a lunar image.

Please tell me which features make up which parts of the rabbit, that
I may be enlightened.

                      ______meson   Bill Higgins
                   _-~
     ____________-~______neutrino   Fermi National Accelerator Laboratory
   -   -         ~-_
 /       \          ~----- proton   Bitnet: [e-mail]
 |       |
 \       /                          SPAN/Hepnet/Physnet: 43011::HIGGINS
   -   -
     ~                              Internet: [e-mail]

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

Date: 21 Apr 90 07:24:55 GMT
From: netcom![e-mail]  (Marcos H. Woehrmann)
Subject: Re: voyager images on cd

In article <[e-mail]> [e-mail] (Richard
Ottolini) writes:
> >In fact the Neptune images are not yet released. Jupiter, Saturn and
> >Uranus are available from NSSDC on CD-ROM.

Sorry if someone alreay posted this and I missed it but what is the cost
of the voyager image CD-ROMs from NSSDC?   (And what is the address of
NSSDC).

marcos
--
Marcos H. Woehrmann    {claris|apple}!netcom!marcos | marcos@netcom

    "Bicycling is like an X-rated movie.  If at all possible, you'd
     rather do it than watch it." -- Bicycling Magazine 05/90

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

From: [e-mail]
Date: Sat, 21 Apr 90 17:11:24 EST
Subject: Re: Space Tomatoes
Source-Info:  From (or Sender) name not authenticated.



     During NASA's press conference held just after the tomato memo reached
the press the officials stated that the tomatoes are safe and that they
would eat them themselves if asked.  They also mentioned that they don't
want anyone to eat the tomatoes because it is the actual tomatoes that they
wish to study.  With that in mind I'm sure many of the fruit will be analyzed
before they are eaten, if they are eaten at all.

    Although any mutations that might occur in the tomatoes are likely to be
negative, there is still a chance that the mutation could have a beneficial
effect (i.e. increased vitamin content, etc.).

                                     David R. Brierley
                                     Northeastern University

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

End of SPACE Digest V11 #302
*******************