Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V16_5/V16NO536.TXT

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Date: Thu,  6 May 93 05:19:18
From: Space Digest maintainer <[e-mail]>
Reply-To: [e-mail]
Subject: Space Digest V16 #536
To: Space Digest Readers
Precedence: bulk


Space Digest                Thu,  6 May 93       Volume 16 : Issue 536

Today's Topics:
      ASTRONAUTS---What does weightlessness feel like? (3 msgs)
                            BBS in Space?
                     Billboards in Space (2 msgs)
                      Galileo Update - 04/22/93)
                   Mars Observer Update - 04/30/93
                         NASA contributions?
  New gedankenexperiment to test for quantum connection information.
                             saturn image
                Space Colony Size Preferences Summary
                 Visas for astronauts after an abort

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

Date: Thu, 6 May 1993 02:14:01 GMT
From: Dave Michelson <[e-mail]>
Subject: ASTRONAUTS---What does weightlessness feel like?
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Henry Spencer) writes:
>
>Nobody has yet found *any* test that can be done on the ground which predicts
>spacesickness especially well.  There is a great deal of interest in being
>able to predict who will get sick, since it hurts productivity on extremely
>expensive missions, but so far no way to do it.  In particular, there is no
>particularly strong correlation between susceptibility to more ordinary

>forms of motion sickness and susceptibility to spacesickness.  At least,
>not that the research people have been able to find -- I don't know if
>they've tried roller coasters :-).

I'm under the impression that spacesickness was a far more serious problem
on Apollo flights than it was on Gemini.  Presumably the far larger (!!)
cabin had a lot to do with it.  Anyone care to confirm or refute?

--
Dave Michelson  --  [e-mail]  --  University of British Columbia

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

Date: Thu, 6 May 1993 04:47:31 GMT
From: Henry Spencer <[e-mail]>
Subject: ASTRONAUTS---What does weightlessness feel like?
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Dave Michelson) writes:
>I'm under the impression that spacesickness was a far more serious problem
>on Apollo flights than it was on Gemini.  Presumably the far larger (!!)
>cabin had a lot to do with it.  Anyone care to confirm or refute?

Indeed, it was barely recognized as an issue until spacecraft got roomy
enough to roam around in.  Evidently, just sitting there doesn't produce
sufficient sensory confusion to give most astronauts trouble.
--
SVR4 resembles a high-speed collision   | Henry Spencer @ U of Toronto Zoology
between SVR3 and SunOS.    - Dick Dunn  |  [e-mail]  utzoo!henry

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

Date: Thu, 6 May 1993 09:22:37 GMT
From: Dave Michelson <[e-mail]>
Subject: ASTRONAUTS---What does weightlessness feel like?
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Henry Spencer) writes:

>>I'm under the impression that spacesickness was a far more serious problem
>>on Apollo flights than it was on Gemini.  Presumably the far larger (!!)
>>cabin had a lot to do with it.  Anyone care to confirm or refute?
>
>Indeed, it was barely recognized as an issue until spacecraft got roomy
>enough to roam around in.  Evidently, just sitting there doesn't produce
>sufficient sensory confusion to give most astronauts trouble.

It's curious that spacesickness is rarely (if ever) associated with EVA.
In the early days, there was a real fear that spacewalking would induce
severe vertigo and disorientation but the only problem reported by Gemini
astronauts was fatigue.

I suppose that it may be a little bit like seasickness in that one generally
feels better when up on deck than down below.  (i.e., the sensory confusion is
less... confusing!)

--
Dave Michelson  --  [e-mail]  --  University of British Columbia

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

Date: Thu, 6 May 1993 01:51:30 GMT
From: Gary Coffman <ke4zv!gary>
Subject: BBS in Space?
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Ralph Buttigieg) writes:
>
>This is just an idea that has occurred to me. We can make telephone calls to
>international aircraft via the imarasat satellite system. Can such calls be
>made to an orbiting space craft? If it is possible perhaps we should see
>what would be involved in setting up a BBS on Mir or an eventual
>international Space Station. Reckon having a space station as part of fido
>or Internet would be neat.

MIR already has a BBS on board. It's accessed by amateur radio packet
transmissions on 145.55 MHz. It's not the internet, but it works. I'd
hate to imagine a Usenet feed via Airphone, it'd probably be cheaper
to launch mag tapes. :-)

Gary

--
Gary Coffman KE4ZV          |    You make it,     | gatech!wa4mei!ke4zv!gary
Destructive Testing Systems |    we break it.     | uunet!rsiatl!ke4zv!gary
534 Shannon Way             |    Guaranteed!      | emory!kd4nc!ke4zv!gary
Lawrenceville, GA 30244     |                     |

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

Date: Thu, 6 May 1993 00:07:14 EDT
From: Fred.Houlihan:[e-mail];,
Subject: Billboards in Space
Newsgroups: sci.space

If this topic has already been covered please forgive me.  I cut an
article out of the Oman Daily Observer (South West Asia) last month
titled "Billboards in Space" with a dateline Washington but no date
or news agency indicated.  I was surprised not to see any followup
om sci.space but I have been out of the country and may have missed it.

The article described how Space Marketing Company of Georgia is
offering a one mile wide mylar baloon developed by the Lawrence
Livermore Labs to orbit in space displaying corporate logos for
$25-$30 million.  The first project was to have been launched over
the city of Atlanta in 1996 to mark the olympic games but was vetoed
by mayor Jackson.

"We could actually fly McDonalds golden arches in space says Space
Marketings director Mike Lawson", who adds that billboards could
look as big as the moon.  "It's horrifying" commented Rick Parks
of the American Physical Society who is rallying American  scientists
against the idea.

Is this article a hoax or are people actually considering this?  I
can fax the article to anyone interested.

Fred Houlihan

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

Date: Thu, 6 May 1993 06:44:02 GMT
From: Harri P J Tavaila <[e-mail]>
Subject: Billboards in Space
Newsgroups: sci.space

I remember having read about various space billboard designs that were
suggested in France some years ago (I believe they were supposed to be
launched in order to celebrate La Tour d'Eiffel).  Two of the designs
I remember quite well:

1) A small concave mirror, that was supposed to collect the reflected
sunlight so that visual effect would have been just about the same as
that of a flash - a very bright spot (brighter than full moon) that
would have lasted just few seconds.  However this would have been
visible only on very small regions.
  The astronomers became quite worried - such a device could easily
wreak photomultipliers..

2) An orbital clock (no, not a digital one, but analog).  A ring of
12 aluminized spheres and two hands - showing Paris time for all
wiewers.  The size of the ring would have been just about the same
as that of the Moon seen from ground.

Also, lets not forget that experiement the russians did couple of months
ago.  Remember - it's all done with mirrors..

H Tavaila



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

Date: Wed, 5 May 1993 22:36:14 +0000
From: Andrew Haveland-Robinson <[e-mail]>
Subject: Galileo Update - 04/22/93)
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Dave Tholen) writes:

>Alan Carter writes:
>
>>> 3.  On April 19, a NO-OP command was sent to reset the command loss timer to
>>> 264 hours, its planned value during this mission phase.
>
>> This activity is regularly reported in Ron's interesting posts. Could
>> someone explain what the Command Loss Timer is?
>
>The name is rather descriptive.  It's a command to the spacecraft that tells

Indeed, it is very descriptive when you *know* what it is!

I had no idea what it was either, like many of the terms favoured here.
When put in context it all starts to become clearer...

+-----------------------------------------------------------------------+
| Haveland-Robinson Associates   | Email: [e-mail]         |
| 54 Greenfield Road, London     |        [e-mail] |
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<<>> Those that can, use applications. Those that can't, write them! <<>>
> Some dream of doing great things, while others stay awake and do them <

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

Date: 6 May 93 05:44:40 GMT
From: Philip Young <[e-mail]>
Subject: Mars Observer Update - 04/30/93
Newsgroups: sci.space,sci.astro,alt.sci.planetary

|> Forwarded from the Mars Observer Project
|>                                                      [...]  Entry into
|> Contingency Mode was verified when signal was reacquired and telemetry
|> indicated that the spacecraft was sun coning.

What is sun coning?

--
Philip R. Young
Data General Australia Pty. Ltd.


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

Date: 6 May 93 01:30:25 GMT
From: Bruce Watson <[e-mail]>
Subject: NASA contributions?
Newsgroups: sci.space

In article <[e-mail]| [e-mail] writes:
|
|In article <[e-mail]|, [e-mail] writes:
||Teflon? A contribution from the space program? Since the French were using
||Teflon on household items in the early 1950's, it is unlikely that it was
||invented by NASA. As for pacemakers and calculators, again those are
||anecdotally connected with NASA.
|
|According to the "inventors" here at TI (corporate ego at stake), the handheld
|calculator came about as a "we can do better than that" while looking at some
|desktop monsters.  It really had nothing to do with the space program.

The TV series "The Machine That Changed the World" hints that as Fairchild
Semiconductor was pioneering MOS technology, NASA was interested
since they were always seeking minituration of everything and made
some money available to keep things going. TI (and several other
calculator companies) took advantage of the result. It is correct
that the handheld calculator was not developed for the space program.

--
Bruce Watson ([e-mail])

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

Date: Thu, 6 May 1993 05:35:48 GMT
From: Jack Sarfatti <[e-mail]>
Subject: New gedankenexperiment to test for quantum connection information.
Newsgroups: sci.physics,sci.optics,fj.sci.physics,sci.crypt,sci.space

Stephen Barnett in NATURE 362, 11 March 1993 p.113 commenting on experiments
of Poizat and Grangier (Phys. Rev. Letters 70, 271-274, 1993) writes:

"With a QND detector for light we could measure any information encoded on
the amplitude of a laser beam without degrading the the quality of the
information left on the beam ... it allows us to tap into an optical signal
and measure the amplitude modulation without changing the signal ...

Poizat and Grangier's quantum optical tap works by the nonlinear optical
effect of cross-phase modulation ... In a sodium cell .. the index change
will be proportional to the intensity of the light, so it leads to an
intensity dependent phase modulation.

It is this phase modulation that is responsible for the production of
solitons (self-sustaining wave packets) in optical fibres. When two beams
are present, the intensity-dependent modification of the refractive index
induced by one beam can produce a modulation of the phase in the second
beam. This cross-modulation means that the phase change of one beam is
proportional to the intensity of the other, so by monitoring the phase of
the 'meter' beam which has interacted with the signal beam we can infer the
intensity of the signal.

.. the signal is not absorbed .. Poizat and Grangier in fact measure the
signal by conventional means after the QND measurement. Their comparison of
these two measurements shows that the signal does not become appreciably
depleted, and that the signal and meter beams are correlated so that the
measurement carried out on the meter tells us something about the signal
amplitude. This new experimental arrangement has achieved the sensitivity
required to push the nondemolition measurement into the quantum regime where
the signal degradation is lower and the correlation between the the meter
and signal beams is stronger than could be achieved in any classical
arrangement."

This is a new test for quantum nonlocality. The strong correlation here is
like the strong correlation in the photon pair polarizations that violate
Bell's locality inequality.

"A conventional measurement would either have to degrade the signal more to
achieve the same degree of accuracy in the measurement, or sacrifice
accuracy in order to leave the signal intact.

Measurement of the amplitude scrambles the phase of the signal beam. The
nonlinear interaction between the meter and signal beams, causing a
correlation between the signal intensity and the meter phase, also
correlates the signal phase and the meter intensity. In monitoring the meter
phase we discard information about the meter intensity and hence introduce
additional uncertainty into the signal phase."

Roughly speaking, in second quantization, n = a*a is canonically conjugate
to the phase @ where

a = n^1/2 e^i@

aa* - a*a = 1

A rigorous treatment is complicated and we cannot really use @ but need
things like cos@ operators. There's a lot of published literature on this
problem. I did some of the original work on this as a graduate student with
Lenny Susskind and Jonathan Glogower back at Cornell in 1963.  I introduced
the problem to Susskind. It grew out of a paper I published in Nuovo
Cimento.

The question is, can we use this as a communication device? That is, can the
choice to monitor or not monitor the meter phase transmit a bit to the
signal beam?  Thus, suppose we do not monitor the meter phase, then the
signal phase stays stable and with the proper interferometer splitting the
signal beam we can see fringes. On the other hand, if we monitor meter phase
we randomize the signal phase to that when it recombines with the signal
reference beam the fringes are destroyed.

Thus

Fig.1 Cross-phase modulation communicator gedankenexperiment (my invention)


                         cross-phase modulator           phase detector
 meter                       _____
 ---------------------------|     |--------------------------|   | S
                            |     |                       transmitter
                /-----------|_____|-----------\
                |                             |
                |                             |
                |                             |
                |                             |
                |                             |
                |                             |
                |                             |
                |                             |
                |                             |
 signal         |        reference            |
----------------/-----------------------------\------------- R1
                                              |
                                              |
                                              |
                                              |      receiver
                                              |
                                              |
                                              | R2

If the phase detector at S is switched "on" it randomizes the phase in the
upper signal sub-beam relative to the reference beam. Therefore, counters R1
and R2 click at equal rates. On the other hand, if the phase detector at S
is not switched "on", the relative phase in the split signal sub-beams is
stable. Since there is an i unitary reflection phase shift at each splitter,
using phase plates, we can arrange destructive interference at R1 and
constructive interference at R2, allowing the observer at the receiver to
infer whether or not a phase measurement was made at S. This is local
decoding. The spacetime interval between the phase measurement event at S
that transmits the bit, and the counter clicks at R that decode the bit can
be spacelike. We can even arrange R to be in the timelike future of R.

So where is the error?

"In an interesting variation on the QND theme, Grangier and colleagues also
used a nonlinear optical crystal to produced two amplified copies of the
information contained in one quadrature component of an input signal (Phys.
Rev. Lett 70, 267-270, 1993)."

This shoots to hell the significance of the famous Wooters-Zurek result that
Bennet assumes in his "quantum teleportation" scheme. You may not be able to
clone a single-photon eigenstate, but, apparently there is no problem
cloning Glauber and squeezed states.

"Thus an amplitude modulated signal is converted into two beams, each more
intense than the original and carrying the same amplitude modulation.
Observation of the amplitude of one beam reveals the modulation carried by
its partner."

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

Date: Thu, 6 May 1993 06:56:22 GMT
From: Harry Butler <[e-mail]>
Subject: saturn image
Newsgroups: sci.space

I would like colour images of the planet saturn, preferably voyager images, showwing the ring details. If you have such images could you forward copies to me by e-mail to [e-mail].

Thanks in Advance

Harry Butler

--
Harry Butler                                               |    |  |~~~~|
[e-mail]                   |----|  |----|
Department of Mathematics and Computing, USQ, TOOWOOMBA    |    |  |____|

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

Date: Thu, 29 Apr 1993 18:40:29 GMT
From: Jay Thomas <[e-mail]>
Subject: Space Colony Size Preferences Summary
Newsgroups: sci.space

I thought I was the only one who ocasionally designed space colonies.

Well, anyways, here are my preferences:

Size: at least 50,000 people.

Shape: I like the cylinders. If you play with your mirrors and lighting
right, you can even see stars.

Size: at least Island 3 size.

Also: space colonies really should have large 0-G areas. I think multicubic
mile free areas would not be undesirable. Also there should be lots of 0-G
cafes, observation areas, etc.

Finally, how about several underground floors under the surface. Perfect
place for extra agriculture, storage, or ECLSS

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

Date: Thu, 6 May 1993 00:23:34 EDT
From: Fred.Houlihan:[e-mail];,
Subject: Visas for astronauts after an abort
Newsgroups: sci.space

There was a recent major airline crash in India where the survivors
complained that evacuation and medical assistance were witheld by the
authorities until their papers were determined to be in order.  This
happened within the last two months.  Lots of people died in that crash.

Fred

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

End of Space Digest Volume 16 : Issue 536
------------------------------