Space & Astronomy/Space and Astronomy (October 1993).iso/pc/text/spacedig/v15_1/v15no129.txt

Internet Message Format | 1993-07-13 | 35KB

Date: Fri, 21 Aug 92 05:00:06
From: Space Digest maintainer <[e-mail]>
Reply-To: [e-mail]
Subject: Space Digest V15 #129
To: Space Digest Readers
Precedence: bulk


Space Digest                Fri, 21 Aug 92       Volume 15 : Issue 129

Today's Topics:
                     Calculating Planet Positions
                   Germans drop European Shuttle ?
                          Home made rockets
                    Hubble visible in evening sky
            Inflatable Space Stations - Why Not ? (3 msgs)
                              PAVE PAWS
                        Private space ventures
                            Saturn dreams
                           SPS feasibility
             SPS feasibility / Astrophysical Engineering
         SPS feasibility and other space development (2 msgs)
     superstrings & supralight (was SPS feasibility and other

    Welcome to the Space Digest!!  Please send your messages to
    "[e-mail]", and (un)subscription requests of the form
    "Subscribe Space <your name>" to one of these addresses: listserv@uga
    (BITNET), rice::boyle (SPAN/NSInet), utadnx::utspan::rice::boyle
    (THENET), or [e-mail] (Internet).
----------------------------------------------------------------------

Date: Thu, 20 Aug 1992 13:29:33 GMT
From: Emil Lips <[e-mail]>
Subject: Calculating Planet Positions
Newsgroups: sci.space

Help!

Ive a problem with the book "Astronomie & Ordinateur" written by
Guy Serane (Paris, Dunod, 1987)

I am using the routines described in that book to calculate the
position of the planets. Now I have encountered a difference between
the results the program gives and the ephemerids provided by NASA
(which I belief to be more accurate). The error is below 1 degree
but bigger than 1/2 a degree over the range of the next 100 years.
I get the worst results for Pluto and Neptun, but Jupiter and Saturn
do also give errors in the range of 1/5 degree.

So if you have had the same problems with these routines or know of
a more accurate one, I would be glad if you could drop me a note.

Yours Milo

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

Date: Thursday, 20 Aug 1992 11:23:51 CET
From: [e-mail]
Subject: Germans drop European Shuttle ?
Newsgroups: sci.space

Don't laugh about an overweight Hermes: it's been an in-joke for
months now that the Ariane 5 plus Hermes has a negative lift capability:
when the motors are ignited, the whole caboodle sinks slowly into the
ground.......

Just my own opinion, and not that of my Employers.
(Who are doing a great job, really).

RaF

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

Date: Thu, 20 Aug 92 15:19:22 BST
From: [e-mail]
Subject: Home made rockets

> "(according to the U.S. General Accounting Office) 138,490
Americans

> have been killed or wounded over the last 10 years by gun-wielding

> _children_ under _six_ years of age."   Definitely Just Not Worth
It.

>


I find the above figures highly questionable. That is 14K/year. The
number of gun accidents, murders and everything else if probably not
much larger than that. This looks more like the total figure due to
all caueses. (This probably doesn't belong here, so I will leave me
response at this.)

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

Date: 19 Aug 92 23:16:54 GMT
From: Bruce Watson <[e-mail]>
Subject: Hubble visible in evening sky
Newsgroups: sci.astro,sci.space,sci.space.shuttle

Just a reminder that the Hubble Space Telecope is appearing in the evening
twilight for the next few weeks for northern hemisphere observers. For
those of us much further north thatn approx. 35 degrees, it will
be low on the horizon towards the south.

--
Bruce Watson (wats@scicom)  Tumbra, Zorkovick; Sparkula zoom krackadomando.

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

Date: 20 Aug 92 12:12:34 GMT
From: "Joseph A. Beernink" <[e-mail]>
Subject: Inflatable Space Stations - Why Not ?
Newsgroups: sci.space

In article <[e-mail]> [e-mail] writes:
>Whatever became of the idea of inflatable space habitats/workstations ?
>The savings on initial cost and on launch weight should be very great.
>Add to that the large size and configurational possibilities and you
>have an incredibly good deal. Modern materials, esp tri-weave carbon
>fiber, could strengthen an envelope and protect against ripping or
>bursting. All you need is a docking hatch and a few hard points to attach
>odds and ends to. The rest is just hot air. Internal partitions and
>compartments would be easy to build into such a structure ... or glue in
>later on. The large internal free volume of air would also add safety
>against explosive decompression. Self-sealing layers could deal with
>micrometeorites. If desired, thin interlocking plates of metal could be
>attached to the envelope to armor the whole thing.
>
>What's the problem ? Is this perhaps a TOO CHEAP solution - meaning that
>the contractors couldn't steal enough money during development ? If we
>want nice BIG space stations, with loads of internal room, with easy
>expandability ... inflatable spheres sound like the economical solution.
>Any feedback on this ?
>
>-- Jim Mason

I was tossing this idea around last summer, and discussed with a few
physics and space science professors here at York U.  There are a few
major problems, the way I understand it.
1.  Many of the materials we would like to use, are 'biodegradable' in
space.  They tend to be broken apart easily by radical oxygen and other
compounds floating about in LEO.  Something like .1 - 3 cm thickness per
year for somethings. (Just off the top of my head)  Needless to say,
at the upper limit of this decomposition, many structures would not
last ten years.

2.  Blowing up the 'balloon' in space means dealing with radical pressure
differences, trying to create an volume of gas in a vacuum, and expecting
to stay where you put it is not an easy task.  Thus, the material would
probably have to be as strong as kevlar, or the like.

3.  The material would also have to be able to deal with the rapid
fluxuations in solar radiation.

Now don't get be wrong.  I am by no means an expert on any of this. (As
certain people on the net will be quick to point out), and I would
love to see this get started (hell I'd love to work on it), but
according to my professor friends, its just not possible now.  But
maybe things have changed.  I know they pulled down a satellite carrying
materials research projects, but I have heard too much about that.
If someone who has heard could post the news, I'm sure many people would
be appreciative.
------------------------------------------------------------------
Joseph A. Beernink             | "Failure isn't a reason to quit...
[e-mail]            | it's a reason to try harder." me
[e-mail] | [phone] - York U. Toronto, Ont.

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

Date: 20 Aug 92 12:32:29 GMT
From: "Joseph A. Beernink" <[e-mail]>
Subject: Inflatable Space Stations - Why Not ?
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Joseph A. Beernink) writes:
>In article <[e-mail]> [e-mail] writes:
>>Whatever became of the idea of inflatable space habitats/workstations ?
>>The savings on initial cost and on launch weight should be very great.
>>Add to that the large size and configurational possibilities and you
>>have an incredibly good deal. Modern materials, esp tri-weave carbon
>>fiber, could strengthen an envelope and protect against ripping or
>>bursting. All you need is a docking hatch and a few hard points to attach
>>odds and ends to. The rest is just hot air. Internal partitions and
>>compartments would be easy to build into such a structure ... or glue in
>>later on. The large internal free volume of air would also add safety
>>against explosive decompression. Self-sealing layers could deal with
>>micrometeorites. If desired, thin interlocking plates of metal could be
>>attached to the envelope to armor the whole thing.
>>
>>What's the problem ? Is this perhaps a TOO CHEAP solution - meaning that
>>the contractors couldn't steal enough money during development ? If we
>>want nice BIG space stations, with loads of internal room, with easy
>>expandability ... inflatable spheres sound like the economical solution.
>>Any feedback on this ?
>>
>>-- Jim Mason
>
>I was tossing this idea around last summer, and discussed with a few
>physics and space science professors here at York U.  There are a few
>major problems, the way I understand it.
>1.  Many of the materials we would like to use, are 'biodegradable' in
>space.  They tend to be broken apart easily by radical oxygen and other
>compounds floating about in LEO.  Something like .1 - 3 cm thickness per
>year for somethings. (Just off the top of my head)  Needless to say,
>at the upper limit of this decomposition, many structures would not
>last ten years.
>
>2.  Blowing up the 'balloon' in space means dealing with radical pressure
>differences, trying to create an volume of gas in a vacuum, and expecting
>to stay where you put it is not an easy task.  Thus, the material would
>probably have to be as strong as kevlar, or the like.
>
>3.  The material would also have to be able to deal with the rapid
>fluxuations in solar radiation.
>
>Now don't get be wrong.  I am by no means an expert on any of this. (As
>certain people on the net will be quick to point out), and I would
>love to see this get started (hell I'd love to work on it), but
>according to my professor friends, its just not possible now.  But
>maybe things have changed.  I know they pulled down a satellite carrying
>materials research projects, but I have heard too much about that.
                                     not^
>If someone who has heard could post the news, I'm sure many people would
>be appreciative.

Sorry about the mistake - will happen again.
                           not^
------------------------------------------------------------------
Joseph A. Beernink             | "Failure isn't a reason to quit...
[e-mail]            | it's a reason to try harder." me
[e-mail] | [phone] - York U. Toronto, Ont.

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

Date: 20 Aug 92 13:05:45 GMT
From: "Allen W. Sherzer" <[e-mail]>
Subject: Inflatable Space Stations - Why Not ?
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Joseph A. Beernink) writes:

>>Whatever became of the idea of inflatable space habitats/workstations ?

I don't think the idea is dead but rather that there just aren't any
projects which need them. If and when SEI ever gets going we may see
that change.

>I was tossing this idea around last summer, and discussed with a few
>physics and space science professors here at York U.  There are a few
>major problems, the way I understand it.

>1.  Many of the materials we would like to use, are 'biodegradable' in
>space.  They tend to be broken apart easily by radical oxygen and other
>compounds floating about in LEO.  Something like .1 - 3 cm thickness per
>year for somethings. (Just off the top of my head)

The LLNL Great Exploration design provides a coating of material which
takes care of this problem. I can't remember what they use and I can't
find my reference material but it is in the LLNL repsonces to the
NASA critique of the Great Exploration.

>at the upper limit of this decomposition, many structures would not
>last ten years.

The design life of the LLNL station is 10 years. This isn't a problem
since they are cheap and we can always put up another.

>2.  Blowing up the 'balloon' in space means dealing with radical pressure
>differences, trying to create an volume of gas in a vacuum, and expecting
>to stay where you put it is not an easy task.  Thus, the material would
>probably have to be as strong as kevlar, or the like.

The LLNL design does use Kevlar as well as other design features to
deal with this problem.

>3.  The material would also have to be able to deal with the rapid
>fluxuations in solar radiation.

Can't address specifics on this one.

>according to my professor friends, its just not possible now.

the maker of all of NASA space suits since Apollo, ILC Dover, who also
makes other large fabric aerospace structures doesn't agree. They studied
the LLNL design and concluded that it was agressive but doable.

   Allen
--
+---------------------------------------------------------------------------+
| Allen W. Sherzer | "If they can put a man on the Moon, why can't they     |
|  [e-mail]     |  put a man on the Moon?"                               |
+----------------------246 DAYS TO FIRST FLIGHT OF DCX----------------------+

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

Date: 20 Aug 92 09:15:00 EST
From: "HUNTRESS GARY B" <[e-mail]>
Subject: PAVE PAWS

>>PAVE PAWS radar in Georgia for warning of SLBM attack, which I
>>think had a good chance of seeing a meteoroid off Daytona Beach.

>The system at Warner Robbins AFB has only been activated at full power
>*one* time.  The effects at the (then) SAC flight line were such that
>the system hasn't been turned on since. Can you say boondoggle? I
>knew you could.

I worked at PAVE PAWS "East" on Cape Cod when the system at Warner Robbins
was brought online.  Their system was an upgraded version of ours, with the
primary addition being more active array elements, hence more transmit power.
I understood the problem to be associated with emi levels on the flight line
especially regarding the ejection seat explosive initiators.  I know that WR
was online when I left the Cape in '87, but at the lower power level.

(second msg):
: I don't even know if they run PAVE PAWS 24 hours/day x 7 days/week anymore.
: Budget cuts and our friends the Russians' ya know...
:[e-mail]

Although the primary mission of PAVE PAWS is detection of SLBM, it's not the
ONLY mission.  A satellite "breaking the fence" looks pretty much like a SLBM
until the Cybers figure out range-deltas-RCS etc...  So, the 24 hour/day x 7
day/week mission is to detect, catalog, and track something like 5000
different space objects.

And, as far as being a boondoggle or subject to budget cuts, the system was
relatively cheap to build and very cheap to run.

Gary Huntress
[e-mail]

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

Date: 20 Aug 92 10:03:24 GMT
From: Nick Szabo <[e-mail]>
Subject: Private space ventures
Newsgroups: sci.space

>In article <[e-mail]>, [e-mail] (dann cutter) writes:
>> Could anybody out there please tell me the current status of the private
>> space industry world wide. What comapnies exist... what they have done...
>> thanks
>>

Aside: those interest in space commerce might wish to subscribe
to the space-investors mailing list ([e-mail]).

I don't have info for worldwide, or specific companies handy on-line.
Vince Cate does keep a very long list of space-related companies.
I do have info on trends in the U.S. commercial space market from
Wales Larrison a while back:

########################
[References: Space Business Indicators 1991, US Industrial Outlook
1992-Space Commerce, and private communications on preliminary data
for 1992]..... breakout from US Industrial Outlook -1992 for Space
Commerce is as follows:
                   $ Millions           88     89    90    91    92
                                    ------- ----- ----- ----- -----
 Commercial Satellites                 550    900  1000   800  1000
 Satellite Services                    600    750   800  1200  1350
 Satellite Ground Equipment            600    790   860  1300  1700
 Commercial Space Launches               0    150   570   380   400
 Remote Sensing Data and Services       90    115   140   170   200
                                    ------- ----- ----- ----- -----
                      Total           1840   2705  3370  3850  4650
      Note the 1992 data shown here is projected to end of this year,
and the 1991 data is through last December.  The latest data I have
shows revision of the 1991 actuals UPWARDS by another $250-300
Million, and of the projected 1992 revenues UPWARDS by another $300-
400 Million.  But, even before the revised data is included, the
data supports a statement that "space commerce revenues are expected
to grow by 20%".  My data shows growth in space commerce revenues to
be expected in upper end of the 20-25% range for 1992.
   The other part of your question "What exactly is included in the
term 'space commerce'?" should be answered by the breakout shown
above.  If you have any more questions, I can provide another level
of detail.
  [Aside to the net] Ever wonder why I think folks can make money from
space businesses?  There's up to $5 billion in U.S. business going
on from commercial space systems right NOW.  And it's been showing
greater than 20% annual growth rate for the past 5 years....
   There's definitely potential for profitable investments here.
 -----------------------------------------------------------------
Wales Larrison                           Space Technology Investor

####################
--
[e-mail]  Public Access User --- Not affiliated with TECHbooks
Public Access UNIX and Internet at [phone] (1200/2400, N81)

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

Date: 20 Aug 92 12:26:45 GMT
From: "Allen W. Sherzer" <[e-mail]>
Subject: Saturn dreams
Newsgroups: sci.space

[Dennis writes about using F-1's for a series of vehicles from MLV to HLV]

>That is the reason that is backed up by the same market dynamics that Allen
>pursues.

Not quite the same Dennis, your only going half way. You are using existing
technology and continuous improvment to reduce cost but your still having
the govenrment pick the winner.

If your approach is actually cheaper then in a free market somebody will
do it.

>My only argument with Allen is that the HL Delta and Atlas is
>fundamentally limited to his next step.

Actually that is only because I only view them as interm verhicles. We
could use them until the SSTO concept works. There seems little doubt
that the technology needed for SSTO is either here now or we are only
a few % away in terms of materials and engines.

   Allen

--
+---------------------------------------------------------------------------+
| Allen W. Sherzer | "If they can put a man on the Moon, why can't they     |
|  [e-mail]     |  put a man on the Moon?"                               |
+----------------------246 DAYS TO FIRST FLIGHT OF DCX----------------------+

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

Date: 20 Aug 92 09:40:44 GMT
From: Nick Szabo <[e-mail]>
Subject: SPS feasibility
Newsgroups: sci.space

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

>[SPS & launch cost]

The cheapest launch is still Ariane, $25,00/max. kg to GEO.  At
100 kg/kw the cost of launching a 1-GW SPS is $2,500 billion at
that rate, three orders of magnitude higher than Earthside 1-GW
plants for the launch costs alone.

>Even at $700.oo, we'd see
>remarkable increases in space activity, including, among other
>things, attempts to answer those questions at the heart of the SPS
>debate on this thread.

At even half today's cost, $12,000/kg to GEO, large-scale direct broadcast and
mobile satellites in GEO become feasible, as well as a much greater
climate monitoring and military observation & communications presence.
These high-power satellites can eventually evolve into SPS, but a factor
of 1,000 is a much longer way to go than a factor of 2.

Tapping native resources -- comet or asteroid ices, Martian
CO2 and ices, regoliths, etc. -- for space propellant, construction and
raw materials will become economical sooner.  cf. especially my
ice-rocket proposal, which could be economical at half today's launch
costs if we find ice in the Apollos or Phobos/Deimos or with a
high-energy stage to Jupiter-family comets.

The main market will be materials substitution for current
satellites -- the redesign of communications & observations
platforms made from mostly native products.  Once this kind of industry
is in space, tapping platinum from metal asteroid regoliths and
alluvial gold ores on Mars (if they exist) becomes economical. The
largest market is probably microgravity and vacuum manufacturing using
native materials.  Those markets alone could give us $200 billion/year
in industry, fourteen times the current NASA budget and run by private
industry.  At some later point, with _very_ mature space industry,
we can start building SPS from native materials captured into GEO and
this could be quite competitive beamed to Earth.  But it must follow on a
series of intermediate evolutionary steps, each of which can generate
large amounts of revenue and space industrial capability in their own right.

>Serously, wouldn't a drop in launch costs by only a factor of ten imply,
>maybe even necessitate, a corresponding increase in space activity?
>How about a factor of 2?

I suspect that the ratio is on the opposite side, that a factor of 2
decrease in launch costs would bring a factor of 4 increase in space
industry.  We've more than tripled the comsat industry in the last
decade just from the very modest gains made by Ariane over Delta
and Atlas, combined with value/lb. advances in the communications
payload itself.

>Imagine how cheap shuttle launches would
>be if the workers were paid comparably to Arabian oil workers.

Imagine how expensive Saudi oil would be if the oilfield workers cost
the same as astronauts, $10 million per hour.  :-(

>Sure, we'll continue designing and modelling, and finding
>cheaper ways to do it.  But oil is fundamentally limited.  It will become
>permanantly more expensive, possibly in our life-times.

Doubtful.  Oil prices have been at or near their all-time lows since
the mid-1980s, so if there is any long-term price trend it is down, not up.

Saudi oil costs $3/barrel to pump.  But elsewhere is more expensive
so it sells for $20/barrel on the market.  If we can get a reasonably
export-tax-free market in Siberia, that oil could be pumped for less than
$10/barrel at least through 2030.  After that, there are many other
kinds of deposits (tar sands, etc.) as well as synfuels from coal,
natural gas, and/or biomass that could be tapped for less than
$40/barrel with today's technology, and probably less than $20/barrel
with 2030 technology.  Even $40/barrel would less than double the cost
of gasoline at the pump (most of the retial cost is refining and taxes).  The
major constraint on fossils is probably global warming from CO2, not supply.

>[The argument] seems more along the lines of "SPS will never be worth it."

My argument is that there are many other kinds of space industries that
will be economical long before SPS, and they can provide us the money
and industrial capability to build SPS and habitats in space.  SPS may or
may not ever be competitive for Earthside power.  We should
concentrate on those intermediate industries, and start by working to
expand the industries we have now.


--
[e-mail]  Public Access User --- Not affiliated with TECHbooks
Public Access UNIX and Internet at [phone] (1200/2400, N81)

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

Date: 20 Aug 92 13:22:34 GMT
From: Dave Jones <[e-mail]>
Subject: SPS feasibility / Astrophysical Engineering
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Dave Jones) writes:
>In article <[e-mail]> [e-mail] (Dani Eder) writes:
>>[e-mail] (Gary Coffman) writes:
>>
>>>Numbers could be 2X either way. That's still a near *planetary* body
>>>we're talking about plating with solar cells in any case. That's so
>>>unreal I'm surprised *anyone* would seriously consider it.
>>
>>I'm working on a book that discusses DISMANTLING planetary bodies
>>(and rebuilding them more to our liking, sigh - all that wasted
>>mass inside planets doing nothing more useful than holding
>>atmospheres down, sheesh what poor design).
>>
>>(1) The energy required to dismantle a planet is 0.6Mgr, where
>>M is the mass, g is the surface gravity, and r is the radius.
>>
>>(2) If we calculate the amount of solar energy falling on a
>>planetary body, and relate it to the disassembly energy, we can
>>derive a natural time constant: how long will it take to dismantle
>>a planet using the sunlight falling on an area the size of the
>>planet?
>>
>(0.8)d.r^2 / F(e) where d is density, r is radius, F(e) is energy
>flux in units/unit area/time.  I was looking for the result to be

Make that (0.8).d.g.r^2/F(e).  'Scuse my slip.


--
||)) Dump the Whatizit!  Ren and Stimpy for Olympic mascots in '96 ! )))))))|
||)) "What is it, man?!?" ))))))))))))))))))))))))))))))))))))))))))))))))))|
||))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))|
||Dave Jones ([e-mail]) | Eastman Kodak Co. Rochester, NY   |

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

Date: 20 Aug 92 06:00:51 GMT
From: "Frederick A. Ringwald" <[e-mail]>
Subject: SPS feasibility and other space development
Newsgroups: sci.space

In article <[e-mail]>
[e-mail] writes:

> Faith allowed Neil Armstrong and Buzz Aldrin to ignore both computer problems
> and fuel near exaustion to pilot the Lunar Module to the surface of the moon.

That was more like self-preservation. The only alternative to landing
was crashing.

> Faith says that you can go home to your wife [stuff deleted].

The level of professionalism in this is abysmal, as is its relevance.

> Reason is limited. It takes faith to move a civilization forward.

Medieval history suggests differently.

> It takes
> action based upon a premise that we will find the answers out there even if
> we do not have conclusive evidence for it.

Faith alone is poor basis for any scientific endeavor. If the answers
come out differently from what how you want them to come out, you must
have the integrity to admit it, or else it won't be science for long.

[...]
>
> All other discussion along this line is not appropriate for sci.space

Suits me fine, although I will make just one last reply to another of
your posts.

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

Date: 20 Aug 92 11:51:15 GMT
From: "Frederick A. Ringwald" <[e-mail]>
Subject: SPS feasibility and other space development
Newsgroups: sci.space

In article <[e-mail]>
[e-mail] writes:

[...]
> Risk takers are an endangered species in America in large part because too
> many "experts" are on the sidelines asking questions to infinity and not enough
> engineers have the testicles to tell them to shove off.

This statement is as unprofessional as it is irrelevant. I'M an
experimental scientist: uncritical, unquestioning acceptance of ideas,
no matter how appealing, is as bad for experimenting as it is for
theory. The funding will be wasted on doing inappropriate experiments;
the experiments will not be designed or run properly; and if someone
else does do a good experiment, biased interpretation of the data will
make them useless. It really helps to know what you're doing, and
nationality has nothing to do with it. (By the way, never lecture an
American astronomer about risk-taking. Openings for permanent jobs are
almost non-existent these days, and many of the best are living off
their research grants, hoping they'll get renewed. If you don't believe
me, see the science section in the New York Times for Tuesday, August
18. Even Riccardo Giacconi, director of the Space Telescope Science
Institute, is emigrating.)

> >Uncritical acceptance of ideas, no matter how appealing they might
> >seem, is harmful to any field. Space is no exception. People will hold
> >you to promises you make, and will hold it against you if you tell
> >them things that aren't right. Undisciplined grand speculation isn't
> >even good science fiction. At best, boosterism (good pun intended) is
> >misleading; at worst, it makes you look kooky. Believe me, kooky is
> >NOT an image you want to project when writing a research proposal,
> >especially not when you get to the budget section!
>
> Blind questioning of everything that anyone tries to do is more harmful
> than the other extreme that you posit.

Sorry, but I'm going to keep asking questions: you can't stop me! Nor
could they stop Galileo, although they did stop him from doing it
publicly. But they were wrong. And my questions are not "blind": I ask
questions, because I want to know the answers, and I have reasons why I
want to know the answers.

> It is far better to do something,
> make a mistake, and try again than to sit on your part that you are busy
> covering and continually ask questions. If you fear to make mistakes
> then you never will do anything of note.  The present American cover your
> ass and never do anything that might be percieved as a failure is the
> primary cause of the decline of our once great nation.

By "not right", I had in mind public statements like "50 flights per
year" or "too cheap to meter." Sorry, but there's an enormous
difference between an error and a blunder, about the same difference as
between curiosity and dishonesty. Serendipity is wonderful and perhaps
the most *fun* aspect of science, but *alone* it cannot justify *any*
project - because it may happen in any project, any at all. It takes an
open, unbiased, prepared, and questioning mind even to recognize
serendipity: the happy error itself is not so important, it's the
realization "...but even so,..." Again, it really helps to know what
you're doing. Haphazard tinkering (as opposed to real experimentation
to test ideas or explore concepts or the Universe) is unproductive,
wasteful, and can even be dangerous. One should have at least some idea
of what's going to happen before mixing charcoal, sulfur, and saltpeter
and lighting it with a match. (This is the old argument between
Galilean and Baconian scientific method.)
[...]
As far as scientific literature references go, the best are usually
from refereed journals, and the very best are often refereed invited
reviews. Conference proceedings will do in a pinch, although not if
serious doubts have been raised about an author's methods: proceedings
often aren't refereed, and so might still contain blunders. Not that
the refereeing process is completely infallible, either, but bypassing
it is always suspicious: look at the Cold Fusion flap, which began with
a media circus. Try not to use magazines or newspapers, except strictly
for news items; reporters rarely have the background for detailed
technical discussion.
[...]
Well, I've had more than enough of this, and I shall not post again on
it, no matter what the provocation. This discussion of scientific
method has too little to do with SPS anyway; but in a way, it has
everything to do with it. Whatever, I suggest everyone have a look at
Advice to a Young Scientist, by Peter Medawar. His scientific
achievements are unimpeachable, and his writing style is delightful. I
think you'll need to know this book, if you want to become an effective
PI on many projects. (The GAS Winchester disk experiment sounds like an
excellent concept, by the way: was it your idea?)

P.S. Much of this discussion applies equally well to engineering. The
emphasis is different - for example, in the development stage, the LAST
thing you want is serendipity - but an engineer must have the integrity
to tell whether or not the work matches the specifications, and to
admit it if it doesn't and get back to the old CAD board.

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

Date: 20 Aug 92 12:08:35 GMT
From: "Frederick A. Ringwald" <[e-mail]>
Subject: superstrings & supralight (was SPS feasibility and other
Newsgroups: sci.space

In article <[e-mail]>
[e-mail] writes:

> > P.S. There's a preprint running around by Richard Gott (that may or may
> > not yet have come out in Physical Review D) that actually takes
> > faster-than-light travel seriously, basically as a consequence of what
> > two superstrings passing each other do to spacetime. Thorne and others
> > are trying their hardest to find what's wrong with it, as it severely
> > strains the notion of causality...
> >
>
> Now all we have to do is find a pair of superstrings. Details,
> details.... :-)
>

Well, what do you think those two big tube-things on the Enterprise are
for?

> PS: when it comes out I'd love the citation so I can go dig it out.

To my chagrin, I find it's been out for some time, and not in Physical
Review D. It's

Gott, J. R. 1991, Physical Review Letters, v. 66, p. 1126

but he shouldn't go out and spend all his money in anticipation of the
Nobel foundation giving him one of their large checks, as the
thrashing-out process is still in progress; see:

Caroll, S. M., Farhi, E., and Guth, A. H. 1992, Physical Review
Letters, v. 68, p. 263

(this paper has a VERY surprising title for a refereed journal article,
check it out), and

Deser, S., Jackiw, R., and t'Hooft, G. 1992, Physical Review Letters,
v. 68, p. 267.

The buzzphrase here is "Closed Timelike Curve," or CTC, the distortion
of spacetime that the parallel, moving cosmic strings cause. Every now
and then, interest in this kind of thing flares up; in the late '60s
there was a flurry of experiments to search for tachyons, as quantum
field theory at the time suggested they might be worth looking for (for

some solutions of the field equations, a tachyon is the same as a
magnetic monopole). A kindly old professor who'd been involved in this
told me, "if you ever get an opportunity to do a tachyon experiment
cheaply - for less than $100,000, in less than a year - DO IT!" I think
I'll lay off this here, though, as it's getting perilously close to
sci.physics territory.

By the way, there's no need to shy away from math any more, as programs
like Mathematica are doing to math in general what calculators did to
arithmetic. I learned Mathematica's essentials over a weekend; it's
easy to use, although it requires a pretty good computer to run well.
That Sunday afternoon, I re-did ALL the math I'd ever taken in high
school, college, and grad school, in about four hours! It was like
standing at the edge of the Grand Canyon or Valles Marineris, looking
at untold wonders spread out before me. (No, I'm not getting any money
from Stephen Wolfram to endorse Mathematica; perhaps I ought to.)

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

End of Space Digest Volume 15 : Issue 129
------------------------------