HDTenEightyP/NetNews huggingface dataset:
From: bill@bessel.as.utexas.edu (William H. Jefferys)
Newsgroups: sci.astro
Subject: Re: Hubble's mirror
Date: 10 Nov 92 04:51:56 GMT
Article-I.D.: ut-emx.83302
Organization: McDonald Observatory, University of Texas @ Austin

In article <83281@ut-emx.uucp> I wrote in haste (ready to go out the door and catch the bus):

#as it turned out, a fleck of the black paint got scraped off,

OF THE END CAP

#and a significant return from the end of the bar 

not the bar, the END CAP 

#was obtained.
#Thus, the bar was positioned too far away from the laser, and
#the other end of the bar (which was positioned against the
#field lens) was 1.3 mm from where it should have been.

Bill
Newsgroups: sci.astro
From: mje@pookie.pass.wayne.edu (Michael Joseph Edelman)
Subject: Re: celestron "vixen" scopes?
Reply-To: mje@pookie.pass.wayne.edu
Organization: Wayne State University
Date: Thu, 12 Nov 1992 13:27:32 GMT

In article DJD@ccu.umanitoba.ca, vspicer@ccu.umanitoba.ca writes:
> i've gone through the telescope buying FAQ but need some more advice. i
> used to own an astroscan 2001 until someone i lent it to a year or so
> ago totally destroyed it. i've been using some cheapie binoculars
> from the former USSR called "Tento" for general gazing. i'm torn between
> getting a  good pair of binoculars (like Orion Explorer 7x50) and possibly
> a 4.5" newtonian. does anyone have experience with the japanese "vixen"
> telescopes imported by celestron?
> 
> thanks in advance
> 	vic spicer
>  
Vixen makes a great deal of the equipment sold as Celestron. The Polaris and Super
Polaris mounts, *all* the Celestron refractors, and a lot of componant parts
as well. Their stuff is of good quality. 
 
There's quite a difference in cost between Orion Explorer binocs and a 4.5" Vixen.
My personal predjudice is that you should get a good pair of binoculars before
you get anything else. My 8x56 Ultimas always go outside with me, whether or not
I take a telescope as well. Spend $200 or so on a pair of Ultimas, Alderblicks or
equivalent optics first. 
 
                 --mike 
> ------
> vic spicer, recent PERL convert/ data systems,instrument electronics and
> software person with the Time of Flight Mass Spec. Lab> at the University of Manitoba Dept. of Physics





Newsgroups: sci.astro
From: gbt@cray.com (Greg Titus)
Subject: Re: Questions about P/Swift-Tuttle
Organization: Cray Research, Inc.
Date: 5 Nov 92 16:02:46 CST

In article <1992Nov5.204200.3056@sfu.ca> palmer@sfu.ca (Leigh Palmer) writes:
>In article <1992Nov5.081635.1201@horizon.com> schriber@horizon.com (Mike
>Schriber) writes:
>
>>My other question is a bit more limited.  I have a program called Dance of
>>The Planets by ARC.  I've tracked Swift-Tuttle with this program and found
>>the comet to be outbound, near the orbit of Mars on 8/14/2126.  Dance of
>>the Planets is suposed to be a first rate orbital simulator (Gavitic forces
>>only) and I'm curious as to why it's so far off.  Is anyone else using this
>>program that can shed a little light on my mystery?
>
>According to Marsden's calculation the comet will be intersecting Earth's orbit
>fifteen days earlier than the apocalyptic date you've used. Could that be part
>of the problem?
>

Or is ARC's Dance using the "old" orbit, which had perihelion
several years ago?  It seems that doing so would put S-T quite
a bit farther out than Mars' orbit on the given date, though.

greg
-- 
--------------------------------------------------------------
Greg Titus (gbt@zia.cray.com)             Compiler Group (Ada)
Cray Research, Inc.                               Santa Fe, NM
Opinions expressed herein (such as they are) are purely my own.
Newsgroups: sci.astro,alt.sci.planetary,sci.geo.geology
From: cain@geomag.gly.fsu.edu (Joe Cain)
Subject: Re: Questions About Nickel-Iron Meteorites
Organization: Florida State University Geology Dept.
Date: Fri, 13 Nov 92 09:58:33 GMT

In article <69421@cup.portal.com> mmm@cup.portal.com (Mark Robert Thorson) writes:
>I have some questions about the Wilmarstatten (sp?) patterns in
>meteorites. 

>I remember hearing somewhere that metal meteorites cool very slowly
>-- over many years or even centuries -- and that these patterns are
>caused by the large grain structure which develops.
>
>This has always bothered me.  I don't see how they could cool so slowly.
>Although surrounded by vacuum, which is an excellent thermal insulator,
>meteorites are also surround by the cold blackness of space.  I would
>guess that a quantity of molten metal placed in space would freeze solid
>and become cold to the touch within a few days at most.

I am no advocate of conventional wisdom, but can quote a few points
from the excellent article by John A. Wood in chapter 19 of "The New
Solar System": Fig 14...Widmanstatten (umlaut over the last a)
structure, which consists of intersecting plates of kamacite alloy
with taenite in the interstices...(and later in the text in reference
to the kamacite and taenite) "the proportions and compositions which
vary with temperature if the alloys are allowed to react with one
another to equilibrium. The degree to which they do continue
reacting..depends on how fast the system cools. ....substantial
uncertainty in the method, but the cooling rates it points to (10-20
deg K per My) are those that would be experienced 30-50 km deep
...insulating effect of the rock above it."

thus the theory seems fairly solid vs known asteroid sizes. There are
a number of references cited.



Joseph Cain		cain@geomag.gly.fsu.edu
cain@fsu.bitnet		scri::cain
Newsgroups: sci.astro
From: gregg@gordian.com (Gregg Bone)
Subject: Re: Experiences with telescope mail order
Keywords: telescope, mail order
Organization: Gordian
Date: Sat, 7 Nov 1992 00:36:29 GMT

In article <1992Nov3.102808.18336@news.unige.ch>, pfennige@scsun.unige.ch (PFENNIGER Daniel) writes:
> I am considering purchasing a Schmidt Cassegrain telescope to one of the 
> companies advertising in Sky and Telescope.  Has anybody any advice or
> good or bad experience to share with the sci.astro group (or with me by e-mail)?

I recently purchased a Televue Genisis outfit from Adorama and got what I
deserved for ordering through a big NYC mail order company.  I placed the order
on 1-Sep, my credit card was billed on 1-Sep.  They had told me the Super
Polaris mount and tripod was backordered, but the Genisis and everything else
I ordered would be shipped right away.  I received a post card saying my
entire order was not being shipped because of the Super Polaris backorder on
10-Sep.  I called customer service, they knew nothing, not even that my order
existed, so they obviously could not help.  I called back and talked to my
sales person, and after a while he remembered me and my order, he would check
and call back.  He actually called back!!!  I was shocked. He said the Super
Polaris mount was in so they would ship the entire order the next day, and
sorry about the customer service problem, the camera customer service knows
nothing about the scope department.  My order, missing the "free" 16mm Nagler,
arrived on 18-Sep.  I called my sales guy again, he was out, I got transfered
to customer service.  They knew nothing about the Nagler promotion, told me
they had shipped three boxes and should wait until all three boxes arrived.
I told them I had received three boxes.  They said to wait to make sure nothing
else came a few days later.  I hung up, went to Yosemite for rock climbing and
viewing with my new Genisis (Wow nice intrument!).  I called my sales guy again
when I got back,  he groaned, said he would call back...  He called, and I got
my Nagler on 29-Sep.

A few other things, Adorama charged $65 shipping and handling for a UPS
shipment that cost them $24.  The sales guy I talked to was Peter, if after
this story you still want to buy through them at least he tries hard.  I
called several other mail order places before buying from Adorama and their
price was $200 less then next best price and $400 less than my local telescope
store.  Was it worth it?:-)

Clear Skies!

-- 
Gregg Bone (gregg@gordian.com)     US Mail: Gordian
Phone:     (714)850-0205                    20361 Irvine Ave
Fax:       (714)850-0533                    Santa Ana Heights,CA 92707-5637
Xref: sparky sci.astro:11793 sci.space:15545
From: bill@bessel.as.utexas.edu (William H. Jefferys)
Newsgroups: sci.astro,sci.space
Subject: Re: Hubble's mirror
Date: 9 Nov 92 14:52:54 GMT
Followup-To: sci.astro
Organization: McDonald Observatory, University of Texas @ Austin

In article <PXiye-Go3@lopez.marquette.MI.US> stick@lopez.marquette.MI.US (Stick,CommoSigop) writes:
#In <yssPTB4w165w@bluemoon.rn.com> gerry@bluemoon.rn.com (Gerard M. Foley) writes:
#
#>dhl@mrdog.msl.com (Donald H. Locker) writes:
#
#>> Now that I know a little about mirror-making, I'd like to hear again
#>> how the Hubble mirror contractor messed up the figure of the main
#>> mirror.  I understand it has spherical aberration, but wonder how
#>> [Rockwell?] managed to do that.
#>> 
#>It wasn't Rockwell (I forget axactly who it was, but it was an
#>otherwise reputable New England outfit) and put briefly, they
#>fouled up the test, performing it incorrectly, and never
#>checked by any independent method.
#
#   According to Dr. Steve Maran, who works on the HST project at the
#Goddard Flight Center, and who was recently a guest lecturer at my college,
#none of the above is true.  The company that ground the mirror did it
#exactly to the specs they were given.
#
#   The specs were wrong.

If my friend Steve Maran really said this, then he's 
incorrect. The specs were fine. What happened was that
Perkin-Elmer mis-manufactured a critical piece of
equipment, a reflective null corrector, that was used
to figure the mirror. A field lens was located 1.3 mm
out of its proper position. The reasons for this having
happened are rather complex and involved. They are 
described in gory detail in the Hartford Courant
report series that I posted information about earlier.
I personally attended many days' worth of reviews where
these events were found out, so I have reason to believe
that what I say is accurate.

The poster to whom you responded had it essentially right.

I don't think that Steve would be as far off base as
this, and I suspect that you have misunderstood him.

Bill Jefferys

Newsgroups: sci.astro,sci.space
From: pad@probitas.cs.utas.edu.au (Paul A Daniels)
Subject: Re: Swift-Tuttle Comet a threat to earth?
Organization: University of Tasmania, Australia.
Date: Thu, 12 Nov 1992 02:11:07 GMT

	If a comet like ST did strike the earth, what would the after effects
be geologically? Would you end up with a large area of vulcanism? 
Would you end up with a hot spot? 
	What would the the result of say a 5km dia. hole in the mantle?

Paul.

Newsgroups: sci.astro,sci.space
From: henry@zoo.toronto.edu (Henry Spencer)
Subject: Re: Hubble's mirror
Date: Sat, 7 Nov 1992 07:18:37 GMT
Organization: U of Toronto Zoology

In article <PXiye-Go3@lopez.marquette.MI.US> stick@lopez.marquette.MI.US (Stick,CommoSigop) writes:
>>... put briefly, they
>>fouled up the test, performing it incorrectly, and never
>>checked by any independent method.
>
>   According to Dr. Steve Maran, who works on the HST project at the
>Goddard Flight Center, and who was recently a guest lecturer at my college,
>none of the above is true.  The company that ground the mirror did it
>exactly to the specs they were given.

You're sure that's what he said?  It's *not* what Lew Allen's review board
found (and documented in detail).  The grinding people at Perkin-Elmer did
indeed produce an essentially perfect mirror to the wrong spec.  But it was
Perkin-Elmer that botched the spec, by mis-building the reflective null
corrector that was used to measure the mirror shape, and Perkin-Elmer that
ignored three successive hints that something was wrong with the RNC.
(First, the error made it impossible to build the RNC without a slight
design change; the change was made without anyone asking why it was
necessary.  Second and third, results from two other measurements were
disregarded because the RNC was thought to be superior.)
-- 
MS-DOS is the OS/360 of the 1980s.      | Henry Spencer @ U of Toronto Zoology
              -Hal W. Hardenbergh (1985)|  henry@zoo.toronto.edu  utzoo!henry
From: phacb@cc.flinders.edu.au (<A.C.Beresford>)
Newsgroups: sci.astro
Subject: Dance of Planets & Swift-Tuttle
Date: 8 Nov 92 05:40:50 GMT
Organization: Flinders University
Originator: phacb@pippin.cc.flinders.edu.au

This reply was received from ARCsoft about DANCE's capability
and P/swift-tuttle calculations.
You can send a message to Ron at 72600.2121@compuserve.com
Tony Beresford , DANCE ofPlanets owner

Ron Dawes
72600,2121
DANCE & Swift-Tuttle
Tony,
    I've run P/S-T several times through DANCE with different results each
time.  The primary concern is not to run it too fast, and any time there is
potential for appreciable gravitational interaction, slow it down some more.
Also, keep in mind that you must start the simulation as near the epoch date
as possible (ie, 12 Dec 92).  Start it out slowly (Pace 1000-2000).  Once
the comet is well below the ecliptic and clear of significant gravitational
influences, speed it up.  When it gets beyond 10 AU or so, you can push it
to Pace 80k.  This is about the highest pace I could run it and still come
close to Marsden's prediction.  Once again, when you start nearing the
ecliptic on the return path, slow it down to 5k-10k.  And when you reach the
inner solar sytem, drop down to 1000-2000.
    It has taken me as much as an hour to run the simulation this way but it
is necessary in order to achieve the required accuracy.  I've come as close
as 4 days to Marsden's prediction.
    One of the things you might try, just to speed things up, is do what
Roger Sinnott suggested.  Using the same elements, just change the
perihelion date to around July 25, 2126 and start the simulation from that
date.
    Cheers,

Ron
From: mpound@astro.umd.edu (Marc Pound)
Newsgroups: sci.astro
Subject: Re: NEWS: Galileo Cleared of Heresy Charges by Vatican
Date: 6 Nov 92 16:28:17 GMT
Organization: U. of Maryland @ College Park, Astronomy

In article <1992Nov4.193735.16355@sal.wisc.edu> lattis@sal.wisc.edu (Jim Lattis) writes:
>
>...  But Galileo
>had *no valid proof*, neither by their standards nor by ours.  Thus, as
>the seventeenth-century theologians saw it, they were not preventing
>Galileo from speaking the truth.  Rather, they were preventing him from
>declaring *as true* a theory, which he could not prove, that they 
>(mistakenly) saw as dangerous to the authority of the Church and the
>spiritual well-being of its believers.  
>
>-jim lattis, space astronomy lab

He had clear, compelling proof! He observed the phases of Venus, 
and thus showed it went around the Sun not the Earth.
His observations of Jupiter's moons showed not only that they were 
not orbiting the Earth, but that a center of motion (Jupiter) 
could be in motion. At the time, it was argued that Earth could
not be moving because it would leave the moon behind.

Marc Pound
Ast. Dept.
University of Maryland
mpound@astro.umd.edu
Newsgroups: sci.astro,rec.radio.amateur.misc,rec.radio.shortwave
From: oler@rho.uleth.ca (Cary Oler)
Subject: Daily Solar Geophysical Data Broadcast for 06 November
Organization: University of Lethbridge
Date: 10 Nov 92 10:31:00 GMT

!!BEGIN!! (1.0) S.T.D. Solar Geophysical Data Broadcast for DAY 311, 11/06/92
10.7 FLUX=132.9  90-AVG=124        SSN=116      BKI=1233 4322  BAI=012
BGND-XRAY=B4.3     FLU1=3.2E+06  FLU10=5.6E+05  PKI=1133 4332  PAI=012
  BOU-DEV=008,010,036,020,046,023,012,014   DEV-AVG=021 NT     SWF=00:000
 XRAY-MAX= C1.6   @ 1055UT    XRAY-MIN= B3.6   @ 1142UT   XRAY-AVG= B6.1
NEUTN-MAX= +001%  @ 2050UT   NEUTN-MIN= -004%  @ 2150UT  NEUTN-AVG= -0.8%
  PCA-MAX= +1.4DB @ 1335UT     PCA-MIN= -0.4DB @ 1620UT    PCA-AVG= +0.1DB
BOUTF-MAX=55427NT @ 0100UT   BOUTF-MIN=55405NT @ 1832UT  BOUTF-AVG=55417NT
GOES7-MAX=P:+092NT@ 1911UT   GOES7-MIN=N:-024NT@ 0740UT  G7-AVG=+068,+036,+005
GOES6-MAX=P:+107NT@ 1914UT   GOES6-MIN=E:-017NT@ 0054UT  G6-AVG=+085,-003,+034
 FLUXFCST=STD:135,135,140;SESC:135,135,140 BAI/PAI-FCST=015,010,010/020,015,015
    KFCST=1114 4100 0004 4000  27DAY-AP=009,016   27DAY-KP=1133 3223 2214 4443
 WARNINGS=*SWF
   ALERTS=**PROTN10:ENDED@0010UTC;**245STRM:0907-2107UTC
!!END-DATA!!
From: aalpern@hamp.hampshire.edu
Newsgroups: sci.astro
Subject: quantum discussions
Date: 6 Nov 92 22:49:48 GMT
Organization: Hampshire College

Does anybody know if there are any discussion groups out there concerning
quantum mechanics, cosmology, or quantum cosmology(!?)? If so, where can they
be found?
	-Adam
aalpern@hamp.hampshire.edu-- 
Adam Alpern			* "All that is gold does not glitter, not all  *AAlpern@hamp.hampshire.edu	* those who wander are lost." - JRR Tolkien    *				* "When I look in the mirror I see the days to *				* come, and my face is just a trace of where   *				* I'm coming from." - Ani DiFranco	       *
Xref: sparky sci.astro:11808 sci.space:15584
From: BrianT@cup.portal.com (Brian Stuart Thorn)
Newsgroups: sci.astro,sci.space
Subject: Re: Hubble's mirror
Date: Mon,  9 Nov 92 19:25:01 PST
Organization: The Portal System (TM)
  <yssPTB4w165w@bluemoon.rn.com> <PXiye-Go3@lopez.marquette.MI.US>
  <1992Nov8.232547.27419@ke4zv.uucp>

If there is a perfect mirror presumably sitting at Kodak, why doesn't NASA
simply return Hubble to Earth and replace the faulty mirror?
 
I know, I've read many times that returning Hubble to Earth is *not* an
option, but I can't figure out WHY. At 24,000 lbs, Hubble is well within
the Shuttle's landing cargo capacity, and since the only part of Hubble
likely to suffer damage during a 3g return is primary mirror (which
will be replace anyway) I don't understand why NASA doesn't simply swap
mirrors. NASA has already spent a fortune building COSTAR and ESA is
building replacement (no wobble) solar panels. With three spacewalks, the
Shuttle crew will be hard pressed to get all the work done.
 
Doesn't bringing Hubble home for repairs make more sense than jerry-rigging
and dangerous EVAs on orbit? 
  
-Brian
Newsgroups: sci.astro,sci.space
From: bobp@hal.com (Bob Pendleton)
Subject: Re: Hubble's mirror
Organization: HaL Computer Systems, Inc.
Date: Tue, 10 Nov 1992 16:02:38 GMT

From article <69203@cup.portal.com>, by BrianT@cup.portal.com (Brian Stuart Thorn):
> If there is a perfect mirror presumably sitting at Kodak, why doesn't NASA
> simply return Hubble to Earth and replace the faulty mirror?

> Doesn't bringing Hubble home for repairs make more sense than jerry-rigging
> and dangerous EVAs on orbit? 
>   
> -Brian

Depending on whose figures you believe a shuttle launch costs some
where between $100,000,000 US and $250,000,000 US.

Repair on orbit requires 1 launch. Repair on the the ground requires 2
launches. 

Thus, repair on orbit, saves somewhere between $100 and $250 million
dollars. As the US is rapidly approaching it's legal debt limit of
roughly $4,100,000,000,000 dollars (your share, if you are a US
citizen, is roughly $16,000) we really can afford to piss away
$250,000,000 for the convenience of some astronauts and astronomers.
Especially when we are borrowing the money to fix it.

As much as I value the information that we can get from Hubble. I'm
not willing to go $0.01 US more than is needed to fix it.

I think it is time to face the simple fact that as long as we are
paying $300,000,000,000 US in interest on the Debt we (US) are not
going to be spending money on large, long term, space programs.

The interest on the Debt is the single largest item in the US Federal
budget.

			Bob P.

P.S.

What we pay in interest on the Debt, if spent on education, would just
about double what we spend per student in the K-12 grades.


P.P.S

Do we need nuclear weopons anymore? Or can we destroy the worlds
economy by just defaulting on the our loans?
-- 
Bob Pendleton             | As an engineer I hate to hear:
bobp@hal.com              |   1) You've earned an "I told you so."
Speaking only for myself. |   2) Our customers don't do that.
                   <<< Odin, after the well of Mimir. >>>
Newsgroups: sci.astro
From: pad@galaxy.nsc.com (Paul Denny x8349)
Subject: perseids
Organization: National Semiconductor, Santa Clara
Date: Wed, 4 Nov 1992 21:29:38 GMT

The recent return of swift tuttle was as I understand
it predicted by the recent increase in the number of 
perseids and a new sharper peak. Can someone explain
why the debris that cause the meteors should preceed
the comet by over a year? I would expect fresh debris
to follow the comet due to it being blown away from the
sun by solar wind like the tail. 

Also in the discussion on impact by Swift tuttle 
a change in arrival time of several days is claimed
to be possible due to non gravitational effects
but I thought that the new peak in the perseids
is only a few hours different from the old one
implying to me that the orbit has only changed a few
hours after 135 years - why should it change several
days next time round?

Any experts? thanks - Paul
Newsgroups: sci.astro,sci.space
From: kfarmer@wsuaix.csc.wsu.edu (keith farmer;S10000)
Subject: Re: Swift-Tuttle Comet a threat to earth?
Organization: Washington State University
Date: Sat, 7 Nov 92 23:22:03 GMT

Thanks to those who wrote to me about the typo... I don't use the name often.

Keith

Xref: sparky sci.astro:11949 sci.space:15858
From: kentm@aix.rpi.edu (Michael V. Kent)
Newsgroups: sci.astro,sci.space
Subject: Re: Japanese X-ray satellite: Astro_D
Date: 13 Nov 92 04:02:56 GMT
Organization: Rensselaer Polytechnic Institute, Troy, NY

In article <BxL4vr.EIw@constellation.ecn.uoknor.edu> rwmurphr@wildcat.ecn.uoknor.edu (Robert W Murphree) writes:
>
>The US hasn't launched any free-flyers in the X-ray since 
>HEAO or Eistein 10 years ago, have they? A few detectors on
>other people's satellites of course, but nothing big since
>Einstein.

The German-American Rosat was launched in June 1990, the Broad Band X-Ray
Telescope flew with the Astro payload on the Shuttle during STS-35 in 
December 1990, and the Diffuse X-Ray Spectrometer is scheduled to fly
on the upcoming STS-54 mission to deploy a TDRS satellite in January 1993.

I'm not sure the Shuttle fits your definition of free-flying or not, but some
missions have been launched recently.

Mike

-- 
Michael Kent                                   kentm@rpi.edu
McDonnell Douglas                              Rensselaer Polytechnic Institute

Tute Screwed Aero Class of '92                              Apple II Forever !!
Newsgroups: sci.astro