HDTenEightyP/NetNews huggingface dataset:
From: ss6349@tyr.albany.edu (Steven H. Schimmrich)
Subject: Cratering rate estimates.
Originator: ss6349@tyr.albany.edu
Organization: Department of Geological Sciences, SUNY at Albany
Date: Thu, 3 Sep 92 20:33:38 GMT


   I'm looking for estimates of cratering rates throughout geologic time for
the earth, moon, and inner planets.

   I would like primary references (i.e. journal papers) or the name(s) of
anyone who's done work in this area.  Can anyone help me out?

   Thanks.

--
Steven H. Schimmrich     Department of Geological Sciences         "Non semper
ss6349@csc.albany.edu    State University of New York at Albany   ea sunt quae
ss6349@albnyvms.bitnet   Albany, New York 12222  (518) 442-4466   videntur."
Newsgroups: sci.astro
From: ahabig@bigbang.astro.indiana.edu (Alec Habig)
Subject: Re: Particle/Cosmology/Relativity Texts?
Organization: Indiana University Astrophysics, Bloomington, IN
Distribution: na
Date: Fri, 28 Aug 1992 11:11:26 GMT

A real good text on cosmology is the book by Rocky Kolb and Mike Turner.  Can't
think of the exact name now, but the authors and the topic should get you
there.

	Alec
From: dominop@en.ecn.purdue.edu (Philippos A. Peleties)
Newsgroups: sci.astro
Subject: Re: Anthropic Principle?
Date: 27 Aug 92 21:02:56 GMT
Organization: Purdue University Engineering Computer Network

In article <1992Aug22.002050.7540@organpipe.uug.arizona.edu> newberry@newton.as.arizona.edu (Mike Newberry) writes:
>In article <gill.714437283@physics.ubc.ca> gill@physics.ubc.ca (Arnold Gill) writes:
>>clarke@acme.ucf.edu (Thomas Clarke) writes:
>>
>>>What do you netters think of the anthropic principle? (AP for short)
>>>That is the idea that the universe is the way it is because
>>>we are here to observe it.  If it were different we wouldn't
>>>be here.
>>
>>     I think it is something to seriously consider.  I find this especially
>>     true in those cases where someone says "this could never happen over the
>>     lifetime of the Solar System", and throws out a theory because of that.
>>     Perhaps the odds are something like that, and perhaps life evolved on 
>>     Earth because our solar system was the one in a billion with the right
>>     conditions.  Observing here, we can only see the one positive case, not
>>     the billion negative ones.  Perhaps life is extremely unlikely, but it
>>     did happen at least once -- here.
>>
>>--
>>Arnold Gill --- astrophysician trainee in exile             gill@physics.ubc.ca
>
>
>I look at this whole idea as being something of a nonsequitur--what's the
>point?  Does this lead to anything?  I think we have to be especially careful
>about this kind of... well, for lack of a better word, "religion". The 
>direction of causality in the use of "because..." bothers me a great deal.
>If you reversed the sentence, then it would destroy the anthropic principle
>but make a heck of a lot more sense to me; to wit, "We are here to observe
>the universe because of the way it is", an obvious fact. As stated, the AP

You make it sound circular (chicken and egg kind of thing.) I think it is not.
The AP might not be (intellectually?) satisfying (desn't really tell you much)
but it is nevertheless an interesting proposition. It makes sense
philosophically (in my mind at least :-))

>can't help but carry some baggage about an omnipotent entity created in
>Man's own image who cares more about humankind than about the rest of the

How so? Where is this implication within the AP?

>universe.  In short, I have no use for the Anthropic Principle.
>
>Mike Newberry


I agree that it has no "use", however I don't think that one is needed either.



-- 


I speak for myself, I think for myself, I work for myself ... but I don't want
to play by myself ... so bring your toys and let's share ...
Newsgroups: sci.astro,rec.radio.amateur.misc,rec.radio.shortwave
From: metares@well.sf.ca.us (Tom Van Flandern)
Subject: Re: A super-blue branch of super-massive stars?
Organization: Whole Earth 'Lectronic Link
Date: Mon, 31 Aug 1992 00:57:55 GMT


Earlier, I wrote:

>> How about a UIT composite image of the core of these galaxies?  I would
>> expect a UV excess to be found there, although I have not yet found a way
>> to predict its strength as a function of galaxy type.  -|Tom|-

and gsh7w@fermi.clas.Virginia.EDU (Greg Hennessy) replied:

> Well, the core of M31 was CERTAINLY imaged by UIT, and there are no super
> bright stars. There is the UV excess as found by Art Code 20 years ago with
> OAO, but the emission is certainly smooth, NOT superbright-supermassive
> stars.

     I did not know about the known UV excess when I suggested that it ought
to be there based on the reasoning in my preceding messages.

     Since individual stars are not resolvable in the core of M31, how can
you say that the UV excess is not due to supermassive stars?  It surely must
come from stars (or what then?).  Those stars must be hot and early type
(e.g. O-stars).  What exactly rules out something hotter and brighter than O-
stars?

     P.S. Travel reminder.  I won't be around for the next two weeks if you
respond soon to this post.  -|Tom|-

-- 
Tom Van Flandern / Washington, DC / metares@well.sf.ca.us
Meta Research was founded to foster research into ideas not otherwise
supported because they conflict with mainstream theories in Astronomy.
From: ELC@SLACVM.SLAC.STANFORD.EDU
Newsgroups: sci.astro
Subject: Re: > C8 stories + radial guider bug
Date: 27 Aug 92 22:25:24 GMT
Organization: Stanford Linear Accelerator Center

I know very little about optics, but I have a question.  How do you get astig.
in a symetric system that is theoretically perfect?  I assume that the ray trac
e program works on a perfect system.  Just thought I would ask.
                                  Thanks
                                  ELC@SLACVM
From: j.jahn@abbs.hanse.de (Jost Jahn)
Newsgroups: sci.astro
Subject: Sunspots at 29.08.1992.
Date: 29 Aug 92 21:01:00 GMT
Reply-To: j.jahn@abbs.hanse.de
Distribution: sci
Organization: ABBS AstroMail, D-W 2121 Dahlenburg / Germany
X-Version: ZerUU V6.45c

Sunspots at 29.08.1992., 0 h UT.

No.    Pos.  Cl.  Ar.  Mag. SF  F  M  X
---------------------------------------
7267 02N 02W Dso   50   b
7268 05N 63W Cao   50   b    3


No optical or x-ray flares yesterday observed.


 
--
------------------------------------------------------------------------------
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------------------------- for amateur astronomers ----------------------------
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From: bunner@vms.macc.wisc.edu (Dana A. Bunner)
Newsgroups: sci.astro
Subject: Advice needed for Purchase (Novice)
Date: 3 Sep 92 18:20:26 GMT
Organization: University of Wisconsin Academic Computing Center

I am in the market to purchase a simple, low-cost telescope for use in my
backyard by children (and me).  I've read Ronnie Kon's FAQ (thanks, I learned
a lot) but still have some questions.

Usage will be light, fairly undemanding ... just looking at the moon, 
planets, interesting stars.  No photography is planned, no detail on objects
other than the moon is expected.  I'm 12 miles out of town & up 300' from
the plain and we have excellent viewing except toward the north where 
Madison's light obscures all but the brightest objects.  Several visitors
from Madison have argued with me when visiting that the cloudy shape overhead
at night is a cloud, they usually have to watch it for 15-20 minutes to 
realize it's the Milky Way.  Poor city folk.

My local store recommended the Edmunds 3" f/6 reflector for $198 complete
with 15mm eyepiece, and tripod.  The FAQ recommends the 8" Odyssey, but 
that's a bit too bulky for what I had in mind.  It also speaks well of 
an Orion refractor.  Ads in _Astronomy_ cite favorable reviews of the
Meade 4420 reflector, but at $300+, it's a little more than I want to
spend.  But I'm willing to consider it if the quality is significantly
better than the Edmunds.

I'm trying to avoid the trash usually found in department stores but I'm
out of water in this field.  I would appreciate any recommendations or 
advice offered.  

Sorry to add to the noise level.

Dana
From: dsc@gemini.tmc.edu (Doug S. Caprette Bldg. 28 W191 x3892)
Newsgroups: sci.astro
Subject: Re: Telescope question
Date: 4 Sep 92 19:02:06 GMT
Organization: NASA GSFC CDP VLBI

In article <mcdonald.266@aries.scs.uiuc.edu> mcdonald@aries.scs.uiuc.edu (J. D. McDonald) writes:
>In article <168576E18.MEDELMA@cms.cc.wayne.edu> MEDELMA@cms.cc.wayne.edu (Michael Edelman) writes:
>
>
>>It's
>>certainly possible to build compound reflecting telescopes that outperform
>>most achromats- cf Questar, for one. 
>Not really. An 8 inch Questar would be inferior to an 8 inch Meade
>or Celestron because of the dramatically worse chromatic aberration
>in the Maksutov.
>

My understanding is that a spherical shell, is achromatic for the same reason
that an ordinary window pane is achromatic--the two surfaces are parallel.
Please comment further, Mr. (Dr.?) McDonald, I know from experience that
you can justifiy your statement above.

That said, my own experience with the 7" Questars (They never made an 8"
model, did they?) has been disappointing.   They were no better than the
typical (not Doug McDonald's) 8" SCT. 

>
>>However....a properly figured newtonian of long focus (f/8+) with a small
>>secondary can rival a refractor for contrast and resolution. The major
>>mass-market manufacturers don't make such a telescope. Pity.
>
>The reason for that is that no one would buy them. Long focal length 
>implies mounting problems .... and if you can mount a 6 inch f/8,
>you can equally mount an 8" f/6 or 10 inch f/5, which will,

No, way.  A mount which is just adequate for a 6" f/8 will be quite inadequate
for a 10" f/5.  While the focal lengths are about the same, the respective
weights of the two tube assemblies are not.  I would expect the typical 10" 
RFT (light bucket) to weigh about 3 times as much as a typical 6" f/8.

>you can equally mount an 8" f/6 or 10 inch f/5, which will,
>with good figure, annihilate the performance of the 6 inch. There is
>no substitute for aperture.
>
>Doug McDonald

Indeed, there certainly is not any substitute for aperture which is why the
popularity of the SCT's is so disheartening.  After all, for what a typical
8" SCT costs, one could buy a 12 1/2" Newtonian, which would annihilate the
SCT.  

Next comes the portability argument.  Etc.

As someone else has recently posted, the 'best' scope is the one the user
uses to best advantage.  I'll stick to Newtonians for the simple reason that
I can build them myself--that way they are optimised for me!
From: gross@maxwell.ucsc.edu (Mike Gross)
Newsgroups: sci.astro
Subject: Re: Particle/Cosmology/Relativity Texts?
Date: 28 Aug 92 23:23:15 GMT
Distribution: na
Organization: University of California, Santa Cruz
NNTP-Posting-Host: maxwell.ucsc.edu

In <Btoxr3.B1o@usenet.ucs.indiana.edu> ahabig@bigbang.astro.indiana.edu (Alec Habig) writes:

>A real good text on cosmology is the book by Rocky Kolb and Mike Turner.  Can't
>think of the exact name now, but the authors and the topic should get you
>there.

>	Alec

It's "The Early Universe", Edward Kolb and Michael Turner, Redwood City,
CA: Addison Wesley, c.1990 ISBN 0-201-11603-0. There is also a companion
book "The Early Universe: Reprints", but this isn't worth it if there
is a halfway decent library anywhere near you.

Another nice book (though rather advanced) is Andre Linde's most recent
book, "Particle Physics and Inflationary Cosmology" (Chur, Switzerland:
Harwood Academic Publishers, c.1990, ISBN 3-7186-0490-6).

Good luck in your textbook search.

Mike Gross
Physics Board
Univ of California                 GO SLUGS!!!!!
Santa Cruz, CA 95064
gross@maxwell.ucsc.edu
From: sysevm@nsrvan.vanc.wa.us
Newsgroups: sci.astro
Subject: C8 astrophotgraphy, optical specs
Date: 1 Sep 92 19:11:22 GMT
Article-I.D.: nsrvan.1992Sep1.111122.25
Organization: National Systems & Research, Vancouver WA


	Well,

	In the C8 astrophoto thread we've looked into field curvature, coma,
astigmatism and other aberations in addition to changing the corrector plates
position and add on corrector lenses.

	Now on to the raytrace that was kindly provided. I too have run
raytraces for 8" SCT's but as was stated in 'Telescope Optics, Evaluation and
Design' by Rutten/van Venrooij ( a book that I recommend ) none of the SCT
manufactures have published the optical specs for their SCT's. Now, I know that
the book and other sources do raytraces of those instruments but that is for a
"typical" SCT.

	I have looked into converting the 8"SCT into a Schmidt camera and or
adding correctors for flat field photography. The rub in optimizing the design
has been that lack of accurate curves and refractive index for the corrector.

	Does anyone have the optical spec for each of the elements of a SCT?

	How about the specs for the elements of the paracorr and the celestron
	MPCC?

Ethan
Newsgroups: sci.astro
From: fcrary@ucsu.Colorado.EDU (Frank Crary)
Subject: Re: Space Poop
Organization: University of Colorado, Boulder
Date: Fri, 4 Sep 1992 00:04:08 GMT

In article <eric-030992134550@131.211.80.202> eric@cs.ruu.nl (Eric Nieuwland) writes:
>Can't we make a "trash bumper" ? It would be some strong and heavy thing
>that could bump the trash such that its orbit would bring it to the upper
>atmosphere where it then would burn.

Entirely the wrong answer, I'm afraid: The current problem isn't the
amount of junk currently in orbit (at best that's a slight inconvienence).

The key problem is the effect of _any_ impact between debris and another
object. Such collisions generally spall off several additional pieces
of debris. So you have a race between the loss of debris (from atmospheric
drag and re-entry in low orbits, and perturbation out of heavily used
orbits in the case of high orbits) and the rate of new production
(now mostly from collisions with other objects). If collisions 
were frequent enough, the situation could rapidly get out of hand.
So a solution that involved intentional collisions wouldn't work...

                                             Frank Crary
                                             CU Boulder
From: mcovingt@athena.cs.uga.edu (Michael A. Covington)
Newsgroups: sci.astro
Subject: Re: Telescope question
Date: 3 Sep 92 16:46:40 GMT
Organization: University of Georgia, Athens

In article <168576E18.MEDELMA@cms.cc.wayne.edu> MEDELMA@cms.cc.wayne.edu (Michael Edelman) writes:

>From what I've read and seen in the past year, I'd add a few comments to
>that. One, the *average* commercial newtonian has a pretty poorly figured
>mirror, adding to the problem. [...]
>However....a properly figured newtonian of long focus (f/8+) with a small
>secondary can rival a refractor for contrast and resolution. The major
>mass-market manufacturers don't make such a telescope. Pity.

Right.  Couple more things:

(1) We now know that the traditional 1/4-wave accuracy for figuring a
reflector just isn't good enough.  It should be 1/10 or 1/20 wave.

(2) Newtonians tend to be short-focus (f/8 or shorter), and this increases
aberrations in most kinds of eyepieces.  If you put a Huygenian eyepiece
on a reflector -- as people did in the 19th century -- you'll _really_
be disappointed.


-- 
+ Michael Covington - Artificial Intelligence Programs - U of Georgia - USA 
+ Unless otherwise noted, these are private opinions, not official statements.
+ VOTE NO GEORGIA LOTTERY - we need not imitate mistakes of other states.
From: benoit@netcom.com (BENOIT SCHILLINGS)
Newsgroups: sci.astro
Subject: > C8 stories + radial guider bug
Date: 27 Aug 92 17:30:02 GMT
Organization: Netcom - Online Communication Services  (408 241-9760 guest)

Yes the radial guider is broken !!!
I've checked it last night after reading your message and
one of the two aluminum piece was already 3/4 broken.
I've started fixing it with silicon and will see if it's
ok.
I've called Celestron to notify them, one person told me
that the whole design was a problem.
They will send me another one for now and call me back
monday to see what could be done to improve the design.
Send me your feedback.
One thing they could do i guess is to put a larger prism !


About Coma, i've receive quite a lot a contradictory
reports.
What i call Coma could be Cassegrain astigmatism ?

Some people report that they have those fuzzy stars
are the corner of the field, other dont.

Could someone raytrace a star image at 0.5 inches from
the optical axis for a C8 f/10. This could be
the best way to know for sure.

Another question, What's the best guiding eyepiece 
around for the radial guider.
The Celestron one seems good but they have cluttered
the field with so many gadget !

Also does someone has some info about re-programming
the PEC computer. I'm full of idea for that one.


Benoit

benoit@netcom.com
benoit@be.com
Newsgroups: sci.astro
From: yaron@astro.as.utexas.edu (Yaron Sheffer)
Newsgroups: sci.astro
Subject: Re: When is the annular eclipse over Kansas?
Date: 4 Sep 92 15:49:20 GMT
Distribution: usa
Organization: University of Texas, McDonald Observatory

In article <24585@oasys.dt.navy.mil> wolfe@oasys.dt.navy.mil (Ernest Wolfe) writes:
>I experienced the total eclipse in Norfolk a few years
>ago and it was almost a religeous experience.

???
You mean, you've also had religious "experiences", and this Astronomical
spectacle of Nature couldn't match them? Or perhaps you never had the
former, and the eclipse was the closest approximation to them as far as
you imagine them to be? So perhaps it's still possible that you are wrong
and the Eclipse was as impressive and moving as 10,000 religious
"experiences"? BTW, WHAT is a religious "experience"? Can it happen
to you in Reality? Is this not an oxymoron? Please explain.

Ronny

Newsgroups: sci.astro,rec.radio.amateur.misc,rec.radio.shortwave
From: oler@rho.uleth.ca (Cary Oler)
Subject: Daily Solar Geophysical Data Broadcast for 30 August
Organization: University of Lethbridge
Date: 31 Aug 92 20:02:36 GMT

!!BEGIN!! (1.0) S.T.D. Solar Geophysical Data Broadcast for DAY 243, 08/30/92
10.7 FLUX=094.8  90-AVG=124        SSN=045      BKI=1022 3211  BAI=005
BGND-XRAY=B1.3     FLU1=6.4E+05  FLU10=1.5E+04  PKI=1122 3221  PAI=007
  BOU-DEV=009,004,019,019,035,012,005,008   DEV-AVG=013 NT     SWF=00:000
 XRAY-MAX= C1.3   @ 0835UT    XRAY-MIN= B1.1   @ 2358UT   XRAY-AVG= B1.9
NEUTN-MAX= +003%  @ 2220UT   NEUTN-MIN= -001%  @ 1700UT  NEUTN-AVG= +0.9%
  PCA-MAX= +0.1DB @ 2220UT     PCA-MIN= -0.1DB @ 2100UT    PCA-AVG= +0.0DB
BOUTF-MAX=55443NT @ 2333UT   BOUTF-MIN=55391NT @ 1740UT  BOUTF-AVG=55430NT
GOES7-MAX=P:+121NT@ 2003UT   GOES7-MIN=N:-006NT@ 0815UT  G7-AVG=+085,+038,+010
GOES6-MAX=P:+128NT@ 2026UT   GOES6-MIN=E:-018NT@ 1636UT  G6-AVG=+096,-009,+030
 FLUXFCST=STD:100,105,110;SESC:100,105,110 BAI/PAI-FCST=015,015,010/010,010,010
    KFCST=3335 5222 3334 4223  27DAY-AP=005,013   27DAY-KP=1111 2222 3112 3443
 WARNINGS=
   ALERTS=
!!END-DATA!!
Xref: sparky sci.astro:9405 sci.space:12385 news.answers:2748
From: claird@litwin.com (Cameron Laird)
Subject: Re: Red Dog Star, and the health of the Net.
Organization: Litwin Process Automation
Date: Thu, 27 Aug 1992 16:44:46 GMT

The Net works!

Recently, I wrote:

>These newsgroups have more-or-less recently supported
>threads on why (some of) the ancients called Sirius 
>"red".  I recently came across another popular article
			.
			.
			.
>in dynamic interaction with Sirius A and B.  Their con-
>clusion:  "it's too early to choose" (my paraphrase).

I managed to pack an exceptional density of misinforma-
tion into this one posting.  As penance, let me clear
up a few points here:
1.  Sima Qian was a Han astronomer, not Shi.
2.  The most charitable thing that can be said
    about my exposition of the roles of Seneca,
    Horace, Ptolemy, and Cicero was that it was
    confusing.  Ptolemy *post*dated the Romans
    (it's OK to call Seneca Roman, no?), of
    course.  The point remains that their ascrip-
    tions of ruddiness to Sirius likely had some
    genetic connection--Ptolemy in particular
    was more compiler than observer.
3.  The only people who wrote about Gregory of
    Tours seemed to agree that he wasn't looking
    at Sirius, anyway.  If anyone has a good
    reference to the article which explains this,
    I'd appreciate it.

    Long ago, I thought I learned that fellows
    such as Gregory must have been relatively
    uninfluenced by sectarian antique authors,
    as they had no access to the requisite manuscripts.
    Did I miss the point, or has more recent
    scholarship changed the story, or what?
    Follow-ups to sci.classics.
4.  NO one who wrote me believes in an astronomical
    explanation.  This surprised me.  Most asserted
    that it's well-known that Sirius looks red to
    some observers, 'cause it's so low on their
    horizon, and so on.  Hmm.  My best guess is
    that there's more to learn. 

Again, I refer interested readers to the Jan '92 *Re-
cherche*, even though Netcritics have brought into
-- 
Cameron Laird		+1 713 996 8546

claird@litwin.com
claird@Neosoft.com
From: j.jahn@abbs.hanse.de (Jost Jahn)
Newsgroups: sci.astro
Subject: Sunspots at 03.09.1992.
Reply-To: j.jahn@abbs.hanse.de
Date: 03 Sep 92 20:56:00 MESZ
Distribution: sci
Organization: ABBS AstroMail, D-W 2121 Dahlenburg / Germany
X-Version: ZerUU V6.45c

Sunspots at 03.09.1992., 0 h UT.

No.    Pos.  Cl.  Ar.  Mag. SF  F  M  X
---------------------------------------
7267 03N 72W Bxo   20   b
7270 09S 13E Cao  100   b
7271 09S 01E Axx   10   a
7272 11S 53W Dai  140   b    3


No optical or x-ray flares yesterday observed.


 
--
------------------------------------------------------------------------------
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------------------------- for amateur astronomers ----------------------------
    + 49 5851 7896 / V.21, V.22, V.22bis, V.32, V.42, V.42bis and MNP5
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Newsgroups: sci.astro,rec.radio.amateur.misc,rec.radio.shortwave
From: oler@rho.uleth.ca (Cary Oler)
Subject: Daily Solar Geophysical Data Broadcast for 02 September
Organization: University of Lethbridge
Date:  3 Sep 92 07:51:02 GMT

!!BEGIN!! (1.0) S.T.D. Solar Geophysical Data Broadcast for DAY 246, 09/02/92
10.7 FLUX=104.5  90-AVG=124        SSN=077      BKI=1123 4533  BAI=016
BGND-XRAY=B1.7     FLU1=6.0E+05  FLU10=1.7E+04  PKI=2113 3443  PAI=014
  BOU-DEV=008,008,018,030,064,081,033,031   DEV-AVG=034 NT     SWF=00:000
 XRAY-MAX= B4.8   @ 1718UT    XRAY-MIN= B1.5   @ 0754UT   XRAY-AVG= B2.2
NEUTN-MAX= +003%  @ 1035UT   NEUTN-MIN= -003%  @ 1950UT  NEUTN-AVG= +0.6%
  PCA-MAX= +0.1DB @ 1840UT     PCA-MIN= -0.1DB @ 2150UT    PCA-AVG= -0.0DB
BOUTF-MAX=55454NT @ 1315UT   BOUTF-MIN=55403NT @ 1704UT  BOUTF-AVG=55438NT
GOES7-MAX=P:+150NT@ 1733UT   GOES7-MIN=N:-002NT@ 2339UT  G7-AVG=+088,+037,+013
GOES6-MAX=P:+152NT@ 1843UT   GOES6-MIN=E:-037NT@ 1747UT  G6-AVG=+098,-014,+028
 FLUXFCST=STD:107,107,105;SESC:110,110,105 BAI/PAI-FCST=020,020,015/025,040,020
    KFCST=4344 4333 4344 4333  27DAY-AP=019,043   27DAY-KP=2434 4333 3347 7443
 WARNINGS=*AURMIDWCH
   ALERTS=
!!END-DATA!!