Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V15_4/V15NO432.TXT

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Date: Wed, 18 Nov 92 05:00:01
From: Space Digest maintainer <[e-mail]>
Reply-To: [e-mail]
Subject: Space Digest V15 #432
To: Space Digest Readers
Precedence: bulk


Space Digest                Wed, 18 Nov 92       Volume 15 : Issue 432

Today's Topics:
                 *Angle of Attack*: have you read it?
                      All NASA Science In-House?
                       Challenger Legal Action?
                          Clinton's address
                                COSTAR
                         Feynmann's legacy...
                           Hubble's mirror
                     Lunar "colony" reality check
                 Lunar "colony" reality check, part 2
               Saturn V for Freedom deployment (3 msgs)
                     Shuttle replacement (3 msgs)
                    Space suit research? (3 msgs)
              SSTO Viability (was: Shuttle replacement)
                               Titan IV
                 Two sticky questions on astrophysics

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Date: 17 Nov 92 16:57:53 GMT
From: Bill Higgins-- Beam Jockey <[e-mail]>
Subject: *Angle of Attack*: have you read it?
Newsgroups: sci.space

Suddenly I have a desire to know everything I can about *Angle of
Attack*, a new book by Mike Gray, the screenwriter who penned *The
China Syndrome*.  I may have a chance to meet the author this week.

The book is the story of Harrison Storms, the head of North American
Aviation's space division during the development of the Apollo command
module (NAA also developed one of the Saturn V stages, I think).
Storms was canned in the wake of the Apollo fire investigation, much
disucssed here in the past week.

I know John Mechalas of Purdue has read the book.  Anybody else want
to comment on it?  Is it worth buying?  Is there more to it than I
have described?  Does the author think Storms was a scapegoat for
other peoples' mistakes?  I'd appreciate hearing from anybody who's
read it, or even getting pointers to reviews.


Engineer of Hijacked Train:      Bill Higgins
"Is this a holdup?"
                                 Fermi National Accelerator Laboratory
Masked Gunman:
(Hesitates, looks at partner,    Bitnet: [e-mail]
looks at engineer again)         SPAN/Hepnet/Physnet: 43011::HIGGINS
"It's a science experiment!"     Internet: [e-mail]

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

Date: Tue, 17 Nov 92 08:05:36 PST
From: "UTADNX::UTDSSA::GREER"@utspan.span.nasa.gov
Subject: All NASA Science In-House?

I skimmed over the news about NASA's reorganization, thinking it was mainly
some kind of bureaucratic busywork, but now I'm hearing that NASA plans to do
all science in-house.  If this is true, it would mean that space science
departments in universities would no longer get funding from NASA, and I guess
it would also mean that an organization like JPL would no longer receive such
funding either.

If this is true, and if the NSF also shirks its responsibility to fund basic
research [i.e., if Walter Massey has his way], then US space scientists of all
stripes will have to rely increasingly on US military funding [at least THEY
still understand the value of basic research] and certain other nations which
are amenable to international cooperation in this area.

Does anyone out there still have a copy of the NASA reorganization story,
and/or could they tell me what they think this means to the space science
community?

_____________
Dale M. Greer, whose opinions are not to be confused with those of the
Center for Space Sciences, U.T. at Dallas, UTSPAN::UTADNX::UTDSSA::GREER
"Pave Paradise, put up a parking lot." -- Joni Mitchell

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

Date: 17 Nov 92 17:36:12 GMT
From: Claudio Egalon <[e-mail]>
Subject: Challenger Legal Action?
Newsgroups: sci.space

I recall an interview that Roger Boisjoly (the whistle-blower) gave. He
said that he himself had  filled charges against Morton Thiokol's
management (US$1,000,000,000.00) for letting  the Shuttle  fly. I saw
this piece of information in only one source and, since then, I never
heard of the outcome of this action. I do not recall right now the
name of the book that I read this interview (it was a compilation of
articles published in the press about the space program) but if  you
follow up I may try to dig it out for you. BTW  I never could cross
check this info in other publications to make sure  this was true or
not.

Claudio O. Egalon

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

Date: Tue, 17 Nov 92 15:47:50 -0600
From: [e-mail] (Phil G. Fraering)
Subject: Clinton's address

>For such a together dude, why doesn't Clinton (and Gore) have an e-mail
>address and access to the NET???  They'll Never know what's going on
>unless they be on-line.  They should at least be FAQed in.

Probably because some smart-alec joker would put them on the
space-tech and extropians mailing list at the same time, and
their mailbox would be flooded with "moonbase chromium
picolante reality check" material...

At least we knew Lincoln's address...

>Wm. Hathaway

--
Phil Fraering
In the country of the blind....
60 minutes doesn't run stories about people trying to ban hearing

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

Date: 17 Nov 92 15:07:18 GMT
From: Curtis Roelle <roelle@uars_mag.jhuapl.edu>
Subject: COSTAR
Newsgroups: sci.space

Optical improvements introduced by COSTAR should satisfy pent-up
expectations of HST.  Although I have seen the COSTAR mockup at the
STScI and viewed Dana Berry's video, the instrument, like HST itself,
appears to be quite complicated.

Has an assessment of potential risks has been prepared and reviewed?
What could go wrong?  Where are the primary risk areas?  e.g. failure
to grapple the telescope, failure to extract the module COSTAR
replaces, engineering uncertainties that might lead to the new optical
path missing the aperture opening, etc.

My personal wishes for HST are for success.  Just in case I want to be
prepared for the worst, and hear the bad news now.

Curt
[e-mail]

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

Date: Tue, 17 Nov 1992 17:44:22 GMT
From: "Allen W. Sherzer" <[e-mail]>
Subject: Feynmann's legacy...
Newsgroups: sci.space

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

>The impression I got from reading the speeches is that they reflect his
>opinions going into the job - it's not a matter of "read my lips" and a
>promise not to change.

There is also some potential good news in this area. John Pike (likely
next director of the Space Council) was recently briefed on SSTO. His
reaction was a lot more positive than he has been in the past.

>I would assume that at least some of the people who strongly favor these
>programs are writing letters to Clinton/Gore '92, rather than just sitting
>around moaning. :-)

I hope so too. The address is:

President Elect Bill Clinton
PO Box 615
Little Rock AR 72203

  Allen

--
+---------------------------------------------------------------------------+
| Allen W. Sherzer | "A great man is one who does nothing but leaves        |
|  [e-mail]     |  nothing undone"                                       |
+----------------------158 DAYS TO FIRST FLIGHT OF DCX----------------------+

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

Date: 17 Nov 92 17:00:40 GMT
From: "John F. Woods" <[e-mail]>
Subject: Hubble's mirror
Newsgroups: sci.astro,sci.space

[e-mail] (Greg Hennessy) writes:
>PE developed a system of testing that they
>THOUGHT would be good enough. Unfortunately it was not.

According to the report, the system of testing *was* good enough.  Two of the
three tests indicated the mirror was mis-figured.  Perkin-Elmer gave exactly
the attention to those tests that a CERTAIN OTHER manufacturer of space
hardware gave to the tests indicating routine damage to a CERTAIN O-ring in
the Shuttle...

All the managers who approved ignoring those tests (who were probably rewarded
with bonuses for bringing the mirror in on-time) ought to be billed the repair
costs.  (and whoever thought to add random spacing washers to a piece of
*precision* equipment, instead of asking why it didn't fit like it was supposed
to, ought to have boxing gloves surgically attached to his hands so he won't
be tempted to screw up any *other* pieces of equipment...)

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

Date: Tue, 17 Nov 92 16:48:14 GMT
From: Doug Mohney <[e-mail]>
Subject: Lunar "colony" reality check
Newsgroups: sci.space,alt.sci.planetary

In article <[e-mail]>, [e-mail] (Gary Coffman) writes:

>But first you have to mine them, build the processing plants, build the
>machine shops, do site preparation, and actually install the equipment.
>A Lunar base is unlikely to have more than a dozen workers at first, and
>they will have other tasks, like staying alive, that will consume much
>of their time. The infrastructure needed to do large scale mining, refining,
>fabrication, and civil engineering needed to build a power system from
>scratch is rather staggering. Let me drop you and a dozen of your friends
>in the vastly more friendly environment of the Sahara desert and see how
>long it takes you to build a multi-gigawatt power array and then transport
>yourselves to the Gobi desert and build another and interconnect them.
>I don't think Bechtel, with all their resources, could do it here in
>less than decades.

Of course they couldn't. You'd get chewed out for ruining the pristine
environment of the desert. :)

And the native materials of the Sahara aren't available to make solar cells,
for one thing...

Staying alive is mickey mouse in the scheme of things. We know how to do it, and
we have good ideas on how to make it comfortable for long-term stays.

Figuring out the total number of packages needed to provide a "reproducing
and prospering" infrastructure which can produce O2, metals, and silicon or
GaAs for solar cells hasn't been done. I don't think anyone has done
handwaving on it, other than in some general outlines.

I'd say 8-10 years from the initial package set down to at least one and
possibly two sun farms to beam back significant (i.e.: to make a buck) amounts
of power, assuming a serious effort.

Of course, if you want to be petty about it, it will take a couple of decades
to power most of the earth :-)


                 Play in the intelluctual sandbox of Usenet

  -- >                  [e-mail]                        < --

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

Date: 16 Nov 92 21:06:29 GMT
From: "Bruce F. Webster" <[e-mail]>
Subject: Lunar "colony" reality check, part 2
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Nick Szabo) writes:
> Lunar "colony" reality check, part 2:
>
> [More red-flag waving deleted]
>

Sheesh!  Just when things were starting to settle down, too.... ;-)

..bruce..

-------------------------------------------------------------------------------
Bruce F. Webster             | No! I am not Bill Gates, nor would I want to be;
Chief Technical Officer      | I'd rather parse the fish than own the knife;
Pages Software Inc           | (Imagine! Having moby bux but chained
[e-mail]           | to forty million lusers, what a life...)
#import <pages/disclaimer.h> |     -- Jeff Duntemann
-------------------------------------------------------------------------------

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

Date: 17 Nov 92 14:10:37 GMT
From: Doug Egan <[e-mail]>
Subject: Saturn V for Freedom deployment
Newsgroups: sci.space

In <[e-mail]> [e-mail] (Chris Coley) writes:

>My name is Chris Coley, and I am an undergraduate student at Purdue Univesity
>studying Aerospace Engineering.  I am currently working on a research report
>proposing the use of a Saturn V derived heavy launch vehicle, instead of the
>Space Shuttle, for the deployment and resupply of Space Station Freedom.  I
>would like to know if there are any resources available that I could use for
>this topic.  Any information would be greatly appreciated.  Thank You.

    The Saturn V booster consumed extreme amounts of liquid fuel.
    (NOT practical today...)
    I am also under the impression that the design documents were
    somehow lost...  (Maybe to favor the Shuttle program.)

--
 Doug Egan                                  "Old enough to know what's right-
 Lockheed Engineering and Sciences Co.       Young enough not to choose it.
 Houston, TX                                 Wise enough to win the world-
 ***** InterNet:  [e-mail]  *****     Fool enough to loose it." -Rush

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

Date: 17 Nov 92 15:03:27 GMT
From: Paul Dietz <[e-mail]>
Subject: Saturn V for Freedom deployment
Newsgroups: sci.space

In article <dfegan.722009437@node_2204c> [e-mail] (Doug Egan) writes:


  >    The Saturn V booster consumed extreme amounts of liquid fuel.
  >    (NOT practical today...)
  >    I am also under the impression that the design documents were
  >    somehow lost...  (Maybe to favor the Shuttle program.)
  >--
  > Doug Egan
  > Lockheed Engineering and Sciences Co.


Good grief.

All rockets use large amounts of fuel.  Liquid fuels are *cheap*.
Most of the propellant used by the S-V was LOX/RP-1, in the first
stage.  LOX is about $.05/lb, RP-1 somewhere around $.20/lb.  Even if
you use 100 pounds of propellant to put 1 pound of payload into orbit,
the cost is negligible compared to the cost of the S-V's hardware and
the labor involved in its launch.

    Paul F. Dietz
    [e-mail]

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

Date: Tue, 17 Nov 92 15:43:27 -0600
From: [e-mail] (Phil G. Fraering)
Subject: Saturn V for Freedom deployment

>The Saturn V booster consumed extreme amounts of liquid fuel.
>(NOT practical today...)

I love the glib way you say that as if it's actually true that
Saturn's usage of liquid fuel was a problem. I think it used
less than twice as much fuel as the shuttle currently uses to
launch one sixth as much payload.
--
> Doug Egan                                  "Old enough to know what's right-
> Lockheed Engineering and Sciences Co.       Young enough not to choose it.
> Houston, TX                                 Wise enough to win the world-
>***** InterNet:  [e-mail]  *****     Fool enough to loose it." -Rush

--
Phil Fraering
In the country of the blind....
60 minutes doesn't run stories about people trying to ban hearing

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

Date: 17 Nov 92 11:44:46 GMT
From: "Herity D." <[e-mail]>
Subject: Shuttle replacement
Newsgroups: sci.space.shuttle,sci.space

[e-mail] (Michael V. Kent) writes:

>In article <[e-mail]> [e-mail] (Charles Behre) writes:
>>
>>|>   What about the SSTO DC-Y?  It's my understanding that the DC-1 should be
>>|> able to do just about everything that the shuttle can do (with the possible
>>|> exeption of carry the SpaceLab).  And a lot cheapter to boot.

>It will hopefully be able to perform crew transfer and small satellite launches
>more reliably and for less money than the Shuttle or even expendables.  I don't
>see it replacing all of the Shuttle's functions, but it's a start.

AAARRRGGGHHH!!!

The main reason the shuttle failed is that it tried to do too much.
It was specced to be a cheap reusable satellite launcher/crew launcher/space
station/satellite retreiver/glider.
Lets not fall into the same trap with DC-1. Lets settle for cheap reusable
satellite launcher and take it from there. The shuttle can be kept flying
for those tasks where their flexibility is needed until the DC-1 or something
else takes over those functions.

>>What level of success would the DCX testing program have to show to make it a
>>viable candidate?  Does this program have the ability to fascinate congress and
>>Al Gore if it demonstrates what it intendend to do? On the other hand, would a
>>DCX program shifted to taking on the duties of a HL-20 be a disasterous
>>move in terms of the programs efficiency?

Probably. I wouldn't want to risk it. _Why_ risk it? To get funding? If the
politicians set the technical agenda, the project is in big trouble.

--
================================================================================
| Dominic Herity,  dherity@.cs.tcd.ie,                      | Something clever |
| Computer Science Dept, Trinity College, Dublin 2, Ireland.| coming soon to a |
| Tel : [phone] ext 1720 Fax : [phone]        |signature near you|

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

Date: Tue, 17 Nov 1992 17:53:26 GMT
From: "Allen W. Sherzer" <[e-mail]>
Subject: Shuttle replacement
Newsgroups: sci.space.shuttle,sci.space

In article <s#[e-mail]> [e-mail] (Michael V. Kent) writes:

>However, in the current budget climate, I just don't see NASA
>having the money do pursue these ideas until after SSF has reached the
>Permanently Manned Configuration (PMC).

Even if then.

What your assessment ignores is the posibility of BUYING from commercial
sources what you need. Each of the Shuttles capabilities can be replaced
with available or near term commercial systems.

Not only are these systems far cheaper but they don't require a single
dime of development money from the Feds. All that is needed is for the
government to aggree to buy the cheaper service when it is available.

   Allen
--
+---------------------------------------------------------------------------+
| Allen W. Sherzer | "A great man is one who does nothing but leaves        |
|  [e-mail]     |  nothing undone"                                       |
+----------------------158 DAYS TO FIRST FLIGHT OF DCX----------------------+

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

Date: Tue, 17 Nov 1992 18:01:31 GMT
From: "Allen W. Sherzer" <[e-mail]>
Subject: Shuttle replacement
Newsgroups: sci.space.shuttle,sci.space

In article <[e-mail]> [e-mail] (Matt J. Martin) writes:

>  What about the SSTO DC-Y?  [as shuttle replacement]

A set of Delta Clipper vehicles can do most  of what a Shuttle does. It
can launch and retrieve payloads weighing less than 20K pounds but that is
only half the Shuttle payload. A Clipper stationed at SSF could work as an
OTV.

>And a lot cheapter to boot.

At $1 to $10 million per flight it will be a lot cheaper. Just the
expendable for a HL20 will be over ten times this amount.

This BTW is a source of trouble for SSTO. The people working on HL-20
have twice worked on efforts to kill the SSTO program. So far we have
been able to fight back these efforts. If you want to help with the
effort to convince Congress to fund development of a SSTO prototype,
let me know.

  Allen

--
+---------------------------------------------------------------------------+
| Allen W. Sherzer | "A great man is one who does nothing but leaves        |
|  [e-mail]     |  nothing undone"                                       |
+----------------------158 DAYS TO FIRST FLIGHT OF DCX----------------------+

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

Date: 17 Nov 92 10:42:19 -0600
From: [e-mail]
Subject: Space suit research?
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (John Roberts) writes:
>-was a Very Good Thing.
>
>Thanks for the confirmation. 8.4 psi sounds plausible - 10.2 seemed a little
>high, since they always depressurize somewhat in preparation for an EVA.
>
>Anyone recall whether there was an unusually high rate of equipment
>failure for that flight that might be associated with the lower pressure?
>(Other than the fax machine jamming as usual, of course. :-) I remember
>that one or more of the cargo bay lights burned out, but that wouldn't
>be pressure-related.

The orbiter cabin pressure can not be set to 8.4 psi.  The normal cabin
pressure is 14.7 psi (sealevel).  Prior to a planned EVA the cabin pressure
is lowered to 10.2 psi.  If the cabin depress occurs more than 36 hours prior
to the EVA then the mask prebreathe by the EVA crewmembers is not required.

For normal mission operations, only the 14.7 and 10.2 psi regulators are used.
For emergency operations, the orbiter has an 8 psi regulator that is capable
of maintaining a cabin pressure of 8 psi with a two inch hole in the cabin.
Enough nitrogen and oxygen are kept in reserve to allow for an emergency
deorbit and entry with the cabin at the reduced pressure.

--

Pat Oliver -      Lockheed Engineering and Sciences Company at NASA JSC
        [e-mail]
        All standard disclamers apply.

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

Date: Tue, 17 Nov 1992 14:28:20 -0500
From: Kevin William Ryan <[e-mail]>
Subject: Space suit research?
Newsgroups: sci.space

[e-mail] (John Roberts)
>-What's the big push for a earth normal type atmosphere?
>-apollo, etc, ran fine on low pressure pure O2,  does better pressure
>-greatly improve cooling.
>
>(1) Henry says it does.
>(2) It "stands to reason" - five times as many molecules to conduct the
>heat.
>
>-or are there long term bio effects????
>
>There *may* be. For example, one of the Apollo astronauts, after a busy day
>on the moon, had bleeding under his fingernails - thought to be mainly a
>result of the low pressure. Little indications like that made NASA uneasy. :-)

    I would have thought that was from the Apollo suit gloves: they are
quite stiff under pressure and several astronauts reported sore fingers
from forcing them closed.

                                                    kwr

Internet: [e-mail]

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

Date: 17 Nov 92 18:07:45 GMT
From: Doug Mohney <[e-mail]>
Subject: Space suit research?
Newsgroups: sci.space

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

>For normal mission operations, only the 14.7 and 10.2 psi regulators are used.
>For emergency operations, the orbiter has an 8 psi regulator that is capable
>of maintaining a cabin pressure of 8 psi with a two inch hole in the cabin.
>Enough nitrogen and oxygen are kept in reserve to allow for an emergency
>deorbit and entry with the cabin at the reduced pressure.

That's a pretty big hole, once you go through the shuttle tiles and/or glass.
How long would it take for emergency deorbit, assuming *sigh* you still have
all the other systems intact to make it down?


                 Play in the intelluctual sandbox of Usenet

  -- >                  [e-mail]                        < --

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

Date: 17 Nov 92 18:10:45 GMT
From: "Allen W. Sherzer" <[e-mail]>
Subject: SSTO Viability (was: Shuttle replacement)
Newsgroups: sci.space.shuttle,sci.space

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

>What level of success would the DCX testing program have to show to make it a
>viable candidate?

There are two things which need to be validated. First is the aerodynamics of
the 'flip maneuver' they use on re-entry. The second thing is to verify
their models and simulations on tasks needed for rapid operations (can the
engines be serviced as fast as they think, ect).

>Does this program have the ability to fascinate congress and
>Al Gore if it demonstrates what it intendend to do?

I hope so. We are working hard on that (again, let me know if you want
to help). We have shown a few key people that there is support for this.

>On the other hand, would a
>DCX program shifted to taking on the duties of a HL-20 be a disasterous
>move in terms of the programs efficiency?

Depends on who executes it and how.

  Allen
--
+---------------------------------------------------------------------------+
| Allen W. Sherzer | "A great man is one who does nothing but leaves        |
|  [e-mail]     |  nothing undone"                                       |
+----------------------158 DAYS TO FIRST FLIGHT OF DCX----------------------+

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

Date: 17 Nov 92 03:20:18 GMT
From: david michelson <[e-mail]>
Subject: Titan IV
Newsgroups: sci.space.shuttle,sci.space

I've seen quite a bit of Titan IV bashing lately...  Can someone knowledgeable
post a critical summary of the program for us?

--
Dave Michelson
[e-mail]

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

Date: Tue, 17 Nov 1992 10:44:35 GMT
From: Hartmut Frommert <[e-mail]>
Subject: Two sticky questions on astrophysics
Newsgroups: sci.space

Although this belongs to sci.astro or sci.physics (but please don't
crosspost):

[e-mail] (Jeffrey Clark) writes:

>1. Nothing can travel faster then the speed of light. Therefore
>gravitational influence takes time to travel.

Right. An approximate formula for the gravitational potential in the
linearized, Newtonian (weak field) limit of Einstein theory is

  U(r,t) = - G * \int d^3 r' (1/|r-r'|) \rho(r', t - |r-r'|/c)

("retarded" potential)

>Therefore the influence of
>objects on the other side of the galaxy are being felt in our solar system
>as those far flung objects were some 80,000 years ago, yes? More to the
>point the massive centre of our galaxy (possibly contains a mega-black hole)
>will not influence us from it's current position for another 30,000 years.

But from the position where it was 30,000 years ago.

>Now this (according to my naive musings) should not present a problem if we
>are orbiting the centre of our galaxy in a near perfect circular orbit, but
>I would surmise that our solar system would have some eccentricity in it's
>orbit. According to me the solar system is falling toward a non-existant
>centre and has been doing this (as all galactic objects do) since the
>beginning of galactic history.  Should this not cause orbital deviations
>that are measurable? Can someone help me out here please am I missing some
>obvious relativistic point?

Of course there are influences on the Sun's orbit around the galaxy. At
least approximately (i.e. when General Relativity is strictly valid) the Sun
(and with it the Solar System) is moving along a timelike "geodesic", i.e.
the straightest possible line in curved spacetime, where the curvature of
spacetime is caused by the massive bodies in it.

So for now, you can imagine spacetime as a "deformable" substrate, where all
mass and energy cause thedeformation, i.e. curvature, at the place and time
(i.e. "event") they are.
(BTW, this is exactly the physical contents of Einstein field equations.)
The deformations then propagate with the velocity of light, i.e. spacetime
is no more a static background, but dynamically influenced by matter. On the
other hand, matter is "bound" to spacetime, and a particle, or the Sun and
planets, trying to move as straight as possible, move along geodesics, i.e.
are effected by the curvature of spacetime, at the place they are.
(BTW, this is expressed in the equation of continuity for the energy momentum
tensor in GR).

>2. An object is detected 15 billion light years away, pushing the beginning
>of time to at least that many years ago. But surely it pushes that time to
>double 15 billion years (ie 30 billion years).

As nobody has rods to measure the actual distance of the object, one has to
derive the distance from other features. At that large distances you
mention, there are (at least to my knowledge) no "standard candles"
resolvable for telescopes. Instead of a real distance, only the redshift
of the object is measured. According to Hubble's law of expansion, you may
then calculate the corresponding distance, depending on the Hubble constant.
Therefore you can only conclude that the object is seen at a time when the
universe was, say, 10 % as large as now (it's rather complicated, indeed).
This may be 15 billion light years in one and 8 billion in another model.
Thereby you can, of course, never conclude how old the universe is, from the
distance of objects: The 15 billion years come from the theory of stellar
evolution (age of globular clusters in our Milky Way galaxy).

BTW: If we knew H_0  we could determine the approximate distance *today*
  from Hubble's law.

>Nothing can travel faster
>than light.

That is true only locally. But the object observed is (at least
approximately) at rest locally, i.e. moving at most with some % of light
velocity with respect to its own neighborhood. Only at the large distance
it *seems* to move nearly with v=c, because the universe expands. Therefore
it is well possible that there are regions of the universe that seem to
escape faster than light from us.

>The object that generated that radiation did so 15 billion years
>ago from 15 billion light years away. But first we had to get 15 billion
>light years away from this object. Both the object and the particles that we
>consist of must have been together at the Big bang. In order for the light
>to have taken 15 billion years to reach us, the object must have been 15
>billion light years away from our current position 15 billion years ago. In
>other words the earth and the object relative to each other must have been
>travelling for some 15 billion years (at least) to get that far apart before
>the light was emmitted from far-flung object. Once again am I missing some
>obvious relativistic point or have I just doubled the age of the universe?

As above, all the events you describe are local, according to GR. The light
was emitted by the object approx. 15 billion years ago. Then it was moving
with v=c, getting redder and redder due to cosmic expansion, independent of
the emitter as well as the observer. At last, after traveling a long time
and distance, which is difficult to calculate exactly, it arrived at a
telescope, and we can calculate the distance, etc. from the redshift. That
we can observe the latter is only possible because the spectra of the
chemical elements are the same at the place and time of emision in the
distant object and in Earth based laboratories.

>[...] Depending on the answers I've got some other queries as well.

But please don't post them on sci.space.
 Hartmut Frommert                 <[e-mail]>
 Dept of Physics, Univ of Constance, P.O.Box 55 60, D-W-7750 Konstanz, Germany
                                           -- Eat whale killers, not whales --

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End of Space Digest Volume 15 : Issue 432
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