RE: [asa] 10 Evidences for the Age of the Universe

That's good to know, I hadn't written up the summary of that one yet. But I
think parallax still helps in several ways. (However, did you mean to say
"10% accuracy" at 100 parsecs? That doesn't sound too good. Did you mean
10% error?)

I took it from an Ohio State page, which claims it had 10% accuracy .
<http://www.astronomy.ohio-state.edu/~pogge/Ast162/Unit1/distances.html>
http://www.astronomy.ohio-state.edu/~pogge/Ast162/Unit1/distances.html

It seems each object had its own error bars, however. The chart (from site
given below) shows one star (far right on graph) at 150 pc to have better
than about 1%, though the others were much worse.

 
<http://outreach.atnf.csiro.au/education/senior/astrophysics/parallaxlimits.
html>
http://outreach.atnf.csiro.au/education/senior/astrophysics/parallaxlimits.h
tml

Regardless, as far as I know, distances beyond 6000 light years are not
accurate using parallax. yet.

A third purpose might be, and you or someone would have to help me here, is
there some way of calculating the distance to these near stars by other
conventional means (involving the speed of light, etc.)?

All stars are in motion, "peculiar" motions, and the nearby stars can reveal
their distance by these motions. A statistical analysis of large numbers
of stars produces some useful motion values that allow some reasonably
accurate distance values for the nearby stars. Parallax measurements, of
course, will serve to verify this method.

The luminosity of a star is another way to gauge a star's distance, as it
follows the inverse square law, with some adjustment for light attenuation
due to interstellar dust and gas.

This latter circumstance of dust and gas can also be used to determine
distance. The greater the spectral absorption bands, the great the distance
light has had to travel through the gas and dust, thus distance can be
determined. I don't know the accuracy of this, however.

A large percentage of the stars are binary systems. Their distances from
each other can be determined given their orbital period and masses. Their
masses can be determined, somewhat, by their spectrum.

Variable stars, especially the Cepheid class variables, is a great method
for large distances, and was used to determine the distance to the Andromeda
galaxy by Edwin Hubble. [There is at least two types of these and Hubble
did not know this at the time, which gave him a somewhat erroneous value.]

The story of supernova as distance determining objects is quite interesting,
too. Though they had a much lower supernova count, the team that used
multiple filters produced a superior sigma value, which allowed them to be
first to go public with the announcement that the universe is expanding at
an accelerated rate.

If so, can those means combined with the parallax measurement confirm that
the speed of light (or other sources of measurement) is accurate at least
out to 1600 years? This by itself wouldn't prove they were accurate further
back, but it might be one means of dispelling notions such as that the speed
of light was gradually slowing down over time. It would be a much better
test than comparing the speed of light obtained from various tests going
back to lab experiments in the 1600's and 1800's, which I have seen were
within the same order of magnitude but of questionable accuracy.

The speed of light question gets involved as we have no direct way to
measure it at great distances. However, the speed of light is a term in a
number of equations. If the speed of light is actually a variable and not a
constant, certain things should be observable, and those things are not
seen.

I am mentioning SN1987a under "5. Detailed history of stellar events" and/or
#6, I don't recall now. Your last argument would sort of the idea behind my
#3, "Size of Astronomical Objects", but I like the way you put it.

I like trigonometric results as it is a user-friendly term, since it is
something we all had in high school.

Is it universally true that the most distant galaxies appear less mature?

Yes, but that is based on large sampling and not every single one, as far as
I know. Perhaps many do look mature for one reason or another, but the
immature ones are quite obvious.

You might like to look at my argument list for the BBT. It has some items
that you might want to add to your list.

http://www.bautforum.com/148135-post1.html

Coope

From: asa-owner@lists.calvin.edu [mailto:asa-owner@lists.calvin.edu] On
Behalf Of Jon Tandy
Sent: Wednesday, April 01, 2009 5:47 PM
To: asa@calvin.edu
Subject: RE: [asa] 10 Evidences for the Age of the Universe

George,

That's good to know, I hadn't written up the summary of that one yet. But I
think parallax still helps in several ways. (However, did you mean to say
"10% accuracy" at 100 parsecs? That doesn't sound too good. Did you mean
10% error?)

One, it is one of several measurement techniques for getting distances to
stars that is independent of the speed of light. It shows that the distance
to even these near stars is several hundreds or thousands of light years
away, with a (relatively) trivial calculation of geometry.

The second thing it does, along with other measurements, is to place these
stars on a continuum of distance from the earth. There are plenty of other
stars much farther away than 1600 light years, and we can prove it by the
very fact that they are way farther out than we can calculate using
parallax. So by deduction, those stars are significantly more distant than
1600 light years, even if this method can't figure out how far.

A third purpose might be, and you or someone would have to help me here, is
there some way of calculating the distance to these near stars by other
conventional means (involving the speed of light, etc.)? If so, can those
means combined with the parallax measurement confirm that the speed of light
(or other sources of measurement) is accurate at least out to 1600 years?
This by itself wouldn't prove they were accurate further back, but it might
be one means of dispelling notions such as that the speed of light was
gradually slowing down over time. It would be a much better test than
comparing the speed of light obtained from various tests going back to lab
experiments in the 1600's and 1800's, which I have seen were within the same
order of magnitude but of questionable accuracy.

I am mentioning SN1987a under "5. Detailed history of stellar events" and/or
#6, I don't recall now. Your last argument would sort of the idea behind my
#3, "Size of Astronomical Objects", but I like the way you put it.

Is it universally true that the most distant galaxies appear less mature?

Jon Tandy

From: asa-owner@lists.calvin.edu [mailto:asa-owner@lists.calvin.edu] On
Behalf Of George Cooper
Sent: Wednesday, April 01, 2009 4:41 PM
To: asa@calvin.edu
Subject: RE: [asa] 10 Evidences for the Age of the Universe

Current stellar parallax measurements, I think, are much less than the 6000
lightyear range that would be helpful to your list of arguments. The
Hipparchus mission has rough measurements out to 1,000 parsecs (~ 3,250
lightyears), with only 10% accuracy at 100 parsecs.

If the SIM mission takes place (2012 or later), however, 10% accuracy is the
goal for stars at around 25,000 parsecs ( > 80,000 lightyears).

Until then, trigonometric distance determinations may offer greater
argument. Supernova 1987A ( 160,000 lightyears) and V838 Mon (~ 20,000
lightyears) are the best examples.

Galaxy morphology is another argument since the more distant galaxies do
appear less mature.

One of my favorite arguments against a small size for the universe is,
"Wwhere do you put the 130 billion galaxies that the Hubble Telescope's
observations reveal?"

"Coope"

From: asa-owner@lists.calvin.edu [mailto:asa-owner@lists.calvin.edu] On
Behalf Of Jon Tandy
Sent: Wednesday, April 01, 2009 10:33 AM
To: asa@calvin.edu
Subject: [asa] 10 Evidences for the Age of the Universe

I am putting together some summaries of scientific evidences, possibly as a
PowerPoint, etc., as a quick summary of the most powerful evidences that
need to be dealt with by any creation science theory that wants to take
science seriously. Except for the first one, I don't have all the items
identified, so I'm not sure what quantity that I'll end up with. For
instance,

10 Evidences for the Age of the Universe

20 Evidences for the Age of the Earth

20 Evidences against a Global Flood

20 Evidences for the Fossil Record

20 Evidences for Common Descent

20 Evidences from Human History

For my "10 Evidences for the Age of the Universe", I have the following so
far:

1. Speed of Light - distance to objects much further than 4000 light years

2. Stellar Parallax - using geometry to measure distance, independent of
speed of light

3. Size of Astronomical Objects - another geometry issue, huge galaxies of
billions of stars that appear to us only miniscule

4. Star formation and death - time and space required for life cycles of
stars

5. Detailed history of stellar events - details of supernova explosions,
etc., indicate real history over real time

6. Light echoes from supernovas - geometry of space from reflections of
supernovas

7. Redshift of Galaxies - confirmation of expansion of the universe

8. Cosmic Microwave Background Radiation - confirmation of Big Bang theory

9. Age of moon rocks - radiometric dating of rocks from the moon

10. Age of meteorites - radiometric dating of meteorites agrees with moon
and earth rocks

Any other thoughts?

Jon Tandy

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Received on Thu Apr 2 13:12:05 2009