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_Creation Science_
_the_
_Age of the Universe_
_and_
_Stellar Evolution_

_High Resolution Solar Spectrum from the [1]150 foot Solar Tower
Telescope at [2]Mt. Wilson Observatory_

_Young-Earth creationists hold that the entire universe, and not just
the Earth, is 10,000 years old or less. They hold to this position
despite the fact that it stands in stark contrast to virtually
everything learned in a wide variety of scientific disciplines.
Geophysics, astrophysics, cosmology, they all show that the Earth is
billions of years old, and the stars & universe are even older._

_Stellar evolution is one of the most extensive disciplines of study
in astrophysics; it is the study of the life cycles of stars. Like
biological evolution, which deals with the evolution over time of
populations of stars, so does stellar evolution deal with populations.
But, unlike its biological counterpart, in which only populations and
not individual creatures evolve, in stellar evolution, it is the
individual star which evolves. Each star passes through distinct
stages in its lifetime, and these stages can be predicted and modeled
by applying the principles of physics. It certainly is no easy task,
but it is comprehensible nevertheless._

_But of course, young-Earth creationists cannot tolerate or allow such
concepts, for stellar evolution in the standard form takes a long
time, well in excess of the paltry few thousand years the
young-Earthers will allow. One of the founders and leaders of the
modern young-Earth movement, Henry M. Morris, tells us what he thinks
about stellar evolution ..._
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_________________________________________________________________

_"Furthermore, they say, we can still see stellar evolution taking
place in the heavens. We can see stars, galaxies, and planets in
various stages of this cosmic evolutionary process._

_No we can't! The heavens and the earth were "finished." All of
God's heavenly "works were finished from the foundation of the
world" (Hebrews 4:3). As long as people have been looking at the
stars, they have never seen a single star evolve. We do
occasionally see stars disintegrate, but that's not evolution! The
tragedy is that so many leaders of Christian colleges,
publications, churches, and para-church organizations are blindly
following these latter-day apologists for modern scientism._

_Perhaps the greatest anomaly in this situation is the incredibly
weak scientific case for the whole scenario of cosmic evolution.
There can be no "experiments" or "observations" of stars evolving,
in the very nature of the case, so it cannot be scientific, though
it may be naturalistic - all based on mathematical manipulations,
computer simulations, and atheistic or pantheistic philosophies."_

_Henry Morris in [3]Creation by Inflation and Quantum Fluctuation
Back to Genesis 129a, August 1999. The italicized emphasis is from
Morris._
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_________________________________________________________________

_This is much the same as Morris has said from the beginning, so I see
no need for repetitive quotes from the past. Other creationist sources
repeat essentially the same line of reasoning, namely that since we
have not actually seen a star actually evolve right before our very
noses, then we cannot assume that they evolve at all. Indeed, Morris
explicitly says that it cannot even be science, and he is not alone in
this opinion amongst young-Earth creationists._

_Morris' denial that the study of stellar evolution is even science at
all can only seem bizarre to anyone who has actually done science, or
ever learned what it is. Thousands of stellar astrophysicists, in
almost every country in the world, will be greatly surprised to
discover that what they do is not even science. Perhaps it is curious
that only Morris seems to have spotted this essential defect in the
discipline, but it is the message that really counts, and not the
messenger. And so we should explore the questions. Is the study of
stellar evolution science? And if it is, is it good science?_
_________________________________________________________________

_Is it Science?_

_Let's handle the easy one first. Morris' intent & meaning are fairly
obvious I think, that science requires "experiment" and "observation",
and since we do not directly observe stellar evolution in real time,
and do not repeat it in a laboratory experiment, then it cannot be
science. But this ony means that Morris has yet to learn what science
is. He is wrong on two major points._

_First, he is wrong about how "experiment" and "observation" work in
science. It is not necessary to duplicate a phenomenon in order to
scientifically study it. It is only necessary to make an hypothesis
about the phenomenon, and to test the hypothesis. That's where
"experiment" and "observation" come into play, in the testing of an
hypothesis, not in the duplication of the phenomenon. In this case,
the phenomenon is "stellar evolution"; we don't need too see it in
real time, we only need to be able to test hypotheses about it. So the
fact that we don't actually see stars evolve in front of our nose does
not exclude the study of stellar evolution from the halls of science.
This should not come as a surprise. In a courtroom we can convince
ourselves (or more importantly a jury) that a crime has occurred, and
an individual is guilty, yet the entire scenario is a past event that
can never be duplicated. Yet we are sure we know who did it & why.
That same kind of general process leads us to be able to understand
past events in science just as well._

_The other major mistake is in understanding what an "experiment" is.
Most of us associate "experiment" with some scientist wearing a white
lab coat, black horn rimmed glasses, and swirling some strange colored
gunk in a flask. But the mathematical manipulations and computer
simulations that Morris takes so lightly _(a curious response from an
experienced civil engineer, whose own discipline of hydraulics & fluid
mechanics lives and breathes on mathematical manipulations & computer
simulations)_ constitute the "experiments" that Morris is looking for.
By applying the fundamentals of stellar physics and letting the clock
tick, we can see a star evolve, in real time, in front of our noses,
in the computer. So, in this sense overlooked by Morris, we do in fact
see stars evolve._

_There can be no doubt but that the study of stellar evolution is
science, and that Henry Morris is wrong. But is it good science? That
takes a slightly longer time to reach the affirmative answer._
_________________________________________________________________

_Is it Good Science?_

_The observational key to understanding stellar evolution is the
ubiquitous [4]Hertzsprung-Russell Diagram, commonly known as the "HR
diagram", and also referred to as a "color magnitude" diagram by
astronomers._

_Figure 1
HR Diagram for Globular Cluster M5_

_Figure 1 above shows a color - magnitude diagram for [5]globular
cluster M5. Typical globular clusters sport anywhere from 100,000 to
1,000,000 stars. M5 is one of the larger globulars, and so probably
has as many as 1,000,000 stars in it. Each point in the diagram above
represents a single star. The horizontal ("x") axis follows the
difference of the "B band" magnitude minus the "V band" magnitude;
magnitudes are logarithmic, and a smaller number means a greater
brightness. The magnitude difference gives the relative color of the
star, with bluer stars on the left, and redder stars on the right
(which is the standard convention for HR diagrams). The vertical ("y")
axis is the magnitude, or brightness of the star. Bright stars are at
the top, and dim stars at the bottom (also the standard convention).
So stars in the lower right will be relatively dim & red, while stars
in the upper left will be relatively blue & bright._

_The first thing to notice is that the stars, on this plot of color
("x") vs brightness ("y"), are not randomly scattered around; they
form a very distinct pattern. That pattern exists because physics does
not allow a star to have just any old color & brightness, but allows
only colors and magnitudes associated with specific physical states.
The labeled areas of the diagram have specific names as follows:_

_A Main Sequence
B Red Giant Branch
C Helium Flash Zone
D Horizontal Branch
E Schwarzschild Gap
F White Dwarf Zonze (off diagram)_

_It is extremely important at this point to keep in mind that this is
observational data, the plotted brightnesses & colors of real stars.
But this diagram is duplicated in detail by stellar evolution models,
Morris' "mathematical manipulations" and "computer simulations". Input
the laws of physics and a mathematical model of the stars structure
and mass, recreate a cluster in the computer, and you recreate the
color magnitude diagram, including all of the features that are
labeled here _(and many more that are not labled but well known to
astronomers, such as the main sequence turn-off point [above and to
the left of the letter "A"] and the "clump" at the red end of the
Horizontal Branch, and the difference between the "red giant" and
"asymptotic giant" branches, that is not so clear in this diagram)_.
If stars don't evolve, and all models of stellar evolution are wrong,
then it certainly must be miraculous to say the least, that computer
simulations of stellar evolution recreate observed HR diagrams with
fidelity. This looks like not only science, but good science as well._

_The basic scenario is that stars begin as "protostars", to the left
of the main sequence, and then evolve to the left until they reach the
main sequence. Once a star reaches the main sequence it moves slowly
up and to the left, getting slightly brighter and bluer as it ages.
During this time the star is fusing hydrogen into helium in its core.
But when the star runs out of hydrogen in the core, it begins to fuse
hydrogen into helium in a shell that surrounds the core. That makes
the star unstable, and it evolves off to the right and up, from the
main sequence, to the red giant branch. But the helium product of
hydrogen fusion forms a new core, and when it gets hot enough, the
helium in the core will quite suddenly "ignite", and the star enters a
new phase where it is converting hydrogen into helium in the shell
around the core, and helium into carbon and oxygen in the core. That
ignition of helium is called the "helium flash", and happens when the
star gets around area "C" in the diagram. The star then descends
rapidly onto the horizontal branch _(where exactly depends on the
ratio of hydrogen and helium to heavier elements in the star)_. But
eventually the helium core is exhausted just as the hydrogen core was,
and the star now begins to fuse helium into carbon & oxygen in an
inner shell around the core, and hydrogen into helium in an outer
shell around that. Once again the star is unstable, and ascend almost
back up the red giant branch, to the asymptotic giant branch _(just to
the left of the red giant branch, they are not easily distinguishable
in this diagram; the heavy dark clump aboove the letter "B" are red
giants, the few scattered points above them are asymptotic branch
giants, on their second trip up to gianthood)_. On the asymptotic
branch, stars move through all of the stages where heavy elements up
to iron are synthesized by nuclear fusion; these stages of stellar
evolution go by much too fast for the outer layers of the star to
respond, so the changes internally make no difference at the surface.
At that point stars that don't become supernovae, move off to the
left, out of the range of the diagram, becoming very blue and very
bright, with strong stellar winds that form planetary nebulae, and
eventually leave behind small, massive white dwarf stars, that reside
below this diagram, where the arrow next to "F" points. That's stellar
evolution in a nutshell. There are no built in biases or
preconceptions. You create a physical model, and then turn it loose to
do as it pleases. The result is a computerized model of stellar
evolution that just happens to coincide beautifully with stars as they
are observed in nature._

_How far along a star will get, in the story of stellar evolution,
depends on its mass. All stars spend most of their lifetimes on the
main sequence. A star like our sun will sit on the main sequence,
slowly brightening, for about 1010 years. A small, minimum mass
_(about 0.08 solar masses)_ red dwarf star will sit on the main
sequence for about 1014 years _(that's 100 trillion years, for those
of you keeping score)_. But massive stars, say 5 solar masses, will
hang around the main sequence for no more than 100,000,000 years, and
drastically less for very massive star, like 20 solar masses or more.
Our sun will become a red giant, but is not massive enough to make the
second trip, up the asymptotic branch. It will cool down to a helium
white dwarf _(a white dwarf with a helium core; white dwarfs can have
cores of helium, carbon, or iron)_. Exotic, supermassive stars like
Eta Carinae, which is over 100 solar masses, can never be main
sequence stars at all. They are intrinsically unstable, and may even
be too massive to supernova; the instability may blow away essentially
all of the star's mass as a stellar wind. _

All of this is a congruence between stellar evolution modeling on a
computer, and observations of stars, especially in clusters. To say
that stellar evolution is not science is, to be blunt, pathetic. There
is an enormous literature in stellar evolution that describes the
science in excruciating detail. My favorite reference is the book
_Stellar Interiors: Physical Principles, Structure and Evolution_, by
C.J. Hansen & S.D. Kawaler, Springer 1994 [ISBN 3-540-94138-X], but
there are many worthwhile sources no doubt. The 3 volume set
_Introduction to Stellar Astrophysics_ by Erika Bohn-Vitense,
Cambridge university press, 1989-1992 covers stellar evolution
specifically in volume 3. Donald D. Clayton's book _Principles of
Stellar Evolution and Nucleosynthesis_, McGraw-Hill, 1968 is the
classic. Every profession has one book that's on everybody's
bookshelves, and Clayton's is definitely one of those books for anyone
in the nucleosynthesis business.
_________________________________________________________________

_Appendix - Relevant Websites_

* [6]Stellar Evolution and Death - A [7]NASA website
* [8]Stellar Evolution - A [9]University of Oregon website
* [10]The HR Diagram - And stellar evolution, from the [11]Univ of
Massachusetts Amherst
* [12]How Hot is that Star? - From the [13]Science Museum of
Virginia
* [14]Energy Production in Stars - From the [15]University of
Tennessee - [16]Physics and Astronomy Department
[17]Astronomy 162 - Stars, Galaxies and Cosmology
[18]Temperature and Pressure in Stars
[19]The Proton-Proton Chain
[20]The CNO Cycle
[21]The Solar Neutrino Problem
* [22]Stellar Evolution with the Hubble Space Telescope
* [23]Astronomy Unbound - A virtual Astronomy Text from the
University of Hertfordshire, England
* [24]Our Sun and Stellar Structure - A chapter out of
[25]Elementary Astronomy, an online textbook from Bakersfield
College, CA
* [26]The Stanford Solar Center
* [27]National Solar Observatories
* [28]Big Bear Solar Observatory
* [29]150 foot solar tower - Mt Wilson, CA ([30]UCLA)
* [31]60 foot solar tower - Mt Wilson, CA ([32]USC)
* [33]Mees Solar Observatory - From the [34]University of Hawaii
_________________________________________________________________

[35]Tim Thompson

setstats 1

References

1. http://www.astro.ucla.edu/~obs/intro.html
2. http://www.mtwilson.edu/
3. http://www.icr.org/pubs/btg-a/btg-129a.htm
4. http://zebu.uoregon.edu/~soper/Stars/hrdiagram.html
5. http://www.seds.org/messier/m/m005.html
6. http://observe.ivv.nasa.gov/nasa/space/stellardeath/stellardeath_opening.html
7. http://www.nasa.gov/
8. http://zebu.uoregon.edu/~imamura/122/feb23/feb23.html
9. http://www.uoregon.edu/
10. http://donald.phast.umass.edu/preprints/starform/orion/node11.html
11. http://www.umass.edu/
12. http://world.smv.mus.va.us/~jims/student2.htm
13. http://world.smv.mus.va.us/
14. http://csep10.phys.utk.edu/astr162/lect/energy/energy.html
15. http://www.utk.edu/
16. http://www.phys.utk.edu/
17. http://csep10.phys.utk.edu/astr162/lect/index.html
18. http://csep10.phys.utk.edu/astr162/lect/energy/temp-press.html
19. http://csep10.phys.utk.edu/astr162/lect/energy/ppchain.html
20. http://csep10.phys.utk.edu/astr162/lect/energy/cno.html
21. http://csep10.phys.utk.edu/astr162/lect/energy/snu.html
22. http://prancer.physics.louisville.edu/astro/107/week_rev/week7/hst/index.html
23. http://www.herts.ac.uk/astro_ub/
24. http://www.bc.cc.ca.us/programs/sea/astronomy/starsun/strsunin.htm
25. http://www.bc.cc.ca.us/programs/sea/astronomy/book.htm
26. http://solar-center.stanford.edu/
27. http://www.nso.noao.edu/welcome.html
28. http://www.bbso.njit.edu/
29. http://www.astro.ucla.edu/~obs/intro.html
30. http://www.ucla.edu/
31. http://physics.usc.edu/solar/
32. http://www.usc.edu/
33. http://www.solar.ifa.hawaii.edu/mees.html
34. http://www.hawaii.edu/
35. file://localhost/www/sat/files/tim_thompson/index.html