Freethought & Rationalism Archive

Doubting Didymus · 07-10-2002, 10:35 PM

Creationist lit(ter) would have us believe that we evolutionists believe that everything in the universe evolves. Thats everything from 'matter "evolving" from nothingness' to stars and planets "evolving".

Apart from the very broad sense that matter and stars can be said to "evolve" in that they simply change over time, I think that the creationists would have to be correct here in thinking this is just plain codswallop. Stars, planets and matter have no mechanism to evolve in the darwinian sense.

The question is: did anyone actually believe this in the first place? or is this just another creationist lie along the lines of 'evolutionists believe we should kill the sick and the old'?

If there is anyone out there who thinks the theory of evolution can be applied to stars, please make yourself heard, I would dearly love to hear your veiws.

Autonemesis · 07-10-2002, 11:07 PM

Stellar evolution describes how stars change over the course of their "lives", and also accounts for changes from one generation of stars to the next. Later generations of stars are enriched in heavier elements than earlier generations, because heavy elements are produced in a supernova, the explosion that signals the end of massive star's lifetime. The presence of these heavier elements in the makeup of later generations of stars affects their properties, and how they evolve to old age. And the shock waves radiating from the explosion set off a new round of collapse in surrounding gas clouds, giving "birth" to the next generation. So, stars do indeed change from generation to generation, and the changes are a result of the differing environments in which the stars formed, along with some material from the "parent" stars. But the mechanisms are very different from natural selection in organisms, so the similarities between stellar evolution and the evolution of life should only be taken as illustrative. Stars have no genes, and life is not animated by an equilibrium between gravity and nuclear forces.

fando · 07-10-2002, 11:56 PM

Natural selection influencing stellar evolution? No. Stellar evolution is a descriptive name for a nearly deterministic physical process in large balls of gas. Evolution in this context simply means the changing state of a star with respect to time. It's analogous to how a candle "evolves" as it burns.

It is important to remember that stars aren't alive in any sense of the word. We have anthropomorphized the process of stellar evolution merely because it is in our animistic nature to do so.

Tim Thompson · 07-11-2002, 12:28 PM

Stellar evolution might be an unfortunate choice of words, at least in the evo-cre biz, but the science behind it is quite sound.

As Bud already mentioned, stellar evolution refers to the changes that individual stars undergo, during the course of their physical existence, whereas biological evolution refers to the changes that populations of individuals undergo, during the course of their physical existence, while the individuals themselves are treated as unchanging.

Of course, young earth/universe creationists are not just opposed to the idea of biological evolution, but reject all forms of change over time which might imply an "old" earth/universe. This means that they are in the unenviable position of rejecting not only a large chunk of biology, but also have to reject large chunks of such miniscule topics as physics, chemistry, astronomy, geology, and a few more no doubt. This is what also leads them to reject stellar evolution.

<a href="http://www.herts.ac.uk/astro_ub/" target="_blank">Astronomy Unbound</a>
<a href="http://instruct1.cit.cornell.edu/courses/astro101/java/evolve/evolve.htm" target="_blank">Stellar Evolution Simulator</a> (Java; bogs down my CPU, might work better for you).
<a href="http://casswww.ucsd.edu/physics/ph7/StevI.html" target="_blank">Stellar Evolution I - Solar Type Stars</a> (links to continuing chapters).
<a href="http://plabpc.csustan.edu/astro/stars/stars.htm" target="_blank">Stellar Evolution Flowchart</a> (clickable image).
<a href="http://oposite.stsci.edu/pubinfo/stellarevolution.html" target="_blank">Stellar Evolution with the HST</a>
<a href="http://observe.arc.nasa.gov/nasa/space/stellardeath/stellardeath_intro.html" target="_blank">Stellar Evolution & Death</a>

Shadowy Man · 07-11-2002, 01:33 PM

But in a way a "natural selection" process does occur in the life-cycles of stars. When stars "die" they enrich the interstellar medium with heavy elements.

These heavy elements can affect the environment in which other stars are formed.

This process may result in future generations of stars being formed with different mass distributions and elemental abundances. A given star's life-cycle is then affected by its mass and elemental abundances.

So, not only do individual stars "evolve" in the sense that they go through various phases from "birth" to "death", the characteristics of the population of stars in the Galaxy can "evolve" over time.

beausoleil · 07-11-2002, 03:16 PM

So what do they make of galactic chemical evolution?

Doubting Didymus · 07-11-2002, 03:19 PM

Thank you all for clearing that up. Of course, I can't see what grounds creationists have to regect this more practical definition. (That stars change their properties over time).

However, although stars may affect newer generations, they cant pass on any attributes that aid survival. As such they must be distanced from what is generally known as the theory of evolution, and given a new name that emphasises physics. This will be a great help to us biologists when debating creationists, as we can say 'thats got nothing to do with evolution in this sense, go talk to a physicist', like I generally do when the Big Bang comes up.

Thank you all.

Doubting Didymus · 07-11-2002, 03:22 PM

Hello beausoleil, I didn't see you post there.

So what is galactic chemical evolution? Surely that has nothing to do with darwinism? Or is it referring to molecular abiogenesis?

Shadowy Man · 07-12-2002, 06:42 AM

Galactic chemical evolution would be the changes in the elemental abundances of a galaxy's interstellar medium over time.

07-10-2002, 10:35 PM	#1
Doubting Didymus Veteran Member Join Date: Jul 2002 Location: East Coast. Australia. Posts: 5,455	Is Stellar evolution a load of old bollocks? Creationist lit(ter) would have us believe that we evolutionists believe that everything in the universe evolves. Thats everything from 'matter "evolving" from nothingness' to stars and planets "evolving". Apart from the very broad sense that matter and stars can be said to "evolve" in that they simply change over time, I think that the creationists would have to be correct here in thinking this is just plain codswallop. Stars, planets and matter have no mechanism to evolve in the darwinian sense. The question is: did anyone actually believe this in the first place? or is this just another creationist lie along the lines of 'evolutionists believe we should kill the sick and the old'? If there is anyone out there who thinks the theory of evolution can be applied to stars, please make yourself heard, I would dearly love to hear your veiws.

07-11-2002, 12:28 PM	#4
Tim Thompson Regular Member Join Date: Sep 2000 Location: Pasadena, CA, USA Posts: 455	Stellar evolution might be an unfortunate choice of words, at least in the evo-cre biz, but the science behind it is quite sound. As Bud already mentioned, stellar evolution refers to the changes that individual stars undergo, during the course of their physical existence, whereas biological evolution refers to the changes that populations of individuals undergo, during the course of their physical existence, while the individuals themselves are treated as unchanging. Of course, young earth/universe creationists are not just opposed to the idea of biological evolution, but reject all forms of change over time which might imply an "old" earth/universe. This means that they are in the unenviable position of rejecting not only a large chunk of biology, but also have to reject large chunks of such miniscule topics as physics, chemistry, astronomy, geology, and a few more no doubt. This is what also leads them to reject stellar evolution. <a href="http://www.herts.ac.uk/astro_ub/" target="_blank">Astronomy Unbound</a> <a href="http://instruct1.cit.cornell.edu/courses/astro101/java/evolve/evolve.htm" target="_blank">Stellar Evolution Simulator</a> (Java; bogs down my CPU, might work better for you). <a href="http://casswww.ucsd.edu/physics/ph7/StevI.html" target="_blank">Stellar Evolution I - Solar Type Stars</a> (links to continuing chapters). <a href="http://plabpc.csustan.edu/astro/stars/stars.htm" target="_blank">Stellar Evolution Flowchart</a> (clickable image). <a href="http://oposite.stsci.edu/pubinfo/stellarevolution.html" target="_blank">Stellar Evolution with the HST</a> <a href="http://observe.arc.nasa.gov/nasa/space/stellardeath/stellardeath_intro.html" target="_blank">Stellar Evolution & Death</a>

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07-10-2002, 11:07 PM	#2
Autonemesis Contributor Join Date: Feb 2002 Location: I've left FRDB for good, due to new WI&P policy Posts: 12,048	Stellar evolution describes how stars change over the course of their "lives", and also accounts for changes from one generation of stars to the next. Later generations of stars are enriched in heavier elements than earlier generations, because heavy elements are produced in a supernova, the explosion that signals the end of massive star's lifetime. The presence of these heavier elements in the makeup of later generations of stars affects their properties, and how they evolve to old age. And the shock waves radiating from the explosion set off a new round of collapse in surrounding gas clouds, giving "birth" to the next generation. So, stars do indeed change from generation to generation, and the changes are a result of the differing environments in which the stars formed, along with some material from the "parent" stars. But the mechanisms are very different from natural selection in organisms, so the similarities between stellar evolution and the evolution of life should only be taken as illustrative. Stars have no genes, and life is not animated by an equilibrium between gravity and nuclear forces.

07-10-2002, 11:56 PM	#3
fando Veteran Member Join Date: Sep 2001 Location: Los Angeles Area Posts: 1,372	Natural selection influencing stellar evolution? No. Stellar evolution is a descriptive name for a nearly deterministic physical process in large balls of gas. Evolution in this context simply means the changing state of a star with respect to time. It's analogous to how a candle "evolves" as it burns. It is important to remember that stars aren't alive in any sense of the word. We have anthropomorphized the process of stellar evolution merely because it is in our animistic nature to do so.

07-11-2002, 01:33 PM	#5
Shadowy Man Veteran Member Join Date: Jun 2002 Location: A Shadowy Planet Posts: 7,585	But in a way a "natural selection" process does occur in the life-cycles of stars. When stars "die" they enrich the interstellar medium with heavy elements. These heavy elements can affect the environment in which other stars are formed. This process may result in future generations of stars being formed with different mass distributions and elemental abundances. A given star's life-cycle is then affected by its mass and elemental abundances. So, not only do individual stars "evolve" in the sense that they go through various phases from "birth" to "death", the characteristics of the population of stars in the Galaxy can "evolve" over time.

07-11-2002, 03:16 PM	#6
beausoleil Senior Member Join Date: May 2002 Location: US and UK Posts: 846	So what do they make of galactic chemical evolution?

07-11-2002, 03:19 PM	#7
Doubting Didymus Veteran Member Join Date: Jul 2002 Location: East Coast. Australia. Posts: 5,455	Thank you all for clearing that up. Of course, I can't see what grounds creationists have to regect this more practical definition. (That stars change their properties over time). However, although stars may affect newer generations, they cant pass on any attributes that aid survival. As such they must be distanced from what is generally known as the theory of evolution, and given a new name that emphasises physics. This will be a great help to us biologists when debating creationists, as we can say 'thats got nothing to do with evolution in this sense, go talk to a physicist', like I generally do when the Big Bang comes up. Thank you all.

07-11-2002, 03:22 PM	#8
Doubting Didymus Veteran Member Join Date: Jul 2002 Location: East Coast. Australia. Posts: 5,455	Hello beausoleil, I didn't see you post there. So what is galactic chemical evolution? Surely that has nothing to do with darwinism? Or is it referring to molecular abiogenesis?

07-12-2002, 06:42 AM	#9
Shadowy Man Veteran Member Join Date: Jun 2002 Location: A Shadowy Planet Posts: 7,585	Galactic chemical evolution would be the changes in the elemental abundances of a galaxy's interstellar medium over time.

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