humor me, science nerds. i have a question about stars.

carlita · Feb 9, 2005

okay so stars live for a really freakin long time. and it's not like with dinosaurs and stuff where we've got fossils we can play with so that we can map out a timeline and whatnot.

so how exactly do we know what the real life of a star is like since we can't observe it? i mean, it takes WAAAAAAAAAY too long for anyone to have ever witnessed a change. so sure, we've got lots of stars we can see in all different stages of their lives, but how the hell are we supposed to know which stage comes first and which comes last let alone what order they go in in between that?

i tried to ask my dad about this (an engineer at NASA) and either he didn't understand my question or he just really didn't know. i'd like to thing it was the former because if it's the latter he should be ashamed of himself. :razz:

Jeff Canes · Feb 9, 2005

I have head the answer to this before on PBS but cannot recall it exactly

mygrain · Feb 9, 2005

LOL if a NASA engineer can't answer that then who can? My best guess is... First stars are real, and they can be observed. Second they are made up of the same elements that make up every thing else. We can observe stars in many different states and phases of it'slife and observe the elements that make up stars as well. Two hundred mathimatical equations later...you got yer answer. :mrgreen:

oriecat · Feb 9, 2005

Maybe some of this will help

http://www.skeptics.ca/articles/age of universe/home.html

carlita · Feb 9, 2005

mygrain said:
First stars are real, and they can be observed.

are you implying that dinosaurs weren't real?

mygrain · Feb 9, 2005

Nope Im implying that nothing is real...you and the rest of the known galaxy are simply figments of my imagination...you just said nerd and my ears perked up. :wink:

mygrain · Feb 9, 2005

oriecat said:
Maybe some of this will help

http://www.skeptics.ca/articles/age of universe/home.html

Oh and leave is to Orie, the only sane enough person to look anything up, to blow my theory out of the water!!! :greenpbl:

carlita · Feb 9, 2005

haha, orie... "A Newsletter on Teaching Astronomy in Grades 3-12"

wow. 7 years of college have really paid off, eh?! :lol:

"...astronomers (able to glimpse any given star for only a "moment" of its long existence) must examine many stars and hope to find some in each stage of its life. And we have been able to do exactly that..."

see, i don't understand how they can say "and we have been able to do exactly that" as if they've observed everything there is to observe in the universe, or even enough of what's out there (which has got to be about like observing a grain of sand, or a fleck of dust) to then assert that they know the timeline for the life of stars.

i dunno. i guess i just don't buy it.

mygrain · Feb 9, 2005

ya know they sure do act like it's an exact science but I see where yer coming from Carlita. There is tons of room for error from just simply observing the nature of things.

oriecat · Feb 9, 2005

Oh I didn't even notice that about the grades! Don't think I was trying to say anything with that!

carlita · Feb 9, 2005

oh, don't worry... i didn't think you meant anything by it. hell, even if you had it would have been funny! :razz:

MDowdey · Feb 9, 2005

by measuring the varying degrees and magnitude of light emitted by each star, nerds can approximate how far away and how old. im not sure how it works, but thats about it. they have margins of error that are plus or minus a couple million years...

md

mygrain · Feb 9, 2005

MDowdey said:
by measuring the varying degrees and magnitude of light emitted by Chase's butt, nerds can approximate how far away and how old he really is. im not sure how it works, but thats about it. they have margins of error that are plus or minus a couple million years...

md

:shock: MD!!! you should be ashamed of yer self!!!

Hertz van Rental · Feb 9, 2005

It's to do with atomic theory.
You can calculate the mass of a star.
You can use spectral analysis to determine it's composition.
Stars generate energy by hydrogen-hydrogen fusion. You can determine the rate of reaction and, knowing how much hydrogen they contain, calculate first phase length. Second phase is when they run out of hydrogen and start a helium-helium reaction. When they run out of helium they colapse and go out. You can work out an approximate life expectancy.
As for obseving the various stages. There are a lot of stars in the sky. There are bound to be stars at different stages of their life.
If you can find the pleiades in the night sky (the seven sisters) - it is actually a large cloud of dust and gas inside which stars are being born. The crab nebula is the remains of a supernova explosion.
Of course this explanation is very much simplified. Stars are quite complex and the size of the star determines it's life cycle.
The thought that always scrolls my nerd:
Atoms are indestructable. ALL atoms have been forged inside of stars (H+H=He, He+He=C and so on) so all the atoms that make up you have passed through countless stars - or to put it another way: countless stars have lived and died so that you can exist.
Think about that.