Daggah

"Hydrogen, as you should know is constantly being converted into Helium. The universe is almost full of Hydrogen, and not Helium...Atheists and Agnostics alike agree of the force of this evidence. Since there is no evidence of any kind of a hydrogen gensis, the ONLY logical conclusion is that the universe is young (not 6,000 years, but young still)"

I find this absolutely bizarre. I can't find this as a common claim anywhere on TalkOrigins. I'm suspicious of the first statement. Curious. Anyone have any clue about this?

wonderbread

Stars get their energy by combining hydrogen to make helium. I believe that he is trying to argue that if the universe was 14 billion years old, then stars would have used it all up by now. What he doesn't say is why he believes this to be so. He gives no information on how much hydrogen there is and the rate it is being converted. I guess we are just supposed to take his word on it.

theyeti

Hydrogen is only converted to Helium during fusion reactions inside of stars (and H-bombs).

theyeti

edit: oops, cross post.

[ January 03, 2002: Message edited by: theyeti ]</p>

Daggah

Thanks guys.

Jack the Bodiless

Yes, this proves the Universe is young. It is only about 12-15 billion years old.

Coragyps

Coincidentally, Seth K and I have each put some numbers to this issue in the "Do half of you know..." thread here on E/C. 3rd page.
Jack - bullseye!!

Undercurrent

Actually, if I recall the words of my astophysics prof correctly, the amount of helium generated by all the stars in the universe over the history of the universe is a pittence compared to the amount of helium that's already there. The vast majority of the helium in the universe was produced in the big bang nucleosynthesis, and the amount subsequently produced by stars is much smaller than even the error bars on that measurement.

It only makes the original argument even more rediculous, since if you assumed that stars were the only source of helium, it would take trillions of years to build up as much as there is.

m.

Kosh

Ask him how much hydrogen there was when the universe was created. If he actually gives you
an answer, ask him "Were you there?" (ala Ken Hamm).

Seth K

Where pray tell did you find this particular nugget? Pathlight's C/E encyclopedia is about the only creationist site I can think of were one could find dreck of this magnitude.

Michel is essentially right. While stars do constantly fuse H into He, it doesn't signifigantly increase the amount of observable He in the universe. Most of that came from the nucleosysthesis era of the Big Bang. The abundance of He compared to H is 25% by mass, and at most only 1/10 of that He (or 2.5%) comes from stellar fusion.

Keep in mind that stellar fusion occurs in the core of a star: As a rule of thumb, the core is 10% of the stellar hydrogen. Therefore there is no way to get an abundance of 25% from stellar fusion. Also, the core is where most of the He will stay locked up, and thus unobservable. (Plus, as the star dies the He will be fused in to heavier elements.)

Source: Silk, Joseph, The Big Bang, 3rd Ed., W. H. Freeman, 2001. (Particularly Ch. 7)

[ January 04, 2002: Message edited by: Seth K ]</p>

wdog

I'm with coragyps, michael, and seth. the actual fraction of H to He is small and even when a star dies, mostly H remains (except in a neuton star or black hole) or is blown into space.

btw- I'm not really sure that miami beat nebraska since I wasn't actually there, was ken hamm there? I need to know for sure