• Quick note - the problem with Youtube videos not embedding on the forum appears to have been fixed, thanks to ZiprHead. If you do still see problems let me know.

Fossils

swifty

Scholar
S
Joined
Jul 7, 2006
Messages
59
Hey all,

I am seeking information to increase my knowledge further, further in the realms of fossils.

I have google'd my queries but I pretty much came up with different sides of the story type of stuff... nothing really conclusive.

The things I want to learn about are:

How fossils are dated
How these methods were figured out
Is it fair to say fossils prove/disprove evolution

The purpose is to arm myself with knowledge when posed with questions like. "How do scientists know how old fossils are", "How can they prove they are this old", "Insert similar tough question for someone who lacks knowledge in the field...".

So any literature concerning the matter or any answers you can give would be very useful, especially if it is in a manner which I will be able to understand reasonably easily [the descriptive facts with layman's terms/explanations in brackets or something].

Thank you very much.

-Dave
 
the usual basic method is, i believe, by dating the geological stratum they are discovered in. geologists will ascertain what type of rock the fossils lay in and then, with knowledge of that areas geological structure (using geological maps etc to find out when the rock was originally formed) it is possible to reliably date the fossil.
fossils certainly provide evidence how the earths creatures have evolved. as for proving/disproving that process that's too open-ended a question.

BV
 
Last edited:
swifty said:
[...]Is it fair to say fossils prove/disprove evolution[...]
Click to expand...

To answer this questions, you might want to consult "Fossil and Evolution". I apologize for the shameless self-promotion, but the posters who have responded to me, although they didn't necessarily answer my questions in the most straightforward fashion, they provided some excellent information on how fossils bolster the argument for evolution.

I wish you luck in your search for knowledge.

Sincerely,

Michael
 
swifty said:
Is it fair to say fossils prove/disprove evolution
Click to expand...

Since "evolution" is just the phenomenon of forms changing over time, yes fossils prove evolution. The theory of evolution through natural selection is supported by many lines of evidence including fossils.

Absolute (as opposed to relative) methods of dating rocks include Potassium-Argon (K-Ar) Dating and Thermoluminescence (TL) Dating.
 
Last edited:
*I am still reading and one website now looks very promising, therefore the succeeding text needn't be addressed as of yet**

Hm, how do they know such things like:

Samarium-147 , Neodymium-143, Half-life: 106 billion

I can just see someone saying "But how do they know it is 106 billion, they could be wrong!" and me simply saying "... It's science you idiot!" which isn't exactly, uhhh, a proper explanation [albeit a correct one :)].
 
Last edited:
swifty;2515898Hm said:
.
Click to expand...

Weigh a chunk of Samarium 147. Sit next to it with a stop watch and a geiger counter. Count the number of radioactive decays over a set period of time and do a little math. Something to the effect of "Out of these 17 bazillion atoms of Sam 147, we get 15 decay events per fortnight". Rinse and repeat to fine-tune the numbers in hundreds of labs over the last century or so.
 
Ahh right, I thought it was such a slow process that it would be hard to study that way, I guess I didn't consider how many millions of atoms there are... thank you!
 
swifty said:
Ahh right, I thought it was such a slow process that it would be hard to study that way, I guess I didn't consider how many millions of atoms there are... thank you!
Click to expand...

Not millions, not billions. Many, many, more. and that's just a pinoint's worth.
 
For a chunk of Samarian 147 there's in the order of magnitude of:

1,000,000,000,000,000,000,000 atoms per gram.
106,000,000,000 is 106 billion, for reference.
 
SomeGuy said:
For a chunk of Samarian 147 there's in the order of magnitude of:

1,000,000,000,000,000,000,000 atoms per gram.
106,000,000,000 is 106 billion, for reference.
Click to expand...

You mean in that order of magnitude for one molar mass (not per gram).

1 mole of Samarium (6.023 x 10^23 atoms of Sm) weighs about 150 grams.

I think fishbob had the correct unit: bazillions (or, as I prefer using the international form "bajillions").
 
fishbob said:
Weigh a chunk of Samarium 147. Sit next to it with a stop watch and a geiger counter. Count the number of radioactive decays over a set period of time and do a little math. Something to the effect of "Out of these 17 bazillion atoms of Sam 147, we get 15 decay events per fortnight". Rinse and repeat to fine-tune the numbers in hundreds of labs over the last century or so.
Click to expand...

Don't sit right next to it.
 
You must log in or register to reply here.

Back
Top Bottom