Carbon Dating (dinosaur, hell, mission, confess, faith)

[dan]

Much of archeology and anthropology depends on the accuracy of carbon dating, the method of determining age by measuring radioative emissions from carbon 14 atoms and comparing them to the equilibrium level of living organisms. The radioactivity drops of at a constant rate. A simple calculation then gives us the age of the specimen.
Several years ago some workers in Great Britain uncovered a human head in some peat moss by a neighborhood. There was still part of the eye intact and plenty of hair. After some preliminary studies a group had it carbon dated and placed it at 2,000 years old. The skull was then put in the British Museum. If you look up info on a head found in the Lindow Bog you'll find out that the case is pretty much closed. You'll also find that a man living near where the head was found says the head actually belongs to his wife, whom he murdered, dismembered and buried in the Bog. Scientists say he's wrong, but he is in prison for the rest of his life.

That's all the information you'll find, but a professor from a nearby university later examined photos of the dead woman and photos of the skull and says they're too close a match. He wants the British Museum to release the skull for further studies, but they refuse.

If carbon dating is shown to be unreliable then our idea of the universe has to change rapidly!

The bones of an Arcocanthosaurus (this is a dinosaur) were carbon dated in the early nineties and all the dates recorded ranged from 9,890 to 36,500 years old. Interesting.

Living trees were dated at 10,000 years old.

Ice Age materials were dated to the first century AD.

What say you?

[kai]

Apparently the guy confessed to the murder of his wife, the head was not his wife and was 1700 years to old .
http://www.mesh5.com/tension/febmarch/bog.htm

[Halcyon]

Originally Posted by dan

If carbon dating is shown to be unreliable then our idea of the universe has to change rapidly!

Atoms can't lie dan, Carbon-14 becomes Carbon-12 at a measureable rate, there's no way to fake it.

Originally Posted by dan

The bones of an Arcocanthosaurus (this is a dinosaur) were carbon dated in the early nineties and all the dates recorded ranged from 9,890 to 36,500 years old. Interesting.

Dinosaurs can't be carbon dated dan, dinosaur fossils are made of rock, they have no carbon in.

Originally Posted by dan

Living trees were dated at 10,000 years old.

Ice Age materials were dated to the first century AD.

What say you?

I say sources please.

[dan]

Originally Posted by Halcyon

Atoms can't lie dan, Carbon-14 becomes Carbon-12 at a measureable rate, there's no way to fake it.

It's measurable, but it's not always the same rate and many different things can influence how rapidly they decay. Just as people shouldn't have blind faith in religion, you shouldn't have blind faith in science. Any time they do carbon dating they test several samples and they will get a range of dates. That range can be up to 30,000 years, and that's after they throw out the dates that are no where near the other ones. Most scientists will put in the main body of work the numbers that agree with their theories, in the footmotes those that don't entirely disagree, and dismiss as erroneous the ones that don't at all agree. Does that sound like honest science?

Originally Posted by Halcyon

Dinosaurs can't be carbon dated dan, dinosaur fossils are made of rock, they have no carbon in.

You don't really thnk that dinosaur bones have never been living, do you? Anything that has been living at one time or another will have these radioactive emissions, and the longer it's been dead (no matter what form it is now) it has less and less of them. The problem is that past 50,000 years it is too unreliable. The bones in this particular test had a black residue surrounding them that was figured to be a type of fossilization in which the soft tissue of an animal becomes a thin carbon film. It was ground up with the bone to get the samples.

That particular paper was: Fields, W., H. Miller, J. Whitmore, D. Davis, G. Detwiler, J. Ditmars, R. Whitelaw, and G.Novaez, 1990, "The Paluxy River Footprints Revisited"

Originally Posted by Halcyon

I say sources please.

I'll get back to you on that.

[Victor]

Originally Posted by Halcyon

Atoms can't lie dan, Carbon-14 becomes Carbon-12 at a measureable rate, there's no way to fake it.

Last I remember, certain acids in the ground can tweak the rate. The o-zone layer can also affect it and who knows what else.

[Halcyon]

Originally Posted by dan

It's measurable, but it's not always the same rate and many different things can influence how rapidly they decay.

No, it always decays at the same rate, thats how radiation works. What may differ is the amount of carbon-14 originally taken up by the plant, and this can be affected, like Victor says, by cosmic rays and other factors. This is why all carbon dating is calebrated using independant verifiable sources.

Originally Posted by dan

You don't really thnk that dinosaur bones have never been living, do you? Anything that has been living at one time or another will have these radioactive emissions, and the longer it's been dead (no matter what form it is now) it has less and less of them. The problem is that past 50,000 years it is too unreliable. The bones in this particular test had a black residue surrounding them that was figured to be a type of fossilization in which the soft tissue of an animal becomes a thin carbon film. It was ground up with the bone to get the samples.

Fossilised bone contains no original biological material, its all rock. The carbon from the biological tissue is currently powering your car.

The problem is not that after 50,000 years the test just becomes unreliable, the problem is that Carbon-14 has a half-life of 5568 years, which means after 50,000 years there is none left. (note i made an error earlier, carbon-14 becomes nitrogen-14 not carbon-12)

[Seyorni]

No Dan. Ordinary chemical processes don't change the rate of radioactive decay. If you accelerated a specimen to near lightspeed relativistic effects might slow the decay rate, but you're not going to alter physics with any philosopher's stone.

Carbon dating is a touchy process, though. You have to be meticulous in your procedures and the specimen must be pristine. One touch with a bare finger and you can completely skew the results.

A typical fossil contains no organic material. They are impressions formed as actual bone, shell or cellulose molecules float off and are replaced with mineral molecules, forming an exact impression. The minerals or surrounding strata might be dated with radio potassium, uranium or rubidium, but radio carbon won't work.
I did read about a dinosaur fossil discovered a few months ago, I think, that astounded everyone by still containing some organic material, but, being a dinosaur, it's too old for carbon dating.
A fossil that age would normally be Potassium-Argon dated.

[Victor]

The rate of decay is not a constant. Instead, the decay process can be described by a first order rate constant. This means that the rate of decay is proportional to the amount of material present.

Radiocarbon dating depends on the assumption that the relative abundance of the radioactive carbon isotope in the atmosphere has been constant throughout earth's history. Estimation and tests have shown to have gotten rather close and hence why it's used. Unless something like the size and intensity of the o-zone was different in the 1200's or whatever, it's rather reliable.

One of the few things that stuck in Bio class....

[dan]

Originally Posted by Halcyon

The problem is not that after 50,000 years the test just becomes unreliable, the problem is that Carbon-14 has a half-life of 5568 years, which means after 50,000 years there is none left.

How do you figure?