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  1. #1
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    age of artifacts....

    ok so I want to keep this calm I know this question has been debated over time a lot....I want peoples opinions no arguments...I totally understand how they get dates of artifacts by carbon dating rock around it ..my question is how do they know that catastrophic events didn't mix or age rock differently...no one really knows the age of the earth its all theory or at best a guess...I know its a hard question but am I right or wrong saying it is all a guess ...like saying maybe paleo stuf is only 5000 years old...a good example is mt st helens may 1982...a whole mountain was changed instantly ...
    When you are riding in a time machine way far into the future,
    Do not stick your elbow out of the window, Or it will turn into a fossil.

  2. #2
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    Because most types aren't dated by just one site. Repetition increases accuracy.

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  4. #3
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    They aren't carbon dating the rock, they are carbon dating organic material from near the artifact. The science behind it is fairly complex, so I won't pretend to understand it all, but it was worthy of a Nobel prize back in the 60's.

    One date can be easily disregarded as contamination, but when you get hundreds of similar dates at different sites around the country, with science that is pretty much accepted by all legitimate scientists, I generally believe it.

  5. #4
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    Just a little info for you, Swartaramike. The rocks are not carbon dated. Carbon dating is done on something that was alive at one time, such as wood (charcoal in most archaeological circumstances) or bone. Carbon 14 accumulates in living organisms, but ceases accumulation when the living thing dies. At that time, the C-14 begins to decompose at a known rate, with 1/2 of it decomposing in in 5730 +or- 40 years (half life). So after 5730 or thereabouts years, 1/2 of the original C14 is decomposed, and in another 5730 years, 1/2 of the remaining C-14 will have decomposed, leaving 1/4 of the original C14. Carbon dating measures the amount of remaining C14 to determine the probable age. But, it is not perfect, so has a plus or minus factor that says the date probably lies within a certain time frame. There are various methods of dating, and as many methods as possible are used and then compared to each other to verify (or refute) the date(s). One example would be to compare a dendrochronolgy (tree ring) date to a C14 date. One of the problems with C14 dating is contamination of the carbon sample, making it too young if younger carbon is somehow mixed with the C14 sample, or making it too old if older carbon contaminates the sample. I believe the labs have methods to minimize or eliminate the contamination.

    So again, the rocks are not dated by C14 (they were never alive), and the dates obtained are by association of the artifact (rock or whatever) with something that is date-able. In addition, there are innumerable dates for various artifacts, and these artifacts and dates are always compared to each other. That practice tends to throw up a red flag if some dates fall outside of the normal for that type of artifact.

    This is a somewhat simplified, attempted explanation. I hope this helps rather than muddies the water.

    CP
    "Some of life's most exciting moments are spent near the middle of the food chain rather than at the top."

  6. #5
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    interesting..but what is their base for the decomposition rate..
    When you are riding in a time machine way far into the future,
    Do not stick your elbow out of the window, Or it will turn into a fossil.

  7. #6
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    Quote Originally Posted by swataramike View Post
    interesting..but what is their base for the decomposition rate..
    The decomposition rate of carbon 14 is the rate... some things are constant. If it decomposes 0.0005% year one, 0.0005% year two, and 0.0005% the third year more than likely it is going to be 0.0005% the next year (obviously there is more science than I am explaining but you should get the drift).

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  9. #7
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    When you find a Clovis sticking out of a wooly mammoth it's a pretty good indicator of age

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  11. #8
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    cool guys some stuff i really didnt know..
    When you are riding in a time machine way far into the future,
    Do not stick your elbow out of the window, Or it will turn into a fossil.

  12. #9
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    Mike, you wrote that "no one really knows the age of the Earth it's all theory or at best a guess".

    I would have to say that's not really the case at all...

    https://geomaps.wr.usgs.gov/parks/gtime/ageofearth.html

  13. #10
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    It's accurate to say that dating the age of meteorites is actually one of the best ways for determining the age of the Earth as well. Geological processing has removed what would be Earth rocks as old as meteorites unaltered since their formation:

    "The oldest dated moon rocks, however, have ages between 4.4 and 4.5 billion years and provide a minimum age for the formation of our nearest planetary neighbor. Thousands of meteorites, which are fragments of asteroids that fall to Earth, have been recovered. These primitive objects provide the best ages for the time of formation of the Solar System. There are more than 70 meteorites, of different types, whose ages have been measured using radiometric dating techniques. The results show that the meteorites, and therefore the Solar System, formed between 4.53 and 4.58 billion years ago. The best age for the Earth comes not from dating individual rocks but by considering the Earth and meteorites as part of the same evolving system in which the isotopic composition of lead, specifically the ratio of lead-207 to lead-206 changes over time owing to the decay of radioactive uranium-235 and uranium-238, respectively"

    Geologic Time: Age of the Earth

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