[ruminations on radiometric dating]
today I will question authority.
1. I've thought about it long enough and I can't arrive at an answer with logic alone.
say the world is six billion years old. a big number with a large error value to be sure, but it's a starting point for sake of argument.
a vast, vast majority of all the carbon-14 (the isotope used in radiometric dating) now on the planet has been here since near the beginning. no current natural processes produce it in any substantial quantities. given that its half-life is 5730 years, there have been over a million of them since creation; therefore, of the original amount (call it A) of carbon-14 on the planet there now remains A*(2^-1000000), which is by any account as close to zero as makes no difference.
my first question is: since there is certainly more than zero carbon-14 lying around, where did it come from? solar wind? asteroids? (furthermore, did we get a lump-sum at one point, or like the intelligent lottery winner, did we spread our winnings out? how does this variable accumulation affect dating methods?)
2. a few years ago an object was found touted to be 'the oldest known piece of Earth.' fine, that's no problem.
here's a problem. imagine a roman blacksmith, 5 a.d., making a sword out of iron. the sword will be new at the time of forging, but the iron (specifically the carbon-14 in the iron) is as old as the earth. does that mean when we date the sword in the present day we will find it is 2000 years old, or like the crystal above, many billions of years old?
my second question: things are new, ingredients are not. since radiometric dating looks only at ingredients, how can it tell how old the thing itself is?
on an unrelated note, it occurs to me that we have not completed our tax return. my attention span has a half-life of OOOH we should go on a bike ride!
1. I've thought about it long enough and I can't arrive at an answer with logic alone.
say the world is six billion years old. a big number with a large error value to be sure, but it's a starting point for sake of argument.
a vast, vast majority of all the carbon-14 (the isotope used in radiometric dating) now on the planet has been here since near the beginning. no current natural processes produce it in any substantial quantities. given that its half-life is 5730 years, there have been over a million of them since creation; therefore, of the original amount (call it A) of carbon-14 on the planet there now remains A*(2^-1000000), which is by any account as close to zero as makes no difference.
my first question is: since there is certainly more than zero carbon-14 lying around, where did it come from? solar wind? asteroids? (furthermore, did we get a lump-sum at one point, or like the intelligent lottery winner, did we spread our winnings out? how does this variable accumulation affect dating methods?)
2. a few years ago an object was found touted to be 'the oldest known piece of Earth.' fine, that's no problem.
here's a problem. imagine a roman blacksmith, 5 a.d., making a sword out of iron. the sword will be new at the time of forging, but the iron (specifically the carbon-14 in the iron) is as old as the earth. does that mean when we date the sword in the present day we will find it is 2000 years old, or like the crystal above, many billions of years old?
my second question: things are new, ingredients are not. since radiometric dating looks only at ingredients, how can it tell how old the thing itself is?
on an unrelated note, it occurs to me that we have not completed our tax return. my attention span has a half-life of OOOH we should go on a bike ride!
4 very splendid and worthwhile comment(s):
I've always wondered about this too...
(From: http://www.contenderministries.org/evolution/carbon14.php)
Carbon-14 is created in the upper atmosphere as nitrogen atoms are bombarded by cosmic radiation. For every one trillion carbon-12 atoms, you will find one carbon-14 atoms. The carbon-14 that results from the reaction caused by cosmic radiation quickly changes to carbon dioxide, just like normal carbon-12 would. Plants utilize, or “breath in” carbon dioxide, then ultimately release oxygen for animals to inhale. The carbon-14 dioxide is utilized by plants in the same way normal carbon dioxide is. This carbon-14 dioxide then ends up in humans and other animals as it moves up the food chain.
Maybe we need to stop buring people in caskets and let them return to the earth, but it's too nice outside to think about that.
AAAH you made me look at a creationism versus evolutionism website! for the pain my eyes endured you will pay, so-called ghengis.
it was interesting, though. I feel like I should have known about its creation in the atmosphere. I probably heard about it in one of those philosophy of science powerpoint lectures I slept through.
I have reconstructed the answer and the answer is this: carbon-14 is falling down from the sky all the time at a reasonably predictable rate and adding itself to the pile of ingredients we call earth. once an object is formed, its ingredients are fixed, and its origin is fixed in time (a time when the level of carbon-14 was X). by determining the present level of carbon-14 we can determine how long ago it had X, and therefore when the object was formed.
I hope this isn't wrong because it finally, finally makes sense.
you are correct in your theory of the carbon-14 level being a fixed amount for a specific period of time.
what i wonder is this: what made that little speck of nothing any different from the little speck next to it? why test that little speck? if they excavated and found it in a display case that said, "the oldest living speck of almost nothing", i could see why it would be impressive enough to test - but without it showcased like a Mikey Mantle original...i don't think it's worth a trip to a University or museum anymore than the big rock in my back yard.
i don't get a chance to read much anymore and find myself playing catch up to some very interesting reads. it's good to know that whilst i learn accounting; someone is actually thinking.
Oops. In my focused search I didn't even see the point of that page. All I actually read was that one paragraph. Sorry for the eye strain!
Did you know you could eat forever if you eat half of something with each bite?
do not post a comment (or not).
do not go home (the grass is always greener).