Radiometric Dating Accuracies

[Magnetic]

Just curious. A few questions:

1. If a scientist does radiometric tests on something that is known to have died (a tree or something) 500 years ago, will the test show that age, and if so, what is the +/- that accompanies these figures?

2. Have the pyramids, and their 'occupants' been radiometrically dated and have those tests agreed with the historical facts?

3. Have there been any dinosaur remains that have ever been radiometrically dated to around 5,000 to 6,000 years old?

[Shadow WarChief]

3. Have there been any dinosaur remains that have ever been radiometrically dated to around 5,000 to 6,000 years old?

While I can't answer the other 2 questions, I can answer this one very simply.

NO.

[DPDarkPrimus]

1. If a scientist does radiometric tests on something that is known to have died (a tree or something) 500 years ago, will the test show that age, and if so, what is the +/- that accompanies these figures?

That's the margin of error.

2. Have the pyramids, and their 'occupants' been radiometrically dated and have those tests agreed with the historical facts?

I'm not sure if the pyramids have been tested.

3. Have there been any dinosaur remains that have ever been radiometrically dated to around 5,000 to 6,000 years old?

No.

[El Moose Monstero]

From what I can recall of the diagrams from lectures, carbon dating has a margin of error of around 1500 years at optimum efficiency, although it increases the further back you try to go. Might be wrong with that.

Dinosaur fossils I assume are dated with something other than carbon dating since they go well beyond the 60ka maximum dating level for C-dating. Can someone enlighten me on that one? I assume you could use Rubidium 87/Strontium 87 to date the rock for a date of fossilisation?

[Magnetic]

DPDarkPrimus, sorry, I didn't make that clear. I'm aware of the Margin of Error. It was moreso what the Margin of Error would be on realtively recent remains.

[Zero]

I don't know if they do this for dinosaur remains, but I've read that they often use uranium-lead dating to determine how old most rocks are. I think I've also heard that part of the fossilization process involves the bone being replaced by rock, so this same method may be used for dinosaur bones. However, don't trust what I say too well. I'm only doing this from memory alone, and I'm not well-educated in such matters.

[DPDarkPrimus]

DPDarkPrimus, sorry, I didn't make that clear. I'm aware of the Margin of Error. It was moreso what the Margin of Error would be on realtively recent remains.

The margin of error is entirely dependant upon which radiometric dating system you are using.

If you're wondering about C-14 dating, there is a wonderful site with everything you need to know about it.

http://www.c14dating.com/

It also mentions some other radiometric dating methods for dating older materials, so Google those up for information on the specifics. (IIRC, Potassium-Argon dating is used for dating older fossils.)

[Darth Wong]

Basically, for very old things, you date using isotopes with very long half-lives. And if the object in question is not really that old, then why the fuck did these isotopes with incredibly long half-lives decay away?

[GrandMasterTerwynn]

Just curious. A few questions:
2. Have the pyramids, and their 'occupants' been radiometrically dated and have those tests agreed with the historical facts?

Yes, they've been dated. And yes, they generally agree.

3. Have there been any dinosaur remains that have ever been radiometrically dated to around 5,000 to 6,000 years old?

No. Next question.

[Kitsune]

One item is that you can rarely date actual fossils by Radiometric dating, you normally have to date by an ash layer above the fossil layer

[Mr Flibble]

3. Have there been any dinosaur remains that have ever been radiometrically dated to around 5,000 to 6,000 years old?

Given that the only useful radiometric techniques for dating dinosaur fossils, have an error margin of at least +/- 1 million years, the only way anyone is going to get a 5000-6000 year age for one is to use the wrong radiometric technique, or to not have the slightest clue what they are doing.

We had a little on radiometric dating in one of my courses last semester, so if I can find time later this week (highly unlikely as extremely busy at the moment) I'll dig up my notes and write a thorough description of radiometric dating.

[Magnetic]

Okay, thanks for the replies thus far. My purpose is to determine how fairly recent remains (the 500 year old tree), moderately old remains (the pyramid occupants), and very old remains (the dinosaurs) are dated.

If you take a dating methode used to date very old remains and apply it to moderately old remains, would it produce an accurate answer?

If there haven't been any dinosaurs dated to ~ 6,000 years, in all the specimens found, but rather much older, either the dating methode is consistantly seriously flawed, or it is accurate and testable.

Creationists say that dinosaurs lived with man. The dating methods used state that dinosaurs are millions of years older than man. So here's another question:

Has there been any fairly recent species, known to be only a few - several thousand years old (reptiles or birds) that have been dated as being in the millions of years older than they should be?

If there are erroneous test results for dinosaurs, then logically you'd have to assume that there should be with recent animals, if YEC are correct.

I hope I'm addressing these questions well.

[Master of Ossus]

If you take a dating methode used to date very old remains and apply it to moderately old remains, would it produce an accurate answer?

It would produce an answer to within about the same margin of error that it normally produces. The issue is that better tests are often available (ie. using isotopes with more favorable half-lives).

If there haven't been any dinosaurs dated to ~ 6,000 years, in all the specimens found, but rather much older, either the dating methode is consistantly seriously flawed, or it is accurate and testable.

Creationists say that dinosaurs lived with man. The dating methods used state that dinosaurs are millions of years older than man. So here's another question:

Has there been any fairly recent species, known to be only a few - several thousand years old (reptiles or birds) that have been dated as being in the millions of years older than they should be?

Some mollusks absorb radioactive materials from rocks that they live on, creating dates that are "older" than they should be. This is a known problem with dating mollusks.

If there are erroneous test results for dinosaurs, then logically you'd have to assume that there should be with recent animals, if YEC are correct.

Obviously there are outliers with radiometric dating, as with all scientific tests. The point is that these dates are considered fairly definitive because they are consistently so accurate and so consistent.

[Darth Wong]

Okay, thanks for the replies thus far. My purpose is to determine how fairly recent remains (the 500 year old tree), moderately old remains (the pyramid occupants), and very old remains (the dinosaurs) are dated.

If you take a dating methode used to date very old remains and apply it to moderately old remains, would it produce an accurate answer?

No. But that's like asking if you would user a laser rangefinder to measure the transistor spacing on a microchip. It's stupid; different tools for different purposes. If you use a measurement tool designed for very old things on things which aren't that old, it will come back with an age of zero, plus or minus the margin of error. That will obviously tell you that you're using the wrong dating method.

If there haven't been any dinosaurs dated to ~ 6,000 years, in all the specimens found, but rather much older, either the dating methode is consistantly seriously flawed, or it is accurate and testable.

You still don't get it. All dinosaurs date to millions of years old because the margin of error for the relevant dating methods is measured in millions of years, and yet they come back with a dating result that isn't zero.

Creationists say that dinosaurs lived with man. The dating methods used state that dinosaurs are millions of years older than man. So here's another question:

Has there been any fairly recent species, known to be only a few - several thousand years old (reptiles or birds) that have been dated as being in the millions of years older than they should be?

No. The only cases where people claim they've found examples of such as certain mollusks which will absorb volcanic rock into their bodies, and the rock itself will obviously date to millions of years old. But it's rather dishonest to use that as an example of problems with dating methods.

If there are erroneous test results for dinosaurs, then logically you'd have to assume that there should be with recent animals, if YEC are correct.

I hope I'm addressing these questions well.

I don't think you're understanding the nature of an erroneous test result in dating methods. It's impossible for a dating method to somehow produce a result outside of its range, so if it's attempted on an object which is outside of its range, it will produce a nonsensical result. A very old object dated with a short-term method will produce an age result of infinity, and a recent object dated with a long-term method will produce an age result of zero. Ergo, you'll know that you used the wrong method.

[Magnetic]

Okay. I see what you are saying, via methodes of dating old to new finds. Appropriate tests for the appropriate finds.

I'm curious. Have there been any tests done that show these discrepencies you laid out, Darth Wong? In other words, have there been tests done on recent finds, using methods for determining the age much older finds, to determine that you'd get these readings of zero (or infinity for old finds using recent dating methods)?

Here's why I ask. The YEC state that the testing methods are flawed. However, if these dinosaur fossils normally come back showing decay rates indicative of millions of years, even though they actually ARE only 6,000 - 10,000 years old (which I don't believe in), then more recent finds should also indicate the same findings.

In other words, has an YEC person ever explained why dinosaurs have been dated to millions of years and not a falcon, cat, or whatever else that had died in the recent past (expect for the mullosks)?

FWIW, I believe in a very old Earth. So I don't take the side of the YEC.

Thanks for the help here. I'm very 'green' when it comes to dating methods, but the question came to me, so I thought it would be worth asking here.

[Edi]

YECs always lie about radiometric dating. They distort and misrepresent it and data acquired by radiometric tehcniques, relying on the fact that the only method people know or have heard about is carbon dating (the most common method, used for stuff circa 200 - 15,000 years old).

Has there been any fairly recent species, known to be only a few - several thousand years old (reptiles or birds) that have been dated as being in the millions of years older than they should be?

Not in the sense that you are asking about. However, something that YECs might throw at you are species that are living fossils. There is a species of fish living in parts of the Indian Ocean that has been completely unchanged for about 80 million years, so you have fossils of the fish that age, but also living fish of the same species. Certain other types of animals (no reptiles that I know of) also have been almost unchanged for even longer periods (mostly insects, like mosquitoes and termites).

If they bring up these kinds of examples, don't let it fool you.

Edi

[Darth Wong]

Another common creationist trick is to take low-quality rock samples where old and new rock is jumbled together (near geologic fault lines or volcanoes), perform dating on it, find that the results vary wildly between new and old rock (duh), and then declare that radiometric dating is bunk.

[Magnetic]

Another common creationist trick is to take low-quality rock samples where old and new rock is jumbled together (near geologic fault lines or volcanoes), perform dating on it, find that the results vary wildly between new and old rock (duh), and then declare that radiometric dating is bunk.

Along the lines of this question, I've heard one of their (the YEC) arguments were volcanic rock known to have been formed 200 years ago being dated as millions of years ago. Wong, when you say 'new rock', what does that mean, where does it come from? I have a hard time understanding that since even molten rock that comes to the surface from a volcano is still very old, is it not?

[Darth Wong]

Another common creationist trick is to take low-quality rock samples where old and new rock is jumbled together (near geologic fault lines or volcanoes), perform dating on it, find that the results vary wildly between new and old rock (duh), and then declare that radiometric dating is bunk.

Along the lines of this question, I've heard one of their (the YEC) arguments were volcanic rock known to have been formed 200 years ago being dated as millions of years ago. Wong, when you say 'new rock', what does that mean, where does it come from? I have a hard time understanding that since even molten rock that comes to the surface from a volcano is still very old, is it not?

Yes, but it has only recently solidified. The thing is that not 100% of the material which gets vomited up from a volcano is molten.

[Magnetic]

I guess I need to ask perhaps a stupid question (or two).

Let's see, . . . how to word this. . . . . .

At what times do these particles enter the tree/creature/rock in order for the decay to begin? Do I have these particles in me that are in a state of decay?

Along the same lines, what makes the volcanic flow inhabit either new or old rock, and if it is new, what cases that to be the case, since it's been down below the surface before?

[El Moose Monstero]

I guess I need to ask perhaps a stupid question (or two).

Let's see, . . . how to word this. . . . . .

At what times do these particles enter the tree/creature/rock in order for the decay to begin? Do I have these particles in me that are in a state of decay?

Along the same lines, what makes the volcanic flow inhabit either new or old rock, and if it is new, what cases that to be the case, since it's been down below the surface before?

Radioactive decay is a constant process, as soon as an atom of an unstable nature is in existance, it will decay to stabilise itself. When you breathe, you're taking in air from the atmosphere which contains a quantity of radioactive products such as Carbon-14 and Tritium, these then enter your body, and are either locked up in some form or passed through. Obviously because you are constantly breathing in and out, the levels of C-14 are maintained at a constant until you stop breathing, then because there is no more to replenish the reservoir of radioactive C, it simply all decays away at a steady rate.

You've also got other radionuclides kicking around in you, Potassium-40 will be accumulating and decaying in your bones and some organs which I can't remember, as it's found in many foods. When we were at Sellafield, I seem to recall them pointing out that you get more radiation from eating a brazil nut than you do from walking round a nuclear power plant.

Not too sure about your second question though, not quite clear on what you're asking. In the context of there being old rock and new rock, like DW said - new rock will be rock that resolidifies from liquid or melt, and old rock will be any bits of unmolten rock which are carried up with the magma. IIRC, a lot of our knowledge of rock compositions below the crust has come from bits of mantle peridotite that are erupted within lavas.

I hope all that's right, anyway, I could use the practice at all this

[Darth Wong]

I should also point out that isochron dating does away with the need for assumptions of fixed concentrations at the start-point.

[Magnetic]

Not too sure about your second question though, not quite clear on what you're asking. In the context of there being old rock and new rock, like DW said - new rock will be rock that resolidifies from liquid or melt, and old rock will be any bits of unmolten rock which are carried up with the magma. IIRC, a lot of our knowledge of rock compositions below the crust has come from bits of mantle peridotite that are erupted within lavas.

I hope all that's right, anyway, I could use the practice at all this

That was pretty much what I was getting at. I figured that even new magma is still a product of old material in the mantle. So when it comes to the surface, it is at this point when these radionuclides begin accumulating in that new lava?

[El Moose Monstero]

Not too sure about your second question though, not quite clear on what you're asking. In the context of there being old rock and new rock, like DW said - new rock will be rock that resolidifies from liquid or melt, and old rock will be any bits of unmolten rock which are carried up with the magma. IIRC, a lot of our knowledge of rock compositions below the crust has come from bits of mantle peridotite that are erupted within lavas.

I hope all that's right, anyway, I could use the practice at all this

That was pretty much what I was getting at. I figured that even new magma is still a product of old material in the mantle. So when it comes to the surface, it is at this point when these radionuclides begin accumulating in that new lava?

No, there are different radionuclides from different sources. Some come from the Earth's interior, 50% of the Earth's internal heat since it's formation has come from the decay of radioactive elements, mainly those involved with Uranium 235, 238, Thorium 232. Because these decay slowly (Uranium 235 has a half life of around 4.5 billion years, meaning it takes that long for the amount of Uranium to decay into a different isotope), they are still present in large quantities in the core, crust and mantle in different levels of activity. But when elements are in a molten state, I assume (as my knowledge on this bit is sketchy) that this essentially seperates out the atoms of one radioactive isotope from another.

(someone feel free to tell me if I'm wrong in this one, it's not something we've covered, I know that the radioactive clock is reset, but am not sure how)

This essentially means that it is as if the radioactive decay process starts again with what is currently present in the solidified rock. So even though the radionuclides in the rock are the same ones which have been around since the formation of the earth, they only reflect the time since the cooling of the lava.

I'm not sure I explained that very well.