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Author | Topic: Quick radiometric dating question- misused techniques | |||||||||||||||||||||||
Coragyps Member (Idle past 734 days) Posts: 5553 From: Snyder, Texas, USA Joined: |
I think a good response to this would be to show that we can see isotopes decaying in ancient starlight -- I'm assuming we can, though I haven't researched this yet. We can and have - type 1A supernovae show the same rate of decay of nickel-56 to cobalt-56 to iron as we see right here on earth, even out to a few billion years ago. Wikipedia will get you started on the details.
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Kitsune Member (Idle past 4300 days) Posts: 788 From: Leicester, UK Joined: |
Great, thanks. I'm better with astronomy -- nuclear physics was never my strong point!
added in editThis is from one of JonF's favourite sources I think: Evidence About Constants Being the Same in the Distant Past This is a good counter to the claim that decay rates changed in the past, though Joe Meert's Were Adam and Eve Toast? works well too. Trying to find evidence of isotopes with longer half-lives elsewhere in the universe is proving more challenging at the moment. Edited by LindaLou, : No reason given. Edited by LindaLou, : No reason given. Edited by LindaLou, : No reason given.
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JonF Member (Idle past 168 days) Posts: 6174 Joined: |
Radioactive decay rates depend on some deep-down fundamental attributes of the universe, and if they changed traces would be left in a surprising number of places. The Constancy of Constants and The Constancy of Constants, Part 2 are good resources to start with the author is a well-knonw (in some circles) physicist.
Yep, what we see in stars is a good measure. The Oklo reactor is also a great one; Oklo natural nuclear reactor and Natural nuclear fission reactor Finally, one strong indicator that radioactive decay rates havfen't changed to anything near the extent required dby creationists is teh fact that all life was not wiped out by the radiation, nor was all life killed by the melting of the Earth due to the heat released. The RATE group, composed of those few YECs who appear to know how bad the problem is, alludes to this. In Helium Diffusion Rates Support Accelerated Nuclear Decay they write:
quote:{emphasis in original} And, in Helium Diffusion Age of 6,000 Years Supports Accelerated Nuclear Decay:
quote: Not yet fully solved, indeed. Needless to say no progress has been forthcoming in the five years since this paper appeared. Note that they implicitly acknowledge that there is no way that a natural process would accelerater defcay in the manner that they need; it rwequires a miracle. So it ain't science.
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Kitsune Member (Idle past 4300 days) Posts: 788 From: Leicester, UK Joined: |
My library of links is growing rapidly thanks to you.
I've found interesting articles about uranium being detected in old Milky Way stars -- not what I was after, but great stuff to learn (which is why I do this I guess). I'm going to spend some time reading your links here but I'm still wondering how I would answer a claim that we don't know if isotopes with long half-lives really follow the entire logarithmic curve because we "weren't there" to watch it happen. Presumably they'd be trying to argue that the decay rates could be faster at some undefined point -- they certainly wouldn't be arguing that they are slower. In which case, all of this evidence about decay rates being constant would apply.
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Kitsune Member (Idle past 4300 days) Posts: 788 From: Leicester, UK Joined: |
Jon, I'm afraid I need to ask for your, or anyone else's help, again. This is regarding the two links the creationist has been trying to discuss -- I'll post them again here:
Strontium-92 Half-life Measurement Through Accurate Y-Ray Spectrometry He's trying to claim that new measurements had to be made because the decay rates changed. I explained that this article and the one below are about decay rates being measured more accurately, and I started to post evidence that decay rates have not actually changed, starting with SN1987a. I was accused of "misrepresenting links" and I have been banned, though it's possible that the ban will be lifted by the forum owner. Even if it isn't, I'd like to know how best to respond to the other comments here, because I'm curious. The creationist appears to admit that the above article shows that as the decay measurement is more accurate, the margin of error decreased. He's hung up on the fact that in the second article -- which is only an abstract -- the new measurement is outside the margin of error:
Half-life evaluations for 3H, 90Sr, and 90Y. Wading through the meaningless babble in the creationist's post, here is the crux of the matter:
quote: I don't understand enough about how these measurements are done, or how margins of error are calculated, to be able to comment. It's a difficulty in that I am unable to look at the full article, which no doubt explains how the old measurements were improved upon.
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JonF Member (Idle past 168 days) Posts: 6174 Joined: |
Well, I can't get at the second paper either. But measuring half-lives over a period of time much smaller than the half-life is fraught with peril. Stated uncertainties are best estimates, and are statistically based. They are not absolute boundaries. An uncertainly of ±x (2 σ ) means that their best estimate is that there is a 95% probability that the actual value lies between the quoted value + x and the quoted value - x. But there's a 5% chance it lies outside those bounds. And it's still an estimate and subject to its own errors. Again from Begemann, F., Ludwig, K. R., Lugmair, G. W., Min, K., Nyquist, L. E., Patchett, P. J., Renne, P. R. Shih, C.- Y., Villa, I. M. and Walker, R. J. (2001). Call for an improved set of decay constants for geochronological use. Geochim. Cosmochim. Acta 65, 111--21:
quote: Note especially the paragraph numbered 1. Judged from the fact that many of the counting experiments have yielded results that are not compatible with one another within the stated uncertainties, it would appear that not all the difficulties are always fully realized so that many of the given uncertainties are unrealistically small, and that many experiments are plagued by unrecognized systematic errors. But such incompatibilities are not necessarily evidence of change (and if they are, the changes increase half-life as often as they decrease half-life). If there were changes, even a percent or so, there would be other far-reaching effects that we would easily detect. (I'm not enough of a physicist to specify what they would be, but look back at Steve Carlip's posts on constants and reflect of how far-reaching go those effects are). No, they are evidence that we don't understand all the difficulties and complications involved in measuring half-lives well enough to measure them to better than a few percent or so (except for uranium). But we certainly know enough to measure them to a few percent. But the real key is not to get down in the mud and wrestle with the creo on infinitesimal details. Changes less than several orders of magnitude are insufficient to make the creationist position tenable, and changes would have to be correlated among many different and independent mechanisms (alpha decay, beta decay, and electron capture decay … and their many sub-types). Keep pounding away at consilience between wildly different radiometric methods and even with non-radiometric methods (I posted a couple of links showing the latter), and ask for a scientifically verifiable mechanism that accounts for those results. Pound on the heat and radiation and observations of stars problems acknowledged by the RATE group.
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RAZD Member (Idle past 1405 days) Posts: 20714 From: the other end of the sidewalk Joined: |
Hi LindaLou,
Great, thanks. I'm better with astronomy -- nuclear physics was never my strong point! Note the reference in the link to SN1987A, a rather unique nova event that allows us to measure the actual distance to the star ... and the information on cobalt decay during the nova. You may also want to check out Are Uranium Halos the best evidence of (a) an old earth AND (b) constant physics? Say hi to CTD for me, and remind him that half a half-life is not a quarter-life. Edited by RAZD, : U halo by our ability to understand Rebel American Zen Deist ... to learn ... to think ... to live ... to laugh ... to share. • • • Join the effort to solve medical problems, AIDS/HIV, Cancer and more with Team EvC! (click) • • •
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Kitsune Member (Idle past 4300 days) Posts: 788 From: Leicester, UK Joined: |
Hi JonF,
Thanks for the info. It clarifies things for me, but it would be tricky to think of how to phrase some of this to a YEC without them going away thinking, "They're admitting that there's a lot of uncertainty, so none of those radiometric dates are right! It's a method that can't be trusted!" I can imagine them assuming that the decay rate for potassium, for example, is in error, and so while K-Ar dates are in consilience, they're all wrong. So, given the pitfalls described in the paper you quoted from, how is it that we can be confident that the decay rates of elements used in radiometric dating are known to within a few percent or less? How can we be sure that the decay rate of uranium is so precisely understood -- is it because, as you said a few posts back, there have simply been many studies because bombs are big business? How would they have avoided the problems with all the measuring techniques that you outlined? After all, you said,
quote: You couldn't say this in a debate with a YEC, because if your quote applies to isotopes with short half-lives, then it should certainly apply to the longer-lived ones used in radiometric dating. In the case of uranium, perhaps you could cite the unchanged diameter of halos? The final paragraph in your post is sensible, and I did those things. Unfortunately this is a YEC who is very touchy about the subject (understandably, because it invalidates his belief system) and who is also a moderator. If I'm even allowed back onto the forum, I am going to have to take on the subject of the specific isotopes in those papers and why the new measurements are outside of the margins of error, while making sure I don't say so much about uncertainties that the creationist feels free to believe that no radiometric dating method is accurate. I can do the former thanks to you, but the latter could be challenging. Could you tell me where I can find those posts by Steve Carlip that you mentioned? Thanks. Edited by LindaLou, : No reason given.
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Kitsune Member (Idle past 4300 days) Posts: 788 From: Leicester, UK Joined: |
Hi RAZD, thanks for that. I've read information that you've posted here and at Herb Allure about uranium halos. It's particularly amusing that where you find the supposedly parentless polonium halos, there's always a source of uranium nearby, as well as rocks that radon can leach into (for lack of a better scientific term). The information about uranium decay that you linked to in your previous post is well written so that a layperson like me can gain some understanding. I'll have a more thorough read of the thread today.
It was a sad day when Russ decided to start giving moderator positions to the most irritating YECs on the forum. If you get them too wound up, they can kick you out -- as you're well aware. Russ is considering whether CTD's claims that Linear and I have misrepresented those papers are justified. I don't have a great deal of faith in Russ' ability to be objective but you never know. If I'm through there for good, I can spend more time here. Edited by LindaLou, : No reason given.
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JonF Member (Idle past 168 days) Posts: 6174 Joined: |
Thanks for the info. It clarifies things for me, but it would be tricky to think of how to phrase some of this to a YEC without them going away thinking, "They're admitting that there's a lot of uncertainty, so none of those radiometric dates are right! It's a method that can't be trusted!" I can imagine them assuming that the decay rate for potassium, for example, is in error, and so while K-Ar dates are in consilience, they're all wrong. Yes, I know all that. It's a losing proposition. That's why the key is not to go down in the mud, where the can use their lack of knowledge of what statistics, what error estimates are, and how utterly infinitesimal these differences are when compared to the changes proposed by YECs. They complain about extrapolating, then extrapolate over many orders of magnitude! You can't beat them at that game. Fundamentally they want a Biblical version of science; knowledge is graven in stone and known exactly. But I don't know anyone who's good at getting them to address the important points like consilience. If the decay rate for K is wrong, then so are all decay rates, and all by the same factor. To anyone with any knowledge of physics, that's ludicrous. mMybe this point can be gotten across to someone ignorant of physics. I don't know how to even get them to listen.
So, given the pitfalls described in the paper you quoted from, how is it that we can be confident that the decay rates of elements used in radiometric dating are known to within a few percent or less? How can we be sure that the decay rate of uranium is so precisely understood -- is it because, as you said a few posts back, there have simply been many studies because bombs are big business? How would they have avoided the problems with all the measuring techniques that you outlined? Much of the answer is in my previous quote from that paper:
quote: I'll see if I can dig up the Jaffey paper. The reason we can be sure that they are known to a few percent of less is that all of the numerous measurements without known systematic error lie within a few percent or less. Does that prove it? No. Nothing is ever proven in science. It's established far beyond reasonable doubt ... but not beyond unreasonable doubt.
Unfortunately this is a YEC who is very touchy about the subject (understandably, because it invalidates his belief system) and who is also a moderator. If I'm even allowed back onto the forum, I am going to have to take on the subject of the specific isotopes in those papers and why the new measurements are outside of the margins of error, while making sure I don't say so much about uncertainties that the creationist feels free to believe that no radiometric dating method is accurate. I can do the former thanks to you, but the latter could be challenging. Well,that's a situation in which you are near-certain to lose. Facts don't help much there. And I don't know how to teach somebody something that they refuse to learn.
Could you tell me where I can find those posts by Steve Carlip that you mentioned? Thanks. The Constancy of ConstantsThe Constancy of Constants, Part 2 Steve Carlip
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