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Author Topic:   Age Correlations and An Old Earth, Version 2 No 1
JonF
Member (Idle past 168 days)
Posts: 6174
Joined: 06-23-2003


(1)
Message 296 of 1498 (728295)
05-26-2014 3:04 PM
Reply to: Message 293 by NoNukes
05-26-2014 2:40 PM


Re: Snelling Concedes Old Age for Earth
Yes, K40 dates do overlap with U238.
As do many others.
Do we have any 4 billion year old K40 dates that we know were set to zero on earth?
Ther are lots of dating methods.
The oldest claimed date I know of for such is 4.28bya, Neodymium-142 Evidence for Hadean Mafic Crust (free registration required). The abstract:
quote:
Neodymium-142 data for rocks from the Nuvvuagittuq greenstone belt in northern Quebec, Canada, show that some rock types have lower 142Nd/144Nd ratios than the terrestrial standard (ϵ142Nd = —0.07 to —0.15). Within a mafic amphibolite unit, 142Nd/144Nd ratios correlate positively with Sm/Nd ratios and produce a 146Sm-142Nd isochron with an age of 4280+53-81 million years. These rocks thus sample incompatible-element-enriched material formed shortly after Earth formation and may represent the oldest preserved crustal section on Earth.
The Acasta gneiss near Great Slave Lake in north central Canada is purty darn well established at 4.03 bya, e.g. Age of the world's oldest rocks refined using Canada's SHRIMP: the Acasta gneiss complex, Northwest Territories, Canada.

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JonF
Member (Idle past 168 days)
Posts: 6174
Joined: 06-23-2003


Message 303 of 1498 (728465)
05-29-2014 9:29 AM
Reply to: Message 300 by NoNukes
05-28-2014 3:04 PM


Re: Snelling Concedes Old Age for Earth
Yes, I meant 235U.

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JonF
Member (Idle past 168 days)
Posts: 6174
Joined: 06-23-2003


(1)
Message 304 of 1498 (728466)
05-29-2014 9:29 AM
Reply to: Message 302 by edge
05-28-2014 9:53 PM


Expanding a bit:
IMHO the main reason why 235U and 238U are so useful for precise age determinations is that their half-lives are known to significantly greater precision than any other isotope (bombs & reactors, ya know).
With modern equipment (e.g. SHRIMP) analyzing samples on the order of 75 μm3 and accurately measuring the amount of 235U in thos samples I don't see a great advantage in the relative abundance of 238U.
One seldom sees just a 238U age published because it's almost free to do 235U as well and plot a concordia diagram, even for very old material. E.g. from the Acasta gneiss:

(that's the Tera-Wasserberg vesion of a concordia diagram, so it may be unfamiliar).
Or from Wilde et. al., the oldest chunk of stuff found on Earth:
In order to get sub-1% errors in ages it is routine to correct for the presence of some Pb that is "primordial" or "common"; i.e. present when the sample became closed. One common method is to measure 204Pb, which is not radiogenic and is therefore primordial, and use the known ratios of isotopes of U (appropriately projected backwards in time) to calculate the primordial amounts of 235U and 2238U.

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JonF
Member (Idle past 168 days)
Posts: 6174
Joined: 06-23-2003


(1)
Message 312 of 1498 (730464)
06-28-2014 11:06 AM
Reply to: Message 310 by OS
06-27-2014 11:37 PM


Argon-40 seems to take more energy to make from Pottasium-40
Nope. Essentially all of the K->Ar decays emit a 1.460 MeV gamma ray and a neutrino. Therefore process emits energy.

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JonF
Member (Idle past 168 days)
Posts: 6174
Joined: 06-23-2003


(1)
Message 317 of 1498 (730488)
06-28-2014 1:51 PM
Reply to: Message 315 by OS
06-28-2014 1:12 PM


Supercooling has been known to do the reverse of "electron" capture.
You're sounding pretty wacky. Reference, please.
The Wikipedia chart has some example of Argon "decaying" into Potassium
A quick look at Wikipedia and I can't see any such chart. Link to the chart, please.
I also doubt heat and pressure together will ever be tried. It would ruin the lab equipment.
Ah, you're going full-bore ignorant nutjob now. Heat and pressure together have been tried many times. Once you've got a suitable pressure vessel, dab on a little insulation and you've got a heat and pressure vessel.

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 Message 315 by OS, posted 06-28-2014 1:12 PM OS has replied

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JonF
Member (Idle past 168 days)
Posts: 6174
Joined: 06-23-2003


Message 318 of 1498 (730489)
06-28-2014 1:52 PM
Reply to: Message 316 by OS
06-28-2014 1:15 PM


Nope. Essentially all of the K->Ar decays emit a 1.460 MeV gamma ray and a neutrino. Therefore [the] process emits energy.
While I don't agree, that would be a very useful statement.
Yup, nutjob.

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JonF
Member (Idle past 168 days)
Posts: 6174
Joined: 06-23-2003


Message 326 of 1498 (730502)
06-28-2014 4:15 PM
Reply to: Message 319 by OS
06-28-2014 2:33 PM


You're sounding pretty wacky. Reference, please.
I am not your peer.
That's obvious.
Look it up yourself.
When you make a claim, you support it.
A quick look at Wikipedia and I can't see any such chart. Link to the chart, please.
It's under Argon.
I looked. They do note that 39Ar doecaays to 3K. Nothing to do with 40Ar and 40K. Remember you wroe:
Decays of Argon-40 to Potassium-40 could be made by supercooling.
The subject is 40Ar and 40K.
Heat and pressure together have been tried many times. Once you've got a suitable pressure vessel, dab on a little insulation and you've got a heat and pressure vessel.
Yeah, in other words, you think ceramic rock is enough. That's a load of crap.
Edited by JonF, : No reason given.

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JonF
Member (Idle past 168 days)
Posts: 6174
Joined: 06-23-2003


Message 327 of 1498 (730503)
06-28-2014 4:18 PM
Reply to: Message 321 by Coragyps
06-28-2014 3:02 PM


It's under Argon.
Where under "argon?" I think you're making things up.
The Wikipedia article with a chart showing 39Ar decaying to 39K. Whic has nothing to do with his claim that supercooling would turn 40Ar into 40K.
Remember Simple? This guy reminds me of him without the clarity of exposition.
Edited by JonF, : No reason given.

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JonF
Member (Idle past 168 days)
Posts: 6174
Joined: 06-23-2003


(2)
Message 375 of 1498 (730570)
06-29-2014 9:59 AM
Reply to: Message 328 by OS
06-28-2014 4:45 PM


Whic has nothing to do with his claim that supercooling would turn 40Ar into 40K.
Try again, I didn't make that claim. I was investigating possibilities. Did you notice Ar-41 and Ar-42 also?
A common characteristic of nutjobs is not keeping their stories straight. Message 2:
Decays of Argon-40 to Potassium-40 could be made by supercooling.
That's making a claim that it is possible.
It isn't.

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 Message 328 by OS, posted 06-28-2014 4:45 PM OS has replied

Replies to this message:
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JonF
Member (Idle past 168 days)
Posts: 6174
Joined: 06-23-2003


Message 376 of 1498 (730571)
06-29-2014 10:03 AM
Reply to: Message 344 by OS
06-28-2014 6:56 PM


(duplicate)
Edited by JonF, : No reason given.

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JonF
Member (Idle past 168 days)
Posts: 6174
Joined: 06-23-2003


(2)
Message 377 of 1498 (730573)
06-29-2014 10:03 AM
Reply to: Message 344 by OS
06-28-2014 6:56 PM


But what do cold temperatures do to those forces?
Nothing. We've tried.
Extreme cold makes metal brittle, for example
Chemistry and nuclear physics are very different.

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JonF
Member (Idle past 168 days)
Posts: 6174
Joined: 06-23-2003


Message 378 of 1498 (730574)
06-29-2014 10:06 AM
Reply to: Message 354 by RAZD
06-28-2014 8:44 PM


Re: Tree rings and reality
... but you can find the half-life of C-14 with a Geiger counter. ...
False.
That one's true (but, like most of his outpourings, irrelevant).

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Replies to this message:
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JonF
Member (Idle past 168 days)
Posts: 6174
Joined: 06-23-2003


Message 380 of 1498 (730577)
06-29-2014 10:14 AM
Reply to: Message 379 by jar
06-29-2014 10:07 AM


Re: Tree rings and reality
Wouldn't you also need patience, lots of patience?
Yup, but not as much as for the ingrowth technique. And many scientists have exactly that patience. Call for an improved set of decay constants for geochronological use:
quote:
Three approaches have so far been followed to determine the decay constants of long-lived radioactive nuclides.
1. Direct counting. In this technique, alpha, beta or gamma activity is counted, and divided by the total number of radioactive atoms. Among the difficulties of this approach are the self-shielding of finite-thickness solid samples, the low specific activities, imprecise knowledge of the isotopic composition of the parent element, the detection of verylow- energy decays, and problems with detector efficiencies and geometry factors. 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. As the nature of these errors is obscure, it is not straightforward to decide which of the, often mutually exclusive, results of such counting experiments is closest to the true value. Furthermore, the presence of systematic biases makes any averaging dangerous. Weighted averaging using weight factors based on listed uncertainties is doubly dubious. It is well possible that reliable results of careful workers, listing realistic uncertainties, will not be given the weights they deserve—this aside from the question whether it makes sense to average numbers that by far do not agree within the stated uncertainties.
2. Ingrowth. This technique relies on measuring the decay products of a well-known amount of a radioactive nuclide accumulated over a well-defined period of time. Where feasible, this is the most straightforward technique. Ingrowth overcomes the problems encountered with measuring large fractions of low-energy b-particles, as in the case of 87Rb and 187Re. It also comprises the products of radiation- less decays (which otherwise cannot be measured at all) like the bound-beta decay branch of 187Re and the possible contribution to the decay of 40K by electron capture directly into the ground state of 40Ar. Among the drawbacks of this approach is that the method is not instantaneous.The experiment must be started long before the first results can be obtained because long periods of time (typically decades) are required for sufficiently large amounts of the decay products to accumulate. Ingrowth-experiments further require an accurate determination of the ratio of two chemical elements (parent/daughter) as well as an accurate determination of the isotopic composition of parent and daughter element at the start of the accumulation (see below). Moreover, because of the hold-up in the chain of intermediaries, for uranium and thorium measuring the ingrowth of the stable decay products in the laboratory does not work at all.

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JonF
Member (Idle past 168 days)
Posts: 6174
Joined: 06-23-2003


Message 392 of 1498 (730602)
06-29-2014 12:06 PM
Reply to: Message 381 by OS
06-29-2014 11:05 AM


Whic has nothing to do with his claim that supercooling would turn 40Ar into 40K.
Try again, I didn't make that claim. I was investigating possibilities. Did you notice Ar-41 and Ar-42 also?
A common characteristic of nutjobs is not keeping their stories straight.
Decays of Argon-40 to Potassium-40 could be made by supercooling.
It hasn't been tried, especially with proton bombardment. How would you know then?
We understand the process. I don't know if it's been tested; not all incredibly stupid ideas are worth testing.
Another characteristic of nutjobs is never admitting error. You claimed you never said 40Ar could be turned into 40K; when I demonstrated your error you ignored it. An honest person would have said "Oh, yeah, I did say that".
And what's this "especially with proton bombardment" stuff"? Remember you wrote:
Decays of Argon-40 to Potassium-40 could be made by supercooling. I don't know if rapid protons would be necessary.
Now you're saying that it's likely proton bombardment is necessary? Can't keep your story straight. And protons?? 40K decays to 40Ar by emitting a gamma ray and a neutrino.

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 Message 381 by OS, posted 06-29-2014 11:05 AM OS has replied

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JonF
Member (Idle past 168 days)
Posts: 6174
Joined: 06-23-2003


(1)
Message 396 of 1498 (730607)
06-29-2014 12:13 PM
Reply to: Message 382 by OS
06-29-2014 11:10 AM


Re: amusement value
Except that we KNOW that exponential decay matches the evidence and linear decay doesn't.
No, you really don't. It is a thermodynamic calculation
It's a statistical calculation, and exponential decay has been observed literally millions of time. Linear decay has never been observed.
and there is nothing to suggest isotopic concentrations don't have full lives.
WTF? I take it you don't understand the concept of half-life?

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