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Author Topic:   Validity of Radiometric Dating
JonF
Member (Idle past 167 days)
Posts: 6174
Joined: 06-23-2003


Message 150 of 207 (759870)
06-15-2015 5:41 PM
Reply to: Message 148 by mindspawn
06-15-2015 5:29 PM


Re: Interested
Please show your calculations or references for a neutron flux that slows radioactive decay significantly. For all relevant isotopes. Under specified conditions.

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 Message 148 by mindspawn, posted 06-15-2015 5:29 PM mindspawn has not replied

  
JonF
Member (Idle past 167 days)
Posts: 6174
Joined: 06-23-2003


Message 156 of 207 (759927)
06-16-2015 9:01 AM
Reply to: Message 151 by mindspawn
06-15-2015 5:48 PM


Re: Interested
Thanks for posting that, I see most of it was based on faulty reasoning based on rates of sedimentation. The catastrophic model was largely rejected. So hardly accurate stuff.
Yes, inaccurate. But far more accurate that an 10,000-ish year old Earth. As Asimov wrote (well worth reading in its entirety):
quote:
when people thought the earth was flat, they were wrong. When people thought the earth was spherical, they were wrong. But if you think that thinking the earth is spherical is just as wrong as thinking the earth is flat, then your view is wronger than both of them put together.
Same thing. When people derived the age of the Earth from sedimentation they were wrong. But they were approaching truth more than anyone had before.
There would be a current radiation problem if all isotopes decayed rapidly now because of the slow build-up of unstable isotopes over time. But in a world where all isotopes decay rapidly that problem would have never existed.
Wow, that's got to be the dumbest thing anyone's ever said about decay. The problem has nothing to do with the buildup of unstable isotopes, and radioactive decay does not lead to the buildup of unstable isotopes; it leads to the buildup of stable isotopes.
Each decay of a radioactive atom releases heat and radiation. The amount it releases is constant. We are exposed to that heat and radiation today but it's not enough to cause serious problems. In a world where all isotopes decay rapidly the same amount of heat and radiation is produced but over a much shorter period of time. In any scenario YECs have produced that time period is so short that it would melt the Earth and kill all life twice over from the heat and radiation (as acknowledged by the RATE group). Again I post the link: See Heat and radiation destroy claims of accelerated nuclear decay. The math is not difficult, it's just arithmetic.
Proportionality has not been demonstrated over an applicable range, and since the equations of time for decay are non-linear I bet proportionality doesn't do the trick. I may have time to do that formally today.
Alpha decay is not just alpha decay and beta decay is not just beta decay; there are variations. Has the alleged effect been tested on all isotopes used in geochronology? Also, I specifically mentioned electron capture decay of 40K, widely used in radiometric dating. Has that been tested?
(Please don't get into K-Ar dating, that's hasn't been used widely for decades. Ar-Ar dating relies on the same decay and is much more robust and widely used.)
Edited by JonF, : No reason given.

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Replies to this message:
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JonF
Member (Idle past 167 days)
Posts: 6174
Joined: 06-23-2003


Message 157 of 207 (759928)
06-16-2015 9:04 AM
Reply to: Message 152 by NoNukes
06-15-2015 6:40 PM


Re: Interested
In the case of a nuclear reactor high speed muons are easily stopped by lead shielding and steel shielding. Neutrons are stopped by boronated poly shielding.
Don't you have sub experience?
It occurred to me that a nuclear sub well under water would be further shielded by its hull and the water. I don't know how much. Any comment?
I surmise that Navy subs track the state of their fuel pretty closely.

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JonF
Member (Idle past 167 days)
Posts: 6174
Joined: 06-23-2003


(3)
Message 160 of 207 (759946)
06-16-2015 11:17 AM
Reply to: Message 159 by mikechell
06-16-2015 10:43 AM


Re: Radiocarbon dating
When your model doesn't correspond to reality, reality isn't the one that's wrong.

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JonF
Member (Idle past 167 days)
Posts: 6174
Joined: 06-23-2003


(2)
Message 171 of 207 (760157)
06-18-2015 9:13 AM
Reply to: Message 165 by mindspawn
06-17-2015 6:34 PM


Re: Interested
Are you saying that we still have not reached equilibrium on earth yet? Please make up your mind, either there's still a build up of unstable isotopes or we have reached equilibrium already, which is it?
Neither. Duh. It's apparent that you don't have any idea whatsoever what happens in radioactive decay.
Unstable radioactive isotopes decay to stable isotopes (some through a chain of unstable isotopes, but the final isotope in the chain is always stable.) Therefore for any unstable isotope that is not being replenished the total amount of the unstable isotope continuously decreases and the total amount of the stable end isotope increases. (The only relevant isotopes that are being replenished is 14C and some Be isotope of which I forget the number.)
Therefore the vast majority of unstable isotopes are not building up, they are decreasing. What's building up are stable isotopes.
I suppose you could say that we are approaching an equilibrium asymptotically, in which equilibrium there will be no un-replenished unstable isotopes left and all that will exist on Earth are stable isotopes (some of them the result of radioactive decay). It will take many billions of years to get to that state, and the Sun will die and vaporize the Earth long before it happens.
If we have reached equilibrium, then where is the so-called heat problem if the quantity of new unstable isotopes is equal to the quantity of recently stabilized isotopes?
See above; we are billions of years from equilibrium. But you still haven't gasped the most basic fact one can say about radioactive decay; the overall result of radioactive decay is converting unstable isotopes into stable isotopes. The net quantity of new unstable isotopes is zero, the quantity of new stable isotopes is greater than zero. Therefore the quantity of new unstable isotopes is not equal to or greater than the quantity of new stable isotopes. Rather, the net quantity of new unstable isotopes is less than than the quantity of new stable isotopes.
(I would speak of secular equilibrium, which has been reached in almost all the Earth's rocks for those dating-relevant decay chains for which secular equilibrium is meaningful, but you are far from being able to understand that.)
Maybe the "dumbest thing anyone's ever said" relates to your lack of understanding of the macro-situation.
No it relates to your misunderstanding of any aspect of the situation, macro or micro or otherwise.
  • The net result of any radioactive decay is converting unstable isotopes into stable isotopes.
  • In that net production of stable isotopes there is no production of more unstable isotopes.
  • Each decay of an unstable isotope to a stable isotope produces both heat and radiation.
  • More decay over a shorter period of time produces more heat and more radiation.
  • Any speedup of decay that comes anywhere in the ballpark of being compatible with young Earth would produce enough heat to melt the Earth and kill all life except for a few thermophilic bacteria, and enough radiation to kill all life again.
Them's the facks, Jack. Why don't you tell us how old you think the Earth and Life are and I'll be glad to run the numbers for you.
Edited by JonF, : No reason given.

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JonF
Member (Idle past 167 days)
Posts: 6174
Joined: 06-23-2003


(1)
Message 172 of 207 (760158)
06-18-2015 9:24 AM
Reply to: Message 169 by mindspawn
06-18-2015 4:34 AM


Re: Interested
The heat is generated in the decay of the primary atom, yes, so whether the world's parent isotopes are decaying rapidly or slowly, the entire earth is
1) undergoing a net gain in radioactivity
2) undergoing a net reduction in radioactivity
3) has reached equilibrium
2.
The reason has already been explained; All radioactive decay leads to a reduction in the amount of radioactive isotopes and an increase in the amount of stable isotopes. That is the most basic fact there is about radioactivity.
A very few radioactive isotopes are being replenished, none of them relevant to geological dating, and the amount of such unstable isotopes is roughly constant; but they are not in equilibrium with their stable daughter isotopes because the amount of stable daughter isotopes are increasing.
When a 40K atom decays, 89.28% of the time it produces a 40Ca atom. 10.72% of the time it produces a 40Ar atom. 40Ca is stable, and 40Ar is stable. Therefore in this case the number of 40K atoms decreases, the number of 40Ca and 40Ar atoms increases, and no unstable atoms are produced.
The same is true of all the isotopes used in geological dating. (The process of uranium or thorium decay is a little more complex, but the bottom line is the same; reduction in the amount of radioactive isotopes and increase in the number of stable isotopes.)

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JonF
Member (Idle past 167 days)
Posts: 6174
Joined: 06-23-2003


Message 175 of 207 (760166)
06-18-2015 10:19 AM
Reply to: Message 174 by NoNukes
06-18-2015 9:52 AM


Re: Interested
There was a poster, Simple, a few years ago. He and Mindspawn are two of a bewildered kind. In many years those are the two most bewildered posters I've encountered anywhere.
He may have some vague notion of secular equilibrium, but if so he's totally misinterpreting it and doesn't realize it doesn't apply to almost all the relevant unstable isotopes.
He doesn't even realize that he's trying desperately to counter his own claim of no heat/radiation problem. No matter what the final product is, decay of an unstable isotope releases heat and radiation which is an insurmountable problem for AND. If the "final" product is an unstable isotope as Mindie is claiming, then it will decay producing more heat and more radiation and a bigger problem for a condensed time frame.
Edited by JonF, : No reason given.

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JonF
Member (Idle past 167 days)
Posts: 6174
Joined: 06-23-2003


(1)
Message 178 of 207 (760256)
06-19-2015 8:27 AM
Reply to: Message 169 by mindspawn
06-18-2015 4:34 AM


Another thought on this:
As I already pointed out, the equilibrium to which you refer is billions of years in the future. But you seem to think that a radioactive atom decaying to another radioactive atom somehow cancels the heat and radiation produced by the first decay.
There is a state called secular equilibrium, which does apply to the decay of uranium and thorium, which decay in a chain of radioactive isotopes before ending and a stable lead isotope.
Secular equilibrium is different from "equilibrium" as it is usually used. Secular equilibrium does not refer to the amount of any isotope; it refers the the rate at which isotopes are being created or destroyed.
In a chain of decays the top of the chain decays, the intermediates in the chain both decay and are produced, and the bottom of the chain is produced. In secular equilibrium the rates of all the decays and productions are the same. For example, if 238U is decaying in some sample at 100,000 decays per minute, it is producing 234Th at a rate of 100,000 decays per minute and that 234Th is decaying to 234Pa at a rate of 100,000 decays per minute, and the 234 Pa is decaying to 234U at a rate of 100,000 decays per minute, and so on until you get to stable lead atoms being produced at a rate of 100,000 atoms per minute.
The important part of this is that in this chain the amount of each atom is constantly going down. In my example, as the 238U at the top of the chain is decaying at a rate of 100,000 decays per minute then in the nearish future it will be decaying at a rate of 99,999 decays per minute (because the 238U is being used up) and after that it will be decaying at 99,998 decays per minute, and so on until all the 238 U is used up many billions of years in the future. But the secular equilibrium continues because the half-life of 238U is much larger than any of the half-lives in the chain, so the intermediates have "plenty of time to catch up" as it were. This secular equilibrium state will continue for billions of years until all the 238U gone.
But secular equilibrium is not relevant to the heat and radiation issue. If 100,000 238U atomes decay in one minute, and you decrease the half-life by a factor of 10, you increase the heat and radiation by a factor of 10 each. Same applies to all the intermediates in the chain whether or not the system is in secular equilibrium.
Increasing decay rate by any factor, say X, increases the rate of production of heat and radiation by the same factor. No matter how many atoms of any variety there are in the sample. And that's the problem for those who claim AND; any significant changes in decay rate boils the oceans and kills all life.

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JonF
Member (Idle past 167 days)
Posts: 6174
Joined: 06-23-2003


Message 189 of 207 (760318)
06-20-2015 8:13 AM
Reply to: Message 188 by 46&2
06-19-2015 7:28 PM


Re: Interested
Yup.
When YECs get backed into a corner, they call it a world wide conspiracy to fake results. Then they claim it's just human nature acting, subconsciously tweaking to fir preconceptions.
Of course they have no idea how impossible it would be to fake all the consilience even if people consciously tried.

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JonF
Member (Idle past 167 days)
Posts: 6174
Joined: 06-23-2003


(3)
Message 204 of 207 (881799)
08-30-2020 5:30 PM
Reply to: Message 203 by NosyNed
08-29-2020 9:56 AM


Re: Index fossils
Index fossils aren't a dating method themselves and shouldn't be confused with that.
Yup. They are a correlation method.
The formations in which index fossils are found usually cannot be directly absolutely dated by radiometric methods. But many of them can be closely dated by dating igneous layers above and/or below and/or piercing them. If 47 Mya igneous layer A is just above fossiliferous layer B and 52 Mya igneous layer C is just below B,then B is between 47 and 52 Mya.
Once any such fossiliferous layer has been dated, all layers with the same index fossils correlate and have the same date.
(One requirement for a good index fossil is the organism didn't exist for very long in geologic terms.)
Index Fossils
Edited by JonF, : No reason given.

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