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Author Topic:   Validity of Radiometric Dating
NoNukes
Inactive Member


Message 166 of 207 (760138)
06-18-2015 3:11 AM
Reply to: Message 164 by mindspawn
06-17-2015 6:10 PM


Re: Interested
Regarding my agreement with PY, I have realised that there was a tendency to shield for neutrons and not muons during the early establishment of the constancy of decay.
1) Your statement does not apply to nuclear reactors which must shield against radiation other than neutron and which certainly would shield muons. Why isn't the phenomenon observed in shutdown nuclear reactors, all of which contain neutron monitors.
The neutron flux in a shutdown nuclear reactor a few days after shutdown is incredibly tiny. Both the neutron flux and gamma radiation from shutdown reactors are continuously monitored. The effect you claim does not exist. In fact, we have to provide neutron sources to the reactor when it is new in order to start it because the source neutrons are too low.
2) You've still to address about five to six other reasons why your neutron answer is BS.
3) As you requested, I provided calculations of the required neutron flux at the post I referenced. Do you continue to have no comment or rebuttal on the reasoning or calculation?
Edited by NoNukes, : No reason given.

Under a government which imprisons any unjustly, the true place for a just man is also in prison. Thoreau: Civil Disobedience (1846)
History will have to record that the greatest tragedy of this period of social transition was not the strident clamor of the bad people, but the appalling silence of the good people. Martin Luther King
If there are no stupid questions, then what kind of questions do stupid people ask? Do they get smart just in time to ask questions? Scott Adams

This message is a reply to:
 Message 164 by mindspawn, posted 06-17-2015 6:10 PM mindspawn has not replied

  
NoNukes
Inactive Member


Message 167 of 207 (760139)
06-18-2015 3:16 AM
Reply to: Message 165 by mindspawn
06-17-2015 6:34 PM


Re: Interested
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 stabilised istopes?
The heat in question is generated by decay of the primary atom. Equilibrium with the daughter products is not an issue. The problem is the generation of heat in a very short period of time (thousands of years rather than billions.
JonF is correct. Your position is ridiculous.

Under a government which imprisons any unjustly, the true place for a just man is also in prison. Thoreau: Civil Disobedience (1846)
History will have to record that the greatest tragedy of this period of social transition was not the strident clamor of the bad people, but the appalling silence of the good people. Martin Luther King
If there are no stupid questions, then what kind of questions do stupid people ask? Do they get smart just in time to ask questions? Scott Adams

This message is a reply to:
 Message 165 by mindspawn, posted 06-17-2015 6:34 PM mindspawn has replied

Replies to this message:
 Message 169 by mindspawn, posted 06-18-2015 4:34 AM NoNukes has replied

  
NoNukes
Inactive Member


Message 168 of 207 (760140)
06-18-2015 3:30 AM
Reply to: Message 163 by mindspawn
06-17-2015 5:26 PM


Same lame response you gave year and half ago.
Could you kindly provide links or quantify the claims you are making. The existing neutron flux is not dangerous to life, and yet has not yet been quantified. Please provide figures to back up your claim that the flux is not enough to prevent rapid decay. It is currently an unknown quantity.
Wrong. The neutron flux has been quantified. Unlike the case with neutrinos, neutrons are easily detected and measured. The instruments installed in a nuclear reactor measure neutron flux over a range of about 15 decades (orders of magnitude).
Where do you get the idea that we are walking around in an unmeasurable neutron field? Reference please.
And similarly the required neutron flux to meet your proposal can be estimated (at least a reasonable lower limit can be put on the required flux).
It is time to quit your stalling. Since you claim that there are sufficient neutrons, why don't you owe me a quantification? You have yet to demonstrate that your proposal is even feasible. We know that the current neutron flux is about 0.2 neutrons/cm squared/second. Let me know if you need a source for that. You can start with that or provide your own calculation. If you want to claim a higher number explain how you get it with even fewer muons that can be found in the upper atmosphere.
I am not claiming that decays are stopped by neutron absorbtion. They continue. What we know as the "decay rate" is actually the "net decay rate" after some absorbtion has also occurred by the daughter element.
So far this is a bare claim without any evidence. But the absorbtion [sic] you are talking about is neutron absorption. I have provided you with an argument and calculation showing that there are not enough neutrons. You have yet to address that.
Meanwhile, I provided a complete calculation in the post I referenced from the previous discussion. It was available for you to read months ago, but then as now, you seem to run for cover once the math shows up. For ease of reference, here is yet another link to that post: See Message 942 and Message 949 as well for additional quantification.
In the post I provided in this thread, I explained why the current flux was insufficient. You have yet to respond to that reasoning. But here it is in short. The flux must be proportional to the decays being prevented which you have claimed to be somewhere between 100,000 and 1,000,000 times todays decay rate. Not only that, but the require neutrons must exist everywhere regardless of whether radioactive material is or is not present.
I compared the required rate to the current neutron flux. However the number I used for the current flux, which is too small by at least five orders of magnitude, is actually about six orders of magnitude too large. Your claim is flat busted.
And for the record, I want to ask you how you think you could slow the decay rate of something like U-235 from decaying by spraying it with neutrons. Do you have any clue what would actually happen if you did that? U-235 can absorb neutrons and become U-236, but around 80 percent of the time the nucleus would fission within a very short period. No way to get the current long half life by bombarding U-235 with neutrons. Do you really want a source for that?
Do you understand that different atoms have different cross sections of absorption for neutrons and that for such a reason, the slowed rate of decay cannot be proportional for different atoms? Do you need a source for that?
Edited by NoNukes, : No reason given.
Edited by NoNukes, : No reason given.

Under a government which imprisons any unjustly, the true place for a just man is also in prison. Thoreau: Civil Disobedience (1846)
History will have to record that the greatest tragedy of this period of social transition was not the strident clamor of the bad people, but the appalling silence of the good people. Martin Luther King
If there are no stupid questions, then what kind of questions do stupid people ask? Do they get smart just in time to ask questions? Scott Adams

This message is a reply to:
 Message 163 by mindspawn, posted 06-17-2015 5:26 PM mindspawn has replied

Replies to this message:
 Message 170 by mindspawn, posted 06-18-2015 4:48 AM NoNukes has replied

  
mindspawn
Member (Idle past 2659 days)
Posts: 1015
Joined: 10-22-2012


Message 169 of 207 (760143)
06-18-2015 4:34 AM
Reply to: Message 167 by NoNukes
06-18-2015 3:16 AM


Re: Interested
The heat in question is generated by decay of the primary atom. Equilibrium with the daughter products is not an issue. The problem is the generation of heat in a very short period of time (thousands of years rather than billions.
JonF is correct. Your position is ridiculous.
Its great to throw around terminology like "ridiculous" but unfortunately others read your posts and are most likely waiting for a scientific rebuttal. And its easy to see the point I am making here:
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
If your answer is 1 or 2 then please explain why
If your answer is 3, then this proves your heat problem would not be a problem. Because if it takes 5000 years to reach equilibrium, or 500 million years to reach equilibrium the amount of heat produced daily is directly related to the new unstable isotopes produced daily. Once equilibrium is reached the heat is the same whether rapid decay or slow decay.

This message is a reply to:
 Message 167 by NoNukes, posted 06-18-2015 3:16 AM NoNukes has replied

Replies to this message:
 Message 172 by JonF, posted 06-18-2015 9:24 AM mindspawn has not replied
 Message 174 by NoNukes, posted 06-18-2015 9:52 AM mindspawn has not replied
 Message 178 by JonF, posted 06-19-2015 8:27 AM mindspawn has not replied

  
mindspawn
Member (Idle past 2659 days)
Posts: 1015
Joined: 10-22-2012


Message 170 of 207 (760145)
06-18-2015 4:48 AM
Reply to: Message 168 by NoNukes
06-18-2015 3:30 AM


Re: Same lame response you gave year and half ago.
Wrong. The neutron flux has been quantified. Unlike the case with neutrinos, neutrons are easily detected and measured. The instruments installed in a nuclear reactor measure neutron flux over a range of about 15 decades (orders of magnitude).
Where do you get the idea that we are walking around in an unmeasurable neutron field? Reference please.
Have you got a link for your assertion that it has been quantified? If you were reading my posts you will see that I already posted links showing that it is difficult to quantify the neutron flux so I'm interested in your source of information for the extent of the neutron flux. So yes, I definitely need a source, and a recent one that takes into account the underground neutron flux which has a direct bearing on radiometric dates.

This message is a reply to:
 Message 168 by NoNukes, posted 06-18-2015 3:30 AM NoNukes has replied

Replies to this message:
 Message 173 by NoNukes, posted 06-18-2015 9:41 AM mindspawn has not replied

  
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.

This message is a reply to:
 Message 165 by mindspawn, posted 06-17-2015 6:34 PM mindspawn has not replied

  
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.)

This message is a reply to:
 Message 169 by mindspawn, posted 06-18-2015 4:34 AM mindspawn has not replied

  
NoNukes
Inactive Member


(1)
Message 173 of 207 (760159)
06-18-2015 9:41 AM
Reply to: Message 170 by mindspawn
06-18-2015 4:48 AM


Re: Same lame response you gave year and half ago.
You have no shame. You have not provided any references for any claim you have made. This whole scenario is fomented in your head.
Have you got a link for your assertion that it has been quantified?
Yes. Here is a reference. You should have been providing me with a reference when you made this claim. You'll find values for various locations above, on the surface of the earth, and in uranium mines, and other underground places.
http://www.nat-hazards-earth-syst-sci.net/...-3-637-2003.pdf
And your sources document variations in the field which is not the same as saying we cannot measure. And they discuss some other difficulties none of which allow making measurement errors anywhere near the numbers you need. Instead of posting excuses, why don't you work with the numbers your references give you. They are all insufficient.
Or take a value for a lethal neutron field, divide that by ten and show me that such a field is anywhere near sufficient. You have plenty of avenues for doing your own homework.
Besides that...
1. I don't need to provide a value for neutron flux underground. Your claim is that the decay rates currently measured in the laboratory are slowed and that the neutron flux in the past was smaller. Therefore, I don't need data from underground or the past to address that.
According to you, a modern neutron flux is currently dampening decay rates anywhere we try to measure them, so I merely need to provide the neutron flux available on the surface where the U-235 or U-238, or C-14 half life is being currently measured.
1b. In the example of the uranium in the nuclear reactor, the neutron flux is continuously monitored at all times after the uranium is installed. We know its exact value. And reactors do have shielding that stops high energy muons.
2. Your claim is that daughter products are being suppressed. However the half life of long lived products is determined by direct activity measurements. The alpha products given off by decay of Uranium 238 are counted. Those alpha particles are unaffected by neutrons. He-4 nuclei very rarely absorb neutrons because it has a neutron cross section of only 0.007 barns.
Now I want you to document that the neutrons produced by muons in any location are sufficient. After all, this is your nonsense theory. I also want an explanation for how such neutrons can prevent rapid decay of an isotope like U-235 without causing continuous fissioning of the material.
In fact many isotopes of atoms undergo reactions when exposed to neutrons. Why don't you have any evidence of those reactions taking place unexpectedly?
3. Why am I the one who must provide references when you are the one making up crap?
Can you please show evidence that muons were actually shielded in the scenario you are describing? You originally said they did shield for neutrons, now you are saying "muons are easily stopped" but can you prove that they did actually shield for muons.
Nuclear reactors are shielded for all of the radiation produced by the reactor and the shields include lead and steel. Are you claiming that muons pass through such shielding without attenuation and that there are therefore more neutrons than in the surrounding atmosphere?
Of course there is shielding that stops muons.
Your theory here is that the muons readily pass through shielding materials without affect, but are stopped by every radioactive element in just the right ratio to produce your identical effect in every radioactive material. That's crap and I think you know it.
Edited by NoNukes, : No reason given.
Edited by NoNukes, : No reason given.
Edited by NoNukes, : No reason given.
Edited by Admin, : Fix typos: "formented" => "fomented"; "exactly value" => "exact value"; "vary rarely" => "very rarely"; "more neutrons that" => "more neutrons than".

Under a government which imprisons any unjustly, the true place for a just man is also in prison. Thoreau: Civil Disobedience (1846)
History will have to record that the greatest tragedy of this period of social transition was not the strident clamor of the bad people, but the appalling silence of the good people. Martin Luther King
If there are no stupid questions, then what kind of questions do stupid people ask? Do they get smart just in time to ask questions? Scott Adams

This message is a reply to:
 Message 170 by mindspawn, posted 06-18-2015 4:48 AM mindspawn has not replied

  
NoNukes
Inactive Member


(1)
Message 174 of 207 (760161)
06-18-2015 9:52 AM
Reply to: Message 169 by mindspawn
06-18-2015 4:34 AM


Re: Interested
If your answer is 3, then this proves your heat problem would not be a problem. Because if it takes 5000 years to reach equilibrium, or 500 million years to reach equilibrium the amount of heat produced daily is directly related to the new unstable isotopes produced daily. Once equilibrium is reached the heat is the same whether rapid decay or slow decay.
No one could be as stupid as you are demonstrating yourself to be here. If the decay rate in the past was about 1,000,000 times what it is today, then so was the heat generated by decay. The heat balance and the heat generated in the past over that brief 5000 year period has nothing at all to do with the equilibrium of decay products that is a separate issue altogether.
And of course the net reactivity of the planet (ground materials) is decreasing. What would make you claim that it is in equilibrium? We know there is no issue with heat now, mindspawn. But 5000 years ago at the rates you are claiming that the overwhelming majority of the decay took place based on the rates involved?
With respect to the decay products. Given the decrease to current rates a relatively short time ago instead of decaying at a constant rate a long time ago, we would expect the ratios of decay products to alpha particles not to reflect a decay equilibrium. In fact, your theory that the decay products are removed by neutrons leads to the same conclusion. The decay products should not be in secular equilibrium based on the actual removal rate of parent isotopes because the decay of your suppression theory.
And you are still ducking most of the questions I posed to you.
Edited by NoNukes, : No reason given.
Edited by Admin, : Fix typos: "decrease to a current rates" => "decrease to current rates"; "actually removal rate" => "actual removal rate".

Under a government which imprisons any unjustly, the true place for a just man is also in prison. Thoreau: Civil Disobedience (1846)
History will have to record that the greatest tragedy of this period of social transition was not the strident clamor of the bad people, but the appalling silence of the good people. Martin Luther King
If there are no stupid questions, then what kind of questions do stupid people ask? Do they get smart just in time to ask questions? Scott Adams

This message is a reply to:
 Message 169 by mindspawn, posted 06-18-2015 4:34 AM mindspawn has not replied

Replies to this message:
 Message 175 by JonF, posted 06-18-2015 10:19 AM NoNukes has replied

  
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.

This message is a reply to:
 Message 174 by NoNukes, posted 06-18-2015 9:52 AM NoNukes has replied

Replies to this message:
 Message 176 by NoNukes, posted 06-18-2015 10:57 AM JonF has not replied
 Message 177 by NoNukes, posted 06-18-2015 7:02 PM JonF has not replied

  
NoNukes
Inactive Member


Message 176 of 207 (760171)
06-18-2015 10:57 AM
Reply to: Message 175 by JonF
06-18-2015 10:19 AM


Re: Interested
He and Mindspawn are two of a bewildered kind.
I'm not sure why I have the burden of showing that this effect that Mindspawn invented does not work when he has not shown any evidence whatsoever for it.
His tactics right now best remind me of Faith and her evolution cannot work attempted argument.

Under a government which imprisons any unjustly, the true place for a just man is also in prison. Thoreau: Civil Disobedience (1846)
History will have to record that the greatest tragedy of this period of social transition was not the strident clamor of the bad people, but the appalling silence of the good people. Martin Luther King
If there are no stupid questions, then what kind of questions do stupid people ask? Do they get smart just in time to ask questions? Scott Adams

This message is a reply to:
 Message 175 by JonF, posted 06-18-2015 10:19 AM JonF has not replied

  
NoNukes
Inactive Member


(1)
Message 177 of 207 (760225)
06-18-2015 7:02 PM
Reply to: Message 175 by JonF
06-18-2015 10:19 AM


Re: Interested
There was a poster, Simple, a few years ago.
I tried to find this poster by searching through the membership list. I could not locate simple.
I did find him by searching for his posts. Mindspawn is no match for this simple character. Simple was hilarious.
Edited by NoNukes, : No reason given.

Under a government which imprisons any unjustly, the true place for a just man is also in prison. Thoreau: Civil Disobedience (1846)
History will have to record that the greatest tragedy of this period of social transition was not the strident clamor of the bad people, but the appalling silence of the good people. Martin Luther King
If there are no stupid questions, then what kind of questions do stupid people ask? Do they get smart just in time to ask questions? Scott Adams

This message is a reply to:
 Message 175 by JonF, posted 06-18-2015 10:19 AM JonF has not replied

  
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.

This message is a reply to:
 Message 169 by mindspawn, posted 06-18-2015 4:34 AM mindspawn has not replied

Replies to this message:
 Message 179 by edge, posted 06-19-2015 11:34 AM JonF has not replied

  
edge
Member (Idle past 1705 days)
Posts: 4696
From: Colorado, USA
Joined: 01-09-2002


Message 179 of 207 (760273)
06-19-2015 11:34 AM
Reply to: Message 178 by JonF
06-19-2015 8:27 AM


Thank you for interpreting Mindspawn's posts.
As I already pointed out, the equilibrium to which you refer is billions of years in the future.
This link has some discussion about how secular equilibrium is handled in uranium exploration.
"In theory, secular isotopic equilibrium is attained in uranium deposits after approximately 1.7 million years if mineralization behaves as a closed geochemical system."
...
"Secular equilibrium is disturbed if the system is not closed. Uranium dissolved in oxygenated groundwater can be transported away, depleting the site."
http://www.stratamodel.com/gamma.htm

This message is a reply to:
 Message 178 by JonF, posted 06-19-2015 8:27 AM JonF has not replied

  
NoNukes
Inactive Member


Message 180 of 207 (760274)
06-19-2015 11:44 AM
Reply to: Message 164 by mindspawn
06-17-2015 6:10 PM


Muon shielding reference
http://www.pnnl.gov/...rnal/technical_reports/PNNL-20693.pdf
As expected borated poly is poor shielding for muons
quote:
Borated polyethylene is a low-Z material, which shields cosmic ray muons poorly.
However, lead and steel, which are used to shield the submarine crew from gamma radiation are effective shielding for muons.
quote:
Iron, being a high-Z material, shields muons with relative efficiency. Outbound muon flux was categorized into the three energy regions seen in Figure 5.
Lead shows shielding properties comparable to those of iron, as one can observe by comparing Figure 7 below to Figure 1. The trend of each energy range is similar, although there is a larger spike in generated low energy neutrons for small thicknesses through lead.
Lead would be a highly recommended shielding material for cosmic-ray muons.

Under a government which imprisons any unjustly, the true place for a just man is also in prison. Thoreau: Civil Disobedience (1846)
History will have to record that the greatest tragedy of this period of social transition was not the strident clamor of the bad people, but the appalling silence of the good people. Martin Luther King
If there are no stupid questions, then what kind of questions do stupid people ask? Do they get smart just in time to ask questions? Scott Adams

This message is a reply to:
 Message 164 by mindspawn, posted 06-17-2015 6:10 PM mindspawn has not replied

  
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