| Topic: |
Science > Physics |
| User: |
"Jack Linden" |
| Date: |
03 Dec 2006 02:41:58 PM |
| Object: |
Fooling radiocarbon dating |
Hi,
Theoretically speaking, would it be possible to fool modern
radiocarbon dating (e.g. one based on mass-spectrometric
techniques)?
I'm studying the subject (of forged ancient manuscripts etc.) and my
friend from the physics department insists that radiocarbon dating
can't be fooled.
I know how radiometric dating works on a general level: by detecting
the amount of carbon-14 present in the sample. As we know how fast
carbon-14 decays we can calculate the age of the sample by detecting
the amount of carbon-14.
But wouldn't it be possible somehow to reduce the amount of 14-c
from an object? Two methods come to my mind: by simulating the
natural decay, perhaps using some sort of radioactive decay process?
Or, by using some kind of chemical reaction(s) to remove a specific
amount of the 14-c present?
Thanks,
Jack Linden
.
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| User: "" |
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| Title: Re: Fooling radiocarbon dating |
03 Dec 2006 03:06:34 PM |
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In article <Xns988EE79893668nonenowherecominvali@66.250.146.185>, Jack Linden <none@nowhere.com.invalid> writes:
Hi,
Theoretically speaking, would it be possible to fool modern
radiocarbon dating (e.g. one based on mass-spectrometric
techniques)?
I'm studying the subject (of forged ancient manuscripts etc.) and my
friend from the physics department insists that radiocarbon dating
can't be fooled.
I know how radiometric dating works on a general level: by detecting
the amount of carbon-14 present in the sample. As we know how fast
carbon-14 decays we can calculate the age of the sample by detecting
the amount of carbon-14.
But wouldn't it be possible somehow to reduce the amount of 14-c
from an object? Two methods come to my mind: by simulating the
natural decay, perhaps using some sort of radioactive decay process?
Or, by using some kind of chemical reaction(s) to remove a specific
amount of the 14-c present?
You could *increase* the amount of C14 present, but not decrease it.
You cannot make it decay faster and chamical reactions do not
distinguish between C14 and regular carbon.
Mati Meron | "When you argue with a fool,
meron@cars.uchicago.edu | chances are he is doing just the same"
.
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| User: "" |
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| Title: Re: Fooling radiocarbon dating |
05 Dec 2006 11:13:37 AM |
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wrote:
In article <Xns988EE79893668nonenowherecominvali@66.250.146.185>, Jack Linden <none@nowhere.com.invalid> writes:
Hi,
Theoretically speaking, would it be possible to fool modern
radiocarbon dating (e.g. one based on mass-spectrometric
techniques)?
I'm studying the subject (of forged ancient manuscripts etc.) and my
friend from the physics department insists that radiocarbon dating
can't be fooled.
I know how radiometric dating works on a general level: by detecting
the amount of carbon-14 present in the sample. As we know how fast
carbon-14 decays we can calculate the age of the sample by detecting
the amount of carbon-14.
But wouldn't it be possible somehow to reduce the amount of 14-c
from an object? Two methods come to my mind: by simulating the
natural decay, perhaps using some sort of radioactive decay process?
Or, by using some kind of chemical reaction(s) to remove a specific
amount of the 14-c present?
You could *increase* the amount of C14 present, but not decrease it.
You cannot make it decay faster and chamical reactions do not
distinguish between C14 and regular carbon.
Mati Meron | "When you argue with a fool,
meron@cars.uchicago.edu | chances are he is doing just the same"
If it's a thin manuscript, would brief exposure to intense gamma
radiation or a neutron beam reduce the C14 concentration?
Michael
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| User: "" |
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| Title: Re: Fooling radiocarbon dating |
05 Dec 2006 02:32:46 PM |
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\In article <1165338817.175642.32450@16g2000cwy.googlegroups.com>, writes:
mmeron@cars3.uchicago.edu wrote:
In article <Xns988EE79893668nonenowherecominvali@66.250.146.185>, Jack Linden <none@nowhere.com.invalid> writes:
Hi,
Theoretically speaking, would it be possible to fool modern
radiocarbon dating (e.g. one based on mass-spectrometric
techniques)?
I'm studying the subject (of forged ancient manuscripts etc.) and my
friend from the physics department insists that radiocarbon dating
can't be fooled.
I know how radiometric dating works on a general level: by detecting
the amount of carbon-14 present in the sample. As we know how fast
carbon-14 decays we can calculate the age of the sample by detecting
the amount of carbon-14.
But wouldn't it be possible somehow to reduce the amount of 14-c
from an object? Two methods come to my mind: by simulating the
natural decay, perhaps using some sort of radioactive decay process?
Or, by using some kind of chemical reaction(s) to remove a specific
amount of the 14-c present?
You could *increase* the amount of C14 present, but not decrease it.
You cannot make it decay faster and chamical reactions do not
distinguish between C14 and regular carbon.
Mati Meron | "When you argue with a fool,
meron@cars.uchicago.edu | chances are he is doing just the same"
If it's a thin manuscript, would brief exposure to intense gamma
radiation or a neutron beam reduce the C14 concentration?
To the extent that it is even possible to influence beta transition
rates with gamma radiation, an exposure to a level orders of magnitude
less than this required will suffice to convert the sample to a very
hot plasma.
As for neutrons, a sufficient exposure will *increase* the amount of
C14 present, converting the N14 present (there is always some) through
an (np) reaction. Same as the production of C14 in the atmosphere.
Mati Meron | "When you argue with a fool,
meron@cars.uchicago.edu | chances are he is doing just the same"
.
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| User: "Jack Linden" |
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| Title: Re: Fooling radiocarbon dating |
03 Dec 2006 10:42:39 PM |
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You could *increase* the amount of C14 present, but not
decrease it. You cannot make it decay faster and chamical
reactions do not distinguish between C14 and regular carbon.
This is rather far-fetched, but would it be possible first to remove
all the carbon from the material with a chemical reaction (or
reactions) and then add back some carbon with a known and desirable
amount of C14?
I realize removing carbon with a chemical reaction could be rather
impossible from a large object but we were mainly discussing papyrus
and manuscripts, these are quite thin and therefore a chemical would
be able to penetrate through the entire material with no problem.
Jack
.
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| User: "" |
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| Title: Re: Fooling radiocarbon dating |
04 Dec 2006 12:11:16 AM |
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In article <Xns988F44F3FE4EBnonenowherecominvali@66.250.146.185>, Jack Linden <none@nowhere.com.invalid> writes:
You could *increase* the amount of C14 present, but not
decrease it. You cannot make it decay faster and chamical
reactions do not distinguish between C14 and regular carbon.
This is rather far-fetched, but would it be possible first to remove
all the carbon from the material with a chemical reaction (or
reactions) and then add back some carbon with a known and desirable
amount of C14?
Not without utterly destroying the object.
I realize removing carbon with a chemical reaction could be rather
impossible from a large object but we were mainly discussing papyrus
and manuscripts, these are quite thin and therefore a chemical would
be able to penetrate through the entire material with no problem.
Sigh. You cannot remove the carbon from carbon based material without
utterly and irreversibly destroying it. And by "destroying" I don't
mean "broken to pieces" but "broken to individual atoms".
Mati Meron | "When you argue with a fool,
meron@cars.uchicago.edu | chances are he is doing just the same"
.
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| User: "" |
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| Title: Re: Fooling radiocarbon dating |
03 Dec 2006 04:30:36 PM |
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Mati, an honest question for you.
In radiocarbon dating, how exactly is the carbon baseline determined
and secondly, how is radioactive contamination from other sources other
than C14 eliminated?
I have a rather limited understanding of how carbon dating is
performed. Can you shed light on this? Also, I have never read of
carbon dating being performed on coal, which seems curious at least. I
would have expected coal to the the starting point and major
calibration point, since it's age is readily determinable by other
methods.
Harry C.
mmeron@cars3.uchicago.edu wrote:
In article <Xns988EE79893668nonenowherecominvali@66.250.146.185>, Jack Linden <none@nowhere.com.invalid> writes:
Hi,
Theoretically speaking, would it be possible to fool modern
radiocarbon dating (e.g. one based on mass-spectrometric
techniques)?
I'm studying the subject (of forged ancient manuscripts etc.) and my
friend from the physics department insists that radiocarbon dating
can't be fooled.
I know how radiometric dating works on a general level: by detecting
the amount of carbon-14 present in the sample. As we know how fast
carbon-14 decays we can calculate the age of the sample by detecting
the amount of carbon-14.
But wouldn't it be possible somehow to reduce the amount of 14-c
from an object? Two methods come to my mind: by simulating the
natural decay, perhaps using some sort of radioactive decay process?
Or, by using some kind of chemical reaction(s) to remove a specific
amount of the 14-c present?
You could *increase* the amount of C14 present, but not decrease it.
You cannot make it decay faster and chamical reactions do not
distinguish between C14 and regular carbon.
Mati Meron | "When you argue with a fool,
meron@cars.uchicago.edu | chances are he is doing just the same"
.
|
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| User: "" |
|
| Title: Re: Fooling radiocarbon dating |
03 Dec 2006 05:49:54 PM |
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In article <1165185036.728190.113660@79g2000cws.googlegroups.com>, "hhc314@yahoo.com" <hhc314@yahoo.com> writes:
Mati, an honest question for you.
In radiocarbon dating, how exactly is the carbon baseline determined
and secondly, how is radioactive contamination from other sources other
than C14 eliminated?
I was newver directly involved in this so I can only offer guesses.
As I see it, the best way to establish a baseline would be by using a
(large) number of objects the age of which can be well established by
independent means. As for contamination from other sources, well,
relying on actually counting the decays is rather imprecise since the
decay is beta, thus spectroscopy is less accurate than for gammas. I
think that there aren't many natural sources in an energy range close
to this of C14 but betas inherently don't have a sharp spectrum so
contamination cannot be ruled out. Modern techniques, AFAIK, rely not
on decay counting but on accelerator mass spectroscopy where you
vaporize a sample and count ions of each mass. You need a good enough
mass resolution to distinguish C14 from N14 but that's easily done
nowadays.
I have a rather limited understanding of how carbon dating is
performed. Can you shed light on this? Also, I have never read of
carbon dating being performed on coal, which seems curious at least. I
would have expected coal to the the starting point and major
calibration point, since it's age is readily determinable by other
methods.
I didn't hear of any measurement done on coal but I would expect the
result to be null since the youngest coal is few thousands C14
lifetimes old so you don't expect any C14 to be left. In fact, would
you find any C14 there, that would invalidate the whole method.
Harry C.
mmeron@cars3.uchicago.edu wrote:
In article <Xns988EE79893668nonenowherecominvali@66.250.146.185>, Jack Linden <none@nowhere.com.invalid> writes:
Hi,
Theoretically speaking, would it be possible to fool modern
radiocarbon dating (e.g. one based on mass-spectrometric
techniques)?
I'm studying the subject (of forged ancient manuscripts etc.) and my
friend from the physics department insists that radiocarbon dating
can't be fooled.
I know how radiometric dating works on a general level: by detecting
the amount of carbon-14 present in the sample. As we know how fast
carbon-14 decays we can calculate the age of the sample by detecting
the amount of carbon-14.
But wouldn't it be possible somehow to reduce the amount of 14-c
from an object? Two methods come to my mind: by simulating the
natural decay, perhaps using some sort of radioactive decay process?
Or, by using some kind of chemical reaction(s) to remove a specific
amount of the 14-c present?
You could *increase* the amount of C14 present, but not decrease it.
You cannot make it decay faster and chamical reactions do not
distinguish between C14 and regular carbon.
Mati Meron | "When you argue with a fool,
meron@cars.uchicago.edu | chances are he is doing just the same"
Mati Meron | "When you argue with a fool,
meron@cars.uchicago.edu | chances are he is doing just the same"
.
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| User: "OG" |
|
| Title: Re: Fooling radiocarbon dating |
03 Dec 2006 06:18:46 PM |
|
|
<mmeron@cars3.uchicago.edu> wrote in message
news:CoJch.21$45.356@news.uchicago.edu...
In article <1165185036.728190.113660@79g2000cws.googlegroups.com>,
"hhc314@yahoo.com" <hhc314@yahoo.com> writes:
Mati, an honest question for you.
In radiocarbon dating, how exactly is the carbon baseline determined
and secondly, how is radioactive contamination from other sources other
than C14 eliminated?
I was newver directly involved in this so I can only offer guesses.
As I see it, the best way to establish a baseline would be by using a
(large) number of objects the age of which can be well established by
independent means. As for contamination from other sources, well,
relying on actually counting the decays is rather imprecise since the
decay is beta, thus spectroscopy is less accurate than for gammas. I
think that there aren't many natural sources in an energy range close
to this of C14 but betas inherently don't have a sharp spectrum so
contamination cannot be ruled out. Modern techniques, AFAIK, rely not
on decay counting but on accelerator mass spectroscopy where you
vaporize a sample and count ions of each mass. You need a good enough
mass resolution to distinguish C14 from N14 but that's easily done
nowadays.
Again, I've no direct experience, but I would have thought that chemical
reactions would be performed to produce pure CO2 from the sample that would
then be subjected to mass spectrometry to measure the proportion of C12 to
C14. Ensuring N14 does not contaminate the mass spectrometer result is only
dependent on the rigour of the chemical processes.
C14 dating was initially done on the basis of current relative abundances in
the atmosphere and in living organic materials and dating was done by
measuring the reduction in C14 abundance in historic samples using the known
half-life of 5730 years.
Later studies using tree ring data dating back to several thousand years ago
led to revision of the assumption of constant atmospheric C14 amounts (I
think this was referred to as calibration in the recent C14 thread), and
hence an improvement in the accuracy of the measurement of sample ages using
C14.
I believe that ice core samples include trapped air bubbles that allow
direct measurement of historic C14 abundances (adjusted for half life
losses) which improves the scale further.
.
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| User: "" |
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| Title: Re: Fooling radiocarbon dating |
03 Dec 2006 08:22:06 PM |
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Thanks Maty and OG. Both have improved my knowledge of the subject.
Harry C.
OG wrote:
<mmeron@cars3.uchicago.edu> wrote in message
news:CoJch.21$45.356@news.uchicago.edu...
In article <1165185036.728190.113660@79g2000cws.googlegroups.com>,
"hhc314@yahoo.com" <hhc314@yahoo.com> writes:
Mati, an honest question for you.
In radiocarbon dating, how exactly is the carbon baseline determined
and secondly, how is radioactive contamination from other sources other
than C14 eliminated?
I was newver directly involved in this so I can only offer guesses.
As I see it, the best way to establish a baseline would be by using a
(large) number of objects the age of which can be well established by
independent means. As for contamination from other sources, well,
relying on actually counting the decays is rather imprecise since the
decay is beta, thus spectroscopy is less accurate than for gammas. I
think that there aren't many natural sources in an energy range close
to this of C14 but betas inherently don't have a sharp spectrum so
contamination cannot be ruled out. Modern techniques, AFAIK, rely not
on decay counting but on accelerator mass spectroscopy where you
vaporize a sample and count ions of each mass. You need a good enough
mass resolution to distinguish C14 from N14 but that's easily done
nowadays.
Again, I've no direct experience, but I would have thought that chemical
reactions would be performed to produce pure CO2 from the sample that would
then be subjected to mass spectrometry to measure the proportion of C12 to
C14. Ensuring N14 does not contaminate the mass spectrometer result is only
dependent on the rigour of the chemical processes.
C14 dating was initially done on the basis of current relative abundances in
the atmosphere and in living organic materials and dating was done by
measuring the reduction in C14 abundance in historic samples using the known
half-life of 5730 years.
Later studies using tree ring data dating back to several thousand years ago
led to revision of the assumption of constant atmospheric C14 amounts (I
think this was referred to as calibration in the recent C14 thread), and
hence an improvement in the accuracy of the measurement of sample ages using
C14.
I believe that ice core samples include trapped air bubbles that allow
direct measurement of historic C14 abundances (adjusted for half life
losses) which improves the scale further.
.
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| User: "" |
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| Title: Re: Fooling radiocarbon dating |
03 Dec 2006 02:55:03 PM |
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Jack Linden <none@nowhere.com.invalid> wrote:
Hi,
Theoretically speaking, would it be possible to fool modern
radiocarbon dating (e.g. one based on mass-spectrometric
techniques)?
I'm studying the subject (of forged ancient manuscripts etc.) and my
friend from the physics department insists that radiocarbon dating
can't be fooled.
I know how radiometric dating works on a general level: by detecting
the amount of carbon-14 present in the sample. As we know how fast
carbon-14 decays we can calculate the age of the sample by detecting
the amount of carbon-14.
But wouldn't it be possible somehow to reduce the amount of 14-c
from an object? Two methods come to my mind: by simulating the
natural decay, perhaps using some sort of radioactive decay process?
How would one do that other than a time machine?
Or, by using some kind of chemical reaction(s) to remove a specific
amount of the 14-c present?
Since that would involve grinding up the artifact, it would probably
be noticed.
Further, at the chemical level, there is no difference among the
various isotopes.
Thanks,
Jack Linden
--
Jim Pennino
Remove .spam.sux to reply.
.
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| User: "tadchem" |
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| Title: Re: Fooling radiocarbon dating |
04 Dec 2006 04:51:03 AM |
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Jack Linden wrote:
Hi,
Theoretically speaking, would it be possible to fool modern
radiocarbon dating (e.g. one based on mass-spectrometric
techniques)?
Theoretically, yes. Practically, no.
I'm studying the subject (of forged ancient manuscripts etc.) and my
friend from the physics department insists that radiocarbon dating
can't be fooled.
It *can*, but the effort involved is beyond the means of most people
and requires expensive work, so the cost-benefits are problematic.
I know how radiometric dating works on a general level: by detecting
the amount of carbon-14 present in the sample. As we know how fast
carbon-14 decays we can calculate the age of the sample by detecting
the amount of carbon-14.
But wouldn't it be possible somehow to reduce the amount of 14-c
from an object? Two methods come to my mind: by simulating the
natural decay, perhaps using some sort of radioactive decay process?
It is hypothetically possible to cause a radioactive nucleus to decay
deliberately by means other than a fission bomb or a nuclear reactor.
This has *NOT* yet been done in the laboratory. The only ways we know
of to directly affect the nucleus of an atom *through* the shielding
provided by its electrons (without ionizing the atom) require either
high-energy radiation (neutrons or gamma rays, for instance) or intense
magnetic fields such as those in a magnetic resonance device. Neither
of these techniques are developed enough to stimulate selective decay
of certain isotopes with high selectivity and efficiency.
Or, by using some kind of chemical reaction(s) to remove a specific
amount of the 14-c present?
That would require total disintegration of the sample. Carbon-14
dating itself destroys the available sample.
The best way to "spoof" a carbon-14 date would be to prepare the object
initially with a source of carbon which had an artificial isotope
mixture. One could relatively easily spoof and older date in the
following manner:
(1) build an hermetically sealed greenhouse.
(2) supplement or replace the CO2 in the greenhouse with CO2 from
geological source such as carbonate minerals or petrochemical exhaust
which have practically no carbon-14
(3) grow the plants to provide the raw materials (wood, silk, rope
fibers, etc.) for your object exclusively within this greenhouse
(4) produce your object using carbon-based materials exclusively from
this reduced carbon-14 greenhouse.
It would be theoretically possible as well to spoof a younger date by
adding carefully measured amounts of artificial carbon-14 during the
initial set-up.
Caution would be advised as carbon-14 is the only known natural
material that is a 100% effective mutagen - when a carbon-14 atom in a
DNA molecule decays, it positively will cause genetic damage, and the
cell tends to concentrate carbon into DNA.
Tom Davidson
Richmond, VA
Thanks,
Jack Linden
.
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| User: "Jack Linden" |
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| Title: Re: Fooling radiocarbon dating |
05 Dec 2006 11:00:58 AM |
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The best way to "spoof" a carbon-14 date would be to prepare
the object initially with a source of carbon which had an
artificial isotope mixture. One could relatively easily spoof
and older date in the following manner:
....
It would be theoretically possible as well to spoof a younger
date by adding carefully measured amounts of artificial
carbon-14 during the initial set-up.
Thank you very much for this information! It sounds almost too easy,
at least in theory.
Jack
.
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| User: "tadchem" |
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| Title: Re: Fooling radiocarbon dating |
08 Dec 2006 04:53:23 AM |
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Jack Linden wrote:
The best way to "spoof" a carbon-14 date would be to prepare
the object initially with a source of carbon which had an
artificial isotope mixture. One could relatively easily spoof
and older date in the following manner:
...
It would be theoretically possible as well to spoof a younger
date by adding carefully measured amounts of artificial
carbon-14 during the initial set-up.
Thank you very much for this information! It sounds almost too easy,
at least in theory.
* In theory, there is no difference between theory and practice. But,
in practice, there is."
- Jan L. A. van de Snepscheut
Tom Davidson
Richmond, VA
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| User: "" |
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| Title: Re: Fooling radiocarbon dating |
04 Dec 2006 11:21:38 AM |
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In article <1165229463.434705.47050@79g2000cws.googlegroups.com>, "tadchem" <tadchem@comcast.net> writes:
Jack Linden wrote:
Hi,
Theoretically speaking, would it be possible to fool modern
radiocarbon dating (e.g. one based on mass-spectrometric
techniques)?
Theoretically, yes. Practically, no.
I'm studying the subject (of forged ancient manuscripts etc.) and my
friend from the physics department insists that radiocarbon dating
can't be fooled.
It *can*, but the effort involved is beyond the means of most people
and requires expensive work, so the cost-benefits are problematic.
I know how radiometric dating works on a general level: by detecting
the amount of carbon-14 present in the sample. As we know how fast
carbon-14 decays we can calculate the age of the sample by detecting
the amount of carbon-14.
But wouldn't it be possible somehow to reduce the amount of 14-c
from an object? Two methods come to my mind: by simulating the
natural decay, perhaps using some sort of radioactive decay process?
It is hypothetically possible to cause a radioactive nucleus to decay
deliberately by means other than a fission bomb or a nuclear reactor.
This has *NOT* yet been done in the laboratory. The only ways we know
of to directly affect the nucleus of an atom *through* the shielding
provided by its electrons (without ionizing the atom) require either
high-energy radiation (neutrons or gamma rays, for instance) or intense
magnetic fields such as those in a magnetic resonance device. Neither
of these techniques are developed enough to stimulate selective decay
of certain isotopes with high selectivity and efficiency.
Or, by using some kind of chemical reaction(s) to remove a specific
amount of the 14-c present?
That would require total disintegration of the sample. Carbon-14
dating itself destroys the available sample.
The best way to "spoof" a carbon-14 date would be to prepare the object
initially with a source of carbon which had an artificial isotope
mixture. One could relatively easily spoof and older date in the
following manner:
(1) build an hermetically sealed greenhouse.
(2) supplement or replace the CO2 in the greenhouse with CO2 from
geological source such as carbonate minerals or petrochemical exhaust
which have practically no carbon-14
(3) grow the plants to provide the raw materials (wood, silk, rope
fibers, etc.) for your object exclusively within this greenhouse
(4) produce your object using carbon-based materials exclusively from
this reduced carbon-14 greenhouse.
It would be theoretically possible as well to spoof a younger date by
adding carefully measured amounts of artificial carbon-14 during the
initial set-up.
Caution would be advised as carbon-14 is the only known natural
material that is a 100% effective mutagen - when a carbon-14 atom in a
DNA molecule decays, it positively will cause genetic damage, and the
cell tends to concentrate carbon into DNA.
Tom Davidson
Richmond, VA
Thanks,
Jack Linden
Mati Meron | "When you argue with a fool,
meron@cars.uchicago.edu | chances are he is doing just the same"
.
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