Carbon Dating Question
I'm highly skeptical when it comes to carbon dating. I'm hoping that some of the folks here can lessen or remove some of my skepticism.
My contention: Carbon dating is a measurement tool that has a flawed foundation and cannot be reliably counted on to accurately determine age.
Fact: All elements in existence come from stars, expelled at various stages in a stars death throes.
If the "birth" of elements being measured with carbon dating are unknown how can anyone determine half-life or set anything more than a best guess based on other equally flawed readings?
Even if we were to actually destroy an element in its entirety and conclusive establish its death, we still could not determine its half-life or its birth-date.
I know that there are scientists and science types here. What am I missing?
** this is not a faith or religious oriented discussion, lets not make it one.
My contention: Carbon dating is a measurement tool that has a flawed foundation and cannot be reliably counted on to accurately determine age.
Fact: All elements in existence come from stars, expelled at various stages in a stars death throes.
If the "birth" of elements being measured with carbon dating are unknown how can anyone determine half-life or set anything more than a best guess based on other equally flawed readings?
Even if we were to actually destroy an element in its entirety and conclusive establish its death, we still could not determine its half-life or its birth-date.
I know that there are scientists and science types here. What am I missing?
** this is not a faith or religious oriented discussion, lets not make it one.
C14 is 'manufactured' starting from Nitrogen in the atmosphere. The rate of production is essentially constant within a small range.
The rate of decay is a statistical issue. We call it half life and it's a rule... Statistically a C14 atom has a 50% chance of decaying back into Nitrogen every ~5700 years.That doesn't guarantee that any particular atom will decay, just that after 5700 years about 1/2 of them will have decayed.
Carbon dating is only useful for dating living things after they've died. Living things take up carbon. Plants from the air, animals from the plants. While the thing is alive the ratio of C14 to normal Carbon is in equilibrium with the environment. When the thing dies the carbon it holds stops moving and the C14 that's trapped decays without being replaced with fresh atoms.
By measuring the amount of C14 in the unknown sample and comparing it to the amount in a series on KNOWN samples, a timeline of C14 intensities is established.
That's the important part that is usually glossed over. It's not one test, it's based on the tens of thousands of tests that various researchers have made! Every test adds to the database. making individual lookups VERY reliable.
For the most part, C14 dating is considered 'reliable' for measurements at least 50,000 years into the past, and indicative for twice as long. C14 dating is not used to measure the drift of continents, but it's a great tool to learn when a campsite was abandoned.
Half-life quantifies the rate of decay of a system that undergoes exponential decay. It is the time it takes for half of the sample to decay.
It is a statistical concept so an exact time for 'life' is not implied.
Radio carbon dating gives good results for up to about 50,000 years ago. It is used only on organic remains,
C-14 decays with a half-life of 5,730 years.
C-14 is an isotope of carbon, a constituent of all living things - as we understand life. organic, organism.
A mathematical formula can be used to calculate the half-life (of say C-14) from the number of breakdowns per second in a sample. At higher cost, accuracy is improved by using longer periods and larger samples.
A claim that half-life has varied over time is made by creationists to try to discredit radiometric dating. Measurements of radiation from supernova, 100,000 years distant, suggest no change in decay rates over 100,000 years.
Here, we call that a furthy, there are many others. An old colleague used to say 'One fool can throw more stupid objections than ten of the wise can quelch".
Different results between radiometric dating and other methods are known. Of those that were significant, the 'known history' method has given way, eg whether megalith building came later in Europe than in the middle east.
see also:
http://chem.tufts.edu/answersinscienc... and
https://www.boundless.com/physics/tex...
So, an appreciation of what exponential decay means, and knowing that half-life is not half of a life and does not depend on knowledge of some creation date, should resolve the difficulty.
dN/dt = -kN
so
N(t) = N(0)*exp(-kt)
This implies that the half life, which is the time it takes for 1/2 the remaining amount to decay, is a constant, and that the number of atoms left is:
initial number of atoms N(0) * (1/2)^(t/half-life) -- which means the remaining amount after decay is determined by repeatedly halving the original amount by the number of half-lives over the duration.
Because this is expressed in terms of instantaneous rates and a fixed half-life, the half-life is an attribute of an atom that can be measured over a short period of time expressed as a small fraction of the half-life.
The physical explanation and confirmation is summarized on this same page at https://www.galtsgulchonline.com/post...
The remaining carbon atoms in the entity being dated are observably the same now as any other carbon atoms today, with the same structure and identity and therefore the same physical actions: causality is identity applied to action, everything does what it does because of what it is. The value of the half-life depends on the type of radioactive atom.
Carbon is used for dating past living entities because plants absorbed CO2. An isotope of Uranium with it's much longer half life is used for rocks, putting the age of the earth at about 5 billion years, etc.
The dating of living things has been limited to about 50,000 years because after about 9 half-lives the original amount is divided in half 9 times and there is too little left to measure. That isn't the case for longer half-lives like uranium.
That physics is a separate issue from the question of what was the concentration of radioactive Carbon atoms in the atmosphere, and therefore in a living entity, at the beginning of the decay process long ago, which becomes relevant because actual measurements in applying the principle are in terms of the ratio of decay rates expressed as concentration fractions of radioactive material remaining at the different times t:
f(t) = initial fraction f(0) * (1/2)^(t/half-life).
The observed decay rate per gram of both radioactive and non-radioactive atoms translates to concentration through the relation dN/dt = -kN.
Creationists don't seem to understand that distinction when they attack the concept and physical principles of 1/2 life and mix it with concentrations in the atmosphere.
What Lucky said
Many errors can occur, for example if the biomass sample was found in any place which has (or has ever had) water contamination, then the water will have introduced fresh atmospheric carbon into the sample since its death. Any fresh carbon will then reduce the resulting age. Also, with any age more than a few multiples of the half-life, the result should be quoted with a very wide margin of error. If it does not, then don't trust the source.
In his book, he has an excellent discussion on carbon dating. I'll present it word for word:
"Radiocarbon years and real years are not the same thing, hence the calibration. When Libby developed the radiocarbon dating method, he assumed that the proportion of carbon 14 to other carbon isotopes in the atmosphere had been constant throughout the 50,000- year period that can be dated by his method. This assumption has since proven to be false. Radiocarbon experts such as Minze Stuiver, professor emeritus at the University of Washington, have used tree rings and carbon trapped in annual layers in lakes, oceans, and polar ice caps to demonstrate that the proportion of radiocarbon in the atmosphere has varied through time. Radiocarbon dates thus can differ from actual ages by more than 1,000 years. The reason for this discrepancy is primarily that the cosmic radiation striking the earth has not remained constant. During periods of high solar activity, the flow of matter outward from the sun - known as solar wind - increases and effectively blows the cosmic radiation away from the solar system. During these times, less carbon 14 is produced, so dates from these times are correspondingly older than they should be. Likewise, when solar activity is low, radiocarbon ages are too young. By dating hundreds of samples of known ages, Stuiver and his colleagues have produced a calibration curve for radiocarbon ages that now extends more than 14,000 years into the past. The curve is not smooth, however, so that some radiocarbon ages correspond to more than one calendric age. Thus the radiocarbon age of Kennewick Man - which turned out to be 8,410+/-60 B.P. - is actually between 9,330 and 9,580 calendar years, or from about 7330 to 7580 B.C. Throughout the rest of this book, I will give ages in calendar years, not radiocarbon years."
Amazing!
However, new understanding is always possible. There have been some measurements that suggest that solar activity alters the weak force in some as yet not understood manner. It is suggested that somehow neutrino emission has some previously unknown influence on the behavior of the weak force and thus could alter radio isotope decay rates. While this remains to be confirmed it is an area of active study. If true it would require a significant modification to the standard model of quantum physics.
Thanks AJ - that is one of the questions that have been wandering around in my mind for some time as well, but I couldn't think of a good way to present it. When it gets answered (hopefully) I have a number of more questions to sneak in as time and patience permits.
Well,...Gamma rays from the sun continually create new C14 by converting some of the Nitrogen in the atmosphere to Carbon-14 Plants and animal then ingest the mildly radioactive C14 and it becomes a part of them. The percent of C14 in the living plants and animals reflects the percent of C14 in the atmosphere. But once they die, they stop ingesting new C14 and the C14 in their system begins to decay away. The decay 1/2 life of C14 is 5730 years, so after an animal is dead for 5730 years it will have 1/2 the C14/C12 ratio of a living animal. Since we can measure the percent of C14/C12 very accurately in living and death organic matter, we can estimate the date of death fairly accurately. Does all that make sense?
So here is my question about C14 dating,...Are we sure the percent of C14 in the atmosphere has been constant over time? Because if 10000 or 20000 years ago it were higher or lower, than would create errors in the C14 dating results.
Sincerely,
Scientist of the Gulch.
Good article: http://c14.arch.ox.ac.uk/embed.php?Fi...
Jan
Jan
1. An alternative method of dating is used to establish milestone markers. This means that an artifact or item is dated using a well-known well-established method to determine the age then the amount of carbon 14 in the sample is determined. This provides a marker. This process is repeated until several markers are made so that the basic carbon-14 dating process has a known basis.
2. A new sample or unknown sample is then examined to determine its carbon-14 levels. These carbon-14 levels are then compared to the “known sample” and the age established.
3. This method clearly has some issues because the further back you go the less certain the alternative scientific methods for determining age are.
Carbon-14 dating has known issues some of which you indicated. I have read that anything more than about 5000 years is moving into larger and larger uncertainty. Unfortunately I can’t remember where I read this. Hope this helps a little bit.
If I’m wrong and I certainly could be feel free to knock my silly ideas down.
http://science.howstuffworks.com/envi...
It still raises the question, even though we know how C14 is created how can someone say conclusively that its half-life is 5,700 years (making its entirely life cycle 11,400 years)?
I suppose one could examine the last moments of a C14 life and then, knowing the rate of decay, mathematically work backwards until the C14 is at its fully potential (aka new). And if C14 is known to last 11400 years how can something be said to be 50-60K years old or more with any degree of certainly?
Also, I'm sure that there are factors that influence the rate of decay adding a variable to the theory.
Interesting stuff
No, no, that's not what 'half life' means. If you have a sample containing C14, then after 5700 years half of the C14 atoms will have decayed into N14. In another 5700 years half of those atoms remaining will also have decayed. The process continues until the number is statistically unverifiable by experiment.
How do we get the starting point from which the C14 decays? That's the incorporation of ambient carbon into the growth of a living thing. Once the carbon is stuck into some wood or a piece of leather or whatever, the fraction of the original C14 in the sample can be determined with an instrument that is sort of like a Geiger counter but sensitive to the particular 0.156476 MeV beta decay.
That's just touching the surface. Go hunt up material written by physicists to get the full details. The basic physics was done by Kamen and others over 60 years ago.
Jan
http://www.coolmath.com/algebra/17-ex...
Yes there is use for high school algebra. Just plug in what you know and solve for what you want. Financial calculations use somewhat similar methods, especially in continuously accrued interest calculations.
https://en.wikipedia.org/wiki/Exponen...
A friend of times long ago used to say, "It stands to reason that ..." and then introduce some cockamamie theory he'd just invented. He was certain that because (1) he used the word "reason" and (2) HE had thought of it, that it was true. Was it Mark Mark Twain who said that only in science can you reap such a wholesale return of conjecture from such a tiny investment of fact?
The usual cockamamie theories involve perpetual motion machines or astrology. Occasionally electronics or automobiles. I once listened for three hours to a fellow who claimed to have invented a computer that ran at "1.5L" which he said was 1.5 time the speed of light. that's "L" not "c".
Because the decay is exponential you approach zero as an asymptotic limit. The closer you are to the limit the more difficult it becomes to measure the precise time at which you have reached "zero C14 atoms remain," and the more difficult it becomes to detect those few remaining atoms. Additionally, you have the other side of the balance, which is C14 genesis through ambient cosmic radiation. (I don't want to think about measuring it!)
You have indicated an error in embracing the idea that these forms of carbon are created in stars and so might imply that the starting point of decay occurs in the stars. 14C is created from Nitrogen in the Earth's atmosphere and is produced by "collisions" of thermal neutrons from cosmic radiation in the upper atmosphere, and is transported down to earth to be absorbed by living biological material. 14N + 1n → 14C + 1H
Finding calibrating factors for the presence of 14C presence amidst 12C and 13C increase accuracy of the dating technique using tree rings, ice cores, and sea floor sediment observations.
Ratios are detectable by exposing Carbon atoms to a strong electric field. As the atoms pass thru the field the difference in the polarity causes the different isotopes to deflect into one or other detectors where the clicks are counted over time to determine the ratios of the various isotopes of carbon. Calibrating them to known times of death of an organism and accounting for various variables in the creation of 14C like the nuclear air testings have been taken into consideration in the calibration of 14C dating.
Is your orange juice from oranges or has it had corn sugar added? the different characteristics of the two different plants makeup in 12 and 13 C can be used in the counters with streams bending the two by different amounts into counting detectors and lo, the FDA can nail those falsely advertizing a product of juice from concentrate when it is in fact adulterated with corn sugar. Lots to learn about the techniques and calibrations. My fav has been the Teaching Company's course, The Physics of History. Covers some hard stuff. How does Special Relativity allow increased accuracy in calibration of methods of dating. It does and from some amazing properties inherent in the E=mc^2 equation. I'd say you were missing the course: http://www.thegreatcourses.com/course...
to this group -- the knowledge, the intelligence is
wonderful and impressive! . it is great to have access
to all of this education! . Thank You, All. -- john
.
I remembered an article from the 1990's and I actually found a link to the article. GG Internet.
http://www.nytimes.com/1990/05/31/us/...
Measurement standards had to be recalibrated as are any measurement standards are as new data are discovered. Standards are not arbitrary. Much work goes into them and they get more and more precise. Some, like the speed of light, are determined to be a constant or set to be a constant. Then other constants are recalculated using that value. They usually are composed of measured values of other constants. As better measurements are made the constants are adjusted. There is no absolute revealed data in science. It all has to be discovered and non-contradictory with all other data or it has to be discarded.
Maybe if we were going in the right direction as a country there would be time and energy to work on things like this. Unfortunately a lot of things like this are relative wastes of time right now.
Example: a tribe of Indians would not release a skull to archeologists for examination. The feared - correctly - that when the archeologists did genetic testing on the bones they would determine that the Indians were not the 'original settlers' of their land, but had replaced an earlier group of different genetic heritage. This impacts the sense that we 'owe' American Indians for the land we took from them by force...the truth turns out to be that the current Indians occupying the land took it from someone else by force as well.
So, if you are looking only at a practical use for such knowledge, knowing these things can effect our modern lives. Aside from that, though, intellectual pursuits are worthwhile for their own sake.
Jan
But science and innovation are always important. If Archimedes, Copernicus, Galileo, Newton, and many many others had not continued their pursuits under far less than ideal conditions before even the Enlightenment, their followers who kept going through various forms of statism and tribalism would not have had that base to work from, and we would have had much less for the Industrial Revolution through today. And everything they did furthered their own individual lives through their pride in accomplishment and understanding despite what else they had to put up with.
And yes, I agree that science is worthwhile per se. Technological advancement may eventually make Hillary and her ilk moot (and us too).
Jan
from https://www.upress.umn.edu/book-divis...
Recall that my assertion is that discoveries in paleoanthropology can effect our modern world. I do not say anything about 'should' or 'logic'...just that they 'do'.
Jan
Indians do not deserve reparations no matter what happened in their past. If the public does not understand that then nothing else matters. It is a matter of ethical principles. No history lessons will change the philosophical premises driving the multiculturalists.
I can foresee much turmoil in the next 4 years with the inflated currency and regulations under a Hillary administration that will just make it very difficult for older folks like me to survive.
Jan, wallowing
Very interesting.
enjoy
http://www.theepochtimes.com/n3/10218...
(Mal'ta is in Siberia; not the Malta in the Med.)
Jan
Like rings on a tree, earth ice core samples have layers and rings that can actually be counted. Based on the counting of rings. "And the counting shall be three, not two...not one....but three...", could not help that, but counting them can take you back hundreds of thousands of years.
Based on physical counting of layers, and the empirical measurements of frozen compounds, they can determine temperatures. Tthe APICA graphs http://www.daviesand.com/Choices/Prec... , generated by such core samples proves out eath goes through 100,000 cooling and warming cycles, and today we are on the peak of one of those cooling cycles.
Knowing with reasonable certainty some things dating back hundreds of thousands of years can, if applied help us understand what to expect in the future.
And this subject isn't nonsense. You'll make yourself crazy focusing on whats happening to and in this country today.
The closest it came to bad in my village was when the sheriff with many auxiliary officers wouldn't let me out of town because some idiot rammed a large 30,000 gallon propane tank and caught it on fire and got out of his car and locked himself in the trunk and fried to death. Couldn't leave for 24 hours when the fire burned out. Not quite as bad as being imprisoned for 24 hours. Now consider wanting to leave the USA and get back in. That is getting much harder and will be nearly an imprisonment if Trump gets his way. Just saw that the young boy who built an electronic clock and took it to school is suing the school system because the open case had electronic board in it and the teachers immediately having no idea what a bomb might look like had him handcuffed and removed from school and suspended for three days and if I recall right they wouldn't believe the science teacher that it was not a bomb. There is a change toward complete ignorance in this country which with the 'if you see something, say something' has already cause some injustice. Just lost a car because I don't use it much and someone saw that it wasn't moved in every 10 day period that it was then considered a junk vehicle. No way to find out who told the police. Yes things are getting worse but nowhere near where one should get out to go to some other hell hole.
I think its partly for the protection of the casino hotels, and partly because the mormons want to restrict anything but religious stuff outside the casino district.
Not like LA where my gay nudist brother lives and has his nude cleaning service. They don't even have a religion problem. He and his companion who have just had their 45th anniversary have had no problem finding a church that accepts gays and lesbians. If you don't push it on others out there, I guess all is well. Only trouble here is that heroin use got to next door where a 33 year old woman recently died from an overdose.
So the the middle of a 100,000 year glaciation which was one of the longer series glaciations which followed the series of 40,000 year glaciations which may give evidence for more such glaciations is not important enough to study? That last glaciation was responsible for the demise of the Neanderthal and the large mammals like the mastodon, etc.
I just like any new knowledge. I used to consider myself a nexialist: "here is the formal definition, coined by science fiction author A. E. Van Vogt. Nexialist: One skilled in the science of joining together in an orderly fashion the knowledge of one field of learning with that of other fields." The nexialist character in one of his novels would find causes of deep mysteries in the star travel novels. Trouble was that they had an A is not-A flavor from general semantics.
significantly enhance the accuracy of C-14 dating during this (last 10,000 years) period.
http://phys.org/news/2010-08-radioact...
vary-sun-rotation.html
Still looking for a recent article- past 5 or 10 years that stated that 14C has increased substantially and the Periodic table had to be adjusted also. We expect that this may be a cycle. Also noted: Many things about the planets in our solar system changed also: Venus has increased it's rotational rate and many of the other planets have change their identifying signatures. We might understand that the current sun cycle, going into a grand solar minimum may have something to do with these occurrences.
I sure would like to see that reference to the planets. All planet, including Earth's, rotational rates change for various reasons, such as mass distribution, arrangement of other system bodies, and even being clobbered by large masses.
That grand solar minimum possibility is at present an educated guess by some solar scientists.
Rest assured...I Will find it again. The Venus one is easy to search...it actually decreased, 6 min or so...(my mistake)
Grand solar minimum is a match to the one 400 years ago. (Maunder Minimum) 400 year cycle.
Science, political or not...do not like cycles...no money in it. Laughing
This is something western society has ignored for some reason.
A few things are clear. we need to grow our food differently, perhaps indoors and look back in the past to see what areas of earth were more conducive for growing.
The other thing is that solar panels will be useless with more cloud cover, given their lack of efficiency. It's not the answer.