Whenever the worldview of evolution is questioned, the topic of carbon dating always comes up. Here is how carbon dating works and the assumptions it is based upon. Radiation from the sun strikes the atmosphere of the earth all day long. This energy converts about 21 pounds of nitrogen into radioactive carbon This radioactive carbon 14 slowly decays back into normal, stable nitrogen. Extensive laboratory testing has shown that about half of the C molecules will decay in 5, years.
How old can carbon dating go As far back in time. Red; billion years. Creation seminar how far can think of the age of years based. This radioactive carbon 14 slowly decays back into normal, stable nitrogen. Extensive laboratory testing has shown that about half of the C molecules will decay in 5, years. This is called the half-life. After another 5, years half of the remaining C will decay leaving only 1?4 of the original C May 06, We can get reasonable accuracy to 50, years, better accuracy more recently. This calibration is what limits the accuracy because we know that with a .
This affects the ratio of 14 C to 12 C in the different reservoirs, and hence the radiocarbon ages of samples that originated in each reservoir. There are several other possible sources of error that need to be considered. The errors are of four general types:.
To verify the accuracy of the method, several artefacts that were datable by other techniques were tested; the results of the testing were in reasonable agreement with the true ages of the objects. Over time, however, discrepancies began to appear between the known chronology for the oldest Egyptian dynasties and the radiocarbon dates of Egyptian artefacts.
The question was resolved by the study of tree rings :    comparison of overlapping series of tree rings allowed the construction of a continuous sequence of tree-ring data that spanned 8, years.
Coal and oil began to be burned in large quantities during the 19th century. Dating an object from the early 20th century hence gives an apparent date older than the true date.
For the same reason, 14 C concentrations in the neighbourhood of large cities are lower than the atmospheric average. This fossil fuel effect also known as the Suess effect, after Hans Suess, who first reported it in would only amount to a reduction of 0.
A much larger effect comes from above-ground nuclear testing, which released large numbers of neutrons and created 14 C. From about untilwhen atmospheric nuclear testing was banned, it is estimated that several tonnes of 14 C were created. The level has since dropped, as this bomb pulse or "bomb carbon" as it is sometimes called percolates into the rest of the reservoir. Photosynthesis is the primary process by which carbon moves from the atmosphere into living things. In photosynthetic pathways 12 C is absorbed slightly more easily than 13 Cwhich in turn is more easily absorbed than 14 C.
This effect is known as isotopic fractionation. At higher temperatures, CO 2 has poor solubility in water, which means there is less CO 2 available for the photosynthetic reactions. The enrichment of bone 13 C also implies that excreted material is depleted in 13 C relative to the diet. The carbon exchange between atmospheric CO 2 and carbonate at the ocean surface is also subject to fractionation, with 14 C in the atmosphere more likely than 12 C to dissolve in the ocean.
This increase in 14 C concentration almost exactly cancels out the decrease caused by the upwelling of water containing old, and hence 14 C depleted, carbon from the deep ocean, so that direct measurements of 14 C radiation are similar to measurements for the rest of the biosphere. Correcting for isotopic fractionation, as is done for all radiocarbon dates to allow comparison between results from different parts of the biosphere, gives an apparent age of about years for ocean surface water.
The marine effect : The CO 2 in the atmosphere transfers to the ocean by dissolving in the surface water as carbonate and bicarbonate ions; at the same time the carbonate ions in the water are returning to the air as CO 2. The deepest parts of the ocean mix very slowly with the surface waters, and the mixing is uneven. The main mechanism that brings deep water to the surface is upwelling, which is more common in regions closer to the equator.
Upwelling is also influenced by factors such as the topography of the local ocean bottom and coastlines, the climate, and wind patterns. Overall, the mixing of deep and surface waters takes far longer than the mixing of atmospheric CO 2 with the surface waters, and as a result water from some deep ocean areas has an apparent radiocarbon age of several thousand years. Upwelling mixes this "old" water with the surface water, giving the surface water an apparent age of about several hundred years after correcting for fractionation.
The northern and southern hemispheres have atmospheric circulation systems that are sufficiently independent of each other that there is a noticeable time lag in mixing between the two. Since the surface ocean is depleted in 14 C because of the marine effect, 14 C is removed from the southern atmosphere more quickly than in the north.
For example, rivers that pass over limestonewhich is mostly composed of calcium carbonatewill acquire carbonate ions.
Similarly, groundwater can contain carbon derived from the rocks through which it has passed. Volcanic eruptions eject large amounts of carbon into the air.
Event how long can carbon dating go back sorry
Dormant volcanoes can also emit aged carbon. Any addition of carbon to a sample of a different age will cause the measured date to be inaccurate. Contamination with modern carbon causes a sample to appear to be younger than it really is: the effect is greater for older samples. Samples for dating need to be converted into a form suitable for measuring the 14 C content; this can mean conversion to gaseous, liquid, or solid form, depending on the measurement technique to be used.
Before this can be done, the sample must be treated to remove any contamination and any unwanted constituents.
Particularly for older samples, it may be useful to enrich the amount of 14 C in the sample before testing. This can be done with a thermal diffusion column. Once contamination has been removed, samples must be converted to a form suitable for the measuring technology to be used.
For accelerator mass spectrometrysolid graphite targets are the most common, although gaseous CO 2 can also be used.
The quantity of material needed for testing depends on the sample type and the technology being used. There are two types of testing technology: detectors that record radioactivity, known as beta counters, and accelerator mass spectrometers. For beta counters, a sample weighing at least 10 grams 0.
Radiometric Dating Debunked in 3 Minutes
For decades after Libby performed the first radiocarbon dating experiments, the only way to measure the 14 C in a sample was to detect the radioactive decay of individual carbon atoms.
Libby's first detector was a Geiger counter of his own design. He converted the carbon in his sample to lamp black soot and coated the inner surface of a cylinder with it. This cylinder was inserted into the counter in such a way that the counting wire was inside the sample cylinder, in order that there should be no material between the sample and the wire.
Speaking, would how long can carbon dating go back have hit the
Libby's method was soon superseded by gas proportional counterswhich were less affected by bomb carbon the additional 14 C created by nuclear weapons testing. These counters record bursts of ionization caused by the beta particles emitted by the decaying 14 C atoms; the bursts are proportional to the energy of the particle, so other sources of ionization, such as background radiation, can be identified and ignored. The counters are surrounded by lead or steel shielding, to eliminate background radiation and to reduce the incidence of cosmic rays.
In addition, anticoincidence detectors are used; these record events outside the counter and any event recorded simultaneously both inside and outside the counter is regarded as an extraneous event and ignored. The other common technology used for measuring 14 C activity is liquid scintillation counting, which was invented inbut which had to wait until the early s, when efficient methods of benzene synthesis were developed, to become competitive with gas counting; after liquid counters became the more common technology choice for newly constructed dating laboratories.
The counters work by detecting flashes of light caused by the beta particles emitted by 14 C as they interact with a fluorescing agent added to the benzene. Like gas counters, liquid scintillation counters require shielding and anticoincidence counters.
For both the gas proportional counter and liquid scintillation counter, what is measured is the number of beta particles detected in a given time period. This provides a value for the background radiation, which must be subtracted from the measured activity of the sample being dated to get the activity attributable solely to that sample's 14 C.
In addition, a sample with a standard activity is measured, to provide a baseline for comparison. The ions are accelerated and passed through a stripper, which removes several electrons so that the ions emerge with a positive charge. A particle detector then records the number of ions detected in the 14 C stream, but since the volume of 12 C and 13 Cneeded for calibration is too great for individual ion detection, counts are determined by measuring the electric current created in a Faraday cup.
Any 14 C signal from the machine background blank is likely to be caused either by beams of ions that have not followed the expected path inside the detector or by carbon hydrides such as 12 CH 2 or 13 CH. A 14 C signal from the process blank measures the amount of contamination introduced during the preparation of the sample. These measurements are used in the subsequent calculation of the age of the sample. The calculations to be performed on the measurements taken depend on the technology used, since beta counters measure the sample's radioactivity whereas AMS determines the ratio of the three different carbon isotopes in the sample.
To determine the age of a sample whose activity has been measured by beta counting, the ratio of its activity to the activity of the standard must be found.
To determine this, a blank sample of old, or dead, carbon is measured, and a sample of known activity is measured. The additional samples allow errors such as background radiation and systematic errors in the laboratory setup to be detected and corrected for.
The results from AMS testing are in the form of ratios of 12 C13 Cand 14 Cwhich are used to calculate Fm, the "fraction modern". Both beta counting and AMS results have to be corrected for fractionation. The calculation uses 8, the mean-life derived from Libby's half-life of 5, years, not 8, the mean-life derived from the more accurate modern value of 5, years.
How long can carbon dating go back
Libby's value for the half-life is used to maintain consistency with early radiocarbon testing results; calibration curves include a correction for this, so the accuracy of final reported calendar ages is assured. The reliability of the results can be improved by lengthening the testing time.
Radiocarbon dating is generally limited to dating samples no more than 50, years old, as samples older than that have insufficient 14 C to be measurable. Older dates have been obtained by using special sample preparation techniques, large samples, and very long measurement times. These techniques can allow measurement of dates up to 60, and in some cases up to 75, years before the present. This was demonstrated in by an experiment run by the British Museum radiocarbon laboratory, in which weekly measurements were taken on the same sample for six months.
The measurements included one with a range from about to about years ago, and another with a range from about to about Errors in procedure can also lead to errors in the results. The calculations given above produce dates in radiocarbon years: i. To produce a curve that can be used to relate calendar years to radiocarbon years, a sequence of securely dated samples is needed which can be tested to determine their radiocarbon age.
The study of tree rings led to the first such sequence: individual pieces of wood show characteristic sequences of rings that vary in thickness because of environmental factors such as the amount of rainfall in a given year. These factors affect all trees in an area, so examining tree-ring sequences from old wood allows the identification of overlapping sequences. In this way, an uninterrupted sequence of tree rings can be extended far into the past.
The first such published sequence, based on bristlecone pine tree rings, was created by Wesley Ferguson. Suess said he drew the line showing the wiggles by "cosmic schwung ", by which he meant that the variations were caused by extraterrestrial forces. It was unclear for some time whether the wiggles were real or not, but they are now well-established.
A calibration curve is used by taking the radiocarbon date reported by a laboratory and reading across from that date on the vertical axis of the graph. The point where this horizontal line intersects the curve will give the calendar age of the sample on the horizontal axis. Similarly, scientists do not know that the carbon decay rate has been constant.
They do not know that the amount of carbon 14 in the atmosphere is constant. Present testing shows the amount of C in the atmosphere has been increasing since it was first measured in the s. This may be tied in to the declining strength of the magnetic field. In addition to the above assumptions, dating methods are all subject to the geologic column date to verify their accuracy.
If a date obtained by radiometric dating does not match the assumed age from the geologic column, the radiometric date will be rejected. The so-called geologic column was developed in the early s over a century before there were any radio- metric dating methods.
There are about 7 or 8 radioactive elements that are used today to try to date objects. Each one has a different half-life and a different range of ages it is supposed to be used for. No dating method cited by evolutionists is unbiased. ThousandsNot Billions eBook by Dr. Don DeYoung. Does carbon dating prove the earth is millions of years old? How Carbon Dating Works Radiation from the sun strikes the atmosphere of the earth all day long.
The Assumptions of Carbon Dating Although this technique looks good at first, carbon dating rests on at least two simple assumptions. Radiometric dating would not have been feasible if the geologic column had not been erected first.
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Apologise, how long can carbon dating go back remarkable, rather
Related Posts. Ravi Zacharias Memorial Service. As it stands, the thesis is vulnerable to being shown, in some fashion of this sort, to be a privileged frame of reference argument. That is, treating our location as having magical properties.
As you state it, not quite so, but I think there's enough going on and we can observe enough directionality in the universe that we'd see some pretty strong hints if constants varied in that fashion.
Additionally, not every particle existed at the big bang. They can be created and destroyed yet preserving the conservation laws. How do they know, then, what time it is and how to be properly elongated? In what frame of reference are they to be elongated?
Towards us only privileged frame problems or toward some other body with a different relativistic velocity in another direction? How can it have different elongations of the constants towards different bodies? I'm not Mr. Physics major, but in the end, I don't think this works.
Or, if it does, it will take the next Einstein to explain it. I suppose this is only tangentially related, but it's a question I've been thinking about for a while now, and I don't think it's worth its own thread. I think the place to look for evidence for that the cosmic background radiation is differentiated in some way. But, while space is largely empty, not all of it is. There's patches where it isn't so empty, just by sheer chance and volume of the universe.
Are mistaken. how long can carbon dating go back more
I think you also need to play Einstein and create some equations. While they are hard to detect precisely because they are so energetic, cosmic rays that come through the sun versus from outside the solar system that is, a place where no planets are, especially Jupiter should show, on whatever equations you posit, some sort of difference.
Or, if that creates problems due to the known issues around photons and gravity, some other near-solar incident angle that's far enough away to create the problem in an easily measured way. Versus, of course, nowhere near the sun. Maybe X Rays or other wavelengths would work as well. Gravitational lenses may be useful here although in this case, it would be measuring only "half" of the lensing versus something a bit "farther to the left". I suspect we'd know about it if that sort of thing was true.
Astronomers do look in pretty much every direction and pretty much every wavelength we can even occasionally detect. Unless everyone was asleep possible, I suppose - we don't always look for what we don't expectthen there'd already be people talking about the problem, perhaps trying to attribute it to gravity which is an issue, even for photons or something of the sort.
Not exactly. If that were the case, we'd see lensing effects dramatically different than what we do see. Observable gravitational lensing pretty much agrees with relativity. You would need to give mass some kind of property that changes c. Let's say we do. Gravitational lensing is nothing like how we observe it. If c is faster away from the immediate vicinity of mass, we see less lensing.
If c is slower away from the immediate vicinity of mass, we see more lensing. We don't. Objects do not follow the laws of motion anymore. We see objects either ahead if faster c or behind if slower c where they should be after accounting for the constant speed of light.
Objects do. General Relativity doesn't work, ever, for anything.
GR is based entirely around the immutable assertion of c being constant in all frames of reference. If that's not true, GR doesn't work. It does. Doppler shifting goes crazy. If light slows down it shifts slightly to a higher frequency shorter wavelength to maintain the amount of energy it has. This is mandated by thermodynamics. If light speeds up, it shifts to a longer wavelength. The energy in the velocity as light has momentum has to come from somewhere or go to somewhere.
That somewhere is in the electromagnetic field of the photon. We don't see any of that. Black holes would behave VERY differently. They don't. When slowed or accelerated, the lines added would be shifted. Example: Light magically doubles in speed away from any mass.
We detect light from a distant galaxy cluster carrying the absorption line at We detect the hydrogen line shifted far into UV, yet the rest of the spectrum is redshifted from the galaxy cluster. We'd notice. To date older objects, you need to use different radioisotopes. For dating stuff that's millions of years old, you use K and Ar. As Hat and the others have explained far better than I ever could, decay rates can't have changed appreciably over the history of the universe, otherwise the very nature of matter would have changed in that time, which would be noticeable as we look farther out.
Electron capture can affect the decay rates of certain isotopes appreciably IINM, but that's not a change in the "constant" behind radioactive decay. They've just announced a big improvement in the precision of argon-argon dating. A physicist acquaintance corrected me on this about 35 years ago, as will be evident shortlysaying it's true for Special Relativity, but not GR.
The two principles of GR are equivalence and relativity. Relativity is that the laws of physics are immutable over space and time.
You mean like this? It's not definite yet, but it's starting to seem likely that the fine structure constant is not, in fact, constant and possibly as a result, and I can't emphasize the word possibly strongly enough, the speed of light is not constant either.
Now the variations aren't large enough on the relevant time scale to effect any radiological dating systems we currently use.
Oct 18, As a rule, carbon dates are younger than calendar dates: a bone carbon-dated to 10, years is around 11, years old, and 20, carbon years roughly equates to 24, calendar years Author: Nature Magazine. How Long Can Carbon Dating Go Back is owned by Michael J. Kalous, MA, LCPC. The main focus of his practice is: Specializing in Relationships, Family, Faith, and Self-Development.
Still, the assumption that the physical "constants" of the universe have always been that way is just that, an assumption, and one that is starting to look less likely to be true. You may have misunderstood your physicist friend.
GR expands the scope of what reference frames are valid, but still requires the speed of light to be invariant between valid reference frames. Essentially reference frames that are in free fall are valid. The equivalence principle you mentioned is meant to generalize special relativity to reference frames undergoing gravitational acceleration.
Carbon dating, rate of decay, how far can we go?
Hat Monster. Originally posted by spoof: Unfortunately, I was not able to attend that event, due to prior schedule conflicts. Originally posted by Chuckles: quote:. Ars Legatus Legionis et Subscriptor. Originally posted by UserJoe: quote:. Originally posted by Hat Monster: That's right, it's the weak force that governs beta decay. Moderator et Subscriptor. Isotopic systems that have been exploited for radiometric dating have half-lives ranging only about 10 years e.