Carbon Dating

Carbon Dating can be used on material which was living in the last few tens of thousands of years, and which got its carbon from the air. The method has become more accurate in the last few decades. Carbon Dating is used to determine the age of biological artifacts up to 50,000 years old. This technique is widely used on recent artifacts, but teachers should note that this technique will not work on older fossils (like those of the dinosaurs which are over 65 million years old). This technique of Carbon Dating is not restricted to bones; it can also be used on cloth, wood and plant fibers. Carbon Dating has been used successfully on the Dead Sea Scrolls, Minoan ruins and tombs of the pharohs among other things.

Carbon Dating is a variety of radioactive dating which is applicable only to matter which was once living and presumed to be in equilibrium with the atmosphere, taking in carbon dioxide from the air for photosynthesis.

Cosmic ray protons blast nuclei in the upper atmosphere, producing neutrons which in turn bombard nitrogen, the major constituent of the atmosphere. This neutron bombardment produces the radioactive isotope carbon-14. The radioactive carbon-14 combines with oxygen to form carbon dioxide and is incorporated into the cycle of living things.

The carbon-14 forms at a rate which appears to be constant, so that by measuring the radioactive emissions from once-living matter and comparing its activity with the equilibrium level of living things, a measurement of the time elapsed can be made.

Accelerator Techniques for Carbon Dating: Accelerator techniques for Carbon Dating have extended its range back to about 100,000 years, compared to less than half that for direct counting techniques. One can count atoms of different masses with a mass spectrometer, but that is problematic for Carbon Dating because of the low concentration of carbon-14 and the existence of nitrogen-14 and CH2 which have essentially the same mass. Cyclotrons and tandem accelerators have both been used to fashion sensitive new mass spectrometer analyses. The tandem accelerator has been effective in removing the nitrogen-14 and CH2, and can be followed by a conventional mass spectrometer to separate the C-12 and C-13. A sensitivity of 10-15 in the 14C/12C ratio has been achieved. These techniques can be applied with a sample as small as a milligram.

Radio- Carbon Dating: Radio- Carbon Dating is a method of obtaining age estimates on organic materials. It has been used to date samples as old as 50,000 years. The Radio- Carbon Dating method was developed immediately following World War II by Willard F. Libby and coworkers, and has provided age determinations in archaeology, geology, geophysics and other branches of science. Radiocarbon determinations can be obtained on wood; charcoal; marine and fresh-water shell; bone and antler; peat and organic-bearing sediments, carbonate deposits such as tufa, caliche, and marl; and dissolved carbon dioxide and carbonates in ocean, lake and ground-water sources.

Other factors affecting Carbon Dating: The amount of cosmic rays penetrating the earth’s atmosphere affects the amount of 14C produced and therefore dating the system. The amount of cosmic rays reaching the earth varies with the sun’s activity, and with the earth's passage through magnetic clouds as the solar system travels around the Milky Way galaxy.

The strength of the earth’s magnetic field affects the amount of cosmic rays entering the atmosphere. A stronger magnetic field deflects more cosmic rays away from the earth. Overall, the energy of the earth’s magnetic field has been decreasing, 5 so more 14C is being produced now than in the past. This will make old things look older than they really are.

Also, the Genesis flood would have greatly upset the carbon balance. The flood buried a huge amount of carbon, which became coal, oil, etc., lowering the total 12C in the biosphere (including the atmosphere—plants re-growing after the flood absorb CO2, which is not replaced by the decay of the buried vegetation). Total 14C is also proportionately lowered at this time, but whereas no terrestrial process generates any more 12C, 14C is continually being produced, and at a rate which does not depend on carbon levels (it comes from nitrogen). Therefore, the 14C/12C ratio in plants/animals/the atmosphere before the flood had to be lower than what it is now.

Unless this effect (which is additional to the magnetic field issue just discussed) was corrected for, carbon dating of fossils formed in the flood would give ages much older than the true ages.

Creationist researchers have suggested that dates of 35,000 - 45,000 years should be re-calibrated to the biblical date of the flood.6 Such a re-calibration makes sense of anomalous data from carbon dating—for example, very discordant ‘dates’ for different parts of a frozen musk ox carcass from Alaska and an inordinately slow rate of accumulation of ground sloth dung pellets in the older layers of a cave where the layers were carbon dated.7

Also, volcanoes emit much CO2 depleted in 14C. Since the flood was accompanied by much volcanism, fossils formed in the early post-flood period would give radiocarbon ages older than they really are. In summary, the carbon-14 method, when corrected for the effects of the flood, can give useful results, but needs to be applied carefully. It does not give dates of millions of years and when corrected properly fits well with the biblical flood.