Curve based on too few measurements

How Good Are Those Young-Earth Arguments?
A Close Look at Dr. Hovind's List of Young-Earth Arguments and Other Claims
by Dave E. Matson
Copyright © 1994-2002


Dr. Hovind: The C-14 cannot be accurately measured. It makes up less than one part per million in the atmosphere, and claiming to be able to measure accurately to 7 decimal places is not reasonable.

This is similar to an argument put out by Harold Slusher (1981, p.45). Dr. Hovind adds the bizarre claim that something can't be measured accurately to seven decimal places. Such nonsense is answered by Dr. Dalrymple, an expert in radiometric dating, who noted that: "Modern counting instruments, available for more than two decades, are capable of counting the C-14 activity in a sample as old as 35,000 years in an ordinary laboratory, and as old as 50,000 years in laboratories constructed with special shielding against cosmic radiation. New techniques using accelerators and highly sensitive mass spectrometers, now in the experimental stage, have pushed these limits back to 70,000 or 80,000 years..." (Dalrymple, 1984, pp.86-87).


We can also explore this issue from first principles.


Given that the half-life of carbon-14 is 5730 years, one can calculate that 4 billion C-14 atoms will produce 1 decay per minute on the average. Converting the 4 billion atoms to grams (a nickel weighs 5 grams), we get 0.000000000000093 grams of carbon-14. Consequently, by tallying one click per minute on the Geiger counter, we can measure a whole lot further than 7 decimal places!


A 1-gram, fresh sample of carbon, containing the atmospheric concentration of one ten-billionth percent of carbon-14, will yield about 12 decays per minute. That figure follows directly from the mathematics and, as the atmospheric portion of carbon-14 given above is an approximation, is close enough to Dr. Hovind's present-day figure of 16 counts per minute per gram. Because of atomic bomb tests, the rate is slightly higher today, but the present rate would not apply to animals and plants which died before such tests. One book used a figure of about 13.5 decays per minute per gram for the pre-bomb rate. Consequently, a 64-gram sample of fresh carbon will still give about 7 clicks per minute after 40,000 years. Because of background radiation, that's about as far as one can normally go with this counting method. As noted above, Dr. Dalrymple would extend that to 50,000 years in special laboratories.


Once again, Dr. Hovind has relied on bad data. If you get your information from a creationist source, you'd better triple-check it! Errors get handed down in the creationist literature like the family jewels!


Dr. Hovind: The shape of the curve of the line is based on too few real measurements to be reliable.

It's not clear to me what Dr. Hovind is talking about. If he is referring to the carbon-14 decay curve then he has demonstrated, once again, his ignorance of radiometric dating.


The decay curve is mathematically determined by the fact that every atom of carbon-14 in a sample has the same chance of decaying during each second of time. That much is predicted by quantum mechanics, which is possibly the greatest of our modern, scientific revolutions.


The random character of radioactive decay is a special case of the indeterminacy of quantum theory, as was pointed out in 1928 by George Gamow, Ronald Gurney and Edward Condon. They showed that a particle held inside the nucleus by a "potential barrier" may be able to "tunnel through" the barrier and emerge on the other side, since if the barrier is finite the wave function of the particle is not completely localized and there is a finite probability that the particle will be outside the nucleus.


(Brush, 1982, p.42)


Since we are dealing with millions of C-14 atoms in even the smallest samples, the amount of C-14 remaining with respect to time will be an excellent approximation of an exponential decay curve. Statistics assure us of that. Indeed, it would be absurd to speak of the half-life of a radioactive isotope if it did not have a good exponential decay curve!


Once we have a good approximation of the half-life for carbon-14, its decay curve can be constructed with complete confidence. We don't need Egyptian mummies or what have you at that point. At that point it's just a routine exercise in math. If you want additional assurance that we have the correct half-life, then look at the close correlation between C-14 dates and tree-ring dates (after correcting for variances in C-14 production caused by changes in the earth's magnetic field). The snug fit indicates that the half-life of C-14 is stable and accurately known. Therefore, so is its decay curve.


Today, the half-lives of those radioactive elements used in dating are known to a few percent by careful laboratory study. So, there's no problem in getting an accurate decay curve.