Commentary on Variable Radioactive Decay Rates
Young-earth creationists hold a tender place in my heart. Though I don’t agree with their timeline of creation, I still respect their work and find parts of their effort to harmonize science and Genesis informative and helpful. I do, however, have my concerns and offer the following comments on specific young-earth creationist ideas in regards to radioactive decay rates.
The radioactive dating method works under the following two assumptions: (1) scientists know the abundance of isotopes present at the beginning of a material’s formation; and (2) the decay rate is constant over time. Young-earth creationists disagree with the latter assumption. I have observed that young-earth proponents usually attempt to explain Earth’s appearance of old age (4.5 billion years) by promoting the hypothesis that radioactive decay rates change over time Still, it seems they have yet to find a scientific explanation for these variable decay rates.
Support and Concern for Variable Decay Rate Hypothesis
On July 24, 2012, a nuclear physics preprint was released by Jere H. Jenkins and his team of researchers. They claimed that radioactive decay rates of certain isotopes vary by a few percents under the influence of solar flares.1 The question is, is it possible for young-earth creationists to use these findings as scientific support for the variable decay rate hypothesis?
Radioactive decay, or loss of energy, is a type of nuclear interaction caused by the weak force. The decay rate is proportional to the square of a fundamental physics constant called the weak coupling constant. Both the standard model (theory of electromagnetic, and weak and strong nuclear interactions) and supersymmetric model predict that the weak coupling constant can “run” (or vary) with the energy of nuclear reaction (typically 0.5–1 percent variation for every 10-fold interaction energy change). Therefore, the average 3 percent recurring change in radioactive decay rate reported in the preprint corresponds with a minimum spike of a million-fold solar energy fluctuation on Earth. Needless to say, this kind of solar energy fluctuation is unrealistic. Consequently, using the weak coupling constant as an explanation for solar influence on decay rates is ruled out by default.
Instead, Jenkins and his team propose solar neutrinos (products of nuclear fusion) as the means to influence radioactive decay rates on Earth. In radioactive decay, specifically beta decay, a beta particle (electron emitted from the radioactive nucleus) and an anti-neutrino are emitted. According to the quantum field theory, every particle has an anti-particle. In this case, an anti-neutrino is the anti-particle of a neutrino. Neutrinos interact with matter at an extremely small probability. For this reason, it is highly unlikely that solar neutrinos would affect the decay rates of isotopes on Earth—making Jenkins’ proposal hard to believe. Putting this fact aside, based on a physics model called “crossing symmetry,” anti-neutrinos can, in principle, push the beta decay reaction backward while neutrinos push it forward. The Sun creates about 10,000 times more neutrinos by nuclear fusion than anti-neutrinos by nuclear fission. However, anti-neutrinos are closer to what Jenkins needs for the model.
Furthermore, even if crossing symmetry applies, it is uncertain whether the kinematics and ratio of solar neutrinos and anti-neutrinos will be accurate enough to produce the symmetric data pattern of decay rate fluctuation reported by Jenkins. In fact, Jenkins and his team attempted to verify the neutrino-mediated solar influence hypothesis, but their experiments came up short.
In summary, the problems with the idea of solar influence on decay rate are the following:
- Only some isotopes exhibit variable decay rates. According to the physics principle that causes variable decay rates, what influences some isotopes should influence all of them, not just a few. Therefore, it is an inconsistency.
- Almost all other experiments do not detect any variable decay rate.
- There is no known physics explanation for solar influence on nuclear decay rates; and though it does not necessarily mean the data is invalid, it does not provide an obvious reason to believe it.
Given all these points, it is sensible to suspect that the data reported by Jenkins was a “false alarm” created by subtle systematic errors.
In the end, we don’t have enough solid evidence of solar influence on nuclear decay rates. Rational logic tells us that the decay rates of isotopes 6,000 years ago could not be much faster than they are today. Currently, the world average for terrestrial background radiation is about 3 millisieverts per year. (1 sievert is equivalent to 1 joule of radiative energy delivered to 1 kilogram of mass.) If 5 billion years of Earth’s history is compacted into 10,000 years, the background radiation coming from radioactive decay of terrestrial isotopes must scale up accordingly for a consistent radioactive dating method of the oldest rock on Earth. As a rough estimate of this idea, in a young-earth model, Adam and Eve had to receive a 3×5,000,000,000/10,000=1,500,000 millisieverts dose of radiation. The lethal dose is 4,500 millisievert per year. This estimate infers that there was enough radiation in the Garden of Eden to nuke Adam and Eve more than 300 times, at least.
Given all these physics problems with the young-earth model, there doesn’t seem to be a strong enough theological incentive to warrant opposition of an old Earth. From my observation, when there is nothing left to say, young-earth creationists continue to fall back on the argument that God can do anything. But God will not do anything that contradicts his character or conflicts with his other work. Yes, he can do things quickly (e.g. the various signs and wonders in the Bible), but acting quickly may not always be in his ultimate plan. We see in the Bible that God took a long time to fulfill his promise of bringing the Messiah to Earth. Now, after almost 2,000 years, we are still waiting for the Messiah to return. There is enough biblical data to show that God doesn’t always finish things instantaneously. Creation could very well be one of those things that God took his time to complete.
Alfred Tang received his PhD in theoretical physics from the University of Wisconsin. He also serves as a postdoctoral researcher at Baylor University, The Chinese University of Hong Kong, and Kansas State University.