Variable radioactive decay rates and the changes in solar activity

NASA decay-rates
Figure 1. NASA SDO satellite image (AIA 131) of an X6.9 flare on 9 August 2011.


Recent research by physicists has suggested that there is some correlation between changes in solar activity and radioactive decay rates. Jere Jenkins and Ephraim Fischbach (from Purdue University, Indiana), for instance, have found that there appears to be a correlation between the radioactive decay rate of 32Si and 226Ra on the earth and changes relating to the sun’s activity. This is an important area of research for those who question the constancy of radioactive decay rates, and such variable decay rates may have a bearing upon our understanding of the dating of various rock layers.1

The growing evidence

Discrepancies in the radioactive decay of 32Si and 226Ra on the earth’s surface seem to show a degree of correlation with the annual cycle of the earth’s orbit around the sun; that is between aphelion and perihelion with rates speeding up as the earth gets closer to the sun and decreasing as it moves away (data was gathered by the Brookhaven National Laboratory for the beta decay of 32Si and the Physikalisch-Technische-Bundesandstalt in Germany for the alpha decay of 226Ra).2 The 32Si data was supplied by David Alburger, who had observed anomalies in the decay rate of this isotope through work carried out in 1986. The decay rate seem to be fastest in January–February with a low point in July–August.3 This seems to correlate with a small time lag, or phase shift, between the distance between the sun and earth, and is as yet unexplained. Of course the changes observed in decay rates is small, perhaps of the order of less than 1 percent over the annual cycle, but then any changes in the distance from Earth to the sun is also relatively small.

In another study a sample of 54Mn was found to vary with the occurrence of a significant X-ray solar flare (level X3) and a high-energy solar proton storm (raised flux levels at > 10 MeV protons) on 13 December 2006, and a similar correlation was seen in relation to a weaker X-ray flare on 17 December 2006.4 Furthermore, with the 13 December event the variation in decay rates began to change some 36 to 40 hours prior to the X-ray flare. However, it is noteworthy that the observed decay rate seems to have reduced with the flare, whereas the decay rate in the previous findings increased with closer proximity to the sun, as Barry Setterfield for instance has pointed out.5 The authors suggest that it is unlikely that instrument error is the cause of the differences.

Peter Sturrock of Stanford University has also found that there is evidence of a correlation with the 33-day period spin of the solar core and decay rates of 32Si and 36Cl.6 Sturrock points out that one side of the sun’s inner core emits neutrinos more strongly than the other, and from this accumulating evidence, he has proposed that changes in neutrino flux differences may have some impact upon the rate at which some radioactive isotopes decay. However, this is controversial because neutrinos are notoriously unreactive and difficult to detect, and decay rates are supposed to be unresponsive to change as Jenkins points out.

Why would something apparently so weak affect something so stable? In later work, Fischbach, Jenkins, and Sturrock proposed the existence of a new particle called the neutrello, which in many respects is the same as the neutrino, but differs in its ability to interact with radionuclei.7 Setterfield also points out that if neutrino flux density is the cause then that should have shown up in the decay rates of radioactive material onboard various space probes that have traversed into lower and higher orbits.5

Therefore neutrinos would not be the obvious candidate for a causal link.2,4

Further discussion

Jenkins and Fischbach have discounted geo-magnetic disturbances as a possibility due to lack of correlation, although they have not considered the fact that the solar event of 13 December 2006 also led to a ground-level neutron event (GLE) that may have led to changes in the decay rate of their sample.8 Very high-energy solar proton storms (with raised flux levels at > 100 MeV proton energy level) may increase the background count of neutrons at ground level as secondary products, particularly in high latitudes.

However, these events are relatively short-lived, a matter of a few hours, compared to the length of anomaly found in Jenkins and Fischbach’s study, and it occurred after the decrease in decay rates had begun. A related possibility is the effect of a Forbush decrease on radioactive decay rates. The increase in the high-energy solar proton flux acts in opposition to the flow of cosmic gamma rays, but again the observed decrease in decay rates happened prior to the start of the proton storm. Instead, if there is a correlation it might tie in with the developing sunspot’s magnetic complexity, the tension of which builds up prior to the release of a coronal mass ejection and emission of X-ray flares and associated high-energy proton storms. But as the research suggests, there seems to be changes taking place on or within the sun that precede the flare.

An alternative explanation, however, might be related to differences in the scalar energy field density in the vacuum of space (sometimes called zero point energy or the cosmological constant and observed as the Casimir effect—also related to theories of quantum gravity). The zero point energy is the energy left over in a thermodynamic system when it is reduced to absolute zero (it is equal to ½ hf, where f is the frequency and h is Planck’s Constant). Barrow and Shaw for instance have proposed that the sun’s mass may modify this scalar field ϕ and that changes in the gradient of the field might be the cause of the annual variation in radioactive decay rates of isotopes on earth, as the radius of the earth’s orbit varies in distance over the year. Their proposal is that the electromagnetic fine-structure constant αEM is in fact sensitive to changes in the scalar field, and so affects alpha and beta decay rates.9 However, Jenkins and Fischbach doubt whether variations in the fine-structure constant alone are large enough to account for their findings, although they suggest coupling from two different scalar fields to αEM and to the electron-proton ratio Me/Mp may have a larger impact upon decay rates. Setterfield also favours an explanation involving changes in the density of the zero point energy field that exists in the vacuum of space. He has suggested that the movement of the solar system as a whole through space against this field, and the earth’s motion relative to this, might help to explain the phase shift between the aphelion-perihelion cycle and the variation in radioactive decay rates.

The rate of change found so far is, however, really quite small, and not of the order of magnitude that would immediately benefit creation science, although it does offer the possibility of fruitful future research, particularly the possibility of sensitivity between the fine-structure constant and radioactive decay rates. If it is possible to find a way of accounting for larger disturbances in the scalar energy field, perhaps through amplification of longitudinal waves that modify its density, or constructive/destructive interference of separate waves forms in this field, then that might offer one possibility for accelerated or decelerated decay rates. Tentative possibilities might be related to gravity waves or the shock wave from a supernova explosion for instance.


This recent work provides a glimpse into an area of research that may provide fruitful outcomes for those with an interest in creation science, particularly the variability of radioactive decay rates. Although at present the identified size of changes are quite small, there are perhaps early observational indications that larger changes in decay rates are possible. Future theoretical and observational research may uncover such possibilities. Solutions involving neutrinos do not appear to offer sufficient energetic interaction to be credible, although further research will shed light on this. However, research into the effect of scalar energy fields may offer another way forward. This may also help provide an explanation for rates of helium diffusion and the production of radio-haloes found in zircon crystals, the radioactive decay rate of which is discussed by the RATE team.10

References and notes

  1. Thomas, B., The sun Alters Radioactive Decay Rates, ICR, 3 September 2010,, accessed 19 January 2013. See also Rybka, T.W., Consequences of Time Dependent Nuclear Decay Indices on Half Lives, ICR Impact 106, 1982, Return to text.
  2. Jenkins, J.H., Fischbach, E., Buncher, J.B., Gruenwald, J.T., Krause, D.E. and Mattes, J.J., Evidence for correlations between nuclear decay rates and earth–sun distance, Astro. Part. Phys. 32:42–46, 2009, DOI 10.1016/j.astropartphys.2009.05.004. Return to text.
  3. Mullins, J., Solar ghosts may haunt earth’s radioactive atoms, New Scientist 2714:42–45, 2009; Return to text.
  4. Jenkins, J.H. and Fischbach, E., Perturbation of nuclear decay rates during the solar flare of 13 December 2006, Astro. Part. Phys. 31:407–411, 2009, DOI:10.1016/j.astropartphys.2009.04.005. Return to text.
  5. See: Setterfield, B., Radio Active Decay Rates and the sun (n.d.), Return to text.
  6. Stober, D., The strange case of solar flares and radioactive elements, Stanford Report, Posted on on 23 August 2010,, accessed 25 August 2010. Return to text.
  7. Fischbach, E., Jenkins, J.H. and Sturrock, P.A., Evidence for time-varying nuclear decay rates: experimental results and their implications for new physics, arXiv preprint arXiv:1106.1470, 2011. Return to text.
  8. See for instance, Mavromichalaki, H., Papaioannou, A., Gerontidou, M., Daglis, I., Anastasiadis,A., Sandberg, I., Tziotziou, K., Panagopoulos., I, Nieminen, P., Glover, A. and Uhler, P.B., Solar particle event analysis using the esa standard radiation environment monitor and the worldwide neutron monitor network, Proceedings of the 31st ICRC, Lodz, Poland, 2009; Return to text.
  9. Barrow, J.D. and Shaw, D.J., arXiv:0806.4317v1 [hep-ph], 2008; Shaw, D.J., arXiv:gr-qc/0702090v1, 2007; Uzan, J., Rev. Mod. Phys. 75:403, 2003. This also seems to be Barry Setterfield’s view. Return to text.
  10. Humphreys, D.R., Young helium diffusion age of zircons supports accelerated nuclear decay; in: Vardiman, L. et al. (Eds.), RATE II: Radioisotopes and the Age of The Earth: Results of a Young-Earth Creationist Research Initiative, vol. II, Institute for Creation Research and the Creation Research Society, San Diego, CA, 2005. Return to text.

Helpful Resources

Reader’s comments

Rachel L.
Thank you for this article. I will use it on my debate with my Professor this Friday regarding the reliability of radiometric dating.
Dan R.

I believe that the observed apparent acceleration may have been an artifact of the detection method.

"Scientists of the Physikalisch-Technische Bundesanstalt have now carried out new measurements and have published their results in the journal "Astroparticle Physics". For three years, they checked the activity of samples with 36Cl in order to detect possible seasonal dependencies. Whereas the US-Americans had determined the count rates with gas detectors, PTB used the so-called TDCR liquid scintillation method which largely compensates disturbing influences on the measurements. The result: The measurement results of PTB clearly show fewer variations and do not indicate any seasonal dependence or the influence of solar neutrinos.

See: [Link to article on article published on 10 October 2014 entitled "Old textbook knowledge reconfirmed: Decay rates of radioactive substances are constant" removed as per feedback rules]
Tas Walker
See comment by Joe C. above, and response.
Robert B.
The notion of radioactive decay being merely a function of time; such that unstable nuclei just mark time until the quantum flux gives them a sufficient nudge, always seemed counter intuitive to me. Data that points to the neutrino flux as having a possibly major role promises a measure of personal vindication for me.

I'd like to offer a possible mechanism for a trillion-fold greater neutrino flux than that now observed. That is from the localized bubble of slower time within a cosmology like Russell Humphreys'. If the Earth and solar system were surrounded by enough mass to create the time differential that Humphreys proposed (be it water, plasma, hyper-matter or whatever type fluid), that shell of matter would protect the Earth from all radiation except neutrinos.

Whether God moved this mass away within the creation week or at the time of Noah's flood would be the subject of even more speculation, but lending plausibility to all this is the evidence that there is dark matter totaling in excess of one million solar masses in close proximity to the solar system.
Russ Humphreys
Dear Robert B.:

Though I’m not the author of the article you’re responding to, CMI asked me to respond, perhaps because you mention my cosmology. It’s good that you’re seeking a reason for the apparently-observed annual variation in some nuclear decay rates. However, I wouldn’t look directly to my cosmology for the answer.

First, Scripture (Genesis 1 & Psalm 148:3–4) imply fairly clearly that the waters above the heavens are, and were, far out beyond the stars and galaxies, not close by the Solar System (where we don’t see any such waters presently). I don’t know of any evidence at all for lots of dark matter being anywhere close to the Solar System.

Second, we wouldn’t need any shielding from even a trillion times more neutrinos than we have now; I doubt we’d even notice. As the article points out, neutrinos are not a good answer; they just interact far too weakly, most of them going through the whole earth without interacting with a single nucleus.

Seeking other explanations,

Russ Humphreys
Joe C.
Have you seen this study [Link to article on published on 10 October 2014 entitled "Old textbook knowledge reconfirmed: Decay rates of radioactive substances are constant" removed as per feedback rules] that claims to measure constant decay rates throughout the year? I admit I don't understand the difference between the measurement methods.
Andrew Sibley
The paper by Kossert and Nahle suggests the seasonal correlation is based upon instrument anomalies due to weather and not sun-earth distance. This is an interesting observation. However, other claims, discussed in my paper above, relating the impact on radioactive decay rates to the time of solar flares, or the 33 day cycle of the solar core I would suggest may still need other explanations. This is an on-going area of research and I am sure we haven’t heard the last word on this.
Michael D T.
We are all aware that, in the cores of nuclear reactors, and when atomic bombs are detonated, nuclear decay rates change very significantly.
If decay rates were truly constant, neither of these things would work.
Jim Mason
Nuclear fission (atomic reactors, atomic bombs) and nuclear fusion (hydrogen bombs, stars) are different sorts of reactions than alpha, beta and gamma decay. The former are induced whereas the latter are spontaneous. So in reactors and bombs it is not a decay rate that is changing.

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