Our steady sun: a problem for billions of years
All living things on the earth ultimately obtain their energy from the sun, as do the wind and water cycles. And nuclear reactions power the sun. In theory, as its nuclear fuel ‘burns’ up, the sun’s core should shrink, and this would make the reactions occur more readily. Therefore, the sun should shine more brightly as it ages (see panel below).
But this means that if billions of years were true, the sun would have been much fainter in the past. However, there is no evidence that the sun was fainter at any time in the earth’s history. Astronomers call this the ‘faint young sun paradox’, but it is no paradox at all if the sun is only as old as the Bible says—about 6,000 years.
Evolutionists and long-agers believe that life appeared on the earth about 3.8 billion years ago. But if that timescale were true, the sun would be 25% brighter today than it was back then. This implies that the earth would have been frozen at an average temperature of –3ºC. However, most paleontologists believe that, if anything, the earth was warmer in the past.1 The only way around this is to make arbitrary and unrealistic assumptions of a far greater greenhouse effect at that time than exists today,2 with about 1,000 times more CO2 in the atmosphere than there is today.3
The scientific evidence is consistent with the sun having the age that we would expect from a straightforward reading of the Bible. In 6,000 years or so, there would have been no significant increase in energy output from the sun. It is a problem only for old-age ideas.
Why is the sun getting hotter?
Stars obtain their energy from nuclear fusion, a process in which several small, extremely-fast-moving atomic nuclei join to form a single larger nucleus (the nucleus, plural nuclei, is the tiny positively charged part of the atom that has nearly all the mass). In this process, some mass is lost and converted into a huge amount of energy, as per Einstein’s famous formula, E = mc2. In the sun, 4 million tonnes of matter are converted into energy every second—this is huge, but negligible compared to the sun’s enormous total mass of 1.99x1027 (1,990,000,000,000,000,000,000,000,000) tonnes.
Fusion in stars generally combines four hydrogen nuclei into one helium nucleus.1 Thus, the sun is like a huge hydrogen bomb.2 Fusion produces a vast number of extremely low-mass particles called neutrinos.3 These ghostly particles could go through light years of solid lead. They are now known to switch between ‘flavours’ (types).4
A large, heavy nucleus (such as helium) takes up much less room than four small nuclei (such as hydrogen), so there is a lot more mass in a given volume, i.e. greater density.5 So, as the sun ‘burns’ hydrogen in the core, it contracts. The higher pressure and temperature then make fusion easier, so the core will heat further. Therefore, over billions of years the sun should become much brighter.
References and notes
- Four hydrogen atoms (mass = 1.008) convert to helium (mass 4.0039) losing 0.0281 atomic mass units (1 AMU = 1.66 x 10–27 kg), releasing 4.2 x 10–12 joules of energy.
- Man-made hydrogen bombs use the heavy hydrogen isotopes deuterium and tritium, plus some lithium. The sun uses mainly ordinary hydrogen, which is much harder to fuse, which is a good thing because it means the sun burns steadily. Deuterium is a hard-to-form intermediate step and thus controls the fusion rate in the sun; H-bombs skip this step by starting with deuterium.
- The complete fusion reaction is 4 1H –> 4He + 2e+ + 2νe, where e+ is a positron or antielectron, and νe is an electron-neutrino.
- Before this neutrino oscillation was demonstrated, this was a huge problem for the fusion theory and thus for billions of years. Theoretical physicists taught that neutrinos had precisely zero rest-mass, which would make oscillation impossible. However, in 2001, oscillation was detected, so the theorists were proven wrong. See Newton, R., Missing neutrinos found! No longer an ‘age’ indicator, TJ 16(3):123–125, 2002.
- Evolutionists assume that the sun’s core has 4.5 billion years’ worth of helium, but this has not been directly observed. In any case, even if there was a large amount of helium, the record shows that the sun was never faint. Rather, if the core contained lots of helium it would be a design feature so that the sun would be hot enough. It may also be responsible for the sun’s exceptional stability compared to that of other stars of the same spectral class—see Sarfati, J., The sun: our special star, Creation 22(1):27–30, 1999. Actually, long-agers don’t directly measure the age of the sun at all. Rather, they infer it from the radiometric dating of meteorites, which has its own problems, as we have shown repeatedly—see Q&A: Radiometric dating.
References and notes
- Faulkner, D., The young faint sun paradox and the age of the solar system, TJ 15(2):3–4, 2001.
- As leading day-age defender Hugh Ross does in: The Faint Sun Paradox, Facts for Faith 10, 2002.
- However, analyses of acritarchs (eukaryotic algal microfossils) ‘dated’ to 1.4 billion years ago, when the sun would have been only 88% as bright as today, provide evidence for only 10–200 times today’s level of CO2. Still, the researchers continue to hope that this would have compensated for the fainter sun. Kaufman, A. and Xiao, S., High CO2 levels in the Proterozoic atmosphere estimated from analyses of individual microfossils, Nature 425(6955):279–282, 18 September 2003; comment by Mojzsis, S.J., Probing early atmospheres, same issue, pp. 249–251.
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