Helmholtz's contraction theory says the sun is young

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Contents 1 Claim 2 Source 3 Responses 4 Fallacies contained in this claim 5 External Links 6 Related claims 7 Acknowledgments

Claim

Helmholtz proposed that the sun's energy comes from gravitational contraction. Under this theory, the sun could not be more than about 20 million years old.

Source

• Akridge, Russell, 1980 (Apr.), The Sun is Shrinking. Impact 82. [1]

Responses

1. This theory has been replaced with the alternative theory of nuclear fusion which has successfully related stellar mass, temperature and luminosity.
2. Astronomers have not discovered lower limits for long-term solar contraction that would be sufficient to produce observed temperatures.
3. Helmholtz contraction fails to explain cyclical variations observed in stars.
4. Sustained nuclear fusion can be predicted a priori given knowledge of the sun's mass and temperature.
5. The claim is correct, as far as it goes. It is Helmholtz's proposal that was wrong. Thus, the claim is obsolete.
6. add more responses

Fallacies contained in this claim

• add fallacies

External Links

• Johansson, Sverker, 1998. The Solar FAQ. [2]

Related claims

• Shrinking sun indicates a young sun

Acknowledgments