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Name: Sam
Status: Other
Age: 50s
Location: N/A
Country: N/A
Date: N/A 

Is the temperature of the center of the Earth cooling? It would seem that the temperature of the core at several thousand degrees would lose heat to space over time. Even considering the mass of the Earth, the long time that the Earth has had to cool would have been sufficient to reduce the temperature. Just being under tremendous gravitation pressure would not, in itself, generate heat if the pressure were static? Your input would be appreciated.

The earth would have cooled to an icy cinder many years ago were it not for the decay of radioactive nuclei (principally uranium 238, thorium 232, and potassium 40). Of course, the amounts of these heat-generating nuclei have decayed over time, so their consequent heat output has also fallen. Unless there is some other source of energy in the earth's core that is not accounted for, the temperature MUST be lower than in the past.

Richard E. Barrans Jr., Ph.D.
Assistant Director
PG Research Foundation, Darien, Illinois

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