sun_structure_cutaway_cooling.html

    Caption: The structure of Sun shown in a diagram with a cutaway.

    Features:

    1. For a full description of this diagram, see sun_structure_cutaway.html.

    2. Since the Sun is emitting electromagnetic radiation (EMR) continuously, it would cool off relatively rapidly if heat energy (properly internal energy) weren't continually being resupplied.

    3. The cooling off time is long by the time scale of human existence---about 2 Myr to end life on Earth--see, e.g., If fusion in the Sun suddenly stopped, what would happen?---see also Lord Kelvin's (1824--1907) estimated Sun's cooling time since the formation Formation of the Solar System of ∼ 20 Myr (Wikipedia: Lord Kelvin: Age of the Earth: geology and theology")---but short by the geological time scale---the age of the Earth = 4.54(5) Gyr known accurately/precisely from radioactive dating ---and scale of cosmic time---the age of the universe = 13.799(21) Gyr known from the concordance model which at present seems a pretty good cosmological model and fits all observations quite well.

    Credit/Permission: © User:Kelvinsong, 2012 / Creative Commons CC BY-SA 3.0.
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