• @[email protected]
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    21 day ago

    And Jupiter would have an event horizon 2.8m across and last about 10^67 years (still not forever)

    • @AdrianTheFrog
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      223 hours ago

      Does the energy of light entering the black hole make it last longer?

      • @[email protected]
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        120 hours ago

        I’m not an astrophysicist, but since general relativity says matter and energy are related and light can’t escape if it crosses the event horizon it would add to the black hole

        But a 3m sphere at Jupiter’s distance from the sun wouldn’t catch much mass equivalent light from the sun

        • @AdrianTheFrog
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          19 hours ago

          Yeah, but it does have 10^67 years to catch it.

          Assuming the light isn’t bending at all, I think it should get about 890 watts of light, or 2.8x10^10 joules per year (or 3.1x10^-7 kg per year?) from the sun, which should be enough to cause it to grow, at least while the sun is still around. I expect it would get a lot more mass from gasses, meteors, and dust in that time frame. Based on your numbers above I think it should only be losing like 2x10^-40 kg per year if it was losing mass at a constant rate.

          There’s only about 50 watts per square meter out that far from the sun! We get about 1300 here on Earth. Jupiter’s orbit is a lot larger compared to Earth’s than people normally think.

          • @[email protected]
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            117 hours ago

            The radius collecting will be pirr, r=2.8/2

            3.14 * 1.4^2 (using a calc for precision) = 6.1m^2

            34 to 41 W/m^2 = 207 to 250W

            How did you get 800W? Diameter instead of radius?