Progressive film-maker says he’s more optimistic than he’s ever been since Trump announced first run eight years ago

  • Melatonin@lemmy.dbzer0.com
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    3 个月前

    I’m willing to continue.

    When were these tests instituted? Was it the IAU?

    Is the last test referencing a specific size?

    Does Pluto have anything else in it’s orbit? The other objects of similar size… What would cause a “planet” to clear it vs. a non-planet?

    For example, suddenly there is another Saturn-sized object in Saturn’s orbit. What guarantee is there that Saturn would clear it? Might it not clear Saturn??? After all, it’s of similar size. Does this mean Saturn is not a planet?

    Real questions.

      • Melatonin@lemmy.dbzer0.com
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        3 个月前

        I’m not! I was really wondering like the physics of how an object is able to clear objects of similar size from its orbit.

        I could understand objects of smaller size, but I just don’t get how it does objects of the same size or similar size.

        • Semi-Hemi-Lemmygod@lemmy.world
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          3 个月前

          I am not an astrophysicist, but I imagine it happens during planetary formation. One center of mass gets big enough to disrupt smaller pieces of material, either pulling them into it or flinging them away. Eventually the debris in its sphere of influence gets (mostly) cleared out. Your hypothetical of Saturn just having a second planet in its orbit and clearing it out is not how it happened.

          And if you’re wondering what other object is in Pluto’s orbit, I’d just point to its binary partner Charon. It’s so massive that the center of gravity for the system is in space between the two.

            • Semi-Hemi-Lemmygod@lemmy.world
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              3 个月前

              No, the barycenter of the Earth-Luna system is 5,000km from the center of the Earth, or about 1,300 km down.

              The moon is also only about 1% of the mass of the Earth, which is huge compared to other moons in the solar system, while Charon is 11% the mass of Pluto.

              Edited to add: All of this is publicly available information, you could have googled it if you wanted to learn instead of argue.

              • Melatonin@lemmy.dbzer0.com
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                3 个月前

                Did Google, didn’t understand.

                It’s cool my friend, I didn’t mean to bother you. You go out and have a good time from here on.