• s@piefed.world
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    2 days ago

    It seems to fundamentally change what it means “to orbit” something.

    As I understood the term, orbiting would be used correctly in these cases:

    • A lighter object orbits a heavier object, and both of their paths of motion are elliptical about their barycenter

    • Two objects of identical mass orbit each other, and their paths of motion are circular about their barycenter

    In contrast, the image above implies the following:

    • A lighter object does not orbit a heavier object; they both orbit their barycenter with an elliptical path of motion

    • Two objects of identical mass do not orbit each other; they both orbit their barycenter with a circular path of motion

    Even the Wikipedia page for barycenter, which OP linked to, opens with the following:

    “the barycenter… is the center of mass of two or more bodies that orbit one another and is the point about which the bodies orbit.”

    Perhaps “orbit” as a verb has two meanings, depending on the specificity of the context.

    • bleistift2@sopuli.xyz
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      2 days ago

      I guess your conclusion is right. In situations where the barycenter of two (or more) objects is not sufficiently different from the center of mass of the heaviest object, we simplify the description by assuming that the barycenter and the center of mass of the heavier object are equal.

      Just because I’ve already edited it, here’s an animation of Earth orbiting the Earth–Moon barycenter:

    • mnemonicmonkeys@sh.itjust.works
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      2 days ago

      No, your earlier definitions are incorrect. All orbits happen around the barycenter. The only question is whether one of the bodies is large/massive enough that the barycenter is located within it

        • glitchdx@lemmy.world
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          2 days ago

          Just because a more accurate description exists, doesn’t mean that the less accurate description is fundamentally wrong. Depending on context, the less accurate description may be perfectly suitable for the subject at hand. If your priority is to be the most correct, then by all means go ahead and use the more accurate description.

          I think this logic applies to a lot of things.

          • s@piefed.world
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            2 days ago

            I take issue with how the meme says “Jupiter doesn’t orbit the Sun”, which rejects one valid and common way of using the verb “to orbit”.

            • flughoernchen@feddit.org
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              2 days ago

              It’s articulated as “it’s wrong”, while the message they’re trying to convey is more like “it’s not the entire truth”. The latter is hard to get across is a handful of words though, likely leaving more questions than answers. I believe they did a decent enough job that most of us can read the point between the lines.