Tap for spoiler

The bowling ball isn’t falling to the earth faster. The higher perceived acceleration is due to the earth falling toward the bowling ball.

  • barsoap@lemm.ee
    link
    fedilink
    English
    arrow-up
    4
    arrow-down
    2
    ·
    edit-2
    18 days ago

    BUT earth will move with gM/m1

    No. Multiplication is associative, you can switch the masses around as you please, nowhere in the formula does it say “the greater mass” or “the smaller mass” you could just as well re-arrange the formula and come up with “earth moves with gm1/M”. Last but not least there’s only one force acting on both objects… and gM/m1 is neither a speed nor a force. G * 100kg / 20kg is 5G. Measured in Nm²/kg² which is the same we started with because the two kg cancel each other out.

    They both fall towards their shared centre of gravity. It’s this “the earth revolves around the sun” thing again, no it doesn’t, they both revolve around their shared centre of gravity (which, yes, is within the sun but still makes it wobble). That centre is very far away from the ball and very close to the earth and both are moving at the same speed towards it (because acceleration doesn’t depend on mass), blip to the next frame of the simulation now the centre of gravity moved towards the ball, next frame still closer to the ball, that is the reason both reach it at the same time, not because one is faster than the other.

    …or so it would be, if the shared centre of gravity of ball and earth wouldn’t lie within the earth so they don’t actually both reach it, the earth is in the way, the rest of the acceleration is turned into static friction: Because they both are still falling even when in contact. But really that complication only exists because they have volumes which is why I factored it out from the rest of the reasoning.

    • red@lemmy.zip
      link
      fedilink
      English
      arrow-up
      3
      arrow-down
      6
      ·
      edit-2
      18 days ago

      all that is only brain-rot statements with no technical meaning. lemme make this completly clear

      mf= mass of feather mb= mass of ball me= mass of earth ae=accelaration of earth fg=force experienced by both

      now in case of feather

      force on earth is what? yes thats fg =G.mf.me/r^2

      now thats the net force on earth, now what is newtons law? me.ae=G.mf.me/r^2

      we get ae=G.mf/r^2

      similarly in case of ball ae=G.mb/r^2

      and accelaration of earth is clearly more in case of ball, and yes this is accelaration in non inertial frame study newtons laws of motion again if you didnt know, so your second paragraph is utter nonsense

      instead of nonsense brainrot statements like 'Multiplication is associative, you can switch the masses around as you please, nowhere in the formula does it say “the greater mass” or “the smaller mass” you could just as well re-arrange the formula and come up with “earth moves with gm1/M” tell me where in equations you think i am wrong

      • barsoap@lemm.ee
        link
        fedilink
        English
        arrow-up
        4
        arrow-down
        5
        ·
        edit-2
        18 days ago

        It’s not nonsense when it makes people understand, buddy. And don’t get all “oh be technical” on me when you say things like “earth will move with <something with the same units as G>”. Something that’s definitely something, but not m/s.

        inertial frame

        I was talking about time-steps when I said frame. Hence “simulation”, and “one frame, then another, then another”, referencing successive moments in time.

        • red@lemmy.zip
          link
          fedilink
          English
          arrow-up
          2
          arrow-down
          5
          ·
          18 days ago

          yet another brain rot reply, man i am done,

          ““earth will move with <something with the same units as G>”. Something that’s definitely something, but not m/s” you idiot i was talking about accelwration, if you need units just put in dementions of all the variables, thats trivial stuff you dont understand nlm at all.

          second para is another non technical nonesense

          • barsoap@lemm.ee
            link
            fedilink
            English
            arrow-up
            3
            ·
            18 days ago

            you idiot i was talking about accelwration,

            Then why did you say “move” instead of “accelerate”. And the units don’t match acceleration, either. Best I can tell it’s some fraction of a term. If you want it to be an acceleration then you’re missing a squared distance, and if you want it to be acceleration, why are both mass terms in there.

            For someone who throws around things like “that’s non-technical brainrot” damn is your prose fuzzy.

            • red@lemmy.zip
              link
              fedilink
              English
              arrow-up
              1
              arrow-down
              2
              ·
              18 days ago

              tell me how Gm/r^2 dosent match acceleration, the fact that i wasted my time on low iq person like you

              • barsoap@lemm.ee
                link
                fedilink
                English
                arrow-up
                3
                ·
                edit-2
                18 days ago

                That’s not what you wrote, or at least not what I complained about. You wrote:

                BUT earth will move with gM/m1

                where it was previously established that m1 and M are masses, and I interpreted g to be G (Newton’s gravitational constant) instead of g as in “gravitational acceleration caused by earth” because… well, I’m not actually sure. The whole thing is already a mess of capitalisation but more importantly then it’d be acceleration, not movement, worse, the specific properties of the earth are included twice (once in g, then in one of the mass terms).

                the fact that i wasted my time on low iq person like you

                Maybe you should spend less time on insulting people and more on communicating your thoughts clearly.

                • red@lemmy.zip
                  link
                  fedilink
                  English
                  arrow-up
                  1
                  arrow-down
                  3
                  ·
                  edit-2
                  18 days ago

                  tell me how gM/m1 is not acceleration, what even is your point omg

                  • barsoap@lemm.ee
                    link
                    fedilink
                    English
                    arrow-up
                    2
                    ·
                    edit-2
                    18 days ago

                    You said it was movement, aka change in position over time, not acceleration, or you would have said “x will accelerate at”, not “earth will move at”. I already explained why it’s questionable as a term of acceleration.

                    And this could’ve been over after a single comment of you saying “oh, yeah, misspoke”. Your math in the comment after that misbegotten term checks out, that’s not the issue here, it’s your presentation that went all haywire.