What is gravity? - eviltoast
  • Dr. Coomer@lemmy.world
    link
    fedilink
    English
    arrow-up
    29
    ·
    1 year ago

    Genuinely we can’t tell what it is. We once thought it was just a normal pull due to mass until Einstein proved us wrong during a solar eclipse where we could see stars that shouldn’t be visible from our current position in orbit. Then we get into how it works, WHICH THERE IS NO TELLING AS THERE ARE TO MANY GOD DAMNED VARIABLES INVOLVED.

    • theangryseal@lemmy.world
      link
      fedilink
      English
      arrow-up
      6
      arrow-down
      1
      ·
      1 year ago

      You’re fucking with me, right?

      Stars were visible that shouldn’t have been visible?

      What am I missing?

      • neryam@lemmy.world
        link
        fedilink
        English
        arrow-up
        25
        ·
        1 year ago

        Stars that were behind the sun (within the radius of the sun, geometrically speaking) were visible due to gravitational lensing

          • Classy@sh.itjust.works
            link
            fedilink
            English
            arrow-up
            9
            ·
            1 year ago

            It isn’t directly analogous because one is gravitational and the other is not, but if you’ve ever watched a ship sail beyond the horizon, sometimes you can see a reflection of the sail after it is no longer in direct sight, because the way that light can reflect around the curvature of the earth. It’s a pretty crazy phenomenon.

            https://en.m.wikipedia.org/wiki/Mirage#Superior_mirage

            In the case of the OP, as light from distant stars approach the sun, some of their light that may normally have passed to the side of the sun and beyond the earth, thus rendering them invisible, are instead ‘bent’ back towards the earth by the sun’s gravitational well. But since the sun is so luminous we normally cannot see those stars. If the sun were somehow dark we would see a collection of tiny, distorted stars around the perimeter of it.

            To metaphorize: imagine a ball rolling straight from a point directly in front of you, but at an angle such that it won’t roll to you. Now imagine a dip in the ground, not deep enough to cause it to fall in and not escape, but enough to cause the ball to curve as it rolls, sending it to you instead. The sun acts in a similar manner on light.

            • deadbeef79000@lemmy.nz
              link
              fedilink
              English
              arrow-up
              6
              ·
              edit-2
              1 year ago

              An analogy I’ve used with my children.

              Sit in the middle of our trampoline. Roll a ball in a straight line beside you. Watch it roll around you and fall into the depression you make in the trampoline surface.

              This is a primitive 2 dimensional simulation of gravity.

              The ball “thinks” the surface is a flat plane, as far it knows it’s rolling in a straight line.

              You are the heavy object curving space(time). Your eyes are a higher (3rd) dimensional observer and can see the curvature and it’s effect on the ball.

              If you roll them ball fast enough, it curves slightly and then escapes your “gravity well”. It has changed course slightly. This the gravitational lensing simulation.

          • Krauerking@lemy.lol
            link
            fedilink
            English
            arrow-up
            7
            ·
            1 year ago

            Yeah it sounds silly but like it’s a weird thing to see stars that are literally behind another object because it weighs enough and it’s a interesting story for Einstein who has a moment discovering it.

          • AssholeDestroyer@lemmy.ml
            link
            fedilink
            English
            arrow-up
            3
            ·
            1 year ago

            The James Web Space Telescope’s Instagram page posted the phenomenon recently. Gravity from nearby galaxies magnifies space near them, allowing the telescope to see incredibly far away galaxies.

          • FarceMultiplier@lemmy.ca
            link
            fedilink
            English
            arrow-up
            2
            ·
            1 year ago

            If you really want to be messed up, absolutely nothing is where we think it is because gravitational lensing affects the light of every object in the universe, while we observe. The further away it is, the more light is warped by the masses along the path, and we can’t know what those many masses are or where they are either.

            Our observability of the universe is a guessing game as large as the universe, and there is no conceivable model to assess it all and the interrelations between…everything.

            • theangryseal@lemmy.world
              link
              fedilink
              English
              arrow-up
              1
              ·
              1 year ago

              Now this is something that I knew absolutely nothing about, but I feel like it should have occurred to me with what I did know.

              Thank you.