If I cut a thing in two, are the two pieces together exactly the same size as the original?

Or to rephrase it: does a knife/scissors/etc just split something or does it remove something?

  • givesomefucks@lemmy.world
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    21 hours ago

    Or to rephrase it: does a knife/scissors/etc just split something or does it remove something?

    So, solids aren’t really solid. Like, at an atomic level no two molecules are actually touching. Think of it like a magnet floating above another.

    What you cut it with matters too, something insanely sharp like a medical grade obsidian blade wieled with skill is so sharp, it’s just going to separate the molecules. And remove very little material.

    Try to cut a piece of paper in half with a baseball bat, and lot of material won’t be attached to either of the two biggest pieces. Because it’s a big blunt object.

    • rockerface🇺🇦@lemmy.cafe
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      17 hours ago

      But also, because some of the bonds between atoms/molecules were broken, some of the energy was lost. And energy is mass, so you can lose mass even if all the particles are still on either piece.

      • givesomefucks@lemmy.world
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        16 hours ago

        atoms/molecules

        Two completely different things, on a molecular level that could just be stored potential energy. Like when a mousetrap is set or not, it doesn’t change it’s weight.

        That’s how splitting atoms make atomic bombs there’s potential energy holding shit together, and we poke one to make it release which cause a giant chain reaction which adds up. Even then the “lost” mass is just blown up. I don’t think used my lease fuel gets substantially lighter for example.

        • rockerface🇺🇦@lemmy.cafe
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          16 hours ago

          Not bonds within atoms, bonds between atoms. Or molecules. That depends on the exact material being cut.

          And yeah, on a large scale it gets exploded, but on a scale of cutting paper with scissors it mostly gets lost as heat.