Monday, January 22, 2024
how to make something heavier.
I have always liked thinking about how you get a swing to go, without any external pushes. A dynamic not a static issue. And also the eqivalent problem of trying to balance while putting your sock on. Basically in practice, if you don't move your foot you are going to fall over. Fundamentally you have to split in two parts, one part rotates, and the other falls freely in gravity, and then you rejoin the parts. They only seem like different because one is stable and safe, and the other is unstable and unsafe.
But it made me wonder if you could just miraculously change the mass. And to my surprise you can do this without altering the structure. Now beware the problems of expressing the situation clearly. Just jiggle or rotate something! These atoms are now moving faster, and energy has mass. You can change the centre of gravity, by importing or exporting energy. A hotter body is heavier than a colder body. A spinning object is heavier than a stationary object.
You will still fall over unless you move you foot.
M
