Caledonian, quantum mechanics may limit the sensitivity and discrimination of our observations. Also, if gravity’s so weak on the atomic level in the pebble that its effects would cause a shift in the arrangement of the atoms smaller than the Planck length, it’s not even clear that such a shift exists at all, or what meaning it has.
Julian, I suggested that a very different gravity law might be compatible with the existence of a pebble, not no gravity at all.
In fact, all kinds of things might be different about the laws of physics and the pebble could still exist. E.g. the second Newton’s law could be wrong (look up MOND), which would change the story on galaxies in a big way, but not affect the pebble at all.
It seems plausible that a small familiar object like a pebble already has all the fundamental physical laws baked into it, so to speak, and that these laws could be deduced from its structure. But it isn’t true. It’s easy to overestimate how entangled the tangled web is, too.
Caledonian, quantum mechanics may limit the sensitivity and discrimination of our observations. Also, if gravity’s so weak on the atomic level in the pebble that its effects would cause a shift in the arrangement of the atoms smaller than the Planck length, it’s not even clear that such a shift exists at all, or what meaning it has.
Julian, I suggested that a very different gravity law might be compatible with the existence of a pebble, not no gravity at all.
In fact, all kinds of things might be different about the laws of physics and the pebble could still exist. E.g. the second Newton’s law could be wrong (look up MOND), which would change the story on galaxies in a big way, but not affect the pebble at all.
It seems plausible that a small familiar object like a pebble already has all the fundamental physical laws baked into it, so to speak, and that these laws could be deduced from its structure. But it isn’t true. It’s easy to overestimate how entangled the tangled web is, too.