> what does the mass of an entire mountain condensed into a single pebble mean I find it easier to comprehend in the subatomic context, picturing the space bet

> what does the mass of an entire mountain condensed into a single pebble mean I find it easier to comprehend in the subatomic context, picturing the space between particles like the space between stars and planets on the cosmic scale. Mash all the stars and planets together in, say, our solar system, and the entire solar system would only be about the size of the sun. Then repeat that for all the solar systems in the Milky Way, and the entire Milky Way would only be about the size of the black hole at the center. Relatively, of course!