cross-posted from: https://feddit.org/post/1104168
Technically everything with mass creates its own gravitational field; most things just aren’t massive enough for it to be detectable.
One of my favorite science facts: Because of how the strength of gravity diminishes as you get further away and stronger as you get closer, when you approach to within arms length of another person (approx 1m) the gravitational attraction between the two masses of your bodies can exceed the gravitational attraction between your body and the sun at any given time.
Another fun property of the inverse square law is that an infinite sheet of mass produces a gravitational field that is equally strong no matter how far you are from it.
It applies to any form of flux, like sound amplitude or light intensity.
This is why when you’re sitting on top of Mount Sanitas, you can hear traffic sounds at seemingly full volume. It’s just all the traffic of Boulder, which is roughly like an infinite sheet below you.
This is despite being unable to hear any given car more than a couple blocks away.
It’s also why if Superman flies over manhattan at night, he’s lit from underneath with an amount of light similar to someone who’s 10 feet from a skyscraper.
