A Simple Experiment That (Finally) Explains Just What Gravity Is

What is gravity? It's one of the easiest scientific concepts to understand the effects of, and one of the hardest concepts to understand by itself. Here — using a large sheet of spandex, some marbles, and a couple weights — is a demonstration that makes the entire concept remarkably graspable.


Commenter EtruscanRaider pointed us to the video in this thread on ways to explain some of the most mind-bendingly complex scientific concepts.

In the video, physics teacher Dan Burns explains how to set up and use the visualization, starting with putting up a single large sheet of spandex (or, as Burns calls it, "space-time"), and then using a combination of weights and marbles to explain everything from gravity's basic mechanics to how gravity lets us plot return trajectories from the moon.

Want to try building a gravity visualizer of your own? There are instructions right here.


Obligatory XKCD: