#### Sunday, 19 August, 2001

### Bending Spacetime in the Basement

Most of us take gravity for granted: stuff falls. In high school physics we learn about the universality of gravitation--all objects attract all others--but because gravity is such a weak force we can't readily see the gravitational effects between small objects. Or so I thought. I was cruising the Web the other day and ran across a very cool site called Formilab, on which I found a page titled *Bending Spacetime in the Basement*. The third paragraph explains the title.

This page has a reasonably good discussion of the gravitational force, and introduces an experiment that you can perform at home to demonstrate the gravitational attraction between two small objects. The author also poses an interesting question: could Archimedes have discovered the universal nature of gravitation 1,900 years before Newton published his *Philosophi naturalis principia mathematica*? After pointing out the information available to Archimedes at the time, the author states: "It seems plausible, then, given the knowledge at hand and a chain of inference which, in retrospect at least, appears straightforward, that Archimedes could have suspected the universality of gravitation." He then demonstrates how Archimedes might have proven such a theory using materials that were available to him. It's an interesting speculation: how would history have unfolded if Archimedes had done this?