Since I write mostly about technology issues, I was struck by this description of how the body as a machine works.

The human body is a purpose-built machine, designed for the one-G environment of Earth. Take us into the zero-G of space or the 0.38 G of Mars and it all comes unsprung. Bones get brittle, eyeballs lose their shape, hearts beat less efficiently since they no longer have to pump against gravity, and balance goes awry.

Jeffrey Kluger, in TIME – story about Mark and Scott Kelley. The latter astronaut will spend one year on the International Space Station.

We take gravity so much for granted, don’t we?