The most perfect sphere ever made tests Einstein's theories

This is a refraction of an image of Einstein in the most perfect sphere ever made. The flaws on this quartz sphere are no bigger than forty atoms. It, and other spheres like it, have been sent to space to test out a couple of Einstein's ideas.

These near-perfect spheres are going to be sent to space to demonstrate the geodetic effect. They are going to be spun around until they're turning like little round gyroscopes. Anyone who has played with a gyroscope has noticed that it when the wheel is spun fast enough, the central pillar always points in the same direction. You can nudge the gyroscope to the left or right on the floor, but it will keep standing up straight instead of tipping.

But you're nudging it on a flat floor. And although anything orbiting the Earth seems like it's orbiting on a flat plane, Einstein showed that the Earth's huge mass slightly warps spacetime. The gyroscope is actually moving across a curved surface, and so its central pillar — the central axis — will tip slightly as it travels across a warped plane. That's the geodetic effect. The purpose of sending these perfect, spinning spheres up into space is to see how their axis tips as they move around the curved spacetime. There's a video explaining the effect that you can watch here.

Via Physics Central.