Mar 17, 2009: Roundest Thing, Evah

[xoxoxoBruce]

Wolf came up with this item. It's a ball of fused quartz, and the most perfectly spherical object ever made by man.

It’s only the size of a ping pong ball, but its surfaces are so smooth that were it blown up to the size of Earth, the tallest mountain would be only eight feet high.

Actually it's one of four.
Four? I'll buy making one to, you know, see if you can, but making four means they must have a use for them.
Yes, they go in a space probe.

Not the kind of space probe they used on Burt Campbell.


They're used in "Gravity Probe B", which has been up there a couple years now.

Einstein's theory of General Relativity predicts that Earth, by rotating, twists space and time around with it, forming a mild vortex in the fabric of spacetime around our planet. Researchers call this "frame dragging." Most physicists believe the spacetime vortex is real, but no experiment to date has been sensitive enough to detect it unequivocally.

Enter Gravity Probe B.

They've wanted to test this since the 50s, but nobody had the balls.

It was originally proposed 47 years ago (!!) — but was delayed for decades waiting for funding, waiting for the shuttles to be built to get it aloft, then discovering that, whoops, the shuttles couldn’t actually handle that sort of payload, then designing a rocket to finally get it aloft. They also had wait for all manner of engineering breakthroughs to make those spheres. But what a metaphorically lovely finale: The most perfectly round objects ever made by humanity, flying through the void on one of the purest scientific quests ever.

The whole complicated story can be found here, and here, where they explain all about the Gravity Probe B project...


EXCEPT, how they made the damn balls.