Wednesday, May 4, 2011

Not quantum, but I couldn't resist.

General Relativity, the theory of gravity that has existed since the early 1900s has been exceptionally difficult to prove. Early in the 20th century, several of it's major predictions have been proven, but it has taken a while to prove it's most basic predictions.

General Relativity treats time and space as interwoven (ever hear the term, the fabric of space-time?) and describes gravity as the curvature of space time. It's a very complicated and sophisticated theory - much too difficult for me to explain in detail.

Gravity Probe B, a NASA project to test General relativity was sent into orbit to measure the unconfirmed effects of GR. These were the geodetic effect (how objects curve space-time), and the frame dragging effect (essentially, the motion of an object around a rotating gravitating object is different than predicted by Newtonian gravity). Well, the geodetic effect was confirmed to an uncertainty of less than 0.5% in 2008, but what about the frame dragging effect? This effect is TINY, and requires extremely precise instrumentation. Well, NASA just released results that confirm the frame dragging effect to an uncertainty of less than 1%

What does this mean for you? Well, as it turns out, there a technology that many of us use every day that uses GR. That's GPS. GPS is already incredibly accurate (a couple of centimeters!), but these new advances may improve  the accuracy even more, allowing even better positioning. Being able to accuracy located objects from space is extremely important and has widespread applications.

I'm excited, I'm a big fan of General Relativity and an very excited to see this effect finally proven!

NASA on Gravity Probe B


  1. Yay for general relativity, I was excited to see this and am excited for future implications!

  2. Wow. That's just awesome!