Einstein’s theory of relativity, critical for GPS, seen in distant stars – Phys.org

What do Albert Einstein, the Global Positioning System (GPS), and a pair of stars 200,000 trillion miles from Earth have in common?
The answer is an effect from Einstein’s General Theory of Relativity called the “gravitational redshift,” where light is shifted to redder colors because of gravity. Using NASA’s Chandra X-ray Observatory, astronomers have discovered the phenomenon in two stars orbiting each other in our galaxy about 29,000 light years (200,000 trillion miles) away from Earth. While…

Click here to view the original article.