NASA satellite confirms two of Einsteins theories

first_imgEinstein first introduced his Special Theory of Relativity in 1905 that was later followed up his General Theory of Relativity in 1915 which applied the theory to the universe as whole. Only now, almost 100 years later, have some of Einstein’s space-time theories been confirmed thanks to NASA’s Gravity B Probe (GP-B) spacecraft.The GP-B project has the distinction of being one of the longest running projects in NASA’s history. NASA began funding the project in the fall of 1963 to develop a relativity gyroscope experiment. The project’s technological breakthroughs culminated in the launch of the GP-B spacecraft in 2004 with the sole purpose of confirming two of Einstein’s predictions.AdChoices广告The first part of GP-B’s mission was to confirm the existence of the geodetic effect which is the warping of space and time around a gravitational body. The second was to confirm frame-dragging , the theory that a spinning object pulls space and time as it rotates. The spacecraft did this through the utilization of four ultra-precise gyroscopes.After launch, GP-B was placed into a polar orbit around Earth and pointed at a single star, IM Pegasi. If gravity had no affect on space and time, contrary to Einstein’s theories, the spacecraft’s gyroscopes should have pointed in the same direction indefinitely while in orbit. In a result which would have surely put a smile on Einstein’s face, the gyroscopes experienced measurable changes in the direction of their spin as Earth’s gravity pulled on them. GP-B’s principle investigator, Francis Everitt, explained the effectas like the Earth rotating in honey, with the honey swirling around with the Earth. That same effect is seen throughout space and time.The fruits of labor around the GP-B project don’t stop with simply proving theories. The project has already produced advancements in technology which have been incorporated into Earth-observing satellites and even new innovations related to GPS technologies that allow airplanes to land unaided.Read more at NASABrian’s OpinionConsidering it has taken this long to prove Einstein’s theories, it is a little bewildering to imaging how he came up with his theories to begin with. I have to say that my favorite Einstein theory is around the notion that time is relative meaning that for someone who is in a spacecraft traveling close to the speed of light they may only experience time passing in a matter of hours or minutes while someone else back on Earth would be experiencing time as days or years. This theory was confirmed in October 1971 during what is known as the Hafele-Keating Experiment.The Haefele-Keating Experiment involved four cesium atomic clocks put on commercial jets flying around the world with one trip going eastward and another going westward. Based on the theory of time relativity it was predicted that the clocks flying eastward should have lost nanoseconds while those flying westward should have gained nanoseconds relative to the atomic clocks at the U.S. Naval Observatory. Sure enough, that’s exactly what happened. It’s poetic that the experiment involving the GP-B spacecraft also included four devices that were gyroscopes compared to the atomic clocks used during the Haefele-Keating Experiment.So, what do these theories being confirmed have to do with everyday life? Well, you can thank Einstein for the GPS units in your car and the GPS built-into your smartphone. Work to prove Einstein’s theories led to a number of GPS advances which make the use of GPS satellites possible. The most important of which is the accountability for time dilation since GPS satellites carry atomic clocks that are critical to a GPS device determining its exact position based on the time reported by satellites in orbit. Just think, the next time you program your GPS to go to that new vacation spot you have Einstein to thank when you get there safely.last_img read more

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