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The theory of relativity is still relevant in today's society and is continuing to make everyday impacts with tools such as GPS, Gravity-Probe B telescope, and the discovery of a property of blackhole

__ Here's Some Background Info. on the Theory of Relativity:  __ The theory of relativity is the theory that space and time are relative concepts rather than absolute concepts. Albert Einstein created this theory in the years 1907-1915 and the original theory idea was created by Max Plank in 1908.The theory consists of two different concepts: special relativity and general relativity. Some of the consquences of general relativity are: >  __ GPS __
 * time goes more slowly in higher gravitational fields: also known as gravitational time dilation
 * orbits circle in a way unexpected in Newton's theory of gravity
 * rays of light bend in the presence of a gravitational field
 * and "frame-dragging", when a rotating mass "drags along" the space time around it

The GPS system is made possible thanks to the theory of relativity. This is because it uses the concepts of general relativity and the speed of light. It also, uses some of the smaller details of space, which Einstein talks about. Also, GPS uses satillite signals from the 24 satellites in outer space and signals the device the location on the earth where they are located. This done by a system of clocks in the satellites. The satellites have an atomic clock that when a signal is sent it determines the location on the earth by comparing its location to the other 24 satellites and the time to the nanosecond. Due to the idea of special relativity, compared to the clock on earth: the clocks on the satellites will be behind by 7 micorseconds everyday due to the time diliation. But in another sense, the theory of general relativity states that "clocks closer to a massive object will seem to tick more slowly then those located farther away". So in accordance to the GPS system, the satellites would be 45 microseconds ahead of the clocks on Earth. Using both general and special relativity, that means that the satillites will be 38 microseconds ahead of land-based clocks. 38 microseconds is 38,000 nanoseconds which could total up to be 10 kilometers a day, which would make the GPS system completly unusable. But thanks to Einstein's discovery, the scientists behind the GPS system calculated this and edited the atomic clocks in the satillites to work around this and make it so that it can calculate the right location of an object instead of it being 10 kilometers away(per day)(Pogge 1)

__ Gravity Probe-B __

Gravity Probe-B(or GP-B) was created to test Einstein's theory of relativity. The GP-B consists of 4 spherical gyroscopes and a telescope; which is all in a satellite that is orbiting around the earth 642 kilometers above the earth. The created this to specifically test two of the effects predicted by Einstein's General Relativity. The two theories are: -the geodetic effect--which is the amount by which the earth wraps the local spacetime -the frame-dragging effect(see above)It does this by measuring the displacement angles of the axis of the 4 gyroscopes over a year's time and then they compare their results to the ones' predicted by Einstein's theory. The first test to Einstein's theory was conducted in 1976 by Dr.Robert Vessot and the results showed that Einstein's theory was correct.

__ Rossi X-ray Timing Explorer __ In 1998, NASA determined that after 80's years;they can finally accuratly say that Einstein's theory of relativity: especially the general reletivity rule about frame dragging is correct. They determined that by using x-ray astronomy satillates, like NASA's Rossi X-ray Timing Explorer. They determined that Einstein's theory was correct because they could see evidence of "frame dragging" in disks of gas swirling around black holes. Also, the frame dragging process could have an affect on the swirling/turning of the black hole. The frame dragging could possibly effect the accretion disk precess(spinning of the black hole like a toy top).

__In Conclusion:__

The theory of relativity is still very important in todays society. It helps us create new and helpful tools to help us through everyday tasks from finding our way to our beach house to discovering property of black holes. GPS, Gravity-Probe B and NASA's discovery of a property of blackholes are tools/findings that are very useful and technological to us, but somehow Einstein figured this out 80 years before us. We continue to test his theory, waiting for it to break, but time and time again its still right.

Works Cited:

Dunbar, Brian. "NASA - Relativity." __NASA - Home__. 29 Nov. 2007. 27 Jan. 2009 .

"Einstein, Albert. 1920. Relativity: The Special and General Theory." __Bartleby.com: Great Books Online -- Encyclopedia,__

__Dictionary, Thesaurus and hundreds more__. 27 Jan. 2009 http://www.bartleby.com/173/.

Lightman, Alan. "NOVA | Einstein's Big Idea | Relativity (Lightman Essay) | PBS." __PBS__. 27 Jan. 2009 .

Pogge, Richard. "GPS and Relativity." __The Ohio State University Department of Astronomy__. 15 Dec. 2004. 27 Jan. 2009 .

"Theory: Special Relativity (SLAC VVC)." __SLAC Public Website Server__. 31 Oct. 2008. 27 Jan. 2009 .