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    __Theory of Relativity__          What is the theory?? Special Relativity:      General Relativity:
 * The theory of special relativity was developed in 1905 by Albert Einstein. Einstein stated that any object in the universe is a suitable frame of reference. The motion of a specific object can then be referenced to that object as a frame. He is saying that everything is moving due to the earth spinning on his axis and its orbit around the sun. His final equation E = mc2 which was verified by velocity of light in moving water experiments along with magnetic forces is in moving substances.
 * The theory of general relativity was first developed in 1915. His first hypothesis and conclusion stated that objects accelerated with respect to one another. The entire theory is based off of the principle of equivalence. This theory replaced the hypothesis that objects attract other objects in direct proportion to there mass with the idea that the continuum is curved in the neighborhood of extremely large objects.

How is the theory used today?? Einstein's theory of relativity has had numerous effects on modern society; he has provided information which enables us to utilize GPS systems, x-ray astronomy, and black holes.  GPS Systems: GPS's(Global Positioning System) are used all the time throughout the day. They are used in planes, tanks, and luxury cars on a daily basis. "The current GPS configuration consists of a network of 24 satellites in high orbits around the Earth. Each   satellite in the GPS constellation orbits at an altitude of about 20,000 km from the ground, and has an orbital speed of about 14,000 km/hour"(Pogge 1.) The sattelites are positioned so that from any point on the earth 4 are always visible. To achieve the level of precision that the GPS's have a clock ticks from the GPS satellites at an accuracy of 20-30 nanoseconds (Pogge 1.) The sattelites are always moving, so in order to maintain the 20-30 nanoseconds the theory of special and general relativity must be taken into account. "Special Relativity predicts that the on-board atomic clocks on the satellites should fall behind clocks on the ground by about 7 microseconds per day because of the slower ticking rate due to the time dilation effect of their relative motion"(Pogge 1.) Satellites are in orbits high above the Earth which means general relativity must be taken into account because the curvature of space-time due to the Earth's mass is less than that at the Earth's surface (Pogge 1.) A 45 microsecond per day adjustment must be made after taking general relativity into effect (Pogge 1.) Without Einstein's findings achieving accurate global positioning systems would be virtually impossible. X-ray Astronomy: X-ray astronomy has utilized the relativity theories very often for things such as the way light bends around a neutron star to detecting the effects of a black hole tugging on space itself. They use x-rays to study these areas of space because they can operate where the gravity is strongest. X-ray astronomers use the theory to travel to far off places where gravity is very intense. The field of x-ray telescoping continues to verify key predictions of general relativity; these include "gravitational red-shifting (gravity tugging at a photon, or light particle, as it tries to escape); frame-dragging (a spinning object twisting the actual fabric of space along with it); gravitational lensing (the path of light bent by gravity); and Einsteinian orbits (an innermost stable orbit)" (Lochner 1.) All these proving that the theory of relativity is utilized everyday with x-ray astronomy.

Black Holes: "General Relativity defines gravity as a result of mass distorting both space and time, a four-dimensional concept called space-time" (Lochner 1.) This theory becomes extremely evident when studies are done on black holes ( a place where extreme gravity is produced). Relativity tells us that when you pack matter in tight enough it should have the power to not only bend light but also to contain it; thus creating what we refer to as a black hole. This is just like earth pulling objects back to its surface(balls, Frisbees, etc.) General relativity predicts also that while orbiting, things hav   e an inner most stable orbit. . "The Rossi Explorer has determined that one certain black hole is spinning by virtue of an extremely tight, stable orbit -- an orbit predicted for a spinning black hole of a given mass"( Lochner 1.) In conclusion...  The relativity theories have had a lasting impact on today's society through GPS systems, x-ray astronomy, and black holes. All these things have used the theory of relativity to improve everyday life in our society. Amazingly the things Einstein discovered 100 years ago still work to create today's most advanced technology. He's no longer around but his findings continue to shape our the way we go about our daily routines.

 Lochner, Jim. "Goddard Space Flight Center." __X-ray Astronomy puts Einstein to the test.__ 26 Jan. 2009 < http://imagine.gsfc.nasa.gov/docs/science/mysteries_l2/relativity.html >.

This site is organized in a very easy to read way. All the information is said in terms that the reader can understand and when words are used that the average person would not know they are hyperlinked to a definition explaining the term. The site is put out by a team that is affiliated with NASA so the information is legitimate.

Pogge, Richard. "Ohio State Astronomy" __Real-World Relativity: The GPS Navigation System__. 28 Jan. 2009 .

Richard Pogge does a great job with the content covered throughout this site. All the information is extremely precise and accurate. He explains in extreme detail how general positioning systems work and how they use the theories of relativity to do so. He is a doctor and accredited physicist so all the information is reliable.

Einstein Picture courtesy of http://www.buffalofilmfestival.com/images/167_einstein-1.jpgI chose this picture because it is a good clear picture of Einstein which also shows the famous E=mc2 Black Hole Picture courtesy of http://ocw.mit.edu/NR/rdonlyres/Physics/8-962Spring-2006/A4540EDF-24C6-47C8-8BBB-C56F27AF7816/0/chp_blackhole.jpgThis picture was chosen because it is a very interesting picture that also is accurate and helps readers understand. Light Bending Picture courtesy of http://curious.astro.cornell.edu/images/glens.jpgThis picture shows the great power of gravity over light and conveys it well. Sattelite Picture courtesy of http://upload.wikimedia.org/wikipedia/commons/thumb/8/8d/GPS_Satellite_NASA_art-iif.jpg/748px-GPS_Satellite_NASA_art-iif.jpgThe picture shows a sattelite in high detail and is accurate.