aalbert

= Theory of Relativity =

Relativity is either of two theories of physics developed by Albert Einstein. Those theories are the special theory of relativity and the general theory of relativity. Einstein's theories explain the behavior of matter, energy, and even time and space. They are foundation upon which modern physics is built. Einstein's Special Theory of Relativity describes the motion of particles moving at close to the speed of light. One of the reasons relativity does not play a large role in everyday life is because there are not many particles or objects that move faster than the speed of light on earth.The general theory of relativity describes gravitational forces in terms of the curvature in space caused by the presence of mass. The fundamental principle of general relativity states that accelerated reference frames and reference frames in gravitational fields are equivalent.Although Einstein's idea was misunderstood at the time, it is now universally accepted. **Our society accepts the Theory of Relativity based on the concepts of black hole, Global Postioning System, and gravtational lensing.**

**__Black Holes-__**
Black holes are made up of photons which are massless. These photons move toward the black hole because they travel along the shortest distance between two points. Due to gerneral relativity these photons travel what seems like a curved path bent around a massive object, but instead they are just travling the shortest distance. Example: a flat sheet of paper represents time. You lay a ball in the middle of that paper (this is what a black hole looks like from two dimensions). The ball lying in the middle of the paper creates a bent look to the paper and distorts the regular flat surface, this is what a black hole does in space. Physicist are still not sure what a black hole is made out of or what is in the center of the black hole ("Curious About Astronomy? The Theory of Relativity." par 2). http://curious.astro.cornell.edu/relativity.php

http://curious.astro.cornell.edu/relativity.php **Using general relativity scientist developed the device that is known for giving directions at any time where ever one is located. This common device used in airplanes and cars is known as the GPS. Knowing that clocks tick faster when they are closer to a massive moving opject and slower when they are further from the object. With this in mind scientist placed satilities in the above the earths atmosphere to guide the GPS in a car or airplane and since these satilities are closer to the moving object they would tick through time faster than those on earth. To fix this problem scientist used general relatvity to figure out that the clocks tick 45 microseconds a day faster than those on earth. In the end the problem was fixed by adjusting the clock on the satilite that would show on your GPS system to slow down the ticking frequency of the clocks so that once in orbit they would be correct ("GPS and Relativity." par 1).
 * __GPS (Global Positioning System)-__

http://www.astronomy.ohio-state.edu/~pogge/Ast162/Unit5/gps.html

When light passes through a lens it becomes bent on the other side of the lense. This is because genreal relativity explains that light rays become bent when passing through a massive object. An example is when light from a star passes near the sun, a massive object, it becomes bent and therefore changes the position of the star in the sky, only in appearance though. This example is hard to observe since we only see stars at night when the sun is not present in the sky. However during a solar eclipse this phnomena can be observed since there is still enough sun light and dark enough to see the star light ("General Relativity: Einstein: Physics." par 1).
 * __Gravitational Lensing-__**

http://www4.ncsu.edu/unity/lockers/users/f/felder/public/kenny/papers/gr1.html This Hubble Space Telescope image of the galaxy cluster Abell 2218 is a powerful demonstration of gravity's ability to bend light, a phenomenon predicted by Einstein's theory of relativity. The bright, massive galaxies in the cluster act like optical lenses, bending light from more distant galaxies into the faint arcs and rings visible in this picture.

Because of Einstein's theory of general relativity scientist and the rest of the population now have the oppertunity to understand certain concepts relating to physics. With these three examples of black holes, GPS, and gravitational lensing people can accept the the theory of relativity by observing and reading about these concepts. Black holes and gravitational lensing have impacted society to those who are open and infomred about thier ideas. However with the recent populartiy of Global Postitioning Systems this idea that uses general relativity has impacted many people. The theory of relativity is just an opeing to all the other great theories that will be developed leading to answers of unknowns.
 * Conclusion**

__Works Cited__ "Curious About Astronomy? The Theory of Relativity." __Curious About Astronomy? Ask an Astronomer__. 25 Sep. 2002. 26 Jan. 2009 . The theory of relativity is discussed throughout this website and it is explained how it came about through the thoughts of Albert Einstein. It explains the basic principles of his theory and that it is required when studying objects that are moving in a strong gravitational field of moving near the speed of light. The website also breaks down the principles of the theory of special relativity and the theory of general relativity. It also discusses different applications in which the theory is used, as well as provides links to different websites that will allow you to ask questions that will be answered by a team of graduate students who are studying to get their PhD in astronomy.

"G.P.S and Relativity." __The Ohio State University Department of Astronomy__. 15 Dec. 2004. 26 Jan. 2009 . This is a web page that is used to inform the reader about how a Global Postitioning System is related to the theory of relativity. The audience is the general public because this is a device that is used by many people everyday and it is easy to understand. In this article it is discussed how the GPS satillite could be a few minutes behind the clocks on earth and it continues each year to get faster than regular clocks. This source is very useful because it gives a lot of information on one topic that I could use for one of my examples. Though there is no date on the article it came as a link from another credible source.

"General Relativity: Einstein: Physics." __NC State: WWW4 Server__. 26 Jan. 2009 . This article can be found online on the www4.ncsu.edu site. Gary Felder, a professor at Smith College as well as a Ph.D, wrote this article to help lay a foundation for those who don't really know much about the theory of relativity. It is mainly targeted to students. The site gives a basic overview of the general relativity dealing with space, time and gravity and then proceeds to get into more and more detail. The web page was copyrighted in 2003, but the entire site was copyrighted in 2008 so the information is recent and since both of the authors are professors, the information is credible.