SusanC

= Theory of Relativity = In 1905 the scientific world was shook to its core. This was the day that Albert Einstein published his Special Theory of Relativity. This theory stated that nothing is able to travel between two points faster than the speed of light can (NASA 1). Then, in 1915 another theory was published by Einstein. This one was called the General Theory of Relativity and it proposed that both gravity and motion affect time and space (NASA 1). The main idea of this new theory, called the equivalence principle, was that gravity pulling in one direction is equal to an acceleration in the opposite direction (NASA 1). As a summary, Einstein attributes all forces to acceleration. Everything in the world revolves around these theories, and they are universally excepted. Modern society accepts the theory of relativity due to three modern day example; black holes global positioning systems, and gravitational lensing. http://www.myanmars.net/myanmar-history/albert-einstein.jpg
 * Background Information **

The term black hole is very well-known but is still a mysterious subject. A black hole is a part of space that has an attractive gravitational force that is so strong that nothing is able to escape it (Lightman1). Not even light or a form of communication is able to escape it. Although Albert Einstein himself did not believe in the existence of black holes, their existence was predicted by his theory. His Theory of Relativity itself feed the researchers who are constantly searching for more answers, and also explain what information be believe to this day. Black holes are believed to come from the collapse of extremely large stars. Although, even Einstein’s theory can’t crack the mystery of the black hole. GPS ** Global Positioning Systems, commonly refered to as GPS, are used for all types of transportation, including airplanes and cars. They are used to guide you or give you your exact location in longitude, latitude and altitude and they have an accuracy of five to ten meters (Pogge 1). Satellites are orbiting the earth to give a precise location of the object. GPS's use the special theory of relativity. Due to the fact that from the point of view of an observer the satellites are moving in relation to them. When using this theory we should see the clocks of the satellite clicking more slowly than they are in relation to the satellites themselves. This means that the satellite clocks are actually 7 microseconds per day slower than clocks on the ground (Pogge 1). These Global Positioning Systems also relate to the general theory of relativity. This is because the satellites orbit very high above the earth, and in this space the curvature of space time itself is less than the earth's surface (Pogge 1). Which means that the closer the satellites are to a large object, the more slow they will seem to be ticking from earth, compared to satellites that are farther away. In turn, these satellite clocks will seem faster than clocks on earth, to be exact they are 45 microseconds per day faster. When the effects of both the special and general theory of relativity are combined the clocks are 38 microseconds per day faster, which allow them to track things on earth quickly (Pogge 1). http://blogs.bnet.com/businesstips/images/gps.jpg Gravitational Lensing  ** Its a known fact that when light moves from one place to another it becomes bent. Using this fact, the lens was created in order to focus light. Gravitational lensing explains that light rays bend when they are around a large object, which also means that a large object can perform the same task as a lense does. An example of gravitational lensing is when the light from the stars pass new the sun it bends and changes the location of where the stars appear (Felder 1). There are both strong and weak gravatational lensing (Felder 1). The effects of an eclipse back up Einstein’s theory. http://www4.ncsu.edu/ In Conclusion ** In today’s society, Albert Einstein’s theory of relativity is accepted by examples like black holes, global positioning systems and gravitational lensing. The theory of Relativity was the basis of the discovery of black holes. While that same theory helps satellites navigate people on earth. Finally, gravitational lensing also uses the theory of relativity. Einstein’s theory of relativity greatly impacted today’s society.
 * Black Holes**
 * http://www.nmg-uk.com/blog/black-holes/Black-hole.jpg
 * [[image:http://www4.ncsu.edu/unity/lockers/users/f/felder/public/kenny/images/gr1/starlight.gif width="150" height="107" caption="bent starlight"]]

//Works Cited// "Black Hole". __Black Hole Blog__. 27 Jan. 2009 . -This is a picture that was found on a blog site depicting a black hole.

"Einstein picture". __Myanmars.net__. 27 Jan. 2009 . -This is a picture of Albert Einstein

Felder, Gary. "General Relativity: Einstein: Physics." __NC State: WWW4 Server__. 27 Jan. 2009 . -After further research I found that this site was very reliable and gave credible information regarding the subject theory of relativity

"GPS". __Business Tips Blog__. 27 Jan. 2009 . -This is a picture of a GPS to give an example of the how the theory of relativity is used in modern science

"Gravitational Lensing". __NCSU__. 27 Jan. 2009 <[|http://www4.ncsu.edu]>. -This is a diagram visually explaining gravitational lensing

Lightman, Alan. "NOVA | Einstein's Big Idea | Relativity (Lightman Essay) | PBS." __PBS__. 27 Jan. 2009 . -This is a reliable article found on PBS.org

"NASA - Relativity." __NASA - Home__. 27 Jan. 2009 . -NASA is an exteremly reliable organization, and gives very reliable information

Pogge, Richard. "GPS and Relativity." __The Ohio State University Department of Astronomy__. 27 Jan. 2009 <[|http://www.astronomy.ohio-] state.edu/~pogge/Ast162/Unit5/gps.html>. -This site was found to be very reliable and has a lot of useful information