DanielleZ

**The Theory of Relativity**

**Einstein's Theory of Relativity is accepted by society and science as being accurate based on experiments and tests that have been performed to prove it.** **The formula //E// = //m////c//2 is** **perhaps the most well-known aspect of the Theory of Relativity used today.**



The Theory of Relativity was developed by Albert Einstein
 * There are two types of Relativity: __**Special Relatvity**__ and __**General Relativity**__
 * Special Relativity was Einstein's first stage of the theory developement in 1905
 * Special Relativity states that "all physical laws have the same mathematical form when expressed in an inertial system" __and__ that "the velocity of light is independent of the motion of its source, having the same value when measured by observers moving with constant velocity with respect to each other." *
 * General Relativity was Einstein's second stage in developement of the theory in 1915
 * General Relativty deals with gravity and is based on the idea that "the local effects of a gravitational field and of acceleration of an inertial system are identical." *

In the theory of **__Special Relativity __** there are several points of importance that it deals with. This Theory, comprised of several components, was revolutionary for the time period in which Einstein was living. Newton's three laws of motion were generally accepted by the scientific world. They were, however, built on the basis of normal, everyday speeds. Einstein didn't refute Newton's conclusions, he merely expanded on them, focusing specifically on the speed of light. "Because most of us have little experience with objects moving at speeds near the speed of light, Einstein's predictions may seem strange. However, many years of high energy physics experiments have thoroughly tested Einstein's theory and shown that it fits all results to date." (Special Relativity) Einstein stated that speed is relative. The speed of one object relative to another depends on the motion of both objects. "Note that this is quite different from the motion of ordinary, massive objects. If I am driving down the freeway at 50 miles per hour relative to the road, a car traveling in the same direction at 55 mph has a speed of only 5 mph relative to me, while a car coming in the opposite direction at 55 mph approaches me at a rate of 105 mph. " (Special Relativity)

This theory was found to be quite logical when referring to speed on a much grander scale. Scientific experiments have only proven the theory again and again. "Einstein's theory is now very well established as the correct description of motion of relativistic objects, that is those traveling at a significant fraction of the speed of light." (Special Relativity)

The diagram below shows the changing views of spacetime along the world line of a rapidly accelerating observer. The vertical direction is representing time, and the horizontal direction is representing distance. The moving dotted line shows the observer's world line. The dots represent events in spacetime.



The theory of Special Relativity states that rules of nature can be formulated which don't depend on one specific observation situation. This means that "the effect of a force on an object is the same independent of what causes the force and also of where the object is or what its speed is." (Special Relativity)**Once again, it points out that everything is relative to each other.**

__General relativity__ states that matter causes space to curve. Physicists use embedding diagrams to demonstrate Einstein's idea that a smaller mass will travel toward a larger mass because the space around it is "warped" by the larger mass. (See image below)

These diagrams reprove Einstein's theory every time. (General Relativity)

Nevertheless, there have been some indications of his theory being accepted by the world today.**
 * Because it deals with such a huge scope, relativity isn't used largely in everyday life.

__The formula **//E// = //mc//2** (Energy equals mass times the velocity of light squared) is a mass-energy equivalence used every day.__ This equation is used in:
 * Nuclear Fusion (used to power modern nuclear warheads)
 * Nuclear Fission, which is less powerful, (used in an atomic bomb and in nuclear power plants)
 * Commercial and Residential Smoke Detectors
 * Exit Signs
 * Radiocarbon Dating

**Even though research on the subject of relativity is being done all the time, Einstein's theories have been proven accurate every time. There have been many experiments done for the purpose of proving and/or disproving Einstein's theory but nothing has been able to shake his solid information and knowledge of this aspect of science. His formula E=mc2 is a great working example of the Theory of Relativity.**


 * __Works Cited and Annotations:__**

"General Relativity." Expo/Science & Industry/Spacetime Wrinkles. Ed. The Board of Trustees of the University of Illinois. 1995. The Board of Trustees of the University of Illinois. 24 Jan. 2009 .

The Board of Trustees of the University of Illinois explains the theory of General Relativity by using examples and images to support its statements. The information is objective and unbiased; the editors did not cite any other sources. The article is interesting, but a bit limitted in its information. It does give the reader an idea of what General Relativity is. "Special Relativity." SLAC. Ed. Stanford University for the U.S. Dept. of Energy. 31 Oct. 2008. Stanford University for the U.S. Dept. of Energy. 24 Jan. 2009 .

The Stanford University team gives an in-depth look into the ins and outs of the theory of Special Relativity. It uses a step-by-step approach to explain averything clearly and objectively to the reader. There are formulas and applicable examples to prove its reasoning. It gives a thorough explanation of Einstein's theoretical basis and the different components involved with the theory. The reader can go away feeling informed after perusing this webpage.
 * Dictionary.com -http://dictionary.reference.com/browse/special%20relativity
 * All images have been taken from flickr.com and wikipedia.org