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Yale Unversity Lecture on the Theory of Relativity media type="custom" key="3059004"

Special Relativity
Two basic postulates of special relativity:
 * 1) The speed of light is the same for all observers regardless of their relative speeds.
 * 2) The laws of physics are the same in any inertial (non-accelerated) frame of reference. For example, the laws of physics observed by a hypothetical observer traveling with a relativistic particle are the same as those observed by a stationary observer in the laboratory.

> //v// is the speed of the object in question ||
 * The measurable effects of relativity are based on gamma. Gamma depends only on the speed of a particle and is always larger than 1. By definition:
 * [[image:http://www2.slac.stanford.edu/vvc/theory/mathfigs/eq-gamma.gif width="193" height="70" caption="Equation relating speed of light, speed of object and constant, gamma"]] || //c// is the speed of light
 * [[image:http://www2.slac.stanford.edu/vvc/theory/mathfigs/eq-gamma.gif width="193" height="70" caption="Equation relating speed of light, speed of object and constant, gamma"]] || //c// is the speed of light

For example, when an electron has traveled ten feet along the accelerator it has a speed of 0.99//c//, and the value of gamma at that speed is 7.09. When the electron reaches the end of the linac, its speed is 0.99999999995//c// where gamma equals 100,000. What do these gamma values tell us about the relativistic effects detected at SLAC? Notice that when the speed of the object is very much less than the speed of light (//v// << //c//), gamma is approximately equal to 1. This is a non-relativistic situation (Newtonian).
 * For non-relativistic objects Newton defined momentum, given the symbol //p//, as the product of mass and velocity -- //p = m v.// When speed becomes relativistic, we have to modify this definition -- //p = gamma (mv)//

General Relativity
What this means, in effect, is that a person cannot tell the difference between (a) standing on the Earth, feeling the effects of gravity as a downward pull and (b) standing in a very smooth elevator that is accelerating upwards at just the right rate of exactly 32 feet per second squared. In both cases, a person would feel the same downward pull of gravity. Einstein asserted that these effects were actually the same.
 * A uniform gravitational field (like that near the Earth) is equivalent to a uniform acceleration.




 * The large ball will cause a deformation in the sheet's surface. A baseball dropped onto the sheet will roll toward the bowling ball. Einstein theorized that smaller masses travel toward larger masses not because they are "attracted" by a mysterious force, but because the smaller objects travel through space that is warped by the larger object. Physicists illustrate this idea using **embedding diagrams**.
 * Contrary to appearances, an embedding diagram does not depict the three-dimensional "space" of our everyday experience. Rather it shows how a 2D slice through familiar 3D space is curved downwards when embedded in flattened hyperspace. We cannot fully envision this hyperspace; it contains seven dimensions, including one for time! Flattening it to 3D allows us to represent the curvature. Embedding diagrams can help us visualize the implications of Einstein's General Theory of Relativity.



Bending Light
The first prediction put to test was the apparent bending of light as it passes near a massive body. This effect was conclusively observed during the solar eclipse of 1919, when the Sun was silhouetted against the Hyades star cluster, for which the positi ons were well known. Sir Arthur Eddington stationed himself on an island off the western coast of Africa and sent another group of British scientists to Brazil. Their measurements of several of the stars in the cluster showed that the light from these stars was indeed bent as it grazed the Sun, by the exact amount of Einstein's predictions. Einstein became a celebrity overnight when the results were announced. The apparent displacement of light results from the warping of space in the vicinity of the massive object through which light travels. The light never changes course, but merely follows the curvature of space. Astronomers now refer to this displacement o f light as **gravitational lensing**. But the Sun's gravity is relatively weak compared with what's out there in the depths of space. In the dramatic example of gravitational lensing below, the light from a quasar (a young, distant galaxy that emits prodigious amounts of radio energy) 8 billi on light years away is bent round by the gravity of a closer galaxy that's "only" 400 million light years distant from Earth. **The Einstein Cross** Four images of the quasar appear around the central glow formed by the nearby galaxy. The Einstein Cross is only visible from the southern hemisphere.  What might you see if you were to orbit a black hole? Computer simulations show that light near the hole gets so bent that the myriad stars behind it would appear as a series of concentric rings.

Work Cited
"Theory of Relativity." __Stanford__. 25 Jan. 2009 [[http://www.slac.stanford.edu/vvc/theory/relativity.html This article is about Einstein's Special Theory of Relativity. It gives clear reasoning as to why Newton's Laws are not as precise as Einstein's Theory. It accurately depicts why Newton's Laws are only applicable to particles moving at slower speeds, such as the objects that we see day to day, rather than objects such as light particles. It clearly explains that the speed of light is the same for all "observers", no matter speed. It also states that the laws of physics are the same for any unaccelerated frame of reference. "Theory of Relativity." __Space and Motion__. 25 Jan. 2009 < www.spaceandmotion.com/Physics-Albert-Einstein-Theory-Relativity.htm >.the website's purpose is to provide truth and reality - about how you and everything around human beings exist in space. it provides a simple solution to many of the problems of knowledge that have caused humanity so much conflict and confusion. this site is for people who are interested in the knowledge of science and physics. the site has an extensive collection of information, facts and numbers documented properly without bias.

Bailyn, Charles. "Special and General Relativity." __Academic Earth__. 25 Jan. 2009 http://academicearth.org/lectures/special-and-general-relativity. This is a video lecture of a professor from Yale University on the Black Hole and relation to the Theory of Relativity.

"Putting Relativity to The Test." __NCSA Web archive bounce page__. 31 Jan. 2009 . This website provides the most basic information needed to understand the theory of relativity. The article is credible because it is backed by the organization of PBS. The author is also credible because of his credentals. I would have to say that this article could use the authors point of view or hi oppion on the subject to shown how others feel on the subject. Over all i found this site to very usefull.