CarolineB

=  = = = **The Positive Impacts of the Theory of Relativity** **In 1905, Einstein developed a theory called the Theory of Relativity. This included two different types, general relativity and special relativity. They explain the behavior of matter, energy, and even time and space. The two theories are considered the "foundation blocks" of modern physics (Relativity).** **__General Relativity__: "proposed that gravity, as well as motion, can affect the intervals of time and of space (Lightman)."** **__ Special Relativity__: "proposed that distance and time are not absolute. The ticking rate of a clock depends on the motion of the observer of that clock; likewise for the length of a "yardstick" (Lightman)."** **The Theory of Relativity has positively affected society by changing/ creating linear electron accelerators, chemistry, cosmology and GPS navigation systems.** **Linear Electron Accelerators:** **A linear electron accelerator use potential difference and interact with microwaves to accelerate electrons to a point where they can be used to help people in a positive way. They are used to treat one of the most common diseases, cancer. Several cancers from lung and prostate cancer to neck and brain cancer can be treated using linear electron accelerators. With out relativity several people could be lacking the treatment required for them to stay alive. "The scientists and engineers who build such devices don't ask themselves whether relativity is true - they just use it. If you don't use relativity, you simply get the wrong answer." This same device can be used to treat deep tumors. X-rays are created when electrons collide with a copper block and the kinetic energy created the X-rays that help treat tumors (Wolfe).** **Chemistry:** **"Any chemist will tell you that with no chemistry, there would be no biology, and without biology there would be no psychology.... It's obvious that physics (especially electricity, mechanics and thermal physics) underlies chemistry (Wolfe).” The science behind the science of chemistry is all related to physics and physics foundation is relativity. All of science is proved to be based upon the theory of relativity. A normal school subject that almost every student will have to learn would not even be explainable without Einstein and relativity. The theory has yet another way that it impacted society in a positive way.** **Cosmology:**    **Another science, the study of the universe, is affected by relativity. In 1939, while scientist Robert J. Robert Oppenheimer and Hartland Snyder were manipulating Einstein’s equations involving relativity they discovered that black holes were created when stars collapsed (Lightman). The first black hole physically found was Cygnus X-1 in 1970. Since then several of other black holes have been identified, some 10 million times bigger than our sun (Lightman). “Ironically, Einstein himself did not believe in the existence of black holes, even though they were predicted by his theory (Lightman)." It is crazy the way Einstein discovered things he didn’t even believe in with on theory. This theory has proved to be very helpful in discovering and explaining things in the field of cosmology.**  **GPS Navigation System:**   **A machine that can tell you what state you are in what building you are in and even what room you are in to 3 meters has to be very technological. Of course something this high-tech involves science, to be specific the theory of relativity. A GPS system works with the help of satellites rotating around the earth. 24 satellites rotate around the earth at 4km per second and transmit signals telling the time (a minute of arc in latitude is one nautical mile, or 1800 meters) of the device, therefore giving the location (Wolfe). “There is an effect due to General Relativity (Einstein's theory of gravitation): the satellites are at higher gravitational potential than the receivers, and this makes the satellite clocks run slightly fast (Wolfe).”**  **”At a speed of 4 km per second, the effect of Special Relativity on the clocks seems small: it gives a time dilation of about 1.0000000004, which would tend to make them run slow (Wolfe).” Relativity effects how GPS navigation systems work, without out it we would not have any.** **The Theory of Relativity has had several positive impacts on our society. For instance, cancer can be treated using linear electron accelerators that were created using the idea of relativity. Almost all of science has been explained through relativity. The first black hole was discovered while manipulating Einstein’s equations in his Theory of Relativity. The GPS system is as accurate as it is because of relativity. Who knows where you might be without it. Relativity has proved to have a very large impact on how we view and explain several things today. It is a very interesting topic that will continue to be studied for several years to come.** **Works Cited** Lightman, Alan. "NOVA | Einstein's Big Idea | Relativity (Lightman Essay) | PBS." __PBS__. 5 Feb. 2009 .

"NASA - Relativity." __NASA - Home__. 2 Feb. 2009 .
 * On this site you can learn about how Einstein became famous. It talks about the basics of the theory of relativity and how it came upon. It shows examples and animations to help understand the theory. The site is very creditable, it was written by a physicist who is involoved with a major company, PBS.**

This is a very creditable source with lots of information on every thing from general relativity to in depth information. It also tells about things that relativity has impacted in our society. Wolfe, Joe. "Relativity: Einstein's theory of relativity in animations and film clips. Einstein Light." __School of Physics at UNSW, Sydney, Australia__. 5 Feb. 2009 .

You can learn about realativity in a brief, easy to learn way or in a very detailed complex manner. The site has very good illustrations and animations to help explain the concept. You can learn about how Einsteins theory relates to Galileo's theory along with ither scientist. The author of the website is very creditable. He is a professor and physicist. This site has also won several awards like Yahoo's pick of the year in 2005. =  =