nathanb

--Einstein's Theories of Relativity--



Albert Einstein, the greatest physicist of his time, created two theories of relativity that explained some of the biggest natural phenomenons observed in time and space. The theory of special relativity states that nothing in the universe can go faster then the speed of light (roughly 3 x 10^8 m/s) and that different events occur at different times based on the reference point of the object observing the event. The only problem with that was that Newton's theory of gravity stated that gravity acted instantaneous over any distance. To prove Newton wrong Einstein came up with his theory of general relativity that stated that the 3-d of the universe and the 1-d of time created a 4th dimension that stated how objects in the universe were effected by gravity.

--Special Relativity--

Special relativity is a theory that states that nothing in the universe can go faster then the speed of light(roughly 3 x 10^8 m/s) and that different events happen at different times based on the reference point of the object observing the event.

For example, lets say that a van is traveling down a road and there is someone sitting in the center of the van, there is also someone outside of the van that is watching the van as it drives by. Lets say that right when the the person outside the van is lined up with the person in the middle of the van the van is struck by lightning on both the front and the back. To the person outside of the van observes the two bolts hitting at the same time because they are both the same distance away from him. However, the person inside of the van observes the bolt hitting the front of the van first, and then the other bolt hitting the back of the van. Both of these observations are correct because they are being viewed in different reference points. The reason why the person in the van observes the front bolt as happening first is because the person is going towards it making it reach the person sooner. The reason why the person in the van observes the bolt that hits the back of the van last is because the image has to overtake the velocity of the van to reach the person inside the van.

The theory of special relativity also states that as one object gets closer and closer to the speed of light, time will slow down around it. The reason this occurs is that no matter how fast an object travels, the speed of light will be observed as 3 x 10^8 m/s.To do this, the time and space around the object becomes distorted. "Consider two twins who were born on Earth. One of the twins gets in a spaceship which quickly accelerates to a large velocity (say 0.9 the speed of light for this example) relative to the Earth. This twin travels for a period of proper time, say 10 years, quickly turns around and returns to Earth where he decelerates and stops. To the traveling twin only 20 years have passed, while the twin who stayed on Earth experiences a much larger passage of time. This is illustrated in Fig. 56-9. The prediction of relativity is that 46 years will have passed to the twin who stayed at rest on the Earth." (USC Self Paced Astronomy Courses Unit 56 Essay - The Special Theory of Relativity)

--General Relativity--



Einstein had a little bit of a problem with his theory that nothing in the universe could go faster then the speed of light. The problem was that Newton's theory of gravity stated that gravity acted instantly on an object. It took Einstein 10 years to figure out how to prove this theory wrong. When he finally did, he called it the theory of general relativity.



Newton's theory of gravity stated that gravity effected any object at any given distance instantaneously. The theory of special relativity greatly contradicted Newton's theory of gravity because in order for Newton to be correct, gravity has to be able to go faster then the speed of light. So to prove Newton wrong, Einstein created the theory of general relativity. This theory combined the 3rd dimension of space with the 1st dimension of time to create a 4th dimension of 'space time'. This space time fabric is like a sheet of water that objects move on and deform based on their mass. Objects with greater mass create bigger curves in the fabric that draw other objects closer to it and create what we know as gravity. This then helped Einstein prove that were the sun to just explode it would create a type of wave or ripple on this space time fabric that would move outward at a speed exactly that of the speed of light that would push the earth off its orbit track in a tangent of its orbit path thus proving that gravity moves at the same speed as the speed of light.

 --Conclusion--

Those are just basic ideas of what Einsteins theories of relativity are. They have a lot more depth to them and are very complicated theories to understand because the reader has to take in a lot of different information at once when reading these theories. The theory of general relativity reinforces the theory of spacial relativity where nothing in the universe has the ability to move faster then the speed of light.

 --Works Cited-- Dine, Michael. "NASA - Relativity ." __NASA - Home__. 27 Jan. 2009 .Safko, J. L.. the information on this site was created by NASA and is supported by a lot of other sites that i have found on the internet so i believe that both the author is credible and the information is correct.

"Unit 56. The Special Theory of Relativity" __University of South Carolina Astronomy Center__. 27 Jan. 2009 . the information on this site is directly from a university's textbook so i believe that makes the information and the author accurate.

"The intangible Universe - Relativity,space,time and gravity - part 1 of 4." __Welcome to The Physical World__. 27 Jan. 2009 . this site is meant to accompany several text books and the information on it is a lot like the other information that i have seen on other relevant sites.

"Theory: Special Relativity (SLAC VVC)." __SLAC Public Website Server__. 31 Oct. 2008. 27 Jan. 2009 . the information on this site was created by the people at the Standford university and the information on the site is very similar to other information that i have seen on other relevant sites.