Relativity?

i would like to know the difference between:





1. Einstein's theory of general relativity





2. Einstein's theory of special relativity





also, could you post a website that explains one of the two theories?|||The special theory extends newtons laws of kinematics to situations where the velocity is close c


It deals with particles which are stationary, at constant velocity or accelerating


One implication is if you travel past a clock at close to c, then it will appear to be ticking faster than it should be





The general theory deals with gravity, it implies gravity is not a force but is due to the curvature of space and also that this curvature alters our concept of time


Newton's law of gravity doesn't contain time, this is it's obvious limit, it deals with static problems, it implies that gravity is transmitted instantly rather than at c


One implication is if you view a clock which is in a strong gravitational field it will appear to be ticking slower than it should be





.,.,.,|||The Wikipedia links above ought to be good places to start.





If you want to learn the theories in some detail you should start with special relativity. I recommend the book Space and Time in Special Relativity by N. David Mermin. That helped me a lot when I was in high school. It goes into all the details, and it does so slowly enough so you can stay with the argument.





General relativity is hard! I audited a course on it once but it didn't teach me much (naturally -- I didn't work at it!). The mathematics is much more complex than the math behind special relativity. If you master special relativity I hope you forge ahead and get farther than I have so far.|||General relativity (GR) or General theory of relativity (GTR) is the geometrical theory of gravitation published by Albert Einstein in 1915/16.[1] It unifies special relativity, Newton's law of universal gravitation, and the insight that gravitational acceleration can be described by the curvature of space and time, this latter being produced by the mass-energy and momentum content of the matter in spacetime.





--- http://en.wikipedia.org/wiki/General_rel…





Special relativity (SR) (aka the special theory of relativity (STR)) is the physical theory of measurement in inertial frames of reference proposed in 1905 by Albert Einstein in his article "On the Electrodynamics of Moving Bodies"[1]. It generalizes Galileo's principle of relativity — that all uniform motion was relative, and that there is no absolute and well-defined state of rest (no privileged reference frames) — from mechanics to all the laws of physics, including electrodynamics.





To stress this point, Einstein not only widened the postulate of relativity, but added the second postulate that all observers will always measure the speed of light to be the same no matter what their state of uniform linear motion.[2]





This theory has a variety of surprising consequences that violate common sense, but all have been experimentally verified. Special relativity overthrows Newtonian notions of absolute space and time by stating that time and space are perceived differently in the sense that measurements of length and time intervals depend on the motion of the observer. It yields the equivalence of matter and energy, as expressed in the mass-energy equivalence formula E = mc2, where c is the speed of light in a vacuum. Special relativity agrees with Newtonian mechanics in their common realm of applicability, in experiments in which all velocities are small compared to the speed of light.





The theory was called "special" because it applies the principle of relativity only to inertial frames. Einstein developed general relativity to apply the principle generally, that is, to any frame, and that theory includes the effects of gravity. Special relativity does not account for gravity, but it can deal with accelerations.





Although special relativity makes some quantities relative, such as time, that we would have imagined to be absolute based on everyday experience, it also makes absolute some others that were thought to be relative. In particular, it states that the speed of light is the same for all observers, even if they are in motion relative to one another. Special relativity reveals that c is not just the velocity of a certain phenomenon - light - but rather a fundamental feature of the way space and time are tied together. In particular, special relativity states that it is impossible for any material object to accelerate to light speed.





--- http://en.wikipedia.org/wiki/Special_rel…|||Special relativity is about physics in flat (i.e. pseudo-flat, Minkowsky) 4 dimensional space called spacetime, where distances are measured by the metrics ds^2=dx^2+dy^2+dz^2-dt^2 (the "pseudo" prefix is about the "-" sign before the time component dt). Lorentz transformations apply in special relativity.





General relativity is the physics translated Riemannian geometry of curved manifolds, treating the spacetime as curved. It applies for the areas of space where gravitation exists, meaning that gravity curves the spacetime of the considered area. It's relation with the special relativity is the physically translated Newtonian notion of "local flatness" used in diferential and integral calculus, with the meaning "special relativity laws apply locally". GR is based on metrics in which no all of the coeficients in front of dx,dy,dz and dt are 1 (and -1). The most famous metrics is the Schwarzchild, for spherically-symmetric gravitational field.