explain einstein's theory of relativity....?

Question

explain einstein's theory of relativity....?

Answer 1

Hi im cool



The answers further up this thread are all giving you detail about some of the results of relativity, but not explaining the core. Einstein was motivated primarily by aesthetics. He wanted physics to be neater, and relativity makes physics neater. The core of relativity is this:



* the laws of physics have the same form in every reference frame (principle of general covariance)

* the laws of physics have the same content in every inertial reference frame (principle of general invariance).



A central concept is the idea of an inertial reference frame. You are in inertial motion if you don't have any resultant forces acting on you. Importantly, you can tell if there are forces acting on you, but you can not distinguish between different types of inertial motion. Example:



Suppose you are in a locked box in free space. You can't tell whether that box is at rest or in constant uniform (inertial) motion. If there's no acceleration, you can't tell. This principle of relativity predates Einstein - it goes back to Gallileo and Newton. What Einstein added, to make Special Relativity, was that there is no experiment you can perform (even measuring light speeds) which would tell you whether you were in inertial motion, or at rest. This is where we get the idea of "relative velocity", or inertial motion is relative, and from this stems all the results of special relativity that were mentioned above: time dilation, redshift, length contraction, relativistic mass, mass energy equivalence, etc.



The general theory builds further on this one central concept again. We already know that inertial motion is relative, and that we can't distinguish motion at uniform velocity from rest. Now Einstein tells us that freefall in a gravitational field is also inertial. This means if you are freefalling under gravity you feel no force (this is what weightlessness means), and from this we get the equivalence principle in General Relativity: that freefall is indistinguishable from rest, and that being stationary in a gravitational field is equivalent to accelerating in flat space. From this stems all the results of GR: gravitational redshift and time dilation, curved space-time, etc.



I'd recommend Kip Thorne's book "Black Holes and Time Warps: Einstein's Outrageous Legacy" as an excellent introduction to the central concepts of both theories and the motivation for them, without the (difficult) maths. get the central concepts right, and you'll be better able to understand all the other weird results.





Hope this helps!

The Chicken

Answer 2

Einstein has come up with two theories of relativity: "special relativity", and "general relativity".



Special relativity is the study of how measurable quantities such as: intervals of length, intervals of time, and inertial mass depend on the relative velocity of an object. His conclusions were based upon the (at the time) revolutionary assumption that the speed that we measure light traveling at does not depend upon the velocity an observer is traveling at. (note: it was THIS theory that he came up with when he was a patent clerk).



The findings are that an observer traveling on a rocket ship at a constant (but very high) relative velocity will look out and see that time outside the rocket's window moves slower than time does inside the rocket ship; that length intervals measured along the direction the rocket is traveling will shrink; and finally, the inertial mass of passing objects will also increase dramatically.



The ideas that the rate that time passes, and that there is no such thing as a fixed length is revolutionary and quite counterintuitive. Indeed, understanding the world of special relativity requires a whole new physical intuition. It is all, however, a simple consequence of having a constant speed of light. The constancy of the speed of light has been tested time-and-time-again, and it is a verifiable fact.



General relativity, einstein's second relativity theory, is a lot more difficult. While special relativity can be taught to a high school student, General relativity usually requires several years of physics instruction before it can be properly understood.



It is, as the name suggests, a more General Theory. The idea, in short, is that there is something called "space-time", and that matter causes space-time to bend. The effect of the bending of space-time is what we call "gravity".



Ever notice how all object, regardless of their mass, fall towards earth with the same acceleration? Einstein did too! This realization is one of the fundamental basis of General relativity.



Since it is space-TIME that is bent by massive objects, one result which general relativity predicts is that time will pass SLOWER the higher the gravity is. SO, time passes slower on earth than it does on the moon, or in orbit around the earth! this difference in the passage of time is very slight, but it has been measures.



incidentally, if you fall into a black hole, the curvature of space-time is so violent that the universe outside the black hole will experience an INFINITE amount of time as you cross the "event horizon". So there's NO GETTING OUT, because there's nowhere to get out to! hahahaha

Answer 3

Einstein's Theory of Relativity



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 "yard stick." Published in 1915, General Relativity proposed that gravity, as well as motion, can affect the intervals of time and of space. The key idea of General Relativity, called the Equivalence Principle, is that gravity pulling in one direction is completely equivalent to an acceleration in the opposite direction. (A car accelerating forwards feels just like sideways gravity pushing you back against your seat. An elevator accelerating upwards feels just like gravity pushing you into the floor. If gravity is equivalent to acceleration, and if motion affects measurements of time and space (as shown in Special Relativity), then it follows that gravity does so as well. In particular, the gravity of any mass, such as our sun, has the effect of warping the space and time around it. For example, the angles of a triangle no longer add up to 180 degrees and clocks tick more slowly the closer they are to a gravitational mass like the sun. Many of the predictions of General Relativity, such as the bending of starlight by gravity and a tiny shift in the orbit of the planet Mercury, have been quantitatively confirmed by experiment. Two of the strangest predictions, impossible ever to completely confirm, are the existence of black holes and the effect of gravity on the universe as a whole (cosmology).

Answer 4

It has to do with time being flexible and not as set as we may think. This fluctuation in time is called time dilation. According to Einstein, when something is very massive (like a black hole or neutron star) it can cause time to bend so it will appear to be different to relative parties. If you are standing next to said black hole, you would experience time as per normal but if you are watching someone approach a black hole. time would slow down and the person approaching the hjole would eventually freeze as thery got closer. It is very hard to make sense of, I recommend googoling for a better explanation.

Answer 5

The equation is e=mc^2, meaning amount of energy is equal to mass multiplied by the speed of light squared and it applies to nuclear reactions. This is significant because it disproves the Law of Conservation of Matter which states mass cannot be created or destroyed. Einstein's theory is what caused the Law of Conservation of Matter to be changed to mass cannot be created or destroyed in a chemical reaction. In nuclear fission and fusion mass and energy are conserved together, meaning the sum of mass and energy before a nuclear reaction has to be equal to the sum of mass and energy after a nuclear reaction, but some of the mass can be changed to energy, or vis versa.



Hope that helped...

Answer 6

True quote; Einstein said if he sits next to a beautiful girl for a few minutes, it seems like a second. But if he touched a hot iron for a second, it seemed like a few minutes!!!! That's relativity.



Actually, he meant time changes with speed.

Answer 7

Einstein once stated that even he couldn't explain it!

Answer 8

It is very difficult to explain in a simple form and you cannot understand good

go ahead at wikipedia.com

Answer 9

E=mc^2 is on google.

Answer 10

matter moves and doesn't move. get the picture



lol