can some one explain the theory of reletivity?

Sure. I can explain Special Relativity -- General Relativity is a bit more difficult.

Imagine you are floating in space, far from any planets or stars, when all of a sudden your friend floats past you at 10 miles per hour. Your friend sees you, but she thinks YOU are moving past her at 10 miles per hour. Who's moving? The point is you both have an equal right to claim you're at rest and the other is moving. Non-accelerated motion cannot be defined without a reference point. You need to have something to compare your motion to. No so with the speed of light. Whether you're moving towards that approaching light beam or away from it, you will measure its speed to be 186,000 miles per second. What this means is that, given the formula distance = rate x time, if the speed of light (the rate) is constant no matter what, something else in the formula changes -- time. That means the faster you travel through space, the slower you travel through time relative to an observer in a stationary reference frame. What this also means is that things that appear simultaneous from one reference point don't necessarily happen at the same time from a moving reference point. Einstein was able to do a lot with this. He eventually incorporated "gravity" into these ideas, which is what General Relativity is concerned with. Ultimately, the math that came out of those theories predicted that, given the energetic properties of light, and that matter is nothing but "frozen" energy, Energy = an object's mass times the speed of light squared. In other words, a whole lot of energy is contained in a little bit of matter.

It would take many pages to fully explain, and there have been many excellent books written on the subject. I can give a brief summary of what it's about. It is based on two principles:

a) Relativity principle: There are no forces acting on an object moving at a uniform constant velocity. There is no experiment that can determine a uniform constant velocity without reference to external objects.

b) Light waves are observed to travel at the same velocity regardless of the velocity of the observer with respect to the light source, or the velocity of the source with respect to the observer.

From these two principles the transformations of the Special Theory of Relativity are derived. One consequence of these transformations is that a person observing someone travelling at a speed near the speed of light will observe that time passes more slowly than the person travelling experiences. Another is an increase in mass of objects with velocity. When these transformations are applied to systems involving energy and momentum, the formula for the energy of a moving object comes out

E = mc^2 + .5mv^2, where v = the object's veloctiy.

Note that even if the object is not moving (v=0), there is still energy left, that energy being E = mc^2, and is attributed to the energy contained in the mass itself.

The General Theory is based on the observation that gravitational and inertial mass are identical, and that it is impossible to distinguish between being in gravitational field or being accelerated (again without external reference). From this the field equations of General Relativity are derived, in which gravity is shown to be a distortion of space-time.

Relativity basically says that Mass, Length, and Time change with the speed of the observer. This confirms the hindu cosmological belief that the reality we observe is an illusion and that things aren't the way they appear to us. The only way Einstein could have known this was through divine intervention. This is why Einstein has such a special place in the history of Science. He was an avatar in the hindu sense of the word. God came down and told him personally that Mass, Length, and Time will change with the observer's velocity. Einstein then proceeded to write this in mathematical terms and forever changed the history of the world.

The basis of the Formula E=mc^2 is that matter and energy are all intertwined. Matter could be referred to as "frozen" energy, and given a quantity of matter, times the speed of light squared, one could figure the absolute energy that matter could produce in a 100% efficiency reduction to pure energy. Not specifically referenced to the formula, the Theory can be expounded to include such other theory's as time dialation, and the plausability of faster-than-light travel.

It basically means things are relative to each other. if i jump on the world, it equally jumps off me. another example is someone in a car and someone watching. i think the car is moving, but equally i am moving to the car. it all depends on a reference point

E=Mc2 It's all relative. I think the main point albert einstein was getting at is that all matter is made up of atoms. If you split those atoms, you get one hell of an explosion.

Special Relativity

Newton's laws of motion give us a complete description of the behavior moving objects at low speeds. The laws are different at speeds reached by the particles at SLAC.

Einstein's Special Theory of Relativity describes the motion of particles moving at close to the speed of light. In fact, it gives the correct laws of motion for any particle. This doesn't mean Newton was wrong, his equations are contained within the relativistic equations. Newton's "laws" provide a very good approximate form, valid when v is much less than c. For particles moving at slow speeds (very much less than the speed of light), the differences between Einstein's laws of motion and those derived by Newton are tiny. That's why relativity doesn't play a large role in everyday life. Einstein's theory supercedes Newton's, but Newton's theory provides a very good approximation for objects moving at everyday speeds.

Einstein's theory is now very well established as the correct description of motion of relativistic objects, that is those traveling at a significant fraction of the speed of light.

Because most of us have little experience with objects moving at speeds near the speed of light, Einstein's predictions may seem strange. However, many years of high energy physics experiments have thoroughly tested Einstein's theory and shown that it fits all results to date.

Theoretical Basis for Special Relativity

Einstein's theory of special relativity results from two statements -- the two basic postulates of special relativity:

The speed of light is the same for all observers, no matter what their relative speeds.

The laws of physics are the same in any inertial (that is, non-accelerated) frame of reference. This means that the laws of physics observed by a hypothetical observer traveling with a relativistic particle must be the same as those observed by an observer who is stationary in the laboratory.

Given these two statements, Einstein showed how definitions of momentum and energy must be refined and how quantities such as length and time must change from one observer to another in order to get consistent results for physical quantities such as particle half-life. To decide whether his postulates are a correct theory of nature, physicists test whether the predictions of Einstein's theory match observations. Indeed many such tests have been made -- and the answers Einstein gave are right every time!

The Speed of Light is the same for all observers.

The first postulate -- the speed of light will be seen to be the same relative to any observer, independent of the motion of the observer -- is the crucial idea that led Einstein to formulate his theory. It means we can define a quantity c, the speed of light, which is a fundamental constant of nature.

Note that this is quite different from the motion of ordinary, massive objects. If I am driving down the freeway at 50 miles per hour relative to the road, a car traveling in the same direction at 55 mph has a speed of only 5 mph relative to me, while a car coming in the opposite direction at 55 mph approaches me at a rate of 105 mph. Their speed relative to me depends on my motion as well as on theirs.

Physics is the same for all inertial observers.

This second postulate is really a basic though unspoken assumption in all of science -- the idea that we can formulate rules of nature which do not depend on our particular observing situation. This does not mean that things behave in the same way on the earth and in space, e.g. an observer at the surface of the earth is affected by the earth's gravity, but it does mean that the effect of a force on an object is the same independent of what causes the force and also of where the object is or what its speed is.

Einstein developed a theory of motion that could consistently contain both the same speed of light for any observer and the familiar addition of velocities described above for slow-moving objects. This is called the special theory of relativity, since it deals with the relative motions of objects.

Note that Einstein's General Theory of Relativity is a separate theory about a very different topic -- the effects of gravity.

Relativistic Definitions

Physicists call particles with v/c comparable to 1 "relativistic" particles. Particles with v/c << 1 (very much less than one) are "non-relativistic." At SLAC, we are almost always dealing with relativistic particles. Below we catalogue some essential differences between the relativistic quantities the more familiar non-relativistic or low-speed approximate definitions and behaviors.

suppose to be twice the energy to move one times that of mass anything related to that such as light.

It states that everything is relative even time. you move faster time passes slower.

If your parents didn't have any children, the chances are that you won't either.