Theory of Relativity?

Question

Can somebody eplain the Theory of Relativity in a nut-shell and simple format that a 10 year old can understand?

Answer 1

Relativity theory was coined by Einstein. The two postulated that he formulated is what is called Relativity Theory. as follows;
a=The velocity of light is constant in a medium which he called vacuum.
b= the formulas of physics dont change in form no matter where you are in the Universe.

The special relativity theory based on these potulates develops a relationship about what hapens when things move.

It said that the faster you move the fatter you get in weight shrink in the direction of motion.,and the faster you move the slower you get but you could never move fast enough to reach the speed of light other wise you would be getting too fat and shrink very small .

Andi f you carry a watch as you move the watch would tick slower and you loses time.So the most accurate time your watch could keep is if you dont move.

They call this time dilation.

So the faster you run the later you get to school. It means you dont have to run so fast (dont go at the speed of light)to get to school on time.
Also when you move; it means that your body becomes heavier as you move to the speed of light.

They call this relativistic mass.

If your father see you from one location as fat your mother may see you from another loation as skinny.
they call the location =frame of reference.

So In one frame of reference you may look good but in another frame of reference you dont look so good.

And if you dont move you still have energy equal to mc^2.
This really dont fit commons sense ideas. but they say that relativity defies common sense. Because the Relativity theory formulas prove it.

General relativity relates gravity( that is how much you weight)to the curving of space. the more you curve space the more you weight. Gravity is called a field of space and time.
So the faster you get the more you warp the field of spacetime.
The formula for this is Called Einstein's Field Equation which explains why things happen this way.

So this is what the Theory of Relativity is all about.

You may want to see the formulas but it takes years of math to understand them.Many people dont understand it
and neither do I.
So dont feel bad if all this does not make any sense to you.Because only the Physists are the only ones who really Understand it.

Answer 2

A 10-year-old? Jeez... Okay, let's try this:
First there's general relativity. This states that the presence of matter "curves" spacetime, and this curvature affects the path of free particles and light. Spacetime is a 4-dimensional mathematical model that incorporates the dimension of time into the typical length, width, and height of three-dimensional reality. General relativity is based on the general principle of relativity, which requires all observers to experience the same laws of physics, not just those moving with uniform speed.
Special relativity is a little more complicated, but basically says that the higher your velocity, the more spacetime distorts. There's a great animation showing generally how this happens here: http://en.wikipedia.org/wiki/Image:Lorentz_transform_of_world_line.gif

Answer 3

There's no way I could explain everything in a simple format, but I can give you a start. Say you're on a train moving forward 100 kph. Then say you walk towards the front of the train 10 kph. From the viewpoint of someone sitting on the train you're moving 10 kph. From the viewpoint of someone standing on the ground nearby you're moving 110 kph (your walking plus the speed the train is moving you). From your viewpoint you aren't moving at all! Think about it... your body stays with your viewpoint. From your viewpoint the train pasengers are moving backward 10 kph and the ground is moving back 110 kph.

This stuff was known long before Einstein. Einstein's work comes into play when you start getting to real fast speeds. Say the train that you're now standing in is moving at half the speed of light and you shine a flashlight foward. At first you'd think that the lightbeam would be moving 1.5 times the speed of light from the viewpoint of someone on the ground. But it isn't (and I won't get into the reasons why it isn't here). The lightbeam appears to move at the speed of light for you and for someone on the ground and for everyone else. Some crazy results come from this. Say you shine the lightbeam straight up to the top of the train and it takes the beam a second to hit the top and and another second to get back down (this would be a rather tall train, but bear with me). To an outside observer, the lightbeam is moving at an angle rather then straight up because it's on the moving train. Hence, the lightbeam would actually travel a bit farther then twice the height of the train (just as the sides of a tent are longer then the height of the tent). Before relativity, we'd just say that the lightbeam appears to move faster for the outside observer but we know that the speeds will be the same. So what gives? The lightbeam's bounce actually takes a tad longer for the outside observer then it does for you on the train. This is called time dilation, that from an outsider's perspective time appears to slow down for someone on a moving object.

What makes it really crazy is that for the someone on a moving object the guy standing still is appearing to move in the opposite direction (because if you're on the moving object that's still in your viewpoint). Hence, the outside observer's clock must be slowing down.

Answer 4

Let's try anyway:

Einstein's Theory of Relativity means that space and time are kinda the same thing, and that you'll perceive them differently depending on where you are. For casual, day-to-day stuff, you won't notice much difference; the really weird stuff only starts to happen as you approach the speed of light -- the moving person's clock will seem to move slower than the clock of the person standing still, the moving person's ruler will appear to be shorter compared to the ruler of the static observer, and so on. The one constant is the speed of light -- if I'm on a spaceship travelling at 90% the speed of light and I turn on a flashlight, I observe the light traveling away from me at 100% the speed of light -- not 10%, as your intuition might cause you to expect. The static observer would also see the flashlight beam travel away from me at 100% lightspeed, rather than 190% as you again might expect.

That's all I've got for a primer....anyone else care to join in?

Answer 5

Einstein's Special Theory of Relativity predicted that time does not flow at a fixed rate: moving clocks appear to tick more slowly relative to their stationary counterparts. But this effect only becomes really significant at very high velocities that app roach the speed of light.

In most circumstances in the universe time dilation (change) can become very significant when spacetime is curved by a massive object such as a black hole. For example, an observer far from a black hole would observe time passing extremely slowly for an astronaut falling through the hole's boundary. In fact, the distant observer would never see the hapless victim actually fall in. His or her time, as measured by the observer, would appear to stand still. The slowing of time near a very simple black hole has been simulated on supercomputers at NCSA and visualised in a computer-generated animation.

Basically it all to do with Time being changed (slower or faster)relative to speed and mass (of any moving object).

Answer 6

Theory of relativity in a nutshell.

You're on a boat travelling west at 50 knots.
Your buddy is on the shore watching you pass perpendicular to him. You throw a ball straight up. YOU see the ball go straight up and come straight back down. YOUR BUDDY sees the ball track an arc, following the ship. Likewise if your buddy threw a ball straight up, he'd see it go straight up and down, YOU'D see it travel an arc. Now assume that you can't say for a fact that YOU'RE the one who's actually moving. You may be, but maybe you're standing still and the rest of the world is moving past you.

THATS relativity in a nutshell. YOU are in a reference frame that is different than your buddy's. BOTH ARE PERFECTLY VALID. And the laws of physics behave properly in both (the ball in the above example) Einstein's relativity deals with laws of physics and their inviolatibilty. If a law of physics holds here, it must hold everywhere. The law used is the constancy of the speed of light. (for the special theory). If the speed of light, c, is c, it must be c REGARDLESS of where its measured from (assuming NON-ACCELERATED reference frames (special theory only) ). That leads to some interesting effects. Time dialation, length contraction, and some others.

Answer 7

When people say, "relativity," they mean that there are different points of view that make things "relative." Let's begin with an easy example. If I'm standing far away from you, and you see me, I look really small, don't I? That's because my size is relative to you. In my point of view, I'm the same size I always am, but to you I look very small. Mr. Einstein took his knowledge of these different points of view and constructed a theory that applied the idea of different points of view to the world of physics. He made advancements because he saw that it was impossible for time, space, and mass to remain the same from very different points of view.

If a person is traveling at the speed of light, then they will see the world in a very different way than people who are standing still do. Einstein believed that at very high speeds, things will shrink. Take the case of two rocket ships, both fifty feet in length. One is flying over the other, which is stationary on the ground. The ship that is flying at a very fast speed will have shrunk if measured while it is flying over (you couldn't see it with your eyes though...it would be going too fast). The pilot of the flying ship wouldn't notice, though, because everything in the ship will have shrunk.


The above is a section from the pages i have linked below. Its certainly possible to explain to a child - ie the blotting the sun out with your thumb explanation. With kids its easier to show them than to explain sometimes!

Answer 8

the speed of light is a constant.
No matter where you are in the universe or what you're doing (traveling fast or undergoing acceleration), the speed of light is always 186,220 Miles per second, (in a vacuum), relative to anyone or anything else.

Part 2: Time is not a constant.
A second "here" does not equal a second to someone (think: relative to anyone else), that is traveling fast or is undergoing high acceleration.


that's it.

But boy oh boy there is a LOT of stuff that happens when you take into account what is now known as "relativistic Physics".

tom

Answer 9

I wish! Dang, it's complex!

Special relativity

Albert Einstein's 1905 paper "On the Electrodynamics of Moving Bodies" introduced the special theory of relativity. Special relativity considers that observers in inertial reference frames, which are in uniform motion relative to one another, cannot perform any experiment to determine which one of them is "stationary". This is actually Galileo's principle of relativity; Einstein's contribution was to explicitly include electromagnetism within this principle, which required that the Galilean transformations be replaced by the Lorentz transformations. The resultant theory has many surprising consequences. In particular, it requires that the speed of light in a vacuum be the same for all these observers, regardless of their motion, or the motion of the source of the light, since the invariance of the speed of light is a consequence of Maxwell's equations of electromagnetism.

General relativity

General relativity was developed by Einstein in the years 1907 - 1915. General relativity replaces the global Lorentz symmetry of special relativity with a local Lorentz symmetry in the presence of matter. The presence of matter "curves" spacetime, and this curvature affects the path of free particles (and even the path of light). General relativity uses the mathematics of differential geometry and tensors in order to describe gravitation as an effect of the geometry of spacetime. This theory is based on the general principle of relativity, which requires all observers to experience the same laws of physics, not just those moving with uniform speed, hence its name.

Answer 10

The complete Theory of relativity is too difficult to understand. As Einstein himself claimed, that there are only 12 people living in this world who have ACTUALLY understood the theory completely. But I can put it forward this way....

Suppose there are two bodies, one revolving around the other, for example, the earth and the moon. If you see from the earth, you will feel that the moon is moving around the earth. But if Neil Armstrong sees from the moon, he will see earth moving around the sun. Thus, with respect to a moving body body, the other is always moving irrespective of whether it is actually stationery or moving, and its direction of motion, unless, of course, its motion is in the same direction and with the same velocity as that of the original body.