Einstein's general theory of relativity?

Question

Can someone explain to me in laymens terms what Einstein's general theory of relativity means and how it applies to the world around us. Also explain E=MC2.

Thanks

Answer 1

Everything a person [usually referred to as an observer] sees or perceives is RELATIVE to their frame of reference.
Say you are driving along in your car. You have attached a laser range finder to your outside rearview mirrior and pointed it directly at the ground. For sake of argument, say it reads 3 feet from the ground. So, as you go along, relative to your frame of reference, your rearview mirror has an altitude of 3 feet. Now, you start driving up he side of a mountain. Someone standing at the base of the mountain using the frame of reference of sea level will say you have an altitude of hundreds or even thousands of feet while the range finder still reads 3 feet. Which is the correct altitude? They both are, relative to their respective frames of reference.
Time. motion, speed....
Say you are in something like a moving train in an open car. Your are at the back of the train car and there is a person at the front of the train car. Behind that person is someone with a radar/speed gun. You throw a ball to the person at the front of the car. The other guy with the gun measures the ball's speed at 35mph. The train, while you were throwing, has been steadily moving along the tracks at 35mph. There is also a person on the ground at the side of the tracks with another radar gun. He measures the ball's speed as 70mph. This makes perfect sense since 35mph [the speed ball is thrown] plus 35mph [the speed of the train] equals 70mph. Which radar gun is right? They both are relative to their respective frames of reference.

Now, instead of a ball, let's give you a flashlight. And, instead of normal radar guns, they are devices which can detect and measure the speed of photons of light. So, you click on the flashlight and the guy you shine it at measures the photons' speed as "c". Here's the interesting part, the guy on the ground ALSO measures the photon's speed as "c", not "c" plus the speed of the train. The speed of light [in a vacuum], or "c" is ALWAYS "c" regardless of who measures it or what frame of refeerence they are in. The speed of light is a constant, but time dilates and space warps and curves.
As far as the equation goes....
Right now, the Sun is converting approximately 400 million tons of hydrogen into helium every second through the process of nuclear fusion. Again for sake of argument, let's give the matter of a hydrogen atom a value of 1. When four hydrogen atoms are "fused" together to make a helium atom, one would normally just add them up and think the resulting matter of the helium atom would have a value of 4, as in 1+1+1+1=4. Well, this is not the case. The resulting matter of the helium atom is a little less than the total initial matter of the original hydrogen atoms used to make it. Where did the other matter go? It was converted into energy. What was the factor of conversion? c - or the speed of light squared. This equation came out of Einstein's Special Theory of Relativity and shows the equivalence of energy and matter. It represents the energy of the nuclear processes and forces on the subatomic level, not chemical processes on the molecular level. In other words, chemically burning 1/15th of an ounce of hydrogen will produce enough energy to light up a 100 watt bulb for about 40 minutes. But, if you convert, through nuclear fusion, the atoms in 1/15th of an ounce of hydrogen gas, it would produce enough energy to light up that same bulb for about 56,000 years. The inherent energy in all matter is gargantuan.

Answer 2

ha i just had my physics test on this! E=mc2 is basically Energy equals mass times the speed of light (the speed of light is 3 X 10 to the 8 power). there are two postulates of Einstein's relativity theory. the first postulate states that the speed of light is constant and always will be. the second states that nothing "weird" will happen in your reference point.
There is a very good example of reference points in the Twin Paradox example. in this example, one twin goes in a space ship and the other stays on Earth. when the twin in the ship comes back years later, he is much younger than the twin that stayed on earth. This is because the twins were observing different reference points. i know its confusing, but you can find more information on the Twin Paradox anywhere. even google.

hope i helped!!

Answer 3

E=MC2 is Energy=Mass x Speed of light2

The theory of relativity is basically the idea that all time is relative and all things are relative to time. In theory, if an object could move at the speed of light, time would not affect it. Therefore, time travel is possible. That's how I understand it anyway. Good luck.

Answer 4

It states that, when at rest, we are travelling at the speed of light through time, thus treating time as one of four vectors or axes in the space-time continuum.

Think of it as a car doing runs on a salt lake (like those that you see to break spped records). The car can go at a speed of 300mph. Lets suppose Bob does 4 runs at different times, and each run his time from when he passes the start flag to when he reaches the end flag is longer. When Bob looks at the results, he realizes that his first run was a straight line, but his 2nd run was slightly akewed so that it wasn't a straight line but sloped to the left. The 3rd run was further sloped to the left and the 4th was even more so. Why were the times of the 2nd, 3rd and 4th runs longer?
Because in the 1st run, the car was using all its speed to travel on a straignt, lets say east-west, line. By the 2nd run, part of the cars speed was being used to travel on a north-south axis instead of on the east-west axis, so it took the car longer to travel the same distance in the east-west axis. So, as you see, since the car can only do 300mph max. the speed in one axis is relative to the speed in another axis (is afected by the speed in another axis).

Going back to my first postulate, that we travel through time at the speed of light. Space-time has 4 axis (east-west, north-south, up- down and time). At rest, we travel through time at the speed of light, but as soon as we start moving in any of the other axes, we start "bleeding" our time speed. This explains Einsteins paradox of an astronaut returning from a space mission to find his twin brother is older than him (he "bled" more speed from the time axis, while his brother was "stationary" and thus travelling at the speed of light through time). It also explains why nothing can travel faster than the speed of light.

E=mc^2 is the relationship between matter (represented by the m for mass) and energy (represented by the E). Basically any matter can be described as energy and its energy level is equal to its mass times the square of light speed.

Answer 5

There are TONS of books on the subject, and near enough space here to detail what you are asking. Go to the Library and do some research.

Answer 6

It means that our perception of speed depends on our location, with the speed of light being the only constant.

Answer 7

It is a relation of mass and energy of the object..




E=MC^2