What does the theory of relativity, mean? (E=MC2)?

Question

I just really wonder about what it means.

Answer 1

I don't no.

Answer 2

Hmmmm...

If theory of relativity was so simple and short that I can explain it all here then everybody would be expert at it.

Well, let me try anyway.

Theory of relativity says that everything is relative and speed of light in our universe is the only constant. The consequences of this include that as you go faster and faster, time will slow down for you, your mass will increase, and you will also become shorter in the direction of travel. Einstein also said that since there is no experiment that can be done to differentiate between acceleration and the gravitational force, they both have the same effects. This means that even if I am standing "still" next to a huge star, time would still slow down for me even though I am not moving.

Now notice that these effects happen for small velocities too but they are only obvious and noticeable if your velocity is very close to the speed of light like 95% the speed of light. Since we haven't really invented anything that can go 600,000,000 miles per hour, these effects are not the most obvious things that we notice as we travel in our measly little hummers at 100 miles an hour or our snail-like 3000 miles per hour space shuttles.

Einstein also said that nothing material can go at the speed of light (and we are still trying to make things go at the speed of light) and he also said that nothing can go beyond the speed of light either. It is the ultimate barrier. Because if what I said above is true, then at the speed of light, your mass would be infinite and therefore you would need an infinite amount of fuel to carry you so the total mass in your ship is an even bigger infinity so it is not possible.

Einstein worked the exact math for all this too so if you want to know exactly how much mass you gain when you travel at 60 miles per hour, just google "relativity factor".

As for e=mc^2, Einstein said that matter and energy are the same things. One can be converted to another and how much mass can be converted to how much energy is given by his famous e=mc^2.

E=energy produced
m=mass used
c=speed of light.

Since, the speed of light is huge (c^2 is even bigger), very small amounts of matter can be completely obliterated and huge amounts of energy can be produced. Meaning that the lead in your pencil would be enough to destroy the city in which you live. (Talk about the power of the pen!)

Hence came the nuclear bomb and the hydrogen bomb. Oh, and our sun works the same way, otherwise we wouldn't be here today.

Answer 3

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!

Answer 4

It develop into no longer until eventually 1946 that Einstein printed a paper wherein he developed the equation you point out. This develop into long after the inception of the theories of relativity. to respond to your question. Your mass M would be, and is, 12 stone and in case you need to be completely switched over to means (which God forbid!) you're able to produce Mc^2 !!

Answer 5

There are actually 2 theories of relativity: "the special theory of relativity" and "the general theory of relativity". The general theory of relativity deals with gravity.

Special relativity was a response to the discovery that light travels the same speed regardless of how fast you are traveling relative to it, which breaks the laws of newtonian physics. (in newtonian geometry ("Euclidean geometry"), if i'm traveling 2m/s per second in the same direction as you, and your'e traveling 3 m/s, you should be traveling 1m/s relative to me. Experimental evidence has shown that light violates this principle.)

Special relativity resolves this apparent paradox by using non-Euclidean geometry. It defines a 4-dimensional space-time geometry _for any given point and velocity_ such that:

A. the laws of physics remain the same, regardless of where you are AND what speed you're traveling.

B. the speed of light is constant regardless of where you are AND what speed you're traveling.

To do so, special relativity (SR) uses "metric geometry" (see http://en.wikipedia.org/wiki/Metric_geometry ) to define the geometry of space-time. In metric geometry, a metric defines how to measure distance and angle.

the space-time metric is a 4x4 "metric":
(t=time; x,y,z=space)

t x y z
t -c 0 0 0
x 0 1 0 0
y 0 0 1 0
z 0 0 0 1

where "c" is the speed of light in vacuum. notice that in the metric it's _negative_ c. this is how light is made to travel at a constant speed in einstienian geometry; by putting a "-c" factor in the space-time metric, the speed of light becomes an instrinsic part of the geometry.


using this metric, the distance between two points, (0,0,0,0) and (t,x,y,z) is the square root of (-c*t^2+1*x^2+1*y^2+1*z^2)

thus, if x^2+y^2+z^2 = -c*t^2, the distance between the two points is zero.

so when you do the math to find the distance to, say, a star that is one light year away, and then include a position in the time dimension as well, say 1 year away. Well the spatial distance turns out to be the speed of light times 1 year, and the time distance turns out to be _minus_ 1 year, times the speed of light. so the total space-time distance is zero. Meaning that there is no distance between the light from that star 1 year ago and the light at the point of observation, now. I.e. you're "seeing" light from a year ago.


for a fuller explanation, you can check out the wikipedia article on it: http://en.wikipedia.org/wiki/Special_theory_of_relativity


If you use the newtonian equations for energy, momentum, and mass in relativistic space-time, the laws of conservation:

*energy (E) is conserved (neither created or destroyed)
*mass (m) is conserved (neither created or destroyed)
*momentum (p) is conserved (newton's second law of motion: "an object in motion tends to stay in motion")

break down. (don't hold true anymore)

the equation E^2=m^2*c^4 + p^2c^2 is a correction to the newtonian formula, such that these quantities are conserved in relativistic space-time, or, rather, that this relationship between the 3 quantities (E^2=m^2*c^4 + p^2c^2) is conserved.


Restating the laws of conservation for Einstienian geometry:

*when energy is destroyed or created, it is converted to or from mass and momentum.
*when mass is destroyed or created, it is converted to or from energy and momentum.
*when momentum is destroyed or created, it is converted to or from mass and energy.

And if any two of the quantities (energy,mass,momentum) are known, the third quantity can be precisely calculated.

Today, this relationship is used almost exclusively in nuclear physics. It allows one to predict, for instance, that if a reaction between two particles gives off x energy units of heat, then the total mass of the resulting particles is x/c^2 less than the original two.

Thus, we realize that we can get power out of smashing particles into each other, and the age of nuclear power (and weapons) begins.

Since the contribution to energy (E) from the momentum term (pc) is negligibly small compared to that of the mass term (mc^2) (the mass term's contribution is larger by a factor of the speed of light! (c) ), the momentum term is almost always dropped to make the math easier. (i don't know of a case where it's not.) Thus, the much more familiar form: E=mc^2.

But, to reiterate, the equation E=mc^2 finds its origin, not in subatomic particles, but in the working out of a mathematical system where:

A. the laws of physics remain the same, regardless of where you are AND what speed you're traveling.

B. the speed of light is constant regardless of where you are AND what speed you're traveling.

It just so happened that the only way to satisfy the 3 laws of conservation in a space-time geometry defined by the aforementioned metric:

t x y z
t -c 0 0 0
x 0 1 0 0
y 0 0 1 0
z 0 0 0 1

is to_relate_ the 3 quantities. (that is, put them all in one irreducible equation)

so E=mc2, or, rather, E^2=m^2*c^4 + p^2c^2 means that, for any given point and velocity, the aforementioned metric defines space-time geometry. And in this geometry, the relation between mass, energy, and momentum is conserved, and it is: E^2=m^2*c^4 + p^2c^2.

Answer 6

E = mc² is not actually from Theory of Relativity. It's from Einstein's theory of the photo-electric effect, for which he got the Nobel Prize.

Theory of Relativity, in a tiny nutshell, says measurements of velocity, space, and time are all interdependent, and that "simultaneous" is not the simple idea we thought it was.

Answer 7

Then get an introductory book and read about it. E = MC2 is about 1 percent of it

Answer 8

E=MC^2 reads

The amount of energy in the universe=The amount of mass in the universe multiplied by the cosmological constant squared.

What this basically means is the amount of matter in the universe is directly proportional to the amount of energy in the universe. This "general relativity" is the cornerstone of astrophysics today.

Answer 9

the theory of relativity postulates 2 empirical principles:

1: "the laws of nature are independent of the state of motion of the frame of reference, as long as the latter is acceleration free [this is, inertial]"

2: "light in empty space always propagates with a definite [speed], independent of the state of motion of the emitting body"

E=MC^2:
(Energy) = (Mass) times (propagation of light in a vacuum)^2

an easy way to think of this is the process of the decay of unstable nuclei,

before decay:
lets say you had a substance of mass 2kg

after decay:
lets say 1kg of its mass is converted into mechanical energy,
then the total energy converted will be (1)(c^2) joules.

Answer 10

Las cosas grandes son simples..
La materia se transforma en energia o al contrario

Endergia= materia*velocidad de la luz al cuadrado

Answer 11

It means, relatively speaking, that relative to how you relat...

ehh, I'm boring myself...