In what ways is the theory of relativity?

Question

Most frequently misunderstood?

Can a lay-person gain a working understanding of such theories?

Answer 1

Special relativity is what people have a hard time understand.  General relativity is mostly intuitive (meaning it makes sense) whereas special relativity creates so many paradoxes.  Most people think the paradoxes are confusing, but studying them is actually the way to really understand relativity.  I think a lot of people also want to confuse special relativity with general relativity.  For instance, I've seen a lot of people who think that time dilation only occurs for someone travelling at high speed (and that the person travelling at close to the speed of light will observe time to speed up around them), ie they forget that relativity is all about local inertial reference frames.

Answer 2

People tend to think that relativity proves that time travel is possible. I've also found - largely from this site - that very few people understand why nothing can travel faster than light. They'll assume that "nothing is impossible" and that one day we'll have the technology to do it.

I'm a lay person and I have a reasonably good understanding of relativity. I could definitely give you an explanation here and now which you would completely understand and probably go "ahhhhh....I SEE" - but I won't unless you ask me to.

:-)

Answer 3

The Special Theory of Relativity was published in 1905 and deals with (frames of reference) objects separating with constant high velocities (close to the speed of light). In this first theory, Einstein stated that the speed of light was the absolute limit for all velocities and furthermore all observers, what ever their motion, must measure the speed of light to be exactly the same. Finally, only mass-less objects may attain the speed of light. However, massive objects contract in their direction of motion, their clocks slow down relative to observer's clocks and they gain mass and thus inertia as they accelerate towards the speed of light.

Einstein's theory of General Relativity (1915) is a cause and effect theory. The theory describes the fabric of space-time as a medium that may be distorted by the presence of mass and energy. From his earlier relativity theory, Einstein had related mass and energy in the famous equation: -

E = mc²

From this concept, he described the curvature or distortion of space-time as due to the total sum of mass-energy present within the region of distorted space. It is the curvature of space-time we call gravity. Thus, our planet follows the 'straightest' path or path of least action whilst it orbits the mutually curved space around the Sun. An object falling to earth, under the pull of gravity, is following the curvature of space in the region around the surface of the Earth. Einstein described the relationship between space-time curvature and the mass-energy causing it, in the tensor field equation: -

G = 8πT

Where 'G' is the Einstein tensor representing the 'gravity' or curvature of space-time and 'T' is the total energy tensor representing the mass-energy creating the gravitational curvature of the space-time.

The theory, accurately predicts many features of the solar system, such as the peculiar motion of Mercury’s perihelion, and may be used to account for the gravitational physics of black holes and neutron stars. The extreme high pressure physics at the core of a star may be described using this theory. General relativity also predicted the Big Bang origin of the universe, although Einstein refused to accept the conclusion. He later claimed that this erroneous conclusion was his biggest blunder. Overall, after ninety-three years, General Relativity is still the best theory of gravity that we have!

Answer 4

It is most often not understood. Relativity can mean several things. The idea of spacetime and the connection between observers of the same system in the same inertia are key.

I think the most important one is the general relativity that Einstein said meant the presence of matter curves spacetime and even light rays are affected by gravity. That was proven during a solar eclipse when Einstein predicted heavenly bodies not normally visible would be so during the eclipse, and they were as the light curving around the sun was visible.