Special Relativity

Light would travel to our eyes as waves through the aether like sound travels to our ears as waves in the air. The nature of the aether was unknown but a possible link between the aether and electrical and magnetic fields became apparent during the first half of the nineteenth century. Faraday demon

We think that the simple length of a thing is "invariant". However, as is shown in the illustrations below, what we are actually suggesting is that length seems to be invariant in a three-dimensional coordinate system. ![Coord1b]( (Image: The original uploader was RobinH at English Wikibooks ., CC B

The Lorentz transformation for time compares the readings of synchronised clocks at any instant. It compares the actual readings on clocks allowing for any time delay due to transmitting information between observers and answers the question "what does the other observer's clock actually read now, a

will become redefined and relativity will lead to an entirely new physics. The new physics has an effect at the ordinary level of experience through the relation $K = γ m {c}^{2} − m {c}^{2} \$ whereby it is the tiny deviations in gamma from unity that are expressed as everyday kinetic energy so tha

It is popularly imagined that Special Relativity forbids travel faster than the speed of light or the propagation of signals faster than the speed of light. However, the actual theory does not contain this assumption. The original theory, framed by Einstein in 1905, states that the speed of light in

Second, we shall investigate the Doppler shift phenomenon, in which the frequency of a wave takes on different values in different coordinate systems. Third, we shall show how to add velocities in a relativistically consistent manner. This will also prove useful when we come to discuss particle beha

In short, we can conclude that the action must have the following form: $S = κ ∫ d s$ Recall the definition of the space-time interval $d s$: $d s = \sqrt{{c}^{2} d {t}^{2} − d {x}^{2} − d {y}^{2} − d {z}^{2}}$ After pulling out $c d t$ from the square root, and noting that $\frac{d {x}^{2} + d {y}^

They are a new concept, as unique as numbers themselves, which have been related to the rest of mathematics and geometry by a series of formulae such as linear combinations, scalar products etc. Vectors are defined as "directed line segments" which means they are lines drawn in a particular directio

𝐁$ is: $𝐀 . 𝐁 = {A}_{t} {B}_{t} − {A}_{x} {B}_{x} − {A}_{y} {B}_{y} − {A}_{z} {B}_{z}$ This can also be derived easily from the metric tensor of Minkowski spacetime. The scalar product of two four-vectors x and y is defined (using indicial notation) as: $x ⋅ y = {x}^{a} {η}_{a b} {y}^{b} = ( \beg

From here to the sun? - What is one nanosecond in meters? One second? One day?