Overview
The Special Theory of Relativity is one the theories developed by Albert Einstein during his miracle year of 1905. It threw the concept of the luminiferous ether, and revolutionized how physicists viewed space and time, unifying the two into space-time.
Postulates
- Relativity - the laws of nature are the same in all inertial reference frames
- The speed of light in a vacuum is a constant
Lorentz and Poincare Transformations
One of the primary results of relativity is the development of a set of transformations that describe how to convert the measurements from one inertial observer, to another.
- Lorentz Transformations - includes rotations and boosts.
- Poincare Transformations - a broader class of transformations that contains the Lorentz Transformations as a subset. Includes translations in addition to the Lorentz transformations
Both sets of transformations form a Lie Group. Measurable quantities in Physics undergo transformations when the observer changes from one frame of reference to another. Because not all observable quantities form a 4 vector, not all observable quantities will transform under a Poincare Transformation. However, it is believed that all observable quantities should transform by a transformation that forms a representation of the Poincare Transformation Group.