An Illustrated Guide to Relativity

This class is based on the book, An Illustrated Guide to Relativity,
by Tatsu Takeuchi, of Virginia Polytechnic Institute and State
University, a delightful book that uses simple space-time diagrams to
visualize and teach the basic features of special relativity. This is
done so well that the material can, in principle, be learned directly
from the figures and annotations without referring to the main text
at all.

Online Resources

Review of Using Spacetime Diagrams (Minkowski Diagrams) to Order Events

Review - Inertial Frames of Reference


   In physics, an inertial frame of reference (also inertial
   reference frame or inertial frame or Galilean reference frame) is
   a frame of reference that describes time and space homogeneously,
   isotropically, and in a time-independent manner.

   All inertial frames are in a state of constant, rectilinear motion
   with respect to one another; they are not accelerating in the
   sense that an accelerometer at rest in one would detect zero
   acceleration. Measurements in one inertial frame can be converted
   to measurements in another by a simple transformation (the
   Galilean transformation in Newtonian physics and the Lorentz
   transformation in special relativity). In general relativity, in
   any region small enough for the curvature of spacetime to be
   negligible one can find a set of inertial frames that
   approximately describe that region

Non-Inertial Frames of Reference


   A non-inertial reference frame is a frame of reference that is
   undergoing acceleration with respect to an inertial frame. An
   accelerometer at rest in a non-inertial frame will in general
   detect a non-zero acceleration, and in a curved spacetime all
   frames are non-inertial. The laws of motion in non-inertial frames
   do not take the simple form they do in inertial frames, and the
   laws vary from frame to frame depending on the acceleration.

5. Laws of Physics in Non-Inertial Frames

6. The Special and General Theories of Relativity

7. Some History  <==

8. The Lorentz Transformation


Larmor and Lorentz, who believed the luminiferous ether hypothesis,
were seeking the transformation under which Maxwell's equations were
invariant when transformed from the ether to a moving frame. Early in
1889, Oliver Heaviside had shown from Maxwell's equations that the
electric field surrounding a spherical distribution of charge should
cease to have spherical symmetry once the charge is in motion relative
to the ether.

FitzGerald then conjectured that Heavisideās distortion result might
be applied to a theory of intermolecular forces. Some months later,
FitzGerald published his conjecture in Science to explain the baffling
outcome of the 1887 ether-wind experiment of Michelson and Morley.
This idea was extended by Lorentz and Larmor over several years, and
became known as the FitzGerald-Lorentz explanation of the
Michelson-Morley null result, known early on through the writings of
Lodge, Lorentz, Larmor, and FitzGerald. Their explanation was widely
known before 1905. Larmor is also credited to have been the first to
understand the crucial time dilation property inherent in his

In 1905, Henri Poincare was the first to recognize that the
transformation has the properties of a mathematical group, and named
it after Lorentz. Later in the same year Einstein derived the Lorentz
transformation under the assumptions of the principle of relativity
and the constancy of the speed of light in any inertial reference
frame, obtaining results that were algebraically equivalent to
Larmor's (1897) and Lorentz's (1899, 1904), but with a different