Discovering relativity for yourself

Discovering Relativity for yourself explains Einstein's Theory of Relativity to readers who are daunted by the standard mathematical approach to that profound theory. For twenty years Sam Lilley taught this subject to adults with no science background. Now he has written an explanation of the theory that demands no prior knowledge of mathematics or physics beyond an ability to do simple arithmetic. The first quarter of the book uses no more than arithmetic and a little simple geometry to introduce some of the main concepts of the theory, as well as discussing an impressive experimental test, which comes down strongly in its favour. When eventually further progress demands use of algebra and other mathematical techniques, these are carefully explained in a way that makes them accessible to absolute beginners, using many new and unorthodox methods.

Getting started -- Rough and ready relativity -- The dilation of time -- Three clocks and a pair of twins -- Starting again -- Space-time diagrams -- Time and distance 'over there' -- Co-ordinate systems -- Combining speeds -- Causality and the speed of light -- The nature of spacetime -- Interval -- Old friends revisited -- The scales of the spacetime diagram -- The radar point of view -- Relations between the radar and time-distance systems -- Constant acceleration -- Dynamics-mass, momentum, force -- The mass-energy relation -- The effect of acceleration on time measurement -- Time as experienced by a constant acceleration traveller -- Time and distance measurements of a constant acceleration observer -- The Principle of Equivalence -- The metric -- Introducing geodesics -- How to find ordinary geodesics -- Inverse square law gravity -- Curved spacetime -- The metric around the Sun -- Light and gravity -- The scandal about Mercury -- How Einstein did it -- A few conclusions.