Speaker
Description
We construct spacetime diagrams for special relativity on graph paper that has been rotated by 45 degrees. Boxes in the grid (called “clock diamonds”) represent units of measurement modeled on the ticks of an inertial observer's light clock. Many quantitative results and their physical interpretations can be read off the diagram simply by counting boxes. We use simple geometrical constructions and a little algebra to perform Lorentz-invariant calculations visually. For a pair of events, its “causal diamond” has edges parallel to the rotated grid and has two important features: its area represents the square-interval along the diagonal joining the two events, and the aspect ratio represents the square of the Doppler factor for that diagonal. With our method, we demonstrate the clock effect/twin paradox.
