Make a Lichtenberg Figure the Easy Way

Lichtenberg figures are fern-like branching structures formed from an electrical discharge on or inside of an insulator. Like snowflakes, every Lichtenberg figure is unique – an intricate and beautiful natural work of art. Lichtenberg figures form naturally, sometimes in the skin of lightning strike victims, in lightning strikes into sand […]

This Lichtenberg figure was made by shooting a beam of electrons (~2.2 million volts) through an insulator. The pattern is illuminated by blue LEDs. (Bert Hickman, Wikipedia Commons)

Moving Rulers Are Shorter – Length Contraction Example Problem

Relativity tells us moving objects will have different lengths in the direction of motion, depending on the frame of reference of the observer. This is known as length contraction. This type of problem can be reduced to two different frames of reference. One is the frame of reference where a […]

Moving Rulers are Shorter

Red Light Appears Green

How Fast Would You Have To Go To Make A Red Light Look Green? – Relativistic Doppler Effect

Everyone knows about the doppler effect with sounds. When a train approaches, the pitch of its sound increases. After it passes, the pitch seems to drop off. This is because the sound waves are compressed (wavelength shortened/frequency increased) ahead of a moving sound source. The sound waves expand (wavelength increased/frequency […]