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Special Relativity

Get up to (light) speed on Einstein's theory of relativity.

This course was written in collaboration with Aaron Miller, a PhD in physics from Penn State University, and was integrated into a YouTube video series on MinutePhysics.

Beginning with famous thought experiments and a few intuitive principles from Newtonian mechanics, this course closely follows Einstein's arguments leading to the epiphany that time and space are a single entity, spacetime, where physical processes unfold.

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Concepts and

  1. 1

    Reference Frames and Observers

    Let there be light... and observers.

    1. Relative Motion of Observers

      Refresh yourself on reference frames and relative speeds on the high seas.

    2. Propagation of Light

      Retrace the steps of the first measurement of the speed of light.

    3. The Mystery of the Luminiferous Aether

      How Michaelson and Morley used light to prove that space is empty after all.

    4. Einstein's Postulates

      Can two events ever be simultaneous to all observers?

  2. 2

    Spacetime and Paradoxes

    Face reality in four-dimensional spacetime.

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      Cosmic Ray Muons

      One of the most basic tests of relativity is raining down around you constantly.

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      Spacetime Intervals and Causality

      Could faster-than-light particles send information back in time?

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      Chimp Twin Paradox

      Can a deep-space voyage put years between two identical twins?

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      Rotations in Spacetime

      A different perspective on Lorentz transformations can simplify some difficult problems.

  3. 3

    Energy and Dynamics

    A high-energy ride on the particle safari.

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      Four-dimensional Space Invaders is a much harder game.

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      Energy-Momentum Conservation

      You rely on conservation of 4-momentum and energy each and every day.

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      High-Energy Particles

      Understand the invisible ballet of particle decay that bombards the Earth with cosmic rays.

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      A moving light source is a brighter light source.