Einstein's Theory of Relativity — Without the Formulas
Understanding the Complex: Why your GPS needs Einstein — and what relativity actually says about space and time. 11 lessons, ~150 minutes, free.
Einstein's Theory of Relativity — Without the Formulas
All 11 lessons in order.
What's This Actually About?
Hook: why your GPS would be wrong by ~7 miles per day without Einstein's theory — and the central question this course answers.
Why Should I Care?
Three reasons relativity matters beyond physics class: GPS, gravitational waves, and the fight against 'everything is relative.'
The Basics You Need
Prerequisites: the speed of light as a constant, inertial frames, what 'relative' actually means in physics. Introduces the GPS anchor.
Special Relativity — Time Stretches
Special relativity: time dilation, length contraction, twin paradox. GPS satellites lose −7 μs/day due to speed.
General Relativity — Space Curves
General relativity: the equivalence principle, curved spacetime, gravity as geometry. GPS gains +45 μs/day — net 7 miles of error per day without correction.
What Follows? Black Holes, Gravitational Waves, Universe
Black holes, gravitational waves (LIGO 2015), expanding universe. GPS fully explained. Quantum gravity as the open frontier.
Who's Doing This? Why? Who's Paying?
Einstein, Hilbert, Eddington, Thorne, Weiss, Penrose, Hossenfelder, Carroll. NSF, Max Planck, ESA. As of May 2026.
What's Contested? What Don't We Know?
Three controversies: Is GR the final answer? Dark matter — real or modified gravity? The BICEP2 debacle as scientific self-correction.
What's Next?
Five milestones for relativistic physics in the coming decades.
What If...?
Calibrated speculation — with the lowest risk profile in the series and an explicitly reasoned asymmetry toward the positive.
What Do You Take Away?
Six core ideas. Reading list. Cross-links to Quantum Computing and Theory of Everything. Why you shouldn't trust us blindly.