Physics 01
Why Is a Rainbow 42 Degrees? Descartes' Math Explained
A rainbow sits 42° from the point opposite the Sun because rays leaving a raindrop pile up at a turning point. Derivation, worked numbers and computed plots.
Physics
Physics 02
Why Is the Sky Blue and Not Violet? The Full Answer
Skylight carries more violet than blue, yet the sky looks blue. We compute the scattered spectrum and run it through human cone data to show why.
Physics 03
Twin Paradox Explained: Why the Traveller Ages Less
The twin paradox explained with a worked 0.8c trip: 10 years on Earth, 6 on the ship. Why acceleration is not the cause, plus Doppler counts.
Physics 04
How Many G Can a Human Survive? Duration and Direction
5 g knocks out a relaxed person; 46 g didn't kill John Stapp; 214 g didn't kill Kenny Bräck. The difference is duration and direction. Here is the physics.
Physics 05
Project Hail Mary Astrophage Science: The Real Math
We run the numbers on Astrophage: E=mc² energy, the 1.5 g trip to Tau Ceti, the 25.984 µm Petrova line, and why the Hail Mary's fuel load falls short.
Physics 06
How Much Power Is in a Lightning Bolt? 1.21 GW Checked
Lightning peaks at tens of gigawatts to terawatts but lasts microseconds, so a flash holds about 1 GJ. Doc Brown's 1.21 GW, checked.