Physics
Classical mechanics, quantum physics, relativity, and cosmology
Three-Body Problem: Mathematical Status — Solvable but Computationally Useless
Sundman proved in 1912 that a three-body solution EXISTS as a power series — but it needs ~10^8,000,000 terms, making it useless. The problem is solvable in theory, intractable in practice, and chaotic in behavior.
The Three-Body Problem: Why It Has No General Solution
The three-body problem has no general closed-form solution — mathematically proven, not just computationally hard. Chaos means tiny measurement errors at the 11th decimal determine whether bodies collide or eject.
Proving Earth's Rotation: The Foucault Pendulum
Foucault's pendulum proves Earth's rotation: a long pendulum's swing plane stays fixed while the floor rotates beneath it. Requires a long rope (67m originally), heavy weight, and low-friction pivot.
Why Moving the Sun Closer Wouldn't Make Nights Brighter
Nights would stay dark even with a closer Sun (you're in Earth's shadow). But days would be much brighter — light intensity follows the inverse square law, so half the distance = 4x the brightness.
Superhero Physics: Why Atmospheric Reentry Heat Is Compression, Not Friction
Reentry heat is compression heating (not friction). Whether a superhero survives "falling from space" depends entirely on orbital velocity vs stationary drop — two completely different physics scenarios.
Atmospheric Reentry: Compression Heating, Not Friction
Reentry heat comes from compression heating (not friction), creating 1,600-8,000°C plasma. Vacuum exposure allows 10-15s consciousness and 60-90s survival — no explosive decompression occurs.
Nuclear Blast Effects on a Hypothetically Invulnerable Person
Nuclear ground zero physics: blast launches objects at 350+ mph, radiation comes in three phases, and irradiation differs from contamination — an invulnerable survivor would become a contaminated biohazard.