Motion, Space & Quanta
Start with a swinging weight, bend time with relativity, and end where classical physics breaks down entirely.
18 articles
- 1Physics9 min
The Pendulum
Why a pendulum keeps perfect time at small angles — and breaks down at large ones.
- 2Physics10 min
Resonance and Standing Waves
Why timing beats strength in every oscillating system — from a playground swing to a radio tuner, an MRI scanner, and the strings of a violin.
- 3Physics10 min
Turbulence and the Reynolds Number
Why candle smoke climbs smoothly and then shatters, how a single number predicts the switch, and why a bacterium swims through water as if it were honey.
- 4Physics10 min
Buoyancy: Why Steel Ships Float
Why steel ships float while steel bolts sink: buoyancy comes from the weight of displaced fluid, and floating depends on average density, not on being heavy or light.
- 5Physics10 min
Momentum: The Quantity Collisions Conserve
Why total momentum is always conserved in a collision, how it differs from kinetic energy, and why stretching a collision's time protects you from its force.
- 6Physics10 min
Angular Momentum: Why Skaters Spin Faster
How conservation of angular momentum makes a skater spin faster when she pulls her arms in, and why a spinning gyroscope precesses instead of toppling under gravity.
- 7Physics10 min
Kepler's Laws of Planetary Motion
How Kepler's stubborn refusal to ignore a tiny discrepancy in Mars's orbit produced three laws that Newton later derived from a single inverse-square force.
- 8Physics10 min
The Doppler Effect
Motion crowds the waves in front of a source and stretches the ones behind. That single geometric fact explains sirens, sonic booms, weather radar, and the expanding universe.
- 9Physics10 min
Entropy and the Second Law
Gas released in a corner of a box fills the box and never gathers back — not because a force forbids it, but because overwhelmingly more microstates look spread out than gathered.
- 10Physics9 min
Time Dilation
How Einstein's special relativity predicts that time passes differently for observers in relative motion.
- 11Physics10 min
General Relativity: Gravity as Curved Spacetime
Einstein's 1915 theory recasts gravity as the curvature of spacetime: mass-energy bends geometry, objects follow geodesics, and clocks, light, and GPS all obey.
- 12Physics9 min
Electric Circuits and Ohm's Law
How current, voltage, and resistance fit together in $V = IR$ — and why charge is never used up, only energy is.
- 13Physics10 min
Magnetism: Moving Charges and Aligned Spins
Magnetism is not a force separate from electricity — it comes from moving charges and aligned electron spins, forms only closed-loop dipoles, and grips only a few metals.
- 14Physics10 min
Maxwell's Equations and the Nature of Light
Maxwell combined everything known about electricity and magnetism, found a self-sustaining wave hiding in the algebra, and computed its speed from two bench-top constants. The answer was the speed of light.
- 15Physics10 min
Optics: How Light Bends and Focuses
Light bends when its speed changes crossing a boundary — that is refraction — and lenses harness the same effect to focus rays and form real or virtual images.
- 16Physics11 min
Wave-Particle Duality
Fire electrons one at a time through two slits. What you find will change how you think about reality.
- 17Physics10 min
Nuclear Fission and Fusion
The energy in nuclear reactions comes from mass literally disappearing — and one curve explains why fission and fusion both liberate it.
- 18Physics10 min
Superconductivity
Cool certain metals below a critical temperature and their resistance vanishes entirely. The reason involves electrons pairing up and condensing into a single quantum state.