Quantum mechanics, relativity, and the physics of the very small
22 Aug 2026
How does an atomic clock work? Cesium-133's 9,192,631,770 Hz hyperfine transition locks the SI second, with laser cooling and precision explained.
20 Aug 2026
Bohr model calculator for hydrogen electron energy levels — find transition wavelengths, explore the emission spectrum, and see why orbits are quantized.
29 Jul 2026
Time dilation calculator with an animated light clock, real-world speed presets, and a spacetime diagram that resolves the classic twin paradox.
7 Jul 2026
Half-life calculator with an interactive radioactive decay simulator — find the amount remaining, decay constant and age of a sample from N = N₀e^(−λt).
4 May 2026
Lasers amplify light through stimulated emission — explore the quantum mechanics of population inversion, optical cavities, and how the first laser was built in 1960.
27 Apr 2026
Einstein's Nobel Prize experiment visualised — watch photons eject electrons from a metal plate and discover why frequency beats intensity every time.