Understand how the world works.

From the atoms in your body to the stars in the sky. Explore, experiment, and discover the connections through interactive simulations.

Explore the lessons below ↓

Applied Physics

Follow one hydrogen nucleus in a strong magnet all the way to a finished MRI image.

See how atomic clocks in orbit and the speed of light tell your phone where it is.

Watch a cold hydrogen cloud collapse into the Sun and planets over 4.6 billion years.

Potential and kinetic energy, conservation, heat, temperature and energy at home.

One wave model for water, sound and light: interference, resonance and the Doppler effect.

Build the atom from the ground up, then see how its photons make emission spectra.

Decay, half-life, dose and binding energy, from radiotherapy to nuclear power.