PHYSICS · CLASSES 10, 11 & 12 · 7 EXPERIMENTS

Light isn't what you think. It makes us time travellers.

Change one thing. See what nature actually predicts. Travel through time by looking across space—or by moving close to light speed.

0 / 7 discoveries mastered

SPEED OF LIGHT · VACUUM299,792,458 m/sExactly defined · not a spaceship target

INTERACTIVE PHYSICSLight is an electromagnetic field

MODEL · NOT TO SCALE

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Electric and magnetic fields oscillate across the direction of travel.SCHEMATIC VISUAL

Model accuracy and common myths

Light does not have a valid rest frame. A massive ship may approach, but never reach, c. A telescope reveals past light, not a journey to past events. The visuals use educational scale and idealized models.

Physics sources and equations

The equations and educational notes are based on the SI definition of c, NASA's lookback-time explanations, and OpenStax wave optics, quantum physics and special relativity. The model is not a real telescope, spaceflight simulator or laboratory measurement.

NASA · Lookback time OpenStax · Relativity OpenStax · Photon interference Stanford · Relativistic sky

Bright-star coordinates: HYG v4.1 / Astronexus · adapted subset, J2000. Data licensed CC BY-SA 4.0. Star temperatures and colours are modeled, not measured spectra. WebGL2 is optional.