Special Relativity

Approach the speed of light and reality bends: clocks slow, rulers shrink, and energy soars. Einstein's Lorentz factor governs it all.

Special RelativityLive

time dilation & length contraction

Controls

Presets

Speed v (fraction of c)

Near the speed of light, space and time warp. The Lorentz factor γ = 1/√(1−v²/c²) governs it all: moving clocks run slow by γ (time dilation), moving objects shrink along their motion by 1/γ (length contraction), and energy grows without bound. At everyday speeds γ ≈ 1, so we never notice.

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Data Inspector

Lorentz factor γ1.250

Time dilation×1.25

Length contraction×0.800

Speed180 Mm/s

Governing equation

γ = \frac{1}{1 - β ^{2}} = \frac{1}{1 - 0. 6 ^{2}} = 1.250, Δ t^{'} = γ Δ t

Reading this result: Deep in the relativistic regime — moving clocks run visibly slow and rulers shrink markedly along the motion.

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How it works

The Lorentz factor γ = 1/√(1−v²/c²) is the engine of special relativity. Moving clocks tick slow by γ, moving objects contract along their motion by 1/γ, and kinetic energy diverges as v approaches c. At everyday speeds γ is essentially 1, which is why these effects stay hidden until you reach a large fraction of light speed.

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Frequently asked questions

Is this special relativity time dilation tool really free?▾

Yes. Special Relativity runs entirely in your browser using your device's own compute, so local use is free forever. You only pay Compute Tokens if you scale a job to the cloud.

Do I need to install anything?▾

No. Everything runs client-side in a modern browser — no downloads, no license, no account required to start.

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How accurate are the results?▾

The solver uses established numerical methods, but results are for research and educational purposes and should be validated against experiment or professional review before you rely on them.