Time Dilation — Two-Observer Simulator

Velocity (fraction of c) 0.50

Simulation speed 1.0×

Time-dilation factor

1.155

The moving observer's clock ticks once for every 1.16 ticks of the stationary observer.

Future travel — if observer B spends

in the field, observer A (outside) experiences:

1.155 years

B arrives +0.155 years into A's future.

Engineering cost — to put a 100 kg person in this field

Scenarios (click to load)

What you're seeing
Each frame contains a light clock — a photon bouncing between two mirrors. One bounce = one tick.

In the velocity mode the right clock is moving at v relative to the lab, so from the lab's frame its photon traces a diagonal, longer path. Since c is constant, that clock ticks slower by exactly γ.

In the gravity mode the right clock sits at radius r from a Schwarzschild mass; deeper in the well = slower ticks by √(1 − r_s/r).

The headline: time dilation IS forward time travel. Strictly one-way — you can fast-forward yourself, but you arrive in a future you cannot return from.

lab frame · both clocks visible

Observer A — stationary (lab frame)

0 ticks

proper time τ_A = 0.00 s

Observer B — inside the field

0 ticks

proper time τ_B = 0.00 s · ratio 1.000