EinsteinAtlas

Chapter VI

The Thought Experiment Lab

Think Like Einstein — Two Interactive Engines

Einstein never worked with equations first. He began with vivid mental images — a man falling in an elevator, a teenager racing alongside a light beam. Enter his patent-office mind and explore two of his greatest thought experiments made interactive.

I

Special Relativity Engine

Adjust the velocity slider to observe time dilation and length contraction in real time.

v = 0 (at rest)v = 0.99c (near light)
v = 0% c

Lorentz Factor γ

1.0000

γ = 1/√(1−v²/c²)

How much time dilates and mass increases

Time Dilation

×1.000

t′ = γ · t₀

Moving clocks run this much slower

Length Contraction

100.0%

L = L₀/γ

Object is this fraction of its rest length

Length Contraction

L₀ = rest length

At v = 0%c: length = 100.0% of rest length

Time Dilation

Einstein

This clock runs 1.00× slower than a clock at rest

At v = 0.99c, γ ≈ 7.09. A moving clock ticks only ~14 seconds for every 100 seconds of a stationary clock. A moving spacecraft 1 km long would appear only 141 meters long to a stationary observer. These are not illusions — they are confirmed by particle accelerators and atomic clocks on aircraft daily.

II

General Relativity Engine

Click on the grid to place masses and watch light rays bend in real time.

Click to place a massive body — watch light bend around it
Spacetime fabric
Light ray (bent by gravity)
Massive body

This interactive model demonstrates gravitational lensing — the bending of light around massive objects. Eddington measured this bending in 1919 during a solar eclipse, confirming general relativity and making Einstein the most famous scientist in the world.

"When I examine myself and my methods of thought, I come to the conclusion that the gift of fantasy has meant more to me than my talent for absorbing positive knowledge."

— Albert Einstein, 1929