LMR-085 · Gravity & Time
Length Contraction
Move fast enough and the world flattens in your direction of travel.
§ A first look
§ Depths
Six ways into the same idea — from bedtime story to chalkboard. No order required.
L1 · Crayon
Told like a bedtime story.
For a curious 10-year-old. No jargon. Just a picture in your head.
We're used to thinking that a metre stick is one metre long, end of story, send the invoice. Turns out that's only true if the stick is sitting still next to you. If a metre stick zooms past you at really, really fast speed — close to the speed of light — it actually looks shorter from your point of view than when it was at rest. Not an optical illusion. Not a trick of the eyes. The stick is genuinely squashed in the direction it's moving. This squashing only matters at extreme speeds, which is why you've never noticed it shopping for furniture. The fancy name is length contraction.
§ Strange but true
- 01Move fast enough and the universe shortens in your direction of travel. Not optically — actually.
- 02A spaceship at 99% the speed of light would, from Earth's view, be flattened to 1/7 its length.
- 03The same train, measured by you and by the platform, has two different lengths. Both correct.
§ From the field journal
Length Contraction
"Move fast enough and the world flattens in your direction of travel."
— observed, sketched, not yet fully understood.
§ Nearby