LMR-014 · Light
Redshift
The universe is stretching, and dragging every wavelength of light with it.
§ 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.
When an ambulance drives past you, its siren goes 'eeeee' high while coming closer and 'ooooooo' low after it's passed by. The sound itself didn't change. The moving stretched it on the way out. Light does the same trick. When something in space is moving away from us, its light gets stretched toward the red end of the rainbow on its way over. Nearly every galaxy we look at is doing this. The whole universe is, very slowly, running away from itself. Honestly, mood.
§ Strange but true
- 01Galaxies aren't moving away through space. Space itself is stretching — like raisins drifting apart in rising bread.
- 02JWST has spotted galaxies whose light has been traveling for 13.4 billion years. They look like the dawn.
- 03The cosmic microwave background is light so stretched its wavelength is now the size of your hand.
§ From the field journal
Redshift
"The universe is stretching, and dragging every wavelength of light with it."
— observed, sketched, not yet fully understood.
§ Nearby
Constellations near Redshift
→
Light
You're reading messages that left stars before humans existed.
→
Spectrum
The rainbow keeps going in both directions, forever.
→
Photon
A massless messenger that always travels at the universe's speed limit.
→
Big Bang
Not an explosion in space. An expansion of space.
→
Dark Energy
Something is pushing space apart faster, and we have no idea what.
→
Galaxy
A herd of a hundred billion stars, held together by gravity and dark matter.