Why do old photos turn yellow?
Show answer & explanation
Answer: Chemical reactions with air
Chemical reactions with air ✓ — Correct! Paper contains lignin that oxidizes when exposed to air and light, turning yellow-brown. Acids in paper also break it down over time. That's why archival photos use acid-free paper and are stored in darkness!
Ink fades leaving yellow — Wrong. The yellow isn't hidden underneath. Paper's chemical breakdown creates the yellow color.
Photos were always yellowish — Wrong. Fresh photos weren't yellow. Chemical degradation over time causes the color change.
More Technology questions
- Why can a satellite redness index flag rusting Arctic rivers but still fail to tell which streams are chemically hazardous?
- A service publishes a fresh random number every minute, plus a public log in which each entry carries a fingerprint of the entry before it. What does that chaining add?
- Why can Cloudflare's lava-lamp camera feed improve encryption even though the cryptographic software that consumes it is deterministic?
- If an attacker learns a pseudorandom generator's seed and algorithm after watching several outputs, why can the later outputs become reconstructable?
- Why does a physical noise source provide security against an attacker who knows the code, while a phone game shuffle does not?
- At parking-lot speed, why do quiet EVs need alert sounds before tire noise helps?