Days on Earth are getting longer.
Tidal friction from the Moon slows our spin: days lengthen ~1.8 ms per century; 1.4 billion years ago a day lasted just 18 hours 41 minutes.
HISTORICAL ARCHIVE
Sources · October 19, 2026
Every claim from this day’s challenge, with its verdict, explanation and sources.
Round 1
Diamonds are made of the same stuff as coal.
Both are carbon — but diamonds were never compressed coal. Most formed deep in the mantle over a billion years ago, long before the land plants that later became coal even existed.
Mature sunflowers track the sun across the sky all day.
Only young, growing buds heliotrope; once mature, stalks stiffen and the flower faces east forever.
Round 2
The "lead" in pencils has never contained lead.
Pencils write with graphite; 1500s English miners mistook it for lead ore ("plumbago") and the wrong name stuck for 500 years.
Dead people can get goosebumps.
As rigor mortis sets in, the arrector pili muscles contract, pulling hair follicles upright on the corpse — postmortem goosebumps.
Massive doses of Vitamin C can cure or prevent the common cold.
Clinical trials show no preventative effect for the general public, though it may marginally shorten the duration of cold symptoms once you are already infected.
Round 3
A jellyfish can reverse its own aging.
Turritopsis dohrnii reverts to juvenile polyp stage after maturity, dodging senescence — though it can still be eaten or infected.
There is a mammal completely covered in scales.
The pangolin — the only mammal with overlapping keratin scales, armor evolved against predators.
Bananas stored together make each other radioactive.
A banana's radioactivity comes from its own potassium-40; neighboring bananas contribute nothing. Buy freely.