Octopuses have three hearts and blue blood.
Two hearts pump blood through the gills and one through the body; copper-based hemocyanin — not iron — gives the blue color.
HISTORICAL ARCHIVE
Sources · October 27, 2026
Every claim from this day’s challenge, with its verdict, explanation and sources.
Round 1
Penguins mate for life.
Some do, many don't. Fidelity varies hugely by species: about 89% of Galápagos penguins re-pair, while roughly 85% of emperor penguins switch partners each season.
You should put something in a person's mouth during a seizure so they don't swallow their tongue.
It's impossible to swallow your tongue. Putting objects in someone's mouth can break teeth or block their airway. Instead, keep them safe from injury, turn them on their side and time the seizure.
Round 2
Astronauts get taller in space.
Without gravity compressing the spine, the discs between the vertebrae expand. Astronauts can grow up to 3% taller — about 5 cm for a 1.80 m person — and shrink back within months after returning.
The Great Fire of London in 1666 killed only six people.
That's the official count of verified deaths. But the fire destroyed the homes of about 70,000 people, deaths among the poor often went unrecorded, and historians estimate the real toll was in the hundreds or more.
Drinking coffee dehydrates you.
Caffeine is a mild diuretic, but the water in a typical cup of coffee more than makes up for it. At normal amounts, coffee counts toward your daily fluid intake.
Round 3
Bubble wrap was originally invented as wallpaper.
In 1957, engineers Alfred Fielding and Marc Chavannes sealed two shower curtains together hoping to sell textured wallpaper. It flopped — until it found its calling as packaging.
The QWERTY layout was designed to stop typewriters from jamming.
That's one theory — spreading out common letter pairs reduced jams. Other historians argue it was shaped by telegraph operators transcribing Morse code.
Every drink of alcohol kills off brain cells.
Drinking disrupts how neurons communicate — mainly by damaging dendrites — rather than killing the cells. Heavy long-term drinking can cause real brain damage, but largely through vitamin B1 deficiency, not from each drink.