Facts That Are

Due to general relativity, time passes very slightly faster for your head than your feet because your head is further from Earth's gravitational center. Over a 79-year lifetime, your head ages about 90 nanoseconds more than your feet.

You are literally not the same person you were a decade ago—physically. Your skeleton is replaced every 10 years, your liver every 5 months, your skin every 2-4 weeks. The atoms that made you as a child are now scattered across the planet.

The number of possible chess games (the Shannon number) is around 10^120. The number of atoms in the observable universe is only about 10^80. You could play a unique chess game every second since the Big Bang and never repeat—not even close.

Humans share about 60% of their genetic code with bananas. You share 85% with mice, 96% with chimps, and 70% with slugs. The genetic code of life is so conserved that we're essentially variations on a 4-billion-year-old theme.

Scientists calculated the average color of all light in the observable universe. It's a beige shade officially named "Cosmic Latte." The universe used to be bluer when it was younger—it's slowly getting more red as stars age and die.

Octopuses have three hearts—two pump blood to the gills, one pumps it to the body. Their blood is blue because it uses copper-based hemocyanin instead of iron. Each of their 8 arms has its own mini-brain that can act independently—an arm can "decide" to open a jar while the central brain focuses on something else.

Forests have their own "Wood Wide Web"—a network of fungal threads connecting trees underground. Mother trees recognize their offspring and send them extra nutrients. Dying trees dump their resources into the network as a final gift to the forest.

The Great Pyramid was built around 2560 BC. Cleopatra lived around 30 BC. The Moon landing was 1969 AD. Cleopatra existed closer in time to us watching Netflix than to the construction of the pyramids in her own backyard.

The organ that processes all your pain sensations has no pain receptors itself. Surgeons can operate on a conscious patient's brain while they chat about the weather. The brain literally cannot feel itself being touched or cut.

If you removed all the empty space from the atoms in your body, you would fit into a cube less than 1/500th of a centimeter on each side. Every human on Earth could fit into a single sugar cube.