The human nose can detect about 1 trillion different scents

Crows can recognize individual human faces and hold grudges for years

Crows exhibit facial recognition and long-term memory of humans

The observable universe is about 93 billion light-years in diameter

The observable universe spans approximately 93 billion light-years across

What is the estimated number of galaxies in the observable universe, and what factors contribute to the uncertainty in this estimation?

Approximately 2 trillion galaxies, with uncertainty due to observational limits and cosmic variance

Pi has been calculated to over 100 trillion digits — but 39 digits is enough to measure the observable universe to the width of a hydrogen atom

Pi's 39-digit approximation measures universe's width to hydrogen atom's size

Octopuses have three hearts, blue blood, and nine brains — one central, eight in their arms

Octopuses possess three hearts, blue blood, and a central brain with arm-based mini-brains

A single teaspoon of soil contains more microorganisms than people on Earth

"One teaspoon of soil hosts more microbes than Earth's human population."