On Saturn's moon Titan, gravity is so low and the atmosphere is so thick that humans could fly by flapping arms like wings

There is a black hole at the center of most galaxies

98% of the atoms in the human body are replaced every year with new ones

The Earth's rate of rotation is slowing at a rate of about 17 milliseconds a century. The length of a day for the dinosaurs was closer to 22 hours

Blood vessels

Brain fun fact