Most marine fish can survive in a tank filled with human blood. See more

Your system of blood vessels is over 60,000 miles long. That's long enough to go around the world more than twice! See more

Most dust particles in a US house are made from dead skin. See more

The Netherlands has built 800 miles of massive dikes and sea walls to hold back the sea. See more

Those stars and colours you see when you rub your eyes are called phosphenes. See more

The light from your computer screen streams at you at almost 186,000 miles a second. See more

The microwave was invented after a researcher walked by a radar tube and a chocolate bar melted in his pocket. See more

A cat's urine glows under a black light. See more

The 'save' icon on Microsoft Word shows a floppy disk, with the shutter on backwards. See more