After age 30, the brain shrinks a quarter of a percent (0.25%) in mass each year.
139
One human hair can support 3 ounces.
191
A man's beard grows fastest when he anticipates sex.
239
An unprotected human can survive up to 1.5 minutes in space with no permanent bodily damage.
82
An average heart beats 100,000 times a day, pumping some 2,000 gallons of blood through its chambers. Over a 70-year life span, that adds up to more than 2.5 billion heartbeats.
73
Modern humans first appeared about 200,000 years ago, but record keeping didn't begin until about 6,000 years ago. That means about 97% of human history is lost.
21
Tigers can see 6 times better at night than humans.
305
The average person will go on a date at least 100 times before they finally marry.
33