If Earth's life was compressed into 1 year, then humans would have been around for only 2 seconds.
15
On average, there's 100 billion neurons in the human brain.
83
Having sex can make a woman look younger and more attractive due to the release of estrogen and collagen.
346
Our brains have a negativity bias and will remember bad memories more than good ones.
15
By weight, Bone is five times stronger than steel.
417
It took 200,000 years for humans to reach 3 billion in number. It took 40 years for the next 3 billion.
11
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
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