The oldest stone tools found are dated from 2.7 - 2.9 million years ago. The species that made these tools is unknown.
13
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
Our brains have a negativity bias and will remember bad memories more than good ones.
15
In 30 minutes, the average body gives off enough heat (combined) to bring a half gallon of water to boil.
198
Research has determined that most people are happiest at 7:26pm on a Saturday night.
69
When you are looking at someone you love, your pupils dilate, they do the same when you are looking at someone you hate.
1k
The human brain uses approximately as much energy as a 10 watt light bulb.
120
Your heart will pump about 212 million liters in its lifetime.
26