Pet dogs and elephants are the only animals that seem to instinctively understand human gesture.
14
In one day, adult lungs move about 10,000 litres of air.
11
The average person's skin weighs twice as much as their brain.
131
Coughing can cause air to move through your windpipe faster than the speed of sound - over a thousand feet per second!
197
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
If Earth's life was compressed into 1 year, then humans would have been around for only 2 seconds.
15
The human eye blinks an average of 4,200,000 times a year.
233
The adult human brain weighs about 3 pounds (1,300-1,400 g).
99