Speed
Speed We evolved from our early primate ancestors into modern humans over a period of about 7 million years. Then we walked out of Africa within about 100,000 years and found niches everywhere else on our planet over the next 100,000. We only began to farm fairly efficiently and consistently about 10,000 years ago, eventually resulting in the human population explosion within the last few centuries. Brain bioelectrical signals propagate at about 75 mph (120 kmph). We walk at about 3 mph (5 kmph), run at 6 mph (10 kmph), ride a bicycle or a horse at around 10 mph (16 kmph), and move on paved roads in automobiles at about 75 mph (120 kmph). We fly in jet aircraft at 500 mph (805 kmph), 6 miles (9.7 kilometers) above the surface of earth, where we heretofore roamed very slowly. Human reflexes, like a hand being pulled away from a hot stove, are triggered within 50 milliseconds (1/20 of a second). A quick conscious decision takes a minimum of 200 ms (1/5 of a second). To progress fro...