Aired: Nov 3, 1995Bill follows rivers and streams from their origins and explains their impact ...
Bill Nye, the Science Guy
Season 4 Episode 20: Time
Time affects every living thing on Earth. Trees shed their leaves. Some animals only come out at night. There are even insects that only emerge every 17 years. Days, hours, minutes, and seconds – all of these were invented by humans. Humans came up with these units of time to organize their lives and to study the world. One of the first ways humans told time was by noticing the difference between daytime and nighttime. Humans use the Earth revolving around the Sun to divide time into years an...
