A clip from a Pursuit of Wonder video illustrates how man's ideas of what is true often turns out to be completely false.

In Peru in the middle of the 1400s, there was what is believed to be the largest known child sacrifice in the world, with about 140 children and more than 200 animals killed. The reason: attempting to appease the gods in response to unusually bad weather.

In Europe in the 17th century, just a few hundred years ago, it was widely believed that the earth was the center of the universe and everything else revolved around it. When the now famous astronomer Galileo Galilei published a work that showed that the sun was the center of the universe, and the earth revolved around the sun, the Roman inquisition banned his work and found Galileo guilty of heresy.

In the late 19th century, little more than a hundred years ago, doctors used what are now Schedule 1 drugs to treat common cold symptoms in children. Also, around this time, doctors believed it was foolish to wash their hands before delivering babies or during other medical procedures. Only eighty years ago, it was believed that cigarettes posed no health dangers.

And the list goes on. This Earth is not merely a cemetery of people that once were, but also a cemetery of ideas and beliefs once held to be true but are no longer.

You can watch the video here (2 mins 15 sec - 3 min 57 sec).