Sixty years ago, James Watson and Francis Crick formally announced they had discovered the double helix that forms DNA, the molecule containing the genetic instructions for all living organisms. Although Watson and Crick are credited with this discovery, their research stands on the shoulders of others who came before them.

David Rittenhouse built two orreries that showed solar and lunar eclipses and other astronomical phenomena for a period of 5,000 years, going either forward or backward in time. One went to Princeton University and the other to the University of Pennsylvania.

Many major scientific breakthroughs have been the result of fortuitous accidents. From Post-It notes, to penicillin, the rubber for tires and 'smart dust,' the world would be a different place without unlucky mistakes and keen observations.

A massive volcanic eruption in 1816 led to a worldwide disruption in weather patterns. Snow fell in many parts of the world in the summer, and Taiwan even reported snow flakes. It led to famines in much of Europe, and many families in the U.S. moved from New England to the Midwest.

For many years, Tyrannosaurus Rex fossils have been displayed in pop culture and in museums with the incorrect posture. The actual T. Rex held its tail off the ground, using it to help balance its massive head and jaws. But many students still draw the dinosaur incorrectly, with its tail dragging on the ground.

On January 26, 1700, the largest earthquake to hit the lower 48 states occurred just off the Cascadia Pacific coast. The magnitude 9 quake and resulting tsunami caused damage on the coast and crossed the Pacific and damaged villages in Japan. Now, the Cascadia area is preparing for another "big one."

Daniel Bernoulli came from a family of mathematicians. He found success at a young age and his discoveries about fluid dynamics are still in use today. However his father later became jealous of his success and kicked him out of the house before plagiarizing his work.

The famous Hindenburg crash in 1937 marked the end of the use of zeppelins. However now, almost 60 years later, zeppelins have been improved and are again appearing around the world. We look at the invention of the rigid airship, how it rose to popularity, and when you may see them again.

The roll of the Surgeon General of the U.S. has changed quite a bit since John Maynard Woolworth became the first Surgeon General after a reorganization of the Marine Hospital Fund. Different Surgeon Generals have played different rolls in public health and in the political sphere.

We take an interesting look at 18th century Chemistry labs and the many chemicals that could be found there. Many have unique names that we now know to be very different than originally thought. It includes a look at alchemists and how modern chemistry arose.