- Dr. Carl Sagan (1934 - 1996): Perhaps no one has done as much to bring the wonders of astronomy and our universe to the lay public as Dr. Sagan. It is appropriate to mention him here during a discussion of how large the universe is, since the phrase for which he will always be remembered is "Billions and billions." This was his way of expressing the incredibly large number of stars, planets, and galaxies, during the production of his famous PBS TV series, "Cosmos." He was an astronomer, educator, author, pioneer in exobiology, Director for Planetary Studies, and David Duncan Professor of Cornell University. As someone once said, perhaps his greatest contribution to the world was his commitment to truth. He died of pneumonia on December 20, 1996 after a two year battle with bone marrow disease.
- Dr. Stephen Hawking (1942 - Still Alive): If anyone were to rival Dr. Sagan in popularity among lay persons, it would have to be Dr. Stephen Hawking. Born in Oxford, England, he attended University College there, earning a degree in physics despite his desire to study mathematics and his father's request that he study chemistry. Despite being diagnosed with ALS (amyotrophic lateral sclerosis or Lou Gehrig's disease) in 1963 (at which time, doctors didn't believe he would live to complete is degree), he earned his PhD in 1966. In 1988, he published his famous "A Brief History of Time." By mid 1995 it had been on The Sunday Times best-sellers list for 237 weeks. This broke the previous record of 184 weeks, a feat which is recorded in the 1998 Guinness Book of Records. Despite dire predictions by doctors over the years, Hawking is and married with three children. He uses a wheelchair for locomotion. In 1985, he completely lost the use of his vocal chords in an operation to assist his breathing. Today, he communicates through a computerized speech synthesizer. He is also the editor of Stephen Hawking's A Brief History of Time: A Reader's Companion and has written a number of other excellent books on astronomy. He presently holds Sir Issac Newton's chair as Lucasian Professor of Mathematics at Cambridge University.
Now that we've been amazed by the size of the universe and met some great thinkers, next lesson, we'll start looking closer at some of those stars that are so far away.
Assignment
Read more about Astronomical Units, Light Years, and Scientific Notation. Don't forget the discussion Forum.Fifth Lesson > The Universe Has Gas > Lesson 5, 6, 7, 8, 9, 10
As I mentioned in a previous lesson, we're going to learn a little about a couple of other giants of astronomy of the twentieth century here.
Purchase Related Resources to Astronomy 101
Cosmos: Carl Sagan 7-DVD SetBIOGRAPHY: Carl Sagan: A Cosmic Celebrity
Purchase Related Resources to Astronomy 101
Stephen Hawking's On the Shoulders of Giants BookA Brief History of Time DVD
New posts to the Space forums:
Explore Space / Astronomy
Must Reads
More from About.com
Work Hard, Travel Easy
The best tips for business travelers.Dog Care
Get tips on training and caring for dogs of all ages.48 Hours in Vegas
Plan a hot weekend in Sin City.Hotel Advice
The must-stay hotels worldwide.
©2008 About.com, a part of The New York Times Company.
All rights reserved.