How Eratosthenes measured the size of Earth - GIF

[Floradawg]

Carl Sagan, the first scientist that the public could relate to in a personal way. He would appear on The Tonight Show with Johnny Carson and many other TV shows and explain scientific ideas and theories to the viewers. He had a way of making potentially dull explanations interesting. He helped to mold Neil deGrasse Tyson into the scientist that he is today.