The geological revolution revealed that the Earth is of great antiquity
and yet has a history we can read in the land. We will discuss ideas
of cyclic and linear time, historical versus physical age estimates,
the discovery of geological time, and
radiometric dating methods that give us our present estimate of
4.54+/-0.05 Gyr for the age of the Earth. R ... Show More
Sep 2009
Lecture 3: Imagining Other Worlds
What is the cultural history of our imaginings of other worlds and their possible inhabitants? I will draw examples from history, philosophy, literature, cinema, and popular culture. In the end, our imaginings about other worlds inform us more about ourselves, our
hopes and our f ... Show More
40m 9s
Mar 2022
Comment calculer l'âge d'une étoile ?
La durée de vie d'une étoile peut nous renseigner sur sa composition et sur l'existence éventuelle de la vie dans le cosmos. mais, en dehors du Soleil, il est assez difficile de déterminer l'âge d'une étoile.
L'importance de la masse
En évaluant, grâce à la radioactivité, l'âge d ... Show More
1m 58s