In this lecture we step back and look at the history of life on Earth
from the first signs of life at start of the Archaean Eon 3.5 billion
years ago to just up to the present day. We will review the appearance
of photosynthesis and the rise of oxygen in the atmosphere in the
Proterozoic, the appearance of the first eukaryotes and sexual
reproduction, and ... Show More
Oct 2009
Lecture 19: The Origin of Life on Earth
How did life arise from non-life? Frankly, we don't know, but current
experimental work is aimed at trying to understand how it might work in
biochemical terms. This lecture sets out the problem of "abiogenesis",
and describes our current thinking about the likely origins of life ... Show More
46m 8s
Oct 2009
Lecture 17: Life on the Edge
Extremophiles are organisms that are adapted to survive in extreme environments. This lecture describes the challenges that
extremes of heat, cold, acidity, salinity, and radiation pose to
organisms, and show examples of how evolution has nonetheless allowed
some organisms to ada ... Show More
46m 54s
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