What are space and time? To begin our exploration of the evolving
Universe, we must first understand what we mean by space and time.
This lecture contrasts the Newtonian view of the World, with its
absolute space and absolute time, with that of Einstein, who showed
that space and time were not absolute but relative constructs, and
that only spacetime, unif ... Show More
Feb 2006
Lecture 28: Groups & Clusters of Galaxies
Galaxies are found in groups and clusters, and these are only the
start of a hierarchy of cosmic structures up to the largest scales
observed. This lecture introduces the properties of groups and
clusters of galaxies, superclusters (clusters of clusters), and
large scale structur ... Show More
39m 58s
Jun 2009
Telescopes that Rocked Our World
This year marks the 400th anniversary of Galileo’s use of the first telescope. On this week’s show, we reflect on how telescopes have shifted our perspective on how small we are in size, space, and time. We also discuss how they help astronomers discover new and interesting aspec ... Show More
56 m