Week 4: Space
Introduction
Last week explored how the quantum nature of the world puts a limit on what we can know, especially on very small scales. This week you will turn your attention to the largest scales of all and ask some big questions about the universe as a whole. Does the universe go on forever? If not, how big is it? Can we ever know these things?
Here’s Marcus to introduce this week’s topic.
Download this video clip.Video player: Video 1
Transcript: Video 1 Introduction
MARCUS DU SAUTOY
This week, you’ll discover that the very large offers as many challenges to knowledge as the very small. It’s remarkable that, confined to our tiny insignificant planet, we know so much about the make up of our universe. But are there some questions we’ll never be able to answer? For example: is the universe infinite in size? If it is, could we ever know? Einstein proved that information travels no faster than the speed of light. You’ll find out that this means there is a limit to how far we can see. The discovery that the universe is expanding also has consequences for how much we can know about our universe. And if the universe is finite: how does that work, give that the universe doesn’t have an edge?
Video 1 Introduction
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By the end of this week, you should be able to:
- appreciate that looking out into space equates to looking back in time
- describe the effective boundary of the observable universe
- appreciate that observations of galaxies show how the whole universe is expanding at an accelerating rate
- understand the implications of Einstein’s theory of general relativity on the expansion of the universe.