Explore journey

All 30 lessons in the opening journey

Browse the first journey, find ideas by topic, and see what is ready for you today.

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Day 1

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By the end of this opening journey, you will understand the basic story of the universe: how it began, how stars and galaxies formed, how physics shapes space and time, and why the search for life changes how we see our place in it.

Day 1

The Big Bang: How the Universe Began

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The Big Bang describes space expanding from a hot, dense early state.

CosmologyFoundations

Day 2

Cosmic Microwave Background Radiation

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The cosmic microwave background is relic radiation from the early universe.

CosmologyEvidence