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EXCELLENCE
Excellence Nature
EXCELLENCE NATURE

The Universe, Explained

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LEVEL 1 · 0/3LEVEL 2 · 0/3LEVEL 3 · 0/3LEVEL 4 · 0/3LEVEL 5 · 0/3START
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Astronomy you can explain: why light from the Sun is 8 minutes old, a solar system to scale, the real reason for the seasons and the Moon's phases, what makes a planet, how 6,000 other worlds were found, the universe's 13.8-billion-year story, what it's made of, and how we photographed black holes and heard them collide, from NASA and the research.

2h 59m5 constellations
AT THE SUMMIT, YOU WILL BE ABLE TO

01Feel the scale of space with light time and a scale model

02Explain the seasons and the Moon's phases correctly

03Know what makes a planet and how exoplanets are found

04Tell the universe's story, and its biggest open questions

Every lesson of The Universe, Explained

15 lessons in 5 levels, about 3 hours. Level 1 is free.

Level 1The Scale of SpaceFree · 3 lessons
  1. Light takes timeUse light's travel time to feel the distances in space.11 min
  2. A universe to scaleBuild a scale model that shows how empty space really is.12 min
  3. Checkpoint: sizes and distancesPut the solar system's sizes and distances in order.12 min
Level 2Seasons and the MoonMembership · 3 lessons
  1. Why we have seasonsExplain the seasons correctly, and see why most people don't.12 min
  2. The Moon's phasesExplain the Moon's phases, without Earth's shadow.12 min
  3. Checkpoint: the hard ideasExplain the seasons and the phases: the two ideas most people get wrong.12 min
Level 3Other WorldsMembership · 3 lessons
  1. What makes a planetKnow the official definition of a planet, and why Pluto changed class.12 min
  2. Six thousand other worldsKnow how planets around other stars are found, and how many we know.12 min
  3. Checkpoint: worlds near and farConnect the solar system's planets with the thousands beyond it.11 min
Level 4The Big PictureMembership · 3 lessons
  1. 13.8 billion yearsTell the story of the universe, and how we know its age.12 min
  2. The 5% universeKnow what the universe is made of, and how much is still a mystery.12 min
  3. Checkpoint: the big pictureTell the universe's story in one breath, with its open questions.12 min
Level 5Seeing the InvisibleMembership · 3 lessons
  1. Pictures of black holesKnow how astronomers photographed black holes, and what the pictures show.12 min
  2. Ripples in spacetimeKnow what gravitational waves are and how the first was detected.12 min
  3. Capstone: the universe, explainedPull the path together, and teach one part of it.13 min
FREE

Level 1 is open.

Membership opens every other level of this path.

See membership
AFTER THE CORE

Keep going where this path leads.

Think Like a Scientist: Studies, Numbers and HeadlinesHow evidence becomes knowledge · 2h 59m
Understand Climate ChangeOur own planet's physics · 2h 54m