Tech WondersPlay

Algorithms & EmergenceGraph Theory

Six Degrees

You're about six people away from almost anyone

A president. A farmer in Mongolia. Your favorite singer. How many 'friend of a friend' steps away are they? Far fewer than you'd guess.

You'll find out

  • How 50 friends outgrow the whole planet
  • Why a faraway friend shrinks the world
  • Why Facebook says 3.5, not six

Why it matters

It's why rumors circle the globe in days, data crosses the internet in a few hops, and jobs come via friends of friends.

About 4 min8 interactive slides · 5 questionsLesson 1 · Zone 1

Play this lesson

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More in this zone

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  2. 3Coding TheoryBroken QR Codes Still WorkRip out part of a QR code and it can still scan
  3. 4Map ProjectionsMercator's LieGreenland looks as big as Africa; Africa is 14 times bigger
  4. 5GeographyWhy Flights CurveThe shortest route looks bent on a flat map
  5. 6Natural Language ProcessingWhy AI Can't Count the R's in StrawberryAI reads chunks of words, not letters
  6. 7Internet & WebJourney of a ClickTap a link and your request circles the planet in under a second
  7. 8Visual PerceptionThe Blind SpotThere's a hole in your vision and your brain paints over it
  8. 9InfinityHilbert's HotelA full hotel with infinitely many rooms can always fit more guests