The SAT Question Everyone Got Wrong

How an SAT question became a mathematical paradox. Head to https://brilliant.org/veritasium to start your free 30-day trial, and the first 200 people get 20% off an annual premium subscription.

I invented Snatoms, a molecule modeling kit where the atoms snap together magnetically. Try it at https://ve42.co/SnatomsV

Huge thanks to Dr. Doug Jungreis for taking the time to speak with us about this SAT question.

Thanks to Stellarium, a wonderful free astronomy simulator – https://ve42.co/Stellarium

Thanks to Newspapers.com, a database of historical newspapers – https://ve42.co/Newspapers

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References:

Summary of this problem by MindYourDecisions –

• Why did everyone miss this SAT Math q...

More cool math about this problem by Kyle Hill –

• The SAT Question NO ONE Got Right

Discussion of a solar day by MinutePhysics –

• Why December Has The Longest Days

Murtagh, J. (2023). The SAT Problem That Everybody Got Wrong. Scientific American – https://ve42.co/SATSciAm

United Press International (1982). Error Found in S.A.T. Question. New York Times – https://ve42.co/SAT-NYT

Yang (2020). What's the hardest SAT math problem that you've seen? Quora – https://ve42.co/SATQuora

Coin rotation paradox via Wikipedia – https://ve42.co/CoinParadox

Simmons, B. (2015). Circle revolutions rolling around another circle. MathStackExchange. – https://ve42.co/CircleRoll

Sidereal time via Wikipedia – https://ve42.co/SiderealWiki

Solar Time vs. Sidereal Time via Las Cumbres Observatory – https://ve42.co/SiderealLCO

Images & Video:

Zotti, G., et al. (2021). The Simulated Sky: Stellarium for Cultural Astronomy Research - https://ve42.co/Stellarium

Newspapers from 1980s - 1990s via Newspapers.com – https://ve42.co/Newspapers

SAT Practice Test via the College Board – https://ve42.co/PracticeSAT

Revolution Definition via NASA – https://ve42.co/RevolutionNASA

Revolution Definition via Merriam-Webster – https://ve42.co/RevolutionWebster

Earth motion animation via NASA – https://ve42.co/OrbitNASA

Satellite animation via NASA – https://ve42.co/SatNASA

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Directed by Emily Zhang

Written by Emily Zhang and Gregor Čavlović

Edited by Peter Nelson

Animated by Ivy Tello and Fabio Albertelli

Filmed by Derek Muller

Produced by Emily Zhang, Han Evans, Gregor Čavlović, and Derek Muller

Thumbnail by Ren Hurley

Additional video/photos supplied by Getty Images and Pond5

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