# Einstein's twin paradox explained - Amber Stuver

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TEDEd Animation

## Let’s Begin…

On their 20th birthday, identical twin astronauts volunteer for an experiment. Terra will remain on Earth, while Stella will board a spaceship. Stella’s ship will travel to visit a star that is 10 light-years away, then return to Earth. As they prepare to part ways, the twins wonder what will happen when they’re reunited. Who will be older? Amber Stuver investigates the “Twin Paradox.”

## Consider a 30 ft (9 m) long garage with doors at both the front and the back (these doors can open and close instantaneously). a. Using special relativity, can you describe how to fit a 45 ft (14 m) school bus into this garage and have both doors closed, if only for an instant? b. For the situation you determine, describe what the bus driver sees and what a non-moving observer outside the garage sees. c. Will both of these observers agree that the bus was contained in the garage with both doors shut at the same time? Why or why not? (If you want to learn more about situations like this, research simultaneity in special relativity or the ladder paradox.)

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## Meet The Creators

• Educator Amber L. Stuver
• Director AIM Creative Studios, Rui Almeida
• Narrator Bethany Cutmore-Scott
• Producer Tom Knight
• Sound Designer André Aires
• Animation Mulligan Studio, Ricardo Coelho
• Composer André Aires
• Storyboard Artist Rui Almeida
• Illustrator Rui Almeida
• Character Designer Rui Almeida
• 3D Animator Hélder Vasconcelos
• Music AIM Creative Studios
• Director of Production Gerta Xhelo
• Editorial Producer Alex Rosenthal
• Associate Producer Bethany Cutmore-Scott
• Script Editor Alex Gendler
• Fact-Checker Brian Gutierrez