Grandfather Paradox: Explained in Simple Words

What is the Grandfather Paradox? It's the biggest logical objection to backward time travel — and in this video, we explain it in simple words. If you travel back in time and kill your grandfather, you'd never be born... but then who killed him? We explore this mind-bending paradox, connect it to quantum superposition and closed time loops, and discuss how multi-dimensional time could resolve it — plus a nod to Christopher Nolan's Tenet! 📚 Concepts Covered: - Classical view of time: a straight, one-directional line - The paradox: killing your grandfather prevents your own existence - The logical loop: if you don't exist, grandfather lives → you exist → loop - Quantum superposition: two realities existing simultaneously - Closed time loops: grandfather is both dead and alive - Tenet (2020): "What's happened, happened" - Multi-dimensional time as a potential resolution - Parallel worlds and copies of reality ⏱️ Chapters: 0:00 What would you do with a time machine? 0:26 You can interact with your grandfather — but not kill him 0:45 The Grandfather Paradox defined 0:51 Classical time: a straight line, past → present → future 1:10 The paradox makes backward time travel logically impossible 1:20 Clara's thought experiment: inventing a time machine 1:52 Kill grandfather → father never born → Clara never exists 2:08 No Clara → no time machine → grandfather lives → Clara exists 2:29 The infinite logical loop 2:48 Two parallel realities — quantum superposition 3:16 Superposition: a coin that's heads AND tails at once 3:37 Closed time loops: grandfather is both dead and alive 3:45 Tenet (2020): "What's happened, happened" 4:25 The primary objection to backward time travel 5:04 What if time has more than one dimension? 5:10 Multi-dimensional time resolves the paradox — and implies parallel worlds 👉 Watch Next: ▶ Time Dilation — Einstein's Relativity Explained — https://www.youtube.com/watch?v=yuD34tEpRFw ▶ Quantum Entanglement Explained — https://www.youtube.com/watch?v=fkAAbXPEAtU ▶ Multiverse Theory Explained — https://www.youtube.com/watch?v=TLGcmDbleWQ #grandfatherparadox #timetravel #paradox #quantumphysics #Tenet #scienceabc If you wish to buy/license this video, please write to us at admin@scienceabc.com. Voice Over Artist: John Staughton ( https://www.fiverr.com/jswildwood ) SUBSCRIBE to get more such science videos! https://www.youtube.com/channel/UCcN3IuIAR6Fn74FWMQf6lFA?sub_confirmation=1 Follow us on Twitter! https://twitter.com/abc_science Follow us on Facebook! https://facebook.com/sciabc Follow us on Instagram! https://www.instagram.com/scienceabcofficial/ Follow us on LinkedIn! https://www.linkedin.com/company/scienceabc Follow our Website! https://www.scienceabc.com