Why looking at a particle changes it (The Arrow Game)

Why looking at a particle changes it (The Arrow Game) The retired physics teacher smiles. CHAPTERS 0:00 The question 1:00 Where it shows up 1:58 The wrong guess 2:58 The mechanism 4:14 The number 5:17 The demonstration 6:36 The edge case 8:09 Back to your day 9:30 Recap 10:23 The question WHAT YOU'LL TAKE AWAY • A single particle takes every possible path at once until it is forced to interact with something. • Every possible path gets a spinning arrow as the particle travels. • Add the arrows tip to tail to find the mathematical chance of a hit. • Looking forces a single path, discarding the rest and erasing the wave pattern. THE NUMBERS nineteen eighty-nine: 1,989 seventy thousand electrons: 70,000 fifty years: 50, two doors: 2, three steps: 3, one single particle: 1 (story amounts, chosen for the example) SOURCES nineteen eighty-nine: Akira Tonomura's double-slit experiment with single electrons, published in American Journal of Physics https://aapt.scitation.org/doi/10.1119/1.1... seventy thousand electrons: Approximate number of electrons accumulated in the final frame of the 1989 Hitachi experiment film https://www.hitachi.com/rd/research/materi... We assume things act the same way whether we watch them or not, but the universe keeps its options open until forced to leave a mark. Simplified on purpose; the sources carry the full picture. If this was useful, like it and subscribe, and tell me in the comments what you'd do. PROOF https://zeuboo.com/proof/a_simple_quantum_... RECEIPTS Every number here is sourced, computed from stated inputs, or declared a story amount. The verification page travels with the episode's masters and lists each one with its provenance, the judge's checklist and the rules the script was checked against. Made with AI image, speech and music models under a locked reference set; declared as synthetic media. #science #howitworks #explained #ASimpleQuantumWorld