What If You Found a Tiny Black Hole in Your Pocket?

What would happen if you found a tiny black hole in your pocket? Could you keep it, or would it pull your keys, your hat and the bus queue into orbit? Dave finds something small and dark in a jumble-sale coat, with a mint, a coin and his keys circling it. Lost Property closes at five, so he has seventy minutes and one biscuit tin to hand it in. On the way: why Stephen Hawking said tiny black holes could have formed in the first second of the universe, how a hole that weighs about a billion tonnes can be smaller than an atom, why a black hole glows (and why the smaller it is, the hotter), what a mini black hole would do within two and a half metres, why you can never put it down, and the one place on Earth that can hold it. ⏱ Chapters 0:00 3:50 pm: something dark in a coat pocket 0:59 3:58 pm: a mountain smaller than an atom 1:36 4:10 pm: why black holes glow 2:18 4:22 pm: the pull zone 3:07 4:35 pm: never put it down 3:47 4:45 pm: does it have a name? 4:22 4:58 pm: Lost Property 5:10 The last second Sources: - Hawking, S. (1971), "Gravitationally collapsed objects of very low mass", Monthly Notices of the Royal Astronomical Society 152, 75 - Hawking, S. (1974), "Black hole explosions?", Nature 248, 30-31 - Hamilton, A., JILA, University of Colorado Boulder, "Hawking radiation" (mini black holes: about 10^11 kg, lethal gamma rays, the last second radiates about 1000 tonnes of rest mass energy) - Khriplovich, I. B., Pomeransky, A. A., Produit, N. and Ruban, G. Yu. (2008), Physical Review D 77, 064017, "Can one detect passage of small black hole through the Earth?" (arXiv:0710.3438) - Wikipedia: Hawking radiation; Micro black hole; Primordial black hole; Earth's internal heat budget (47 terawatts) - Universe Today, "What would happen if a small black hole hit the Earth?" - "A relativistic gravity train" (arXiv:1704.04026): the 84-minute fall through the Earth and back - Our own arithmetic from the published formulas: the 1.5-femtometre radius, about 360 megawatts, over 100 billion degrees, the 2.6 metre radius where it pulls harder than Earth, about three trillion years. Primordial black holes have never been observed, so the video says "if". The Earth becomes the owner, and the next question is what happens in that last second. ▶ More What If scenarios: https://www.youtube.com/playlist?list=PLSMv6579_BbM ▶ All Black Hole Life videos: https://www.youtube.com/playlist?list=PLN-K-zF7RNW0 ▶ Subscribe: https://www.youtube.com/@BlackHoleLife?sub_confirmation=1 About Black Hole Life: funny "what if" science, psychology and history, hand-drawn with stick figures. Every number is sourced. New videos every week. #blackhole #whatif #science #hawkingradiation #space