4 of Physics’ (Other) Greatest Mysteries

Physicists are interested in the big questions like "Where did we come from?" and "What is all this stuff?". But the answers to some of these questions, just lead to more questions. Hosted by: Michael ArandaSciShow is on TikTok! Check us out at https://www.tiktok.com/@scishow ----------Support SciShow by becoming a patron on Patreon: https://www.patreon.com/scishow----------Huge thanks go to the following Patreon supporters for helping us keep SciShow free for everyone forever:Alisa Sherbow, Silas Emrys, Chris Peters, Adam Brainard, Dr. Melvin Sanicas, Melida Williams, Jeremy Mysliwiec, charles george, Tom Mosner, Christopher R Boucher, Alex Hackman, Piya Shedden, GrowingViolet, Nazara, Matt Curls, Ash, Eric Jensen, Jason A Saslow, Kevin Bealer, Sam Lutfi, James Knight, Christoph Schwanke, Bryan Cloer, Jeffrey Mckishen----------Looking for SciShow elsewhere on the internet?SciShow Tangents Podcast: http://www.scishowtangents.orgFacebook: http://www.facebook.com/scishowTwitter: http://www.twitter.com/scishowInstagram: http://instagram.com/thescishow----------https://www.space.com/25075-cosmic-inflation-universe-expansion-big-bang-infographic.htmlWhy we need inflation: https://www.space.com/42202-why-we-need-cosmic-inflation.htmlhttps://www.space.com/42261-how-did-inflation-happen-anyway.htmlInflation review: https://arxiv.org/pdf/hep-ph/0304257.pdfEvidence for inflation https://www.forbes.com/sites/startswithabang/2019/05/11/ask-ethan-how-well-has-cosmic-inflation-been-verified/?sh=7ad0a2891d07GW detection: https://iopscience.iop.org/article/10.1088/1475-7516/2021/01/012Penrose cyclic cosmology: https://aip.scitation.org/doi/abs/10.1063/1.4727997?journalCode=apchttps://physicsworld.com/a/new-evidence-for-cyclic-universe-claimed-by-roger-penrose-and-colleagues/Fine-tuning:Fundamental constants: https://www.forbes.com/sites/ethansiegel/2015/08/22/it-takes-26-fundamental-constants-to-give-us-our-universe-but-they-still-dont-give-everything/#4118be154b86Fine-tuning 1: https://www.symmetrymagazine.org/article/fine-tuning-versus-naturalnessFine-tuning 2: https://www.pbs.org/wgbh/nova/article/scientific-approaches-to-the-fine-tuning-problem/Fine-tuning 3: https://www.forbes.com/sites/startswithabang/2019/04/05/fine-tuning-really-is-a-problem-in-physics/Fine-tuning 4: https://plato.stanford.edu/entries/fine-tuning/Fine-tuning 5: https://books.google.co.uk/books/about/Just_Six_Numbers.html?id=4XPhAgAAQBAJ&printsec=frontcover&source=kp_read_button&hl=en&redir_esc=y#v=onepage&q&f=falseFine-tuning 6: https://www.cambridge.org/core/journals/publications-of-the-astronomical-society-of-australia/article/finetuning-of-the-universe-for-intelligent-life/222321D5D4B5A4D68A3A97BBE46AEE45Anthropic principle: https://www.britannica.com/science/anthropic-principleTheory of everything: https://www.quora.com/What-are-the-Grand-Unified-Theory-and-the-Theory-of-Everything-and-what-is-the-difference-between-themGUT: http://nautil.us/issue/46/balance/a-brief-history-of-the-grand-unified-theory-of-physicsTheory of everything 1: https://www.forbes.com/sites/startswithabang/2017/07/08/ask-ethan-how-close-are-we-to-a-theory-of-everything/ToE 2: https://www.space.com/theory-of-everything-definition.htmlAlternatives to string theory: https://www.forbes.com/sites/startswithabang/2015/12/17/what-are-quantum-gravitys-alternatives-to-string-theory/#40cade6f7b1bLQG: https://arxiv.org/abs/0711.0146Unification: https://www.pdcnet.org/jphil/content/jphil_1996_0093_0003_0129_0144Quantum gravity: https://arxiv.org/abs/gr-qc/0108040Causal Set Theory: https://arxiv.org/abs/1903.11544What is String Theory?: https://math.berkeley.edu/~kwray/papers/string_theory.pdfImage Sources:https://www.istockphoto.com/photo/star-field-at-night-gm501655522-81460875https://www.istockphoto.com/photo/large-scale-structure-of-multiple-galaxies-in-deep-universe-3d-illustration-gm516145588-88855813https://commons.wikimedia.org/wiki/File:COSMOS_3D_dark_matter_map.pnghttps://commons.wikimedia.org/wiki/File:Fermilab.jpghttps://en.wikipedia.org/wiki/File:Calabi_yau.jpghttps://commons.wikimedia.org/wiki/File:Spacetime_lattice_analogy.svghttps://commons.wikimedia.org/wiki/File:Storage_ring.jpghttps://svs.gsfc.nasa.gov/10137https://en.wikipedia.org/wiki/File:CMS_Higgs-event.jpghttps://en.wikipedia.org/wiki/File:Planck_satellite_cmb.jpghttps://imagine.gsfc.nasa.gov/educators/programs/cosmictimes/universe_mashup/archive/pages/expanding_universe.htmlhttps://www.istockphoto.com/https://www.storyblocks.com/