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 Aranda SciShow 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.org Facebook: http://www.facebook.com/scishow Twitter: http://www.twitter.com/scishow Instagram: http://instagram.com/thescishow ---------- https://www.space.com/25075-cosmic-inflation-universe-expansion-big-bang-infographic.html Why we need inflation: https://www.space.com/42202-why-we-need-cosmic-inflation.html https://www.space.com/42261-how-did-inflation-happen-anyway.html Inflation review: https://arxiv.org/pdf/hep-ph/0304257.pdf Evidence for inflation https://www.forbes.com/sites/startswithabang/2019/05/11/ask-ethan-how-well-has-cosmic-inflation-been-verified/?sh=7ad0a2891d07 GW detection: https://iopscience.iop.org/article/10.1088/1475-7516/2021/01/012 Penrose cyclic cosmology: https://aip.scitation.org/doi/abs/10.1063/1.4727997?journalCode=apc https://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/#4118be154b86 Fine-tuning 1: https://www.symmetrymagazine.org/article/fine-tuning-versus-naturalness Fine-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=false Fine-tuning 6: https://www.cambridge.org/core/journals/publications-of-the-astronomical-society-of-australia/article/finetuning-of-the-universe-for-intelligent-life/222321D5D4B5A4D68A3A97BBE46AEE45 Anthropic principle: https://www.britannica.com/science/anthropic-principle Theory of everything: https://www.quora.com/What-are-the-Grand-Unified-Theory-and-the-Theory-of-Everything-and-what-is-the-difference-between-them GUT: http://nautil.us/issue/46/balance/a-brief-history-of-the-grand-unified-theory-of-physics Theory 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.html Alternatives to string theory: https://www.forbes.com/sites/startswithabang/2015/12/17/what-are-quantum-gravitys-alternatives-to-string-theory/#40cade6f7b1b LQG: https://arxiv.org/abs/0711.0146 Unification: https://www.pdcnet.org/jphil/content/jphil_1996_0093_0003_0129_0144 Quantum gravity: https://arxiv.org/abs/gr-qc/0108040 Causal Set Theory: https://arxiv.org/abs/1903.11544 What is String Theory?: https://math.berkeley.edu/~kwray/papers/string_theory.pdf Image Sources: https://www.istockphoto.com/photo/star-field-at-night-gm501655522-81460875 https://www.istockphoto.com/photo/large-scale-structure-of-multiple-galaxies-in-deep-universe-3d-illustration-gm516145588-88855813 https://commons.wikimedia.org/wiki/File:COSMOS_3D_dark_matter_map.png https://commons.wikimedia.org/wiki/File:Fermilab.jpg https://en.wikipedia.org/wiki/File:Calabi_yau.jpg https://commons.wikimedia.org/wiki/File:Spacetime_lattice_analogy.svg https://commons.wikimedia.org/wiki/File:Storage_ring.jpg https://svs.gsfc.nasa.gov/10137 https://en.wikipedia.org/wiki/File:CMS_Higgs-event.jpg https://en.wikipedia.org/wiki/File:Planck_satellite_cmb.jpg https://imagine.gsfc.nasa.gov/educators/programs/cosmictimes/universe_mashup/archive/pages/expanding_universe.html https://www.istockphoto.com/ https://www.storyblocks.com/ #SciShow