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

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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/