Head to https://linode.com/scishow to get a $100 60-day credit on a new Linode account. Linode offers simple, affordable, and accessible Linux cloud solutions and services. Scientists like to measure things, but they've had a heck of a time doing that with sharpness. And even if no one agrees on exactly how to measure it, our search for better tools has recently led to some of the sharpest objects we’ve ever created. Hosted by: Hank Green (he/him) ---------- 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: Matt Curls, Alisa Sherbow, Dr. Melvin Sanicas, Harrison Mills, Adam Brainard, Chris Peters, charles george, Piya Shedden, Alex Hackman, Christopher R, Boucher, Jeffrey Mckishen, Ash, Silas Emrys, Eric Jensen, Kevin Bealer, Jason A Saslow, Tom Mosner, Tomás Lagos González, Jacob, Christoph Schwanke, Sam Lutfi, Bryan Cloer ---------- Looking for SciShow elsewhere on the internet? SciShow Tangents Podcast: https://scishow-tangents.simplecast.com/ TikTok: https://www.tiktok.com/@scishow Twitter: http://www.twitter.com/scishow Instagram: http://instagram.com/thescishowFacebook: http://www.facebook.com/scishow #SciShow #science #education #learning #complexly ---------- Sources: https://www.tf.uni-kiel.de/matwis/amat/iss/kap_c/backbone/rc_2_4.html https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1524-4725.1982.tb01093.x https://www.proquest.com/openview/ecab7dfbc6c1cfec6fabf4d0f7a9c53d/1?cbl=44644&pq-origsite=gscholar https://www.sciencedirect.com/science/article/pii/S0003687006000238 https://physics.aps.org/articles/v9/155 https://www.guinnessworldrecords.com/world-records/sharpest-object-man-made https://books.google.com/books?id=gDflDwAAQBAJ&pg=PA71&lpg=PA71&dq=brubacher+edge+sharpness+scale&source=bl&ots=TnEgek-zRV&sig=ACfU3U1V9cHUJ-It0ZUQh9Rjg5G4W9dbqg&hl=en&sa=X&ved=2ahUKEwilpOrJ4eX7AhXTmIkEHajNCYM4KBDoAXoECB0QAw#v=onepage&q=brubacher%20edge%20sharpness%20scale&f=false https://pubmed.ncbi.nlm.nih.gov/12124714/ https://www.jstor.org/stable/44159720?read-now=1#page_scan_tab_contents https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3380774/ https://www.sciencefocus.com/science/whats-the-sharpest-knife-in-the-world/ https://scienceofsharp.com/ https://www.sciencedirect.com/science/article/pii/S0924013604007022 https://www.sciencedirect.com/science/article/pii/S0013794406004073 https://www.scientific.net/KEM.293-294.769 https://www.sciencedirect.com/science/article/pii/S0020740318322665 https://www.cambridge.org/core/journals/robotica/article/abs/modeling-of-blade-sharpness-and-compression-cut-of-biomaterials/33FA54D15E757B60A146F47BAFBA8B6F https://link.springer.com/content/pdf/10.1007/s10816-022-09596-0.pdf?pdf Images: https://commons.wikimedia.org/wiki/File:Crater_knife_edge.jpg https://scienceofsharp.com/2021/06/15/dual-grit-sharpening/ https://www.researchgate.net/figure/Artificial-sapphire-scalpel-a-physical-map-b-OCT-image_fig1_354874023 https://www.southampton.ac.uk/biu/galleries/sem.page https://commons.wikimedia.org/wiki/File:Obsidian_blade_mounted_in_ornamental_handle,_from_Admiralty_Wellcome_M0015133.jpg https://commons.wikimedia.org/wiki/File:Blade_MET_VS1994_35_468.jpeg https://commons.wikimedia.org/wiki/File:Macro_sewing_machine_needles.jpg https://commons.wikimedia.org/wiki/File:Beveled_tip_of_a_hypodermic_needle_20090714_005.JPG https://www.researchgate.net/figure/SEM-image-of-a-carbon-nanotube-nanoneedle-a-A-tungsten-tip-and-b-an-AFM-tip-Scale_fig2_51450738 https://commons.wikimedia.org/wiki/File:Scanning_Tunneling_Microscope_schematic.svg https://commons.wikimedia.org/wiki/File:%D0%9E%D0%B4%D0%BD%D0%BE%D1%80%D0%B0%D0%B7%D0%BE%D0%B2%D0%BE%D0%B5_%D0%BB%D0%B5%D0%B7%D0%B2%D0%B8%D0%B5_%D0%B4%D0%BB%D1%8F_%D0%BC%D0%B8%D0%BA%D1%80%D0%BE%D1%82%D0%BE%D0%BC%D0%B0.jpg https://commons.wikimedia.org/wiki/File:Prehistoric_Denmark_Stone_Knives_%26_Spears_(28471451010).jpg