WHEN did the first ever stars form in the Universe?

Head to https://squarespace.com/drbecky to save 10% off your first purchase of a website or domain using code DRBECKY - AD | One of the ultimate goals of all of astrophysics has always been to work out when the very first stars formed in the Universe. Now you might have heard people talk about how incredible JWST is and how we can see galaxies further back than ever before but JWST can’t see back to the first stars forming. So, if we want to observe the era when the very first stars form, we have to get clever, and turn instead to radio astronomy, to try and detect the impact that the first stars had on the hydrogen gas around them, to pinpoint when that happened in the universe’s history and complete that missing bit of the puzzle. Now people have been trying to do this for years with ever growing radio telescopes, and there was even a tentative claim of a detection back in 2018 from Bowman and collaborators which has been under a lot of scrutiny in the past few years, and now everyone’s hopes are resting on the Square Kilometre Array radio telescope... 00:00 - Introduction 02:44 - Squarespace AD 04:13 - What are the first stars (known as Population III stars) thought to be like? 08:57 - What impact do they have on the Universe 12:02 - How we hope to detect that impact 15:41 - The tentative detection from Bowman and collaborators in 2018 20:19 - How the Square Kilometre Array should help 24:02 - Bloopers Bowman et al. (2018; detection of 21cm reionization signal with EDGES? No) - https://arxiv.org/pdf/1810.05912 Chapman et al. (2022; review of detecting the epoch of reionization with radio telescopes) - https://arxiv.org/pdf/2212.00733 Aguado et al. (2023; most metal-poor star detected) - https://www.aanda.org/articles/aa/ful... Chantavat et al. (2023; the most massive population III stars) - https://arxiv.org/pdf/2302.09763 Frebel et al. (2005; metal-poor star spectrum) - https://articles.adsabs.harvard.edu/p... Maiolino et al. (2023; population III star signatures observed with JWST) - https://arxiv.org/pdf/2306.00953 Pritchard & Loeb (2012; review of 21cm cosmology) - https://arxiv.org/pdf/1109.6012 Singh et al. (2018; SARAS2 experiment description) - https://arxiv.org/abs/1710.01101 Singh et al. (2022; SARAS2 reports no detection of 21cm reionization signal) - https://arxiv.org/pdf/2112.06778 Correction: 14:24 This is an image of Andrew Jaffe, not Jonathan Pritchard or Abraham Loeb. Apologies to Pritchard & Loeb. Video filmed on a Sony ⍺7 IV Video edited by Martino Gasparrini: https://www.fiverr.com/mgs_editing --- 📚 My new book, "A Brief History of Black Holes", out NOW in hardback, paperback, e-book and audiobook (which I narrated myself!): http://lnk.to/DrBecky --- 👕 My new merch, including JWST designs, are available here (with worldwide shipping!): https://dr-becky.teemill.com/ --- 🎧 Royal Astronomical Society Podcast that I co-host: podfollow.com/supermassive --- 🔔 Don't forget to subscribe and click the little bell icon to be notified when I post a new video! --- 👩🏽‍💻 I'm Dr. Becky Smethurst, an astrophysicist at the University of Oxford (Christ Church). I love making videos about science with an unnatural level of enthusiasm. I like to focus on how we know things, not just what we know. And especially, the things we still don't know. If you've ever wondered about something in space and couldn't find an answer online - you can ask me! My day job is to do research into how supermassive black holes can affect the galaxies that they live in. In particular, I look at whether the energy output from the disk of material orbiting around a growing supermassive black hole can stop a galaxy from forming stars. http://drbecky.uk.com