MORE evidence AGAINST dark matter? | What does the GAIA data actually show?

A new research study was published this month claiming to have found smoking-gun evidence for an alternate theory of gravity, called MOND, that doesn’t need dark matter to explain our observations of the Universe. They did the same test that three other research studies have done in the last couple of years, using the same data from the GAIA mission, and somehow all 4 papers have found different results. Some in favour of MOND, and some in favour of our typical theory of gravity: Einstein’s theory of General Relativity. So what is going on here? Chae (2023; evidence for AQUAL MOND from GAIA) - Hernandez (2023; evidence for MOND from GAIA data) - PIttordis & Sutherland (2023; evidence for general relativity from GAIA data) - Hernandez, Cookson & Cortés (2022; evidence for neither MOND nor general relativity from GAIA) - Banik & Zhao (2022; review of all the evidence for MOND) - Hernandez, Jiménez & Allen (2012; proposed test of MOND using GAIA data) - Bekenstein & Milgrom (1984; first MOND paper) - Garret et al. (2021; example model fit using Bayesian statistics) - 00:00 - Introduction 01:10 - What is this alternate theory of gravity, MOND? 03:58 - How do you use binary stars in GAIA data to test MOND? 07:29 - What results have been found doing this test? 10:29 - Same test, different results - what next? Bayesian statistics 11:42 - Some insider gossip 13:01 - Outro 13:34 - Bloopers Video filmed on a Sony ⍺7 IV --- 📚 My new book, “A Brief History of Black Holes“, out NOW in hardback, e-book and audiobook (which I narrated myself!): --- 📚 “The Year In Space“ celebrating all things space in 2022 from me and the rest of the Supermassive Podcast team: --- 👕 My new merch, including JWST designs, are available here (with worldwide shipping!): --- 🎧 Royal Astronomical Society Podcast that I co-host: --- 🔔 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.