Black holes are defined by only three parameters: mass, charge and spin. We know that black holes spin. But how can we measure that? What tools and methods are at our disposal? Answering these questions with Dr Ruth Daly, Professor of Physics at Penn State University.📃 New Black Hole Spin Values for Sagittarius A* Obtained with the Outflow Methodhttps://arxiv.org/abs/2310.12108🦄 Support us on Patreon: https://patreon.com/universetoday📚 Suggest books in the book club:https://www.goodreads.com/group/show/1198440-universe-today-book-club📺 VIDEO VERSIONhttps://youtu.be/9ArfZdNDtzY📰 EMAIL NEWSLETTERRead by 60,000 people every Friday. Written by Fraser. No ads.Subscribe. It's FREE: https://universetoday.com/newsletter🎧 PODCASTSUniverse Today: https://universetoday.fireside.fm/Astronomy Cast: http://www.astronomycast.com/🤳 OTHER SOCIAL MEDIATwitter: https://twitter.com/fcainTwitter: https://twitter.com/universetodayFacebook: https://facebook.com/universetodayInstagram: https://instagram.com/universetoday📩 CONTACT FRASERfrasercain@gmail.com⚖️ LICENSECreative Commons Attribution 4.0 International (CC BY 4.0)Support Universe Today Podcast