[Interview] Black Holes Spin. Now, How Can We Measure That?

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 Method https://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 00:00 Intro 01:11 Black Holes' mass 06:22 Jets from Quasars 09:00 Being near a black hole 10:35 Measuring the Sgr A 18:56 Spinning black holes 26:41 Orientation of Sag A 29:02 Energy of black holes 32:33 Final thoughts 📺 VIDEO VERSION https://youtu.be/9ArfZdNDtzY 📰 EMAIL NEWSLETTER Read by 60,000 people every Friday. Written by Fraser. No ads. Subscribe. It's FREE: https://universetoday.com/newsletter 🎧 PODCASTS Universe Today: https://universetoday.fireside.fm/ Astronomy Cast: http://www.astronomycast.com/ 🤳 OTHER SOCIAL MEDIA Twitter: https://twitter.com/fcain Twitter: https://twitter.com/universetoday Facebook: https://facebook.com/universetoday Instagram: https://instagram.com/universetoday 📩 CONTACT FRASER frasercain@gmail.com ⚖️ LICENSE Creative Commons Attribution 4.0 International (CC BY 4.0)