Uploads from Dr. Becky

Currently Playing: Is falling into a black hole fast or slow? #shorts

When you’re falling into a black hole, how long does it take after you cross the event horizon of a black hole, that sphere of no return, before you reach the singularity? The place where all the matter is crushed down into an infinitely dense infinitely small region of space. How long it actually takes to reach the singularity after becoming trapped beyond the event horizon depends on how massive the black hole is. So for a black hole the same mass as the Sun, it’s a few microseconds, but for a more massive black hole it's longer because the event horizon is also larger. So it's around a minute for the black hole at the centre of the Milky Way, and a few hours for a supermassive black hole billions of times heavier than the Sun. And rather counterintuitively, if you tried to resist the pull of singularity once you’re past the event horizon, by accelerating away from it, for example if you were in a spacecraft firing your engines, that would actually mean you reached the singularity sooner. Because time and space swap inside a black hole. And the singularity becomes a moment in time, a moment in your future, rather than a place in space. So if you accelerate, in whatever direction, in your frame of reference, you get there sooner. At least, that’s the simplified picture of a black hole, the one we all tend to learn about. But real black holes also spin. And that changes everything. Including the nature of the singularity itself, which becomes a donut shape. At least, an infinitely thin donut. Which does even weirder things to time. Video filmed on a Sony ⍺7 IV Video edited by Martino Gasparrini: martino.freelance@gmail.com Video produced by Marina Hui & Dr Becky Smethurst --- 📚 My 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 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. 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