Uploads from Dr. Becky

Currently Playing: Tentative evidence for dark matter?! #shorts

There's been a tentative possible dark matter detection from particle physicists at the Lux-Zeppelin experiment - a large tank of liquid xenon buried underground in South Dakota (NOTE: I incorrectly stated this as Arizona in the video). Because dark matter doesn’t interact with the electromagnetic force, essentially you can’t see it. It doesn’t interact with light, absorb, reflect, emit light in any way. What we look for instead are the really unlikely collisions between a normal matter particle, and a dark matter particle that just happens to come in and collide with it. Like if a cue ball on a pool table was invisible and you’re just looking for the movement of the colourful balls to know that the cue ball was there. So you’re looking for behaviour in the normal matter that you can’t explain. This is why they bury these things deep underground so that they can shield their xenon, their normal matter, from things like cosmic rays that come in and bounce around the normal matter and just add a load of noise. And we can model for the rest of the expected interactions that create noise in your xenon that aren’t dark matter interactions, and we call all those backgrounds. But in June 2023, the LZ team recorded an event that falls outside of what you’d expect for the background noise in the xenon. It’s this black dot here in this figure which falls below the red lines there, and that’s the important point here. That means it’s not far enough away from expected backgrounds, that there’s still a 0.5% chance it is just a fluke of background noise. Being something that is just normal matter like we would expect. So we’re still a long way off claiming a dark matter detection here, notice how the abstract of the paper doesn’t even mention dark matter, but the fact that we are close to the possible evidence of a detection is encouraging to see. 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