JWST’s 3 BIG mysteries of the early Universe

AD - Go to https://ground.news/drbecky to stay fully informed with the latest Space and Science news. Save 40% off the Vantage plan through my link for unlimited access | The cutting edge of science is where all the unknowns are. Where there’s more questions than answers, and it’s all hands on deck to try and understand our observations, experiments and data. And in astrophysics, that has never been truer after the launch of the James Webb Space Telescope - a telescope that could see galaxies at greater distances than ever before, allowing us to see galaxies as they were when the universe was just a few hundred million years old because of how long its taken the light to travel to us. And over the past 4 years, JWST has been taking what we though we knew about the early universe and how galaxies evolved, and just throwing it all out the window. And in particular, there are now 3 big mysteries that have emerged, that we can’t yet explain - which is incredibly exciting, because in the push to understand them we’ll hopefully learn something new, maybe even some new physics and understand our universe better…

Adams et al. (2024) - https://arxiv.org/pdf/2304.13721
Bouwens et al. (2015) - https://arxiv.org/pdf/1403.4295
Bruzual & Charlot (2003) - https://arxiv.org/pdf/astro-ph/0309134
D’Eugenio et al. (2024) - https://arxiv.org/pdf/2311.09908
Harikane et al. (2023) - https://arxiv.org/pdf/2208.01612
Killi et al. (2024) - https://arxiv.org/pdf/2312.03065
Kocevski et al. (2025) - https://arxiv.org/pdf/2404.03576
McLeod et al. (2024) - https://arxiv.org/pdf/2304.14469
Nakane et al. (2025) - https://arxiv.org/pdf/2503.11457
Pérez-González et al. (2024) - https://arxiv.org/pdf/2401.08782
Rusakov et al. (2025) - https://arxiv.org/pdf/2503.16595
Vogelsberger et al. (2020) - https://arxiv.org/pdf/1904.07238
Whitler et al. (2025) - https://arxiv.org/pdf/2501.00984

00:00 Introduction
03:16 The number of bright galaxies
06:58 The amount of heavy metals
10:55 The Little Red Dots


Video filmed on a Sony ⍺7 IV
Video edited by Martino Gasparrini: https://www.fiverr.com/mgs_editing

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👩🏽‍💻 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.


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