A challenge to dark energy (and why cosmologists aren't convinced)

Описание: What if Nobel Prize winning science was wrong? And not wrong in a small way… Wrong in a way that changes everything we think we know about the Universe.

That's the big argument that’s raging in cosmology right now. In 1998, two teams of astronomers discovered that the Universe isn't just expanding, the expansion is accelerating. Dark energy is pushing it apart faster, but we still don’t really know what it is yet. That’s what won the Nobel Prize in Physics back in 2011, and has since become one of the pillars of our best model of the Universe.

But recently a group of cosmologists, Son et al., have claimed the supernovae data used to make the discovery has been hiding a bias for thirty years. Which when you correct for that bias, switches the acceleration of the Universe’s expansion rate to a deceleration.

At the heart of this latest scientific discussion is a question that every cosmologist recognises as a big problem: do we really understand the supernovae we've been using as our cosmic distance measures for the past thirty years?

Papers mentioned:
Tripp (1998) - https://adsabs.harvard.edu/pdf/1998A&...
Reiss et al. (1998) - https://arxiv.org/pdf/astro-ph/9805201
Chung et al. (2025) - https://arxiv.org/pdf/2411.05299
Son et al. (2025) - https://arxiv.org/pdf/2510.13121
Wiseman et al. (2026) - https://arxiv.org/pdf/2601.13785
Murakami et al. (2026) - https://arxiv.org/pdf/2604.16597
Chung et al. (2026) - https://arxiv.org/pdf/2605.21586
Sah et al. (2026) - https://arxiv.org/pdf/2606.09650
Lampeitl et al. (2010) - https://lss.fnal.gov/archive/2010/pub...
Sulivan et al. (2010) - https://arxiv.org/pdf/1003.5119
Rose et al. (2019) - https://arxiv.org/pdf/1902.01433
Tremonti et al. (2004) - https://arxiv.org/abs/astro-ph/0405537
Perlmutter et al. (1999) - https://arxiv.org/pdf/astro-ph/9812133
Cooke et al. (2012) - https://arxiv.org/pdf/1211.2003
Chandrasekhar limit - https://academic.oup.com/mnras/articl...

Videos mentioned:
   • MORE evidence for DARK ENERGY changing wit...  
   • Is the Universe JERKING? #shorts  

CHAPTER MARKERS
00:00 - Introduction
02:14 - I - Why supernovae aren't perfect “standard candles”
08:05 - II - The claims of Son et al. that there’s an age-bias in the supernova data meaning the Universe is decelerating
11:07 - III - Why most cosmologists aren’t convinced just yet
13:28 - IV - What the next generation of telescopes need to do to finally solve this problem
17:03 - Bloopers


Video filmed on a Sony ⍺7 IV
Video edited by Martino Gasparrini: [email protected]
Video produced by Marina Hui & Dr Becky Smethurst

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👩🏽‍💻 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.


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