The Sky at Night Catch up, Big Black Holes and Little Red Dots on BBC 4

The Sky at Night

Big Black Holes and Little Red Dots

Professor Brian Cox joins the team to explore one the greatest current mysteries in astronomy - little red dots. Discovered by the James Webb Space Telescope (JWST), they have upended everything we thought we knew about black holes and the evolution of the universe itself. \n\nAstronomical monsters, with the power to devour stars and even to stop time itself, black holes have both fascinated and troubled physicists for decades. Their study has led to breakthroughs in our understanding of gravity, quantum mechanics and even precision manufacturing. \n\nThe journey begins with black holes 101, as Chris Lintott and Brian Cox discuss what they are. And as it turns out, that is a harder question to answer than you might think. Distortions in space-time. Regions of infinite density. Gateways to other universes. The end of time. These are all descriptions of what black holes are, yet somehow all are insufficient – mathematically accurate yet physically unproven. What we thought we knew was that they are born in the violent deaths of massive stars, but this may not always be the case, and that has huge implications for how the cosmos we see today came to be. \n\nMaggie Aderin travels to the University of Nottingham to meet Dr Emma Chapman, a cosmologist whose work focuses on the early universe. She explains the significance of JWST’s discovery of the little red dots and why they are forcing the scientific community to re-evaluate not only how black holes form but also how galaxies themselves grow and evolve. \n\nReturning to Chris and Brian, the discussion turns to some of the alternative theories, and some of the explanations are truly staggering, from black hole suns, created by partially collapsed stars, to primordial black holes, born in the first moments of creation, and direct collapse black holes. \n\nAt the University of Edinburgh, George Dransfield meets Professor Sadegh Khochfar. Using months of processing time on the world’s most advanced supercomputers, his team have created the most detailed simulations of the universe’s first billion years. Their findings are shedding light on whether direct collapse black holes could exist and whether the density of the early universe could provide the answer to how massive black holes form without first forming stars, something once thought impossible. \n\nWhile the nature of the little red dots themselves are still contested, they are making us re-evaluate what we understand about black holes, and in doing so, they provide a window into conditions so extreme that we’re forced to question our assumptions about the very nature of reality and the fundamental physics that underpins the universe. \n\nBut while understanding the universe is a challenge, there is still always joy in looking up at the skies above, and Dr Becky Smethurst is guest presenting this month’s star guide to take us through the treats coming up in the next few weeks.\n\nJoin us on an exploration of the skies and the latest in our understanding of black holes – the cosmic Rosetta Stones that spark wonder in the scientific community and far beyond.

Source: BBC 4

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