Why haven’t we found aliens? A physicist shares the most popular theories. | Brian Cox

Chances are, we’re not alone in the universe. But if that’s true — why can’t we seem to find our neighbors? This question is known as the Fermi paradox, and it continues to go unsolved. However, some theories could offer potential solutions. Physicist Brian Cox explains the paradox and walks us through our best guesses as to the reason for our quasi-isolation. 0:00 Who is Enrico Fermi? 0:22 What is the Fermi Paradox? 1:29 Rare Earth Hypothesis 2:41 Extinguished Civilizations 3:51 Technological Singularity 4:34 Vast Distances 5:14 Cosmic Quarantine 7:31 The Great Filter 9:51 The Great Silence ---------------------------------------------------------------------------------- Go Deeper with Big Think: ►Become a Big Think Member Get exclusive access to full interviews, early access to new releases, Big Think merch and more. ►Get Big Think for Business Guide, inspire and accelerate leaders at all levels of your company with the biggest minds in business. ---------------------------------------------------------------------------------- About Brian Cox: Brian Cox obtained a first class honors degree in physics from the University of Manchester in 1995 and in 1998 a Ph.D. in High Energy Particle Physics at the DESY laboratory in Hamburg. Brian is now Professor of Particle Physics at the University of Manchester, The Royal Society Professor for Public Engagement in Science and a Fellow of the Royal Society. Brian is widely recognized as the foremost communicator for all things scientific, having presented a number of highly acclaimed science programs for the BBC watched by billions internationally including ‘Adventures in Space and Time’ (2021), ‘Universe’ (2021), ‘The Planets’ (2018), ‘Forces of Nature’ (2016), ‘Human Universe’ (2014), ‘Wonders of Life’ (2012), ‘Wonders of the Universe’ (2011) and ‘Wonders of the Solar System’ (2010). As an author, Brian has also sold over a million books worldwide including ‘Black Holes’, ‘Universal: A Guide to the Cosmos’, ‘Quantum Universe’ and ‘Why Does E=mc2?’ with co-author Professor Jeffrey Forshaw. He also wrote the series of books to accompany his popular television and radio programs.