Mini human brain grows blood vessels; The geoengineering risk of termination shock; Trove of ancient fossils discovered

Episode 343 The task of growing human brains in a lab has taken a step forward. Scientists have been creating brain organoids since 2013, but have now grown blood vessels in them for the first time. These mini brains resemble the developing cortex - the area of the brain that thinks, feels and stores memories. These advancements will help us learn more about the brain and conditions like dementia. But what if we go too far and they become conscious? Geoengineering is being talked about more and more as countries fail to hit emissions targets. Without reductions we are on course to hit 4.5°C of warming by 2100, so new solutions are needed. But will artificially cooling the climate really help, or do even more damage? One popular method is solar radiation management - but that would require at least 100 aircraft working for hundreds of years. And new research shows that while it could work, the moment we stop doing temperatures would rebound rapidly. So is it worth even trying? An incredible trove of ancient fossils have been discovered in a quarry in China, dating from 512 million years ago, just after Earth’s first mass extinction event. More than 8000 fossils have been analysed and nearly 60 per cent of the species are new to science. This group of arthropods, molluscs and brachiopods contain some very weird and wonderful creatures - including one which looks remarkably like a penis with long branching tentacles growing out of the end. Hosted by Rowan Hooper and Penny Sarchet, with guests Carissa Wong, Alec Luhn and Sam Wong. To read more about these stories, visit https://www.newscientist.com/ Learn more about your ad choices. Visit megaphone.fm/adchoices