#250 There are signs that aliens might be harnessing the power of stars in our galaxy to fuel their civilisations. Dyson spheres are structures that surround entire stars to absorb their energy. Although these are just hypothetical, researchers have detected hints of their existence. But aliens aren’t the only possible explanation. Being able to freeze human brain tissue could be a game-changer for medical research. While freezing brains is easy, thawing them out without damaging the tissue is much harder. But now a method involving a cocktail of chemical ingredients seems to have solved the problem..  The largest ever ‘ecoacoustic’ survey is being conducted throughout the forests of Costa Rica. Sound recordings of various habitats, from degraded pastures to regenerating forests, are being gathered to assess the biodiversity and health of the country’s ecosystems. Hear some of the amazing soundscapes that have been captured for the survey. Orchids may share food with their offspring. Lab experiments have shown for the first time that parent orchids may be using fungal pathways – the mycorrhizal network – to send vital sugars to seedlings that cluster around them. Ancient Egyptians were reliant on the Nile river to transport materials used to build the world famous pyramids. But many of those pyramids are built on inhospitable, arid land, far from the Nile. So how did they get the materials there? Geoscientists may have uncovered an ancient clue. Hosts Christie Taylor and Rowan Hooper discuss with guests Jacob Aron, Alexandra Thompson, James Dinneen and Chen Ly. To read more about these stories, visit newscientist.com. Hosted on Acast. See acast.com/privacy for more information.