#237Glaucoma, which can cause blindness by damaging the optic nerve, may be reversible. Researchers have managed to coax new optic nerve cells to grow in mice, partly restoring sight in some. How the treatment works through an eyeball injection and why, for humans, prevention and early detection are still the best options.Black holes, just like planets and stars, spin. But they may be spinning a lot slower than we thought. When black holes gobble up matter around them, they start spinning faster and we’ve largely used this understanding to guess their speed. But new research also weighs the slowing effect of massive gas jets that black holes emit – revealing that many may have slowed dramatically since their births. How these new estimates of spin also offer insights into a black hole’s history. What if we could generate solar power in space, far more efficiently than on Earth – and then beam it down to our houses? An MIT experiment has managed to do one of the most crucial steps of that science fiction-seeming process, converting electricity from a satellite into microwaves that were then successfully received by a collector in California. How these microwaves could supply the power grid on Earth and help ween us off of fossil fuels – if they can overcome some major hurdles. Apes like to playfully tease each other, just like humans do. While their methods may be a bit different from ours – poking, hitting, pulling on hair and stealing – it looks like they’re often doing it for fun, rather than to harass or assert dominance. This new finding could explain why humans evolved to enjoy jokes.Plus: A weird cooling quirk of Antarctica’s atmosphere; the microbes that make your tea taste delicious; and the flamboyant love languages of cuttlefish, scorpions and even dog-loving humans.Hosts Christie Taylor and Chelsea Whyte discuss with guests Michael Le Page, Alex Wilkins and Chen Ly. To read more about these stories, visit newscientist.com. Hosted on Acast. See acast.com/privacy for more information.