Buzz·Posted on Oct 4, 2013The 17 Happiest Science Facts Of All TimeThese will make you feel warm inside.by Kelly OakesBuzzFeed Staff, UK FacebookPinterestTwitterMailLink 1. Lovers' heartbeats synchronise when they stare into each other's eyes. dx.doi.org Scientists got 32 couples to sit and face each other for three minutes (not all at the same time, we presume). After the time was up, the heart rates of the couples were in sync. They didn't sync for people not involved in romantic relationships. 2. That warm feeling you get when you read nice messages from your friends and family actually makes you feel warmer. Flickr: zanehollingsworth 3. Expressing your gratitude to other people has been shown to make you happier. Flickr: jjpacres / Creative Commons So has writing down three good things about your day every evening. 4. Lions cuddle and rub heads to maintain their friendships. Flickr: fanz / Creative Commons Life is harsh for lions, but at least they have their friends. 5. Whales and dolphins have been known to have interspecies friendships. Tap to play or pause GIF Tap to play or pause GIF 6. Humpback whales form lifelong friendships. Flickr: mikebaird / Creative Commons 7. Even sharks make friends. Tap to play or pause GIF Tap to play or pause GIF likeadeadfox.tumblr.com 8. There's a nebula that looks like a manatee, so scientists renamed it the Manatee Nebula in a special ceremony. NRAO/AUI/NSF, K. Golap, M. Goss; NASA’s Wide Field Survey Explorer (WISE). 9. Astronauts grew a rose in space just to see if it would smell different than a rose on Earth. NASA/Marshall Space Flight Center And it did! Volatile compounds that make a flower smell a certain way act differently in microgravity. 10. Falling in love raises levels of nerve growth factor, a protein important for maintaining the central nervous system. Flickr: npmeijer 11. Chimpanzees build a new tree nest to sleep in every night and use the softest leaves as a pillow. Flickr: graphicreality / Creative Commons 12. Science has shown that some things are just so cute you can't help but want to squeeze them. Flickr: pinguino 13. This Californian sea lion can keep a beat. View this video on YouTube She's called Ronan and is the first nonhuman mammal to demonstrate this ability. 14. Dung beetles can use the Milky Way to navigate. Current Biology / Dacke et al. 15. This loggerhead turtle was given prosthetic flippers after losing her own, and now she can swim again. Tap to play or pause GIF Tap to play or pause GIF youtube.com 16. During the Ice Age, 32,000 years ago, a squirrel buried a seed. Now the seed has been used to grow a flower. National Academy of Sciences 17. And of course, almost every element in your body was made in an exploding star. chandra.harvard.edu Which means we really are all made of stardust.