Buzz·Posted on 4 Oct 2013The 17 Happiest Science Facts Of All TimeThese will make you feel warm inside.by Kelly OakesBuzzFeed Staff, UK LinkFacebookPinterestTwitterMail 1. Lovers' heartbeats synchronise when they stare into each other's eyes. 2. That warm feeling you get when you read nice messages from your friends and family actually makes you feel warmer. 3. Expressing your gratitude to other people has been shown to make you happier. 4. Lions cuddle and rub heads to maintain their friendships. 5. Whales and dolphins have been known to have interspecies friendships. Tap to play GIF Tap to play GIF 6. Humpback whales form lifelong friendships. 7. Even sharks make friends. Tap to play GIF Tap to play GIF 8. There's a nebula that looks like a manatee, so scientists renamed it the Manatee Nebula in a special ceremony. 9. Astronauts grew a rose in space just to see if it would smell different than a rose on Earth. 10. Falling in love raises levels of nerve growth factor, a protein important for maintaining the central nervous system. 11. Chimpanzees build a new tree nest to sleep in every night and use the softest leaves as a pillow. 12. Science has shown that some things are just so cute you can't help but want to squeeze them. 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. 15. This loggerhead turtle was given prosthetic flippers after losing her own, and now she can swim again. Tap to play GIF Tap to play GIF 16. During the Ice Age, 32,000 years ago, a squirrel buried a seed. Now the seed has been used to grow a flower. 17. And of course, almost every element in your body was made in an exploding star.