It’s tough to get much closer to flowing lava than this video of freshly forming coastline in Hawaii. Lava is complex fluid, with viscous properties that vary significantly with chemical composition, temperature and deformation. Here, despite being very viscous, the lava flows quickly—perhaps even turbulently. Several times it forms a heap and even shows signs of the rope-coiling instability familiar from viscous fluids like honey. All in all, it’s quite mesmerizing. (Video credit: K. Singson; submitted by Stuart B.)