Fascinating visualization of a black hole surrounded by an accretion disk, illustrating how light is warped by its intense gravitational fields.
During winter hibernation, some turtles can take in oxygen directly from the water through a process called cloacal respiration, breathing through their rear.
Acquaintance cards, a discrete form of flirting during victorian era cards and some early turn of the century. 1880s-1920s.
