Aren't penguins afraid of cold?

Antarctica is the coldest place in the world and the only place on earth without permanent residents. There, the lowest recorded temperature is -89℃. In such a harsh environment, only penguins are still sticking to their white homes alone. Although the Antarctic is extremely cold, penguin feathers have become overlapping and dense scales after tens of millions of years of snowstorms. This special "feather quilt" is not only difficult to soak in seawater, but also the temperature is close to MINUS 100 degrees Celsius, so it can't break through its thermal insulation defense line. Moreover, there is a thick layer of fat under the penguin's cortex, which has a good effect on preventing body temperature loss. Therefore, penguins can survive in the cold Antarctic.

Geometrically speaking, the specific surface area of a spherical object is the smallest, that is to say, its contact area with the outside world is the smallest, and the smallest heat dissipation area means the smallest heat dissipation speed. In terms of body shape, the penguin's body has evolved to be as close to a sphere as possible, with a short and thick body, a short and thick neck, and short and thick legs and feet, which can be retracted under the stomach to reduce the contact area with the outside world and minimize the loss of heat.

Penguins living near the South Pole are covered with thick feathers, and the tips of the feathers are curved like fish scales, so that even water can't penetrate and can resist strong winds. There are dense fluff under that layer of feathers, just like the best quality sweater. With such fine feathers, penguins are like wearing a thick down jacket, which is waterproof, warm and not afraid of cold. At the same time, penguins are thick in fat and can also play a role in heat preservation.