Polar Bear Fur and Black Skin: The Physics of an Arctic Coat
Polar bear fur is transparent, not white. Their skin is jet black. The physics of how they stay warm and why the fibre-optic fur myth was debunked.
April 2026
December 2024
How Fast Can a Polar Bear Run? Speed on Ice
Polar bear speed: 40 km/h sprint, 10 km/h swimming, and the 687 km continuous-swim record. Why they overheat in seconds, and how they hunt despite it.
November 2024
Grizzly Bear Hibernation: The Process
Grizzly bears hibernate 4-7 months, dropping heart rate to 8-19 bpm while females give birth mid-sleep. The physiology, the den, and climate disruption.
Brown Bear Hibernation: Duration and Heart Rate
Scandinavian brown bears hibernate 6-7 months; Romanian bears 4-5. Heart rate drops to 8 bpm, females give birth mid-sleep. Physiology, dens, climate effects.
October 2024
Black Bear Hibernation: Duration, Heart Rate, and Cubs
Black bears hibernate 5-7 months at heart rates of 8-19 bpm. Den types, cub births during hibernation, and how Florida bears barely hibernate at all.