Physiological Effects from Exposure to a Vaccum

Vacuum doesn’t have a temperature of its own, so space is not really that cold. It’s a great insulator too, meaning that your core body heat doesn’t get sucked away. Without an atmosphere to transfer heat away, the risk of exposure is somewhat mitigated. The saliva on your tongue may boil off, as it’s not pressurized like your blood is, and you may get some frost on your skin. Sunburn from direct contact with the sun’s ultraviolet rays is a more immediate danger than perishing from ...

 Hippopotamus as Closest Relative to the Whale

good candidate is the hippopotamus, which, although closely related to terrestrial mammals, is about as aquatic as a land mammal can get. (There are two species, the pygmy hippo and the “regular” hippo, whose scientific name is, appropriately, Hippopotamus amphibius.) Hippos spend most of their time submerged in tropical rivers and swamps, surveying their domain with eyes, noses, and ears that sit atop their head, all of which can be tightly closed underwater. Hippos mate in the water, an...