Because the concept of a time machine breaks several laws of physics. See also Science.
Also known as water bears, these microorganisms can live anywhere on Earth and look awfully like eight-legged bears in puffy space suits. See also Science.
Uranium 235 and Uranium 238 are almost inseparable isotopes. See also Science.
In organic chemistry class, what to name a structure containing at least one benzene ring, when you have no idea what is actually is. See also Science.
Probably inaccurate as to how extinct creatures actually appeared, but, hey, looks cool. See also Science.
Nothing kills time like ripping open the fabric of existence! See also Math, Science.