The cachalot is a giant cetacean seen vary rarely, for they often dive to deep depths. They're also known as sperm whales after their spermaceti, a waxy substance in the whale's head cavity, which is considered valuable.
(ËkÉzmÉªk) adj. 1. (Astronomy) of or relating to the whole universe: cosmic laws. 2. (Astronomy) occurring or originating in outer space, esp as opposed to the vicinity of the earth, the solar system, or the local galaxy: cosmic rays. 3. immeasurably extended in space or time; vast.
Cosmic voids are vast spaces between filaments (the largest-scale structures in the Universe), which contain very few or no galaxies. Voids typically have a diameter of 10 to 100 megaparsecs; particularly large voids, defined by the absence of rich superclusters, are sometimes called supervoids. They have less than one-tenth of the average density of matter abundance that is considered typical for the observable Universe.