Perhaps the first recognition that the matter composing the universe may be different from the one we touch and experience every day has been put in writing by early Greek philosophers and by Aristotle in particular. In his work On the Heavens, Aristotle argues that the nature and movement of the stars and planets is so fundamentally different from Earth-like elements that a new substance is required, a “bodily substance other than the formations we know, prior to them all and more divine than they.” Later on this cosmic element came to be called quintessentia, or fifth element, and drawing on Plato's classification of the elements a dodecahedron's figure was associated with it.

More than two thousand years after, astrophysicists have begun to pile up evidence that a new form of matter pervades our Universe. This idea is based on observations that reminds one of Aristotle's thoughts: the global movement we observe in distant reaches of our cosmos is unexplainable by ordinary matter. All the matter we see on Earth, in the solar system, inside our Galaxy or in similar structures across the Universe has a small or negligible positive pressure and clumps under the influence of gravity. An expanding Universe filled with this form of matter would by necessity slow down. But in 1998, astronomers studying the global expansion by the use of supper novae found that their observed luminosities can be explained only by an accelerated expansion of the Universe.