IUPAC definition. polymerization: The process of converting a monomer or a mixture of monomers into a polymer. An example of alkene polymerization, in which each styrene monomer's double bond reforms as a single bond plus a bond to another styrene monomer.
There is evidence to indicate the Big Bang may have resulted from another, earlier universe collapsing in on itself, rather than from expanding from a point on infinitely hot and dense material. Instead, the universe appears to be going through constant phases of expansion (as it is at present) and contraction in a never-ending cycle. This theory of universe formation, known as the Big Bounce, was first proposed almost a century ago.
The Big Bang theory explains where all the hydrogen and helium in the universe came from. In the 1940s, Ralph Alpher and George Gamow calculated that the early universe was hot and dense enough to make virtually all the helium, lithium and deuterium (hydrogen with a neutron attached) present in the cosmos today; later research showed where the primordial hydrogen came from.