Ultimate fate of the universe

The ultimate fate of the universe is a topic in physical cosmology, whose theoretical restrictions allow possible scenarios for the evolution and ultimate fate of the universe to be described and evaluated. Based on available observational evidence, deciding the fate and evolution of the universe has become a valid cosmological question, being beyond the mostly untestable constraints of mythological or theological beliefs. Several possible futures have been predicted by different scientific hypotheses, including that the universe might have existed for a finite and infinite duration, or towards explaining the manner and circumstances of its beginning.

Quotes

• Blow, winds, and crack your cheeks! rage! blow!
  You cataracts and hurricanoes, spout
  Till you have drench’d our steeples, drown’d the cocks!
  You sulphurous and thought-executing fires,
  Vaunt-couriers to oak-cleaving thunderbolts,
  Singe my white head! And thou, all-shaking thunder,
  Smite flat the thick rotundity o’ the world!
  Crack nature’s moulds, all germins spill at once
  That make ingrateful man!
  • William Shakespeare, King Lear (1608; 1619; 1623), III, ii

• The soul, secur’d in her existence, smiles
  At the drawn dagger, and defies its point.
  The stars shall fade away, the sun himself
  Grow dim with age, and nature sink in years,
  But thou shalt flourish in immortal youth,
  Unhurt amidst the war of elements,
  The wreck of matter, and the crush of worlds.
  • Joseph Addison, Cato, a Tragedy (1712), V, i

• Some say the world will end in fire,
    Some say in ice.
  From what I’ve tasted of desire
  I hold with those who favor fire.
    But if it had to perish twice,
  I think I know enough of hate
    To know that for destruction ice
  Is also great
    And would suffice.
  • Robert Frost, "Fire and Ice", in Harper's Magazine (December 1923)