The shape of the Universe

• The shape of the Universe is determined by a struggle between the momentum of expansion and the pull of gravity.

• The rate of expansion is determined by the Hubble Constant, Ho

• The strength of gravity depends on the density and pressure of the matter in the Universe.

• • G is proportional to  + 3P
  • is the density and P is the pressure

• For normal matter, P is negligible, so the fate of a universe filled with normal matter is governed by the density 