The
rate of the Universe's expansion continued to decelerate until
approximately 8 billion years ago, at which point it began to
accelerate. It is still accelerating today. The change from
deceleration to acceleration is dealt with in
Chapter 4.
Note that the argument above ignores the existence of
latentenergy
(the spin of the gravitons in a gravitonpair). This is done for simplicity's
sake. Every gravitonpair has a measure of latentenergy. The Universe also
has a measure of latentenergy which is the sum of the latentenergy of
its gravitonpairs. Latentenergy can be transmuted to kineticenergy by
collision. Kineticenergy can be transmuted to latentenergy by
collision.