An accelerating universe
As mentioned I'm re-reading the Infinite Book and one topic that came up was with regards to the expansion of the universe. The logic presented in simple fashion goes like this:
The universe initially expanded (accelerated), however with no additional force gravity should 'instantly' start to cause everything to collapse.
In everyday terms if I throw a ball into the air as soon as the initial force of my hand is removed and the ball leaves my hand gravity takes over and 'removes' that force from the ball; until there's none left and the only force remaining is gravity and down comes the ball.
Looking at the universe parts are accelerating. That's like throwing a ball in the air and having its speed increase. Explanations are many and the book seems to settle on dark energy/dark matter etc. which are gravitationally repulsive. Spit-balling I threw some other concepts together and asked what if the acceleration is an illusion?