# Calculating the age of the Universe now and 30 billion years from now [duplicate]

I am confused about the age of the Universe.

If you calculate it by $1 / H_0$, won't the answer be roughly the same today as it will be 30 billion years from now?

I know $H_0$ is a parameter, not a constant, but it doesn't change that much, does it?

And if the expansion is accelerating then $H_0$ is going up, implying the age of the universe $1 / H_0$ was higher in the past than it is today.

## marked as duplicate by Qmechanic♦Sep 25 '13 at 20:42

• The accelerated expansion implies that $\dot{a}$ increases (the derivative of the scale factor). But the Hubble parameter is defined as $H = \dot{a}/a$, which decreases. The age of the universe is calculated here: physics.stackexchange.com/a/63673/24142 and here: physics.stackexchange.com/a/69052/24142 – Pulsar Sep 27 '13 at 21:44