John D. BarrowThere are only certain intervals of time when life of any sort is possible in an expanding universe and we can practise astronomy only during that habitable time interval in cosmic history.
About This Quote
It is a common misconception that we have a limitless supply of time on Earth. It is true that we have a limited supply of time, however, our lives on Earth are often unpredictable, fleeting and contingent. The more we learn about the world around us, the more we find out about the limits of time. That being said, it is possible to live a long and complete life on Earth.
In fact, some people do live long and complete lives here on Earth. Perhaps the most famous example is Bill Gates, who was born in a small town in America at a young age and went on to become one of the richest men in the world.
Source: The Book Of Universes: Exploring The Limits Of The Cosmos