There is no reason that the universe should be designed for our convenience.

There 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.

Once upon a time when there was no time.

When we try to observe things that are very small, the act of observation itself will significantly disturb the state we are seeking to measure.

What cannot be known is more revealing than what can.

We are just strings of quarks living in a suburb of the local density maximum of the universe.

If all the stars and galaxies in the universe today were smoothed out into a uniform sea of atoms, there would only be about one atom in every cubic meter of space.