In the history of physics, there have been three great revolutions in thought that first seemed absurd yet proved to be true. The first proposed that the earth, instead of being stationary, was moving around at a great and variable speed in a universe that is much bigger than it appears to our immediate perception. That proposal, I believe, was first made by Aristarchos two millenia ago ... Remarkably enough, the name Aristarchos in Greek means best beginning.

I belonged to a small minority of boys who were lacking in physical strength and athletic prowess. ... We found our refuge in science. ... We learned that science is a revenge of victims against oppressors, that science is a territory of freedom and friendship in the midst of tyranny and hatred.

It is a test of true theories not only to account for but to predict phenomena.

If our local, observable universe is embedded in a larger structure, a multiverse, then there's other places in this larger structure that have denizens in them that call their local environs the universe. And conditions in those other places could be very different. Or they could be pretty similar to what we have here.

People make their own fates, and if enough of us make our fate to be space explorers, perhaps we can actually get some space exploration done.

About thirty years ago there was much talk that geologists ought only to observe and not theorise; and I well remember some one saying that at this rate a man might as well go into a gravel-pit and count the pebbles and describe the colours. How odd it is that anyone should not see that all observation must be for or against some view if it is to be of any service!