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.

All our surest statements about the nature of the world are mathematical statements, yet we do not know what mathematics "is"... and so we find that we have adapted a religion strikingly similar to many traditional faiths. Change "mathematics" to "God" and little else might seem to change. The problem of human contact with some spiritual realm, of timelessness, of our inability to capture all with language and symbol-all have their counterparts in the quest for the nature of Platonic mathematics.

Apparently, a great deal of dark, unseen material exists, whose gravitational pull is responsible for the motions of the stars and galaxies that we see.

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.

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.

We can predict the present without having to know everything about the past.

We can never know the origins of the universe. The deepest secrets are the ones that keep themselves.