“If time travel is possible, where are the tourists from the future?”

We live in the most probable of all possible worlds.

We are in danger of destroying ourselves by our greed and stupidity. We cannot remain looking inwards at ourselves on a small and increasingly polluted and overcrowded planet.

Science is beautiful when it makes simple explanations of phenomena or connections between different observations.

The meaning in life is not out there but in between our ears. In many ways this makes us the lords of creation.

One, remember to look up at the stars and not down at your feet. Two, never give up work. Work gives you meaning and purpose and life is empty without it. Three, if you are lucky enough to find love, remember it is there and don’t throw it away.

I have noticed even people who claim everything is predestined, and that we can do nothing to change it, look before they cross the road.

There is no unique picture of reality.

People who boast about their I.Q. are losers.

The thing about smart people is that they seem like crazy people to dumb people.

If aliens visit us, the outcome would be much as when Columbus landed in America, which didn’t turn out well for the Native Americans.

Keeping an active mind has been vital to my survival, as has been maintaining a sense of humor.

We don’t let animals suffer, so why humans?

The more you learn, the more you know. The more you know, the more you forget. The more you forget, the less you know. So why bother to learn.

Love the neighbour. But don’t get caught.

Nothing is better than reading and gaining more and more knowledge.

I think the human race doesn’t have a future if we don’t go into space. We need to expand our horizons beyond planet Earth if we are to have a long-term future.

Only put off until tomorrow what you are willing to die having left undone.

The hardest thing, I think, is to live richly in the present, without letting it be tainted and spoiled out of fear for the future or regret for a badly-managed past.

The past is no more; the future not yet. Nothing exists except the here and now. Our grand business is not to see what lies dimly at a distance, but to do what lies clearly at our hands.

Let’s go invent tomorrow.

In the future, there will be opened a gateway and a road to a large and excellent science into which minds more piercing than mine shall penetrate to recesses still deeper.

There is no future without forgiveness.

When space travel becomes as common as air travel, the future of civilization will be assured.

Don’t let the mistakes and disappointments of the past control and direct your future.