Stephen Hawking

The universe is a big place, and we are a small part of it. But we are an important part of it.

Meeting an advanced civilization could be like Native Americans encountering Columbus. That didn't turn out so well.

The human failing I would most like to correct is aggression. It may have had survival advantage in caveman days, to get more food, territory or partner with whom to reproduce, but now it threatens to destroy us all.

The development of full artificial intelligence could spell the end of the human race.

We are close to the tipping point, where global warming becomes irreversible. Trump's action could push the Earth over the brink, to become like Venus, with a temperature of 250 degrees [Celsius], and raining sulfuric acid.

Although the chance of a disaster to planet Earth in a given year may be quite low, it adds up over time, and becomes a near certainty in the next thousand or 10 thousand years.

I think [contacting an alien civilization] would be a disaster. The extraterrestrials would probably be far in advance of us. The history of advanced races meeting more primitive people on this planet is not very happy, and they were the same species. I think we should keep our heads low.

I believe the simplest explanation is, there is no God. No one created the universe and no one directs our fate. This leads me to a profound realization that there probably is no heaven and no afterlife either. We have this one life to appreciate the grand design of the universe and for that, I am extremely grateful.

Because there is a law such as gravity, the Universe can and will create itself from nothing. Spontaneous creation is the reason there is something rather than nothing, why the Universe exists, why we exist. It is not necessary to invoke God to light the blue touch paper and set the Universe going.

If aliens ever visit us, I think the outcome would be much as when Christopher Columbus first landed in America, which didn't turn out very well for the Native Americans.

Of course it is possible that UFO's really do contain aliens as many people believe, and the government is hushing it up.

I don't think the human race will survive the next thousand years, unless we spread into space.

I believe alien life is quite common in the universe, although intelligent life is less so. Some say it has yet to appear on planet Earth.

Without imperfection, you or I would not exist.

God did not create the universe and does not direct our fate.

There is no heaven or afterlife for broken down computers; that is a fairy story for people afraid of the dark.

The human race is a single genetic stock, and we are all brothers and sisters. It's time that we started to act like it.

I am not afraid of death, but I'm in no hurry to die. I have so much I want to do first.

The universe is not just full of black holes, it's full of black holes that are eating everything.

I would like to think that the universe is a friendly place. But it's not.