Stephen Hawking Quotes

If the Earth gets hit by an asteroid, it's game over. It's control-alt-delete for civilization.

We could not wipe ourselves out with a nuclear war. I do not want so sound too positive. It would be a catastrophe, but it would not be a final one. We are not powerful enough for that. An asteroid could be that powerful. That is why we need to do our homework.

The best authorities are unanimous in saying that a war with H-bombs might possibly put an end to the human race. It is feared that if many H-bombs are used there will be universal death, sudden only for a minority, but for the majority a slow torture of disease and disintegration.

Every inhabitant of this planet must contemplate the day when this planet may no longer be habitable .. The weapons of war must be abolished before they abolish us.

Space travel leading to skylife is vital to human survival, because the question is not whether we will be hit by an asteroid, but when. A planetary culture that does not develop spacefaring is courting suicide. All our history, all our social progress and growing insight will be for nothing if we perish. No risk of this kind, however small it might be argued to be, is worth taking, and no cost to prevent it is too great. No level of risk is acceptable when it comes to all or nothing survival.

The world generally speaking is now drifting on a more and more devastating course towards the absurd target of extermination - or rather, to be more exact - of the northern hemisphere's towns, fields, and the people who have developed our civilization.

I think the human race doesn't have a future if it doesn't go into space.

Most estimates of the mortality risk posed by asteroid impacts put it at about the same risk as flying in a commercial airliner. However, you have to remember that this is like the entire human race riding the plane - it is one of the few risks that really could wipe us all out.

Today's voguish threats, including climate change, population growth, massive war, and resource depletion, are all amenable to a fix if we act prudently. And even if we don't, these problems are incapable of obliterating all of humanity, let alone destroying the Earth. No, the real End of Days will happen slowly, as the Sun ages.

I don't think the world will destroy itself in a nuclear cataclysm. On the contrary, we have the capacity to save ourselves and save the planet, and we will use it.

Some day we'll move into space and start ensuring the survival of our species beyond Earth, whether it happens in a hundred years or a thousand.

Man now has the power to put an end to his own history.

Not only may our own culture be destroyed by these weapons of mass destruction, but all civilizations as they exist in the world may be retarded and weakened for centuries to come. It all adds up to the most dangerous situation that humanity has ever faced in all history

The human race has today the means for annihilating itself—either in a fit of complete lunacy ... or by a careless handling of atomic technology, through the slow poisoning and of deterioration in its genetic structure.

This is the only global scale catastrophe that we know how to prevent, and for the cost of building a highway overpass.

The reality is the majority of us will not get off this planet. So the long run is, some kind of space exploration has to benefit us here on Earth.

It's all too easy to imagine Trump issuing an ultimate, thermonuclear 'You're fired!' to China, Iran, or another nation - and perhaps to the whole human race.

There are two problems for our species' survival - nuclear war and environmental catastrophe - and we're hurtling towards them. Knowingly.

Human civilization as we know it is like the Titanic headed for the iceberg, whether the iceberg be nuclear, environmental or terrorism-related.

The overarching problem is one of the survival of humanity in the face of the growing nuclear menace. If those bombs go off, nothing else would matter.

There's no question that if we stay on planet Earth and never leave, that eventually we'll be wiped out.

In an all-out nuclear war, more destructive power than in all of World War II would be unleashed every second during the long afternoon it would take for all the missiles and bombs to fall. A World War II every second-more people killed in the first few hours than all the wars of history put together. The survivors, if any, would live in despair amid the poisoned ruins of a civilization that had committed suicide.

Better contraceptives will control population only if people will use them. A nuclear holocaust can be prevented only if the conditions under which nations make war can be changed. The environment will continue to deteriorate until pollution practices are abandoned. We need to make vast changes in human behavior.

I will not sleep fine if Donald Trump wins and I will not sleep fine is Hillary Clinton wins. Whether you are looking at nuclear weapons, whether you are looking at expanding wars and their blowback, which will not stop as long as those wars continue to expand, or whether you're looking at the climate, in my view, we have no choice. This is an existential moment. We are deciding not only what kind of world we will have, but whether we will have a world or not. I think it's very important to get outside this box that tells us we are powerless, when in fact, we are powerful.

We know that to wage a nuclear war today, for example, would be a form of suicide; or that to pollute the air or the oceans in order to achieve some short-term benefit would be to destroy the very basis for our survival.