Stephen Hawking Quotes

The matter in the universe is made out of positive energy. However, the matter is all attracting itself by gravity. Two pieces of matter that are close to each other have less energy than the same two pieces a long way apart. This is because you have to expend energy to separate them. You have to pull against the gravitational force attracting them together. Thus, in a sense, the gravitational field has negative energy. In the case of the whole universe, one can show that this negative gravitational energy exactly cancels the positive energy of the matter. So the total energy of the universe is zero.

Black holes might be useful for getting rid of garbage or even some of one's friends.

So look carefully at the map of the microwave sky. It is the blueprint for all the structure in the universe. We are the product of quantum fluctuations in the very early universe. If one were religious, one could say that God really does play dice.

Heisenberg’s uncertainty principle is a fundamental, inescapable property of the world.

There could be whole antiworlds and antipeople made out of antiparticles. However, if you meet your antiself, don’t shake hands!

To apply quantum theory to the entire universe... is tricky... particles of matter fired at a screen with two slits in it... exhibit interference patterns just as water waves do.

Feynman showed that this arises because a particle does not have a unique history.

That is, as it moves from its starting point A to some endpoint B, it doesn’t take one definite path, but rather simultaneously takes every possible path connecting the two points.

From this point of view, interference is no surprise because, for instance, the particle can travel through both slits at the same time and interfere with itself.

In this view, the universe appeared spontaneously, starting off in every possible way.

Consider the apparent dimension of the universe. According to M-theory, space-time has ten space dimensions and one time dimension. The idea is that seven of the space dimensions are curled up so small that we don’t notice them, leaving us with the illusion that all that exist are the three remaining large dimensions we are familiar with.

You can’t get to a time before the Big Bang because there was no time before the Big Bang. We have finally found something that doesn’t have a cause, because there was no time for a cause to exist in. For me this means that there is no possibility of a creator, because there is no time for a creator to have existed in.

As we shall see, the concept of time has no meaning before the beginning of the universe. This was first pointed out by St. Augustine. When asked: “What did God do before he created the universe?” Augustine didn’t reply: “He was preparing Hell for people who asked such questions.

If there were events earlier than this time, then they could not affect what happens at the present time. Their existence can be ignored because it would have no observational consequences.

Intelligence is the ability to adapt to change

Another prediction of general relativity is that time should appear to run slower near a massive body like the earth.

No boundary condition: The idea that the universe is finite but has no boundary (in imaginary time).

A scientific law is not a scientific law, if it holds only when some supernatural being decides not to intervene

one has a singularity contained within a region of space-time known as a black hole.