Quotes About Space

The idea of 10 dimensions might sound exciting, but they would cause real problems if you forget where you parked your car.

When we see the Earth from space, we see ourselves as a whole. We see the unity, and not the divisions. It is such a simple image with a compelling message; one planet, one human race.

In an infinite universe, every point can be regarded as the center, because every point has an infinite number of stars on each side of it. The

Cuando miramos al universo, lo vemos tal como fue en el pasado

Today, we commit to this next great leap into the cosmos because we're human, and our nature is to fly.

I don't think the human race will survive the next thousand years, unless we spread into space. There are too many accidents that can befall life on a single planet. But I'm an optimist. We will reach out to the stars.

black holes are not really black after all: they glow like a hot body, and the smaller they are, the more they glow.

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

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

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

the future is unknown and open, so it might well have the curvature required. This would mean that any time travel would be confined to the future. There would be no chance of Captain Kirk and the Starship Enterprise turning up at the present time.

So Hamlet was quite right. We could be bounded in a nutshell and count ourselves kings of infinite space.

If so, we might be able to use them for rapid travel around the galaxy or travel back in time. Of course, we have not seen anyone from the future (or have we?) but I discuss a possible explanation for this.

one of the twins went for a long trip in a spaceship at nearly the speed of light. When he returned, he would be much younger than the one who stayed on earth. This is known as the twins paradox, but it is a paradox only if one has the idea of absolute time at the back of one's mind. In the theory of relativity there is no unique absolute time, but instead each individual has his own personal measure of time that depends on where he is and how he is moving.

If you think it is hard to get humans to follow traffic laws, imagine convincing an asteroid to move along an ellipse.

Because gravity shapes space and time, it allows space time to be locally stable but globally unstable. On the scale of the entire universe, the positive energy of the matter can be balanced by the negative gravitational energy, and so there is no restriction on the creation of whole universes. Because there is a law like gravity, the universe can and will create itself from nothing in the manner described in Chapter 6.

One of the great revelations of the space age has been the perspective it has given humanity on ourselves. When we see the Earth from space, we see ourselves as a whole. We see the unity, and not the divisions. It is such a simple image with a compelling message; one planet, one human race.

Anything or anyone who falls through the event horizon will soon reach the region of infinite density and the end of time.

Roger Penrose and I showed that Einstein's general theory of relativity implied that the universe must have a beginning and, possibly, an end.

Why do we see only three space dimensions and one time dimension? The suggestion is that the other dimensions are curved up into a space of very small size, something like a million million million million millionth of an inch. This is so small that we just don't notice it: we see only one time dimension and three space dimensions, in which space-time is fairly flat.

The nonexistence of absolute rest therefore meant that one could not give an event an absolute position in space, as Aristotle had believed. The positions of events and the distances between them would be different for a person on the train and one on the track, and there would be no reason to prefer one person's position to the other's.

In an infinite universe, every point can be regarded as the center, because every point has an infinite number of stars on each side of it.

In other words, the theory of relativity put an end to the idea of absolute time!

In fact, according to quantum physics, each particle has some probability of being found anywhere in the universe.