Quotes About Physics

People have searched for mini black holes of this mass, but have so far not found any. This is a pity because, if they had, I would have got a Nobel Prize.

An asteroid collision would be something against which we have no defence. The last big such collision with us was about sixty-six million years ago and that is thought to have killed the dinosaurs, and it will happen again. This is not science fiction; it is guaranteed by the laws of physics and probability.

The laws of science determine the evolution of the universe, given its state at one time.

But physics and astronomy offered the hope of understanding where we came from and why we are here. I wanted to fathom the depths of the universe. Maybe I have succeeded to a small extent, but there's still plenty I want to know.

if you believe that the universe is not arbitrary, but is governed by definite laws, you ultimately have to combine the partial theories into a complete unified theory that will describe everything in the universe.

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.

DüÅŸük h?z? ve zay?f kuvveti ilgilendiren durumlarda zaman? ve uzay? ayr? ayr? ele alabiliriz. Oysa, genelde zaman ve uzay birbirine geçmiÅŸtir ve bunlar?n geniÅŸlemesi veya s?k??mas? belli oranda birbirine kar??may? içerir.

This says that in any closed system disorder, or entropy, always increases with time. In other words, it is a form of Murphy's law: things always tend to go wrong!

If you fall towards a black hole feet first, gravity will pull harder on your feet than your head, because they are nearer the black hole. The result is that you will be stretched out lengthwise, and squashed in sideways.

The great mystery at the heart of the Big Bang is to explain how an entire, fantastically enormous universe of space and energy can materialise out of nothing. The secret lies in one of the strangest facts about our cosmos. The laws of physics demand the existence of something called "negative energy.

Stephen Hawking

Stephen Hawking

Today scientists describe the universe in terms of two basic partial theories—the general theory of relativity and quantum mechanics

information paradox

In general relativity, bodies always follow straight lines in four-dimensional space-time, but they nevertheless appear to us to move along curved paths in our three-dimensional space. (This is rather like watching an airplane flying over hilly ground. Although it follows a straight line in three-dimensional space, its shadow follows a curved path on the two-dimensional ground.)

any normal object is forever confined by relativity to move at speeds slower than the speed of light. Only light, or other waves that have no intrinsic mass, can move at the speed of light.

Unfortunately, however, these two theories are known to be inconsistent with each other—they cannot both be correct.

Na teoria da relatividade, não existe tempo absoluto único; em vez disso, cada indivíduo tem sua própria medida de tempo, que depende de onde ele se encontra e de como está se movendo.

Do the laws governing the universe allow us to predict exactly what is going to happen to us in the future? The short answer is no, and yes. In principle, the laws allow us to predict the future. But in practice the calculations are often too difficult.

For every event in space-time we may construct a light cone (the set of all possible paths of light in space-time emitted at that event), and since the speed of light is the same at every event and in every direction, all the light cones will be identical and will all point in the same direction.

associates and collaborators were Roger Penrose, Robert

associates and collaborators were Roger Penrose

In order to understand the origin of the universe, one therefore has to incorporate the Uncertainty Principle into Einstein's general theory of relativity. This has been the great challenge in theoretical physics for at least the last thirty years. We haven't solved it yet, but we have made a lot of progress.

This apparent loss of information, known as the information paradox, has troubled scientists for the last forty years, and still remains one of the biggest unsolved problems in theoretical physics.