Stephen Hawking Quotes

A valid scientific theory is predictive, verifiable, and replicable. To me, that's beautiful.

If the facts are contrary to any predictions, then the hypothesis is wrong no matter how appealing.

The only relevant test of the validity of a hypothesis is comparison of prediction with experience.

There is no justifiable prediction about how the hypothesis will hold up in the future; its degree of corroboration simply is a historical statement describing how severely the hypothesis has been tested in the past.

You can't prove any hypothesis, you can only improve or disprove it.

The funny thing is, I sometimes get the impression that some people outside of the field think that there's some element of security that we have in working on a theory that hasn't made any predictions that can be proven false. In a sense, we're working on something unfalsifiable.

Falsifiability for a theory is great, but a theory can still be respectable even if it is not falsifiable, as long as it is verifiable.

To say that prediction is the purpose of a scientific theory is to confuse means with ends. It is like saying that the purpose of a spaceship is to burn fuel. ... Passing experimental tests is only one of many things a theory has to do to achieve the real purpose of science, which is to explain the world.

A good scientific theory is one which is falsifiable, which has not been falsified.

If all that you see, do, measure and discover is the will of a deity, then ideas can never be proven wrong, you have no predictive power, and you are at a loss to understand the principles behind most of the fundamental interconnections of nature.

The hypotheses we accept ought to explain phenomena which we have observed. But they ought to do more than this: our hypotheses ought to foretell phenomena which have not yet been observed.

The truth of a theory can never be proven, for one never knows if future experience will contradict its conclusions.

Science is prediction, not explanation.

The strength of a theory is not what it allows, but what it prohibits; if you can invent an equally persuasive explanation for any outcome, you have zero knowledge.

Science boosts its claim to truth by its spectacular ability to make matter and energy jump through hoops on command, and to predict what will happen and when.

To get at the core of God at his greatest, one must first get to the core of himself at his least, for no one can know God who has not first known himself. This core is a simple stillness, which is unmoved itself but by whose immobility all things are moved and all receive life.

Our belief in any particular natural law cannot have a safer basis than our unsuccessful critical attempts to refute it.

It is a mistake to believe that science consists in nothing but conclusively proved propositions, and it is unjust to demand that it should. It is a demand made by those who feel a craving for authority in some form to replace the religious catechism by something else, even a scientific one.

Empirical laws [...] have only slight or even no value beyond the limits within which they have been observed to be true.

Nature is our kindest friend and best critic in experimental science if we only allow her intimations to fall unbiased on our minds.

Whenever a true theory appears, it will be its own evidence. Its test is, that it will explain all phenomena.

The scientific tradition is distinguished from the pre-scientific tradition by having two layers. Like the latter, it passes on its theories; but it also passes on a critical attitude towards them.

If the evidence says you're wrong, you don't have the right theory. You change the theory, not the evidence.

A single test which proves some piece of theory wrong is more valuable than a hundred tests showing that idea might be true.

There can be no ultimate statements science: there can be no statements in science which can not be tested, and therefore none which cannot in principle be refuted, by falsifying some of the conclusions which can be deduced from them.