Author 193954

Stephen
Hawking
1942

English Theoretical Physicist, Cosmologist, Author, Honorary Fellow of the Royal Society of Arts, Awarded the Presidential Medal of Freedom, the highest civilian award in the United States, Lucasian Professor of Mathematics at the University of Cambridge, Research Chair at the Perimeter Institute for Theoretical Physics in Waterloo, Ontario

Author Quotes

Feynman once wrote, I think I can safely say that nobody understands quantum mechanics.

Nature and Nature?s laws lay hid in night: God said, Let Newton be! and all was light.

The true miracle is that abstract considerations of logic lead to a unique theory that predicts and describes a vast universe full of the amazing variety that we see.

How do I know that a table still exists if I go out of the room and can?t see it? What does it mean to say that things we can?t see, such as electrons or quarks?the particles that are said to make up the proton and neutron?exist? One could have a model in which the table disappears when I leave the room and reappears in the same position when I come back, but that would be awkward, and what if something happened when I was out, like the ceiling falling in? How, under the table-disappears-when-I-leave-the-room model, could I account for the fact that the next time I enter, the table reappears broken, under the debris of the ceiling? The model in which the table stays put is much simpler and agrees with observation. That is all one can ask.

Our universe and its laws appear to have a design that both is tailor-made to support us and, if we are to exist, leaves little room for alteration. That is not easily explained, and raises the natural question of why it is that way.

The universe expanded by a factor of 1,000,000,000,000,000,000,000,000,000,000 in .00000000000000000000000000000000001 second. It was as if a coin 1 centimeter in diameter suddenly blew up to ten million times the width of the Milky Way.

If nature is governed by laws, three questions arise: What is the origin of the laws? Are there any exceptions to the laws, i.e., miracles? Is there only one set of possible laws?

Our very existence imposes rules determining from where and at what time it is possible for us to observe the universe. That is, the fact of our being restricts the characteristics of the kind of environment in which we find ourselves. That principle is called the weak anthropic principle.

There might be one history in which the moon is made of Roquefort cheese. But we have observed that the moon is not made of cheese, which is bad news for mice. Hence histories in which the moon is made of cheese do not contribute to the present state of our universe, though they might contribute to others. That might sound like science fiction, but it isn?t.

If the Earth stopped spinning, then according to Newton's law of any object not tied to the Earth will continue to move at the speed of rotation of the Earth (1100 miles per hour, or 1770 km per hour at the equator)

Quantum physics is a new model of reality that gives us a picture of the universe that in many fundamental concepts for our intuitive understanding of reality meaningless.

Traditionally these are questions for philosophy, but philosophy is dead. Philosophy has not kept up with modern developments in science, particularly physics. Scientists have become the bearers of the torch of discovery in our quest for knowledge.

A few years ago the city council of Monza, Italy, barred pet owners from keeping goldfish in curved goldfish bowls. The measure?s sponsor explained the measure in part by saying that it is cruel to keep a fish in a bowl with curved sides because, gazing out, the fish would have a distorted view of reality.

If the theory is confirmed by observation, it will be the successful conclusion of a search going back more than 3,000 years. We will have found the grand design.

Quantum physics might seem to undermine the idea that nature is governed by laws, but that is not the case. Instead it leads us to accept a new form of determinism: given the state of a system at some time, the laws of nature determine the probabilities of various futures and pasts rather than determining the future and past with certainty.

Until the advent of modern physics it was generally thought that all knowledge of the world could be obtained through direct observation, that things are what they seem, as perceived through our senses. But the spectacular success of modern physics, which is based upon concepts such as Feynman?s that clash with everyday experience, has shown that that is not the case. The naive view of reality therefore is not compatible with modern physics.

Among the heresies was the idea that nature follows laws, because this conflicts with God?s omnipotence. Interestingly, Pope John was killed by the effects of the law of gravity a few months later when the roof of his palace fell in on him.

Ignorance of nature?s ways led people in ancient times to invent gods to lord it over every aspect of human life.

Quantum physics tells us that no matter how thorough our observation of the present, the (unobserved) past, like the future, is indefinite and exists only as a spectrum of possibilities. The universe, according to quantum physics, has no single past, or history. The fact that the past takes no definite form means that observations you make on a system in the present affect its past. That is underlined rather dramatically by a type of experiment thought up by physicist John Wheeler, called a delayed-choice experiment. Schematically, a delayed-choice experiment is like the double-slit experiment we just described, in which you have the option of observing the path that the particle takes, except in the delayed-choice experiment you postpone your decision about whether or not to observe the path until just before the particle hits the detection screen. Delayed-choice experiments result in data identical to those we get when we choose to observe (or not observe) the which-path information by watching the slits themselves. But in this case the path each particle takes?that is, its past?is determined long after it passed through the slits and presumably had to decide whether to travel through just one slit, which does not produce interference, or both slits, which does. Wheeler even considered a cosmic version of the experiment, in which the particles involved are photons emitted by powerful quasars billions of light-years away. Such light could be split into two paths and refocused toward earth by the gravitational lensing of an intervening galaxy. Though the experiment is beyond the reach of current technology, if we could collect enough photons from this light, they ought to form an interference pattern. Yet if we place a device to measure which-path information shortly before detection, that pattern should disappear. The choice whether to take one or both paths in this case would have been made billions of years ago, before the earth or perhaps even our sun was formed, and yet with our observation in the laboratory we will be affecting that choice. In

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.

Anaximander, a friend and possibly a student of Thales, argued that since human infants are helpless at birth, if the first human had somehow appeared on earth as an infant, it would not have survived. In what may have been humanity's first inkling of evolution, people, Anaximander reasoned, must therefore have evolved from other animals whose young are hardier.

In 1992 came the first confirmed observation of a planet orbiting a star other than our sun.

Recent experiments in neuroscience support the view that it is our physical brain, following the known laws of science, that determines our actions, and not some agency that exists outside those laws. For example, a study of patients undergoing awake brain surgery found that by electrically stimulating the appropriate regions of the brain, one could create in the patient the desire to move the hand, arm or foot, or to move the lips and talk. It is hard to imagine how free will can operate if our behaviour is determined by physical law, so it seems that we are no more than biological machines and that free will is just an illusion.

We believe human begins have existed for only a small fraction of cosmic history, because human race has been improving so rapidly in knowledge and technology that if people had been around for millions of years, the human race would be much further along in its mastery.

As a result, in more than three dimensions the sun would not be able to exist in a stable state with its internal pressure balancing the pull of gravity. It would either fall apart or collapse to form a black hole, either of which could ruin your day.

Author Picture
First Name
Stephen
Last Name
Hawking
Birth Date
1942
Bio

English Theoretical Physicist, Cosmologist, Author, Honorary Fellow of the Royal Society of Arts, Awarded the Presidential Medal of Freedom, the highest civilian award in the United States, Lucasian Professor of Mathematics at the University of Cambridge, Research Chair at the Perimeter Institute for Theoretical Physics in Waterloo, Ontario