Quotes About Physics

A singularity is a point or region in spacetime at which some physical quantity such as the density of mass or energy, the temperature, or the strength of the gravitational field, becomes infinite. Whenever they happen, they pose serious difficulties for physics because they signal a breakdown in the description of the world in mathematical terms.

A body at rest or in uniform motion remains in that state of rest or uniform motion unless it is disturbed by forces.

Being at rest becomes merely a special case of uniform motion-it is just motion at zero speed.

I'll describe the original approach of Barbour, but most of what I'll have to say applies to Gomes's version9, as well as more recent work of Barbour and his collaborators. A moment, for them, is a configuration of the universe as a whole. These configurations, according to Barbour and Gomes, are relational configurations, which code all the relations that can be captured in a moment, such as relative distances and relative sizes.

We have to find a way to unfreeze time-to represent time without turning it into space. I have no idea how to do this. I can't conceive of a mathematics that doesn't represent a world as if it were frozen in eternity. It's terribly hard to represent time, and that's why there's a good chance that this representation is the missing piece.

We seem to experience time passing as a smooth flow of moments. Barbour insists that the passage of time is an illusion and that reality consists of nothing but a vast pile of moments, each a configuration of the whole universe. You now are experiencing a moment. Now you are experiencing a different moment. According to Barbour, both moments exist eternally and timelessly, in the pile of moments. Reality is nothing but this frozen collection of moments outside time.

Physics out of quantum equilibrium contains several surprises. One is that it becomes possible to send information faster than light. This is a consequence of another result of Valentini's, which tells us that while the system is out of quantum equilibrium, information and energy can be sent instantaneously, contradicting special relativity.

Because string theory is such a high-risk venture—unsupported by experiment

How can it be that there is no distinction between motion and rest? The key is to realize that whether a body is moving or not has no absolute meaning. Motion is defined only with respect to an observer, who can be moving or not. If you are moving past me at a steady rate, then the cup of coffee I perceive to be at rest on my table is moving with respect to you.

In practice, the greatest amount of information that may be stored behind a horizon is huge - 10^66 bits of information per square centimetre.

So LISTEN UP, class! Today we're going to learn all about chain reactions.

The real problem is in the hearts and minds of men. It is not a problem of physics but of ethics. It is easier to denature plutonium than to denature the evil spirit of man. Albert Einstein

To my great surprise — and slight annoyance — I found that Seth eloquently and lucidly articulated a view of reality that I had arrived at only after great effort and an extensive study of both paranormal phenomena and quantum physics. …" — Michael Talbot, author of The Holographic Universe

The physicists have their hands on the doorknob. If they paid more attention to their dreams, they would know what questions to ask.

I've many questions, but am not eager to know the Baba's answers. They'll be hard kernels between my teeth. Biting down becomes a question of physics, a reply only dentists can give.

The law of right-left symmetry was used in classical physics but was not of any great practical importance there. One reason for this derives from the fact that right-left symmetry is a discrete symmetry, unlike rotational symmetry, which is continuous.

Our minds work in real time, which begins at the Big Bang and will end, if there is a Big Crunch - which seems unlikely, now, from the latest data showing accelerating expansion. Consciousness would come to an end at a singularity.

I have been connected with the Niels Bohr Institute since the completion of my university studies, first as a research fellow and, from 1956, as a professor of physics at the University of Copenhagen. After the death of my father in 1962, I followed him as director of the Institute until 1970.

Statistical physics or Newtonian physics gives way to quantum physics. Very unusual properties of matter emerge at that scale, and you can think about building products in a very different way. You can think about interfacing to biology in a very different way.

In spacetime, all events are baked together: a four-dimensional continuum. Past and future are no more privileged than left and right or up and down.

It's not magic! It's physics. The speed of the turn is what keeps you upright. It's like a spinning top.

Thinking about quantum physics is like unraveling your brain and putting it back together again upside down. Much like studying Kabbalah.

If your car could travel at the speed of light, would your headlights work?

The animal frame, though destined to fulfill so many other ends, is as a machine more perfect than the best contrived steam-engine-that is, is capable of more work with the same expenditure of fuel.