Quotes from Lee Smolin

But Einstein was not the best mathematician around, and others, undeterred by neither the difficulty of the equations nor the war that was ravaging Europe (this was 1916), were able to find solutions. Some of the most important solutions ever found—those that describe the gravitational fields of stars and black holes—were written down by a German officer named Karl Schwarzchild as he lay dying in a field hospital of a skin disease he had picked up in the trenches.

So, Einstein's theory of gravity is a theory of causal structure. It tells us that the essence of spacetime is causal structure and that the motion of matter is a consequence of alterations in the network of causal relations. What is left out from the notion of causal structure is any measure of quantity or scale.

Do I care about these other branches? Should I? There is always the chance that at some time in the future an empty branch recombines with my branch, causing interference, which changes my life

But were we mere atoms, interference between full and empty branches of the wave function would be happening all the time.

For simple black holes, which do not rotate and have no electric charge, the values of the temperature and entropy can be expressed very simply. The area of the horizon of a simple black hole is proportional to the square of its mass, in Planck units. The entropy S is proportional to this quantity. In terms of Planck units, we have the simple formula S = .25 A / h G. Where A is the area of the horizon, and G is the gravitational constant.

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.

The fact that the amount of missing information depends on the area of the boundary of the trapped region is a very important clue.

Expressed in Planck units, the temperature T of a black hole is inversely proportional to its mass, m. This is a third law, Hawking's law: T = k/m. The constant k is very small in normal units. As a result, astrophysical black holes have temperatures of a very small fractionnof a degree.

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.

If a surface can be seen as a kind of channel through which information flows from one region of space to another, then the area of the surface is a measure of its capacity to transmit information. This is very suggestive.

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.

Science is not philosophers sitting in clouds. It is a human activity, as complex and problematic as any other.

Copernicus, 1996). Julian

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

Quantum theory can be described as a new kind of language to be used in a dialogue between us and the systems we study with our instruments. This quantum language contains verbs that refer to our preparations and measurements and nouns that refer to what is then seen. It tells us nothing about what the world would be like in our absence.

It is interesting to note that the quantum-mechanical revolution was made by a virtually orphaned generation of scientists. Many members of the generation above them had been slaughtered in World War I. There simply weren't many senior scientists around to tell them they were crazy.

Basically, string theory is the development of this visionary idea in a context of a fixed background of space and time. Loop quantum gravity is the same idea but developed in a completely background-independent theory.

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.

To quote Richard Dawkins, in The Blind Watchmaker, "The theory of evolution by cumulative natural selection is the only theory we know of that is, in principle, capable of explaining the existence of organized complexity. Even if the evidence did not favor it, it would still be the best theory available." The

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

One way to unify things that appear different is to show that the apparent difference is due to the difference in the perspective of the observers. A distinction that was previously considered absolute becomes relative. This kind of unification is rare and represents the highest form of scientific creativity. When it is achieved, it radically alters our view of the world.