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March 23 - April 13, 2021
understanding does not depend on knowing a lot of facts as such, but on having the right concepts, explanations and theories.
Facts cannot be understood just by being summarized in a formula, any more than by being listed on paper or committed to memory. They can be understood only by being explained. Fortunately, our best theories embody deep explanations as well as accurate predictions.
What makes the general theory of relativity so important is not that it can predict planetary motions a shade more accurately than Newton’s theory can, but that it reveals and explains previously unsuspected aspects of reality, such as the curvature of space and time.
Scientific theories explain the objects and phenomena of our experience in terms of an underlying reality which we do not experience directly. But the ability of a theory to explain what we experience is not its most valuable attribute. Its most valuable attribute is that it explains the fabric of reality itself.
Prediction – even perfect, universal prediction – is simply no substitute for explanation.
The overwhelming majority of theories are rejected because they contain bad explanations, not because they fail experimental tests.
What we test are new theories that seem to show promise of explaining things better than the prevailing ones do.
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. In fact, burning fuel is only one of many things a spaceship has to do to accomplish its real purpose, which is to transport its payload from one point in space to another. 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A theory may be superseded by a new theory which explains more, and is more accurate, but is also easier to understand, in which case the old theory becomes redundant, and we gain more understanding while needing to learn less than before.
We are not heading away from a state in which one person could understand everything that is understood, but towards it.
It is not that we shall soon understand everything. That is a completely different issue. I do not believe that we are now, or ever shall be, close to understanding everything there is. What I am discussing is the possibility of understanding everything that is understood.
That depends more on the structure of our knowledge th...
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The purpose of high-level sciences is to enable us to understand emergent phenomena, of which the most important are, as we shall see, life, thought and computation.
It follows that reality is a much bigger thing than it seems, and most of it is invisible.
The heart of the argument is that single-particle interference phenomena unequivocally rule out the possibility that the tangible universe around us is all that exists.
Therefore, if the best theory available to physics did not refer to parallel universes, it would merely mean that we needed a better theory, one that did refer to parallel universes, in order to explain what we see.
The quantum theory of parallel universes is not the problem, it is the solution. It is not some troublesome, optional interpretation emerging from arcane theoretical considerations. It is the explanation – the only one that is tenable – of a remarkable and counter-intuitive reality.
The problem in genuine science is always to understand some aspect of the fabric of reality, by finding explanations that are as broad and deep, and as true and specific, as possible.
According to inductivism, scientific theories are discovered by extrapolating the results of observations, and justified when corroborating observations are obtained. In fact, inductive reasoning is invalid, and it is impossible to extrapolate observations unless one already has an explanatory framework for them.
If, according to the simplest explanation, an entity is complex and autonomous, then that entity is real.
If a substantial amount of computation would be required to give us the illusion that a certain entity is real, then that entity is real.
Virtual reality is not just a technology in which computers simulate the behaviour of physical environments. The fact that virtual reality is possible is an important fact about the fabric of reality. It is the basis not only of computation, but of human imagination and external experience, science and mathematics, art and fiction.
This too is a property that time machines would have if they existed physically. Not only are they places, they are places with a finite capacity for supporting through traffic into the past.
At present we know of nothing in the laws of physics that rules out past-directed time travel; on the contrary, they make it plausible that time travel is possible. Future discoveries in fundamental physics may change this.
