Aug 14 2008
From The Life of the Cosmos by Lee Smolin.
[T]he fact that general relativity and the quantum are not yet united means that we have no single picture of what the world is that we can believe in. When a child asks, What is the world, we literally have nothing to tell her.
Jul 17 2008
From The Life of the Cosmos by Lee Smolin.
No wonder physics is so hard to learn. As it is usually taught to students, Newton’s physics does not make complete sense, for they are almost never told the whole story. Position, velocity, and acceleration are usually introduced as if they have simple and obvious meanings, but the do not. Even more difficult are the concepts of force and mass; the definitions given of them in textbooks are almost always circular. The students are seldom told that if they are puzzled it may be for good reason, or that the things that confuse them have been debated for centuries. Some figure it out for themselves. Many go away with an unjustified sense that they cannot learn science.
Jul 16 2008
From The Life of the Cosmos by Lee Smolin.
In science, as in politics or love, one can have all the good arguments and still be in the wrong. When it comes down to it, what matters is not whose story is more logical or beautiful, but which leads to the greatest effect.
Jul 12 2008
From The Life of the Cosmos by Lee Smolin.
Does the world consist of a large number of independently autonomous atoms, the properties of each owing nothing to the others? Or, instead, is the world a vast, interconnected system of relations, in which even the properties of a single elementary particle or the identity of a point in space requires and reflects the whole rest of the universe? The two views of space and time underlie and imply two very different views of what it means to speak of a property, of identity, or of individuality. Consequently, the transition from a cosmology based on an absolute notion of space and time to one based on a relational notion - a transition that we are now in the midst of - must have profound implications for our understanding of the place of complexity and life in the universe.
Jul 04 2008
From The Life of the Cosmos by Lee Smolin.
[T]here is no mystery or symmetry needed to explain why the air is spread uniformly in a room. Each atom moves randomly, it is just the statistics of enormous numbers. Perhaps the greatest nightmare of the Platonist is that, in the end, all of our laws will be like this, so that the root of all the beautiful regularities we have discovered will turn out to be more statistics, beyond which is only randomness or irrationality.
This is perhaps one reason why biology seems puzzling to some physicists. The possibility that the tremendous beauty of the living world might be, in the end, just a matter of randomness, statistics, and frozen accident stands as a genuine threat to the mystical conceit that reality can be captured in a single, beautiful equation.
Aug 14 2007
If we restrict ourselves to proposals which are falsifiable, what kind of explanations are available to us? In the history of science there have been two kinds of explanation which generally succeeded: explanations in terms of general principles; and explanations in terms of history. We are used to believing that the former are more fundamental than the latter. If we discover a fact that seems to hold universally, such as that all electrons have the same mass, we believe immediately that the reason for it must rest on principle and not on history. We usually expect a phenomenon to be contingent only if we see that it changes from instance to instance. If asked to justify this, we would say that something that is universally true cannot rest on contingent circumstances, which can vary from case to case. This makes sense, but it is an example of the kind of argument that works well only as long as it is not applied at the scale of the universe as a whole. When we are dealing with properties of the observable universe we no longer have any reason to insist that if something is true in every observable case, it cannot at the same time be contingent. One reason is that we have no justification to assert that the universe we see around us represents a good sample of all that exists, or that has existed, or that might in principle exist. There is in fact no logical reason to exclude the possibility that some of the facts about the elementary particles, which appear to hold throughout our observable universe, might at the same time be contingent.
The argument that Lee Smolin makes is pretty interesting. He suggests that “a process of self-organization like that of biological evolution shapes the universe, as it develops and eventually reproduces through black holes, each of which may result in a new big bang and a new universe. Natural selection may guide the appearance of the laws of physics, favoring those universes which best reproduce.” This is kind of terrifying, but much more interesting than the physics classes I’ve had so far.
