Prototype theory of concept formation

Is Harriman's criticism of the Big Bang based on the idea that the universe cannot logically have an origin, because nihilo ex nihilo -- from nothing comes nothing? If so, I was not aware that the Big Bang theory actually claims that existence arose out of nothing, only that the present state of the universe originated from a very small condensed form of pre-existing matter. Or, at least that's how I've heard it interpreted by some physicists. So, on that interpretation, I don't see any obvious philosophical objection to it.

- Bill

Post 81

Tuesday, February 23, 2010 - 6:01am

Bill,
Looking thru my notes on a couple of Harriman's lectures, I don't find a lot of material on the big bang theory. Here's what I get. In "The Philosophical Corruption of Physics" he refers to the "rationalism of big-bang cosmology". In his talk entitled "The crisis in Physics - and its Cause" he says:

The big bang theory of modern cosmology combines these ideas [the claim that particles can pop out of nothingness in a vacuum, etc.] and claims the entire universe popped out of a singularity about 15 billion years ago. In the words of astrophysicist Bruce Gregory: 'The universe is what the vacuum produces when left to itself.'

I have to admit that I'm not that familiar with the arguments for the big bang theory, other than the need to account for the expanding universe (where's it expanding from; a point, naturally). But I don't understand the singularity argument. Where was the singularity? Space-time didn't exist prior to the creation of the universe in the big bang. So, what vacuum are they referring to when they say the universe resulted from a quantum fluctuation in the vacuum? Also, these particles that can pop out of the vacuum can only exist for a time consistent with the uncertainty principle, which says that the lifetime of a particle is inversely proportional to its energy, where the constant of proportionality is really, really small (Planck's constant).

Those of Harriman's lectures that I'm most familiar with are more concerned with the philosophical foundations of physics in general and of quantum mechanics and relativity in particular. He makes some arguments that seem "out there" until you look at the literature and find that they are still being debated; just not by many physicists. Physicists typically (at least in my experience) are not trained in, or interested in, the philosophy of physics. Just the other night (to give some firm anecdotal evidence), I was talking to a couple of physics grad students here at Cornell and discovered that they had never heard of Logical Positivism.

Thanks,
Glenn

Post 82

Tuesday, February 23, 2010 - 8:17am

And this assertion that big bang theory posits that the universe "popped out of nothing" is false. To pop out of something implies a time and a place at which an event occurred. To say that the universe popped out of nothing is implicitly to accept that space and time are absolute and intrinsic and outside of the universe. Big bang theory, properly understood, does not do this. It holds that spacetime is finite, yet unbounded, just as the surface of a sphere is finite, yet has no edge. The big bang was not an event which occurred at a point in an already existing infinite space - which is the false notion you get from most unsophisticated graphic depictions of an explosion occurring in a black space. There was no black space around or before the big bang. That's just a requirement of our type of vision and visual representation, in the same way we have to depict a black whole as a hole punched in a two dimensional surface, when in fact it is a three dimensional tunnel in a fourth dimensional space.

Big bang theory simply holds that space was much smaller and matter was more densely packed some 15 billion years or so ago, just like the lines of longitude on a globe are much closer at the latitude of the south pole. (Latitude being time and longitude being space.) We don't worry that the south pole "pops into existence" from some further more southerly place. We are sophisticated enough to realize that the world is not flat like a table map, Even though we walk on a locally flat and two dimensional surface, the world is not flat and has no southern edge, just like the universe is not flat, but curved in higher dimensions, and has no earliest boundary in some external absolute spacetime.

Spacetime is not absolute, it is relative. It is not flat with an edge, but curved, and hence finite in extent yet unbounded by any blank space. Hawking does a pretty good job at explaining this in his universe in a nutshell. Harriman's criticism makes it painfully obvious he doesn't understand the theory in its proper form, only a naive, conventional misinterpretation of it.

Post 83

Tuesday, February 23, 2010 - 9:47am

Ted said:

Harriman's criticism makes it painfully obvious he doesn't understand the theory in its proper form, only a naive, conventional misinterpretation of it.

It's not obvious at all, painfully or otherwise. He takes an explanation of the origin of the universe subscribed to at one time by cosmologists, including Bruce Gregory, whom he quoted, and states what it is. As one author puts it in a similar vein:

In Linde's cosmology, bubbles of spacetime foam pop up as quantum fluctuations, inflating into unconnected universes with different physical laws. We are in one of the infinity of these bubbles, with the laws of our universe accidently selected from an infinite variety of possibilities. Our universe is governed by those physical laws that happened to freeze out in one particular bubble.

The statement of Harriman's is all you were given and it was taken out of context. How can you conclude anything about what Harriman understands about the big bang?

So, the big bang theory just says that "space was much smaller and matter was more densely packed" than it is now. So, it's not really a theory of the origin of the universe, just a theory of why it's the way it is now. The big bang just posits the initial conditions. I mean, where did that densely-packed matter come from? I thought that's where the quantum fluctuation idea came in.
Thanks,
Glenn

Post 84

Tuesday, February 23, 2010 - 10:20am

Glenn, are you serious when you ask where did the matter come from? Are you expecting me to tell you what existed before anything existed?

You are much closer to the truth when you say that the big bang theory is not a theory of the origin of the universe, since yes, "origin" implies the prior conditions, and there can be no conditions prior to space or time.

My criticisms of Harriman so far are based on people's reports of his statements. Maybe he has been misserved, and I do intend to listen to what he has to say when I have the time. The strongest formulation of big bang theory is not some obvious nonsense like Linde's which consists of arbitrary speculation about unknowables. Criticsm of Linde is no more criticism of big bang theory than criticism of Lovelock is criticism of Darwin.

I hold two opinions. An understanding of higher-dimensional mathematics allows one to describe spacetime as finite yet unbounded just as the surface of a sphere is finite in extent but has no edges. And the physical evidence we have indicates that spacetime is expanding as if from a singularity or an event horizon on the order of 15 billion years ago, evidence of which is the cosmic background radiation, the redshift, and the more primitive state of more distant (i.e., older) galaxies.

Post 85

Wednesday, February 24, 2010 - 6:04pm

Re:

> The big bang was not an event which occurred at a point in >an already existing infinite space - which is the false notion >you get from most unsophisticated graphic depictions of an >explosion occurring in a black space. There was no black >space around or before the big bang. That's just a >requirement of our type of vision and visual representation, ...

So "the false notion" (of how this event occurred) is a requirement imposed by "our type of vision and visual representation"?

That sounds awfully Kantian.

Post 86

Wednesday, February 24, 2010 - 8:47pm