Friday, September 10, 2010

Time and Eternity

One of those "research as I go" posts --  sorry.  I can't help it sometimes. 

Although Science may solve the problem of ~how the universe began, it can not answer the question: why does the universe bother to exist? Maybe only God can answer that. -- Stephen Hawking. 
I kept stumbling across blogs and other things talking about Stephen Hawking and his new book.   I am a fan of Hawking from way back when I read Brief History of Time.   But obviously I don't subscribe to his religious theories.

The best review of his new book  I've found so far is here.   The question that is being aired on various media sites is not a new one, and could be phrased as Does Science Make Belief in God Obsolete?    Their book of course won't solve that question, and I don't know if that is its primary purpose, but it does allow everyone to air out their thoughts on that old debate.

According to Hawking: 

"To understand the universe at the deepest level, we need to know not only how the universe behaves, but why. Why is there something rather than nothing? Why do we exist? Why this particular set of laws and not some others?" (from here)
This is interesting.  It actually is in the traditional scope of science, but the more recent empiricist view (since Hume, as I understand it) seem to focus more on the "how" questions, the mechanics.  Causality is disallowed as outside the empiricist purview and essentially subjective, a construct of the mind rather than a reflection of what we can truly know from reality.  So it is nice to see a first-rate modern scientist take on the Big Questions.  

Hawking goes on to say  (according to the blurbs released to the news agencies):

"Because there is a law such as gravity, the Universe can and will create itself from nothing. Spontaneous creation is the reason there is something rather than nothing, why the Universe exists, why we exist,....

"It is not necessary to invoke God to light the blue touch paper and set the Universe going," 

"From nothing" -- this is is distinct from the theological "ex nihilo"  --  nothing is defined by Professor Alexander Vilenkin as a

“state with no classical space-time . . . the realm of unrestrained quantum gravity; it is a rather bizarre state in which all our basic notions of space, time, energy, entropy, etc., lose their meaning".

"Spontaneous creation" does not seem to be an explanatory phrase; rather, sort of a placeholder.   The way I understand it, the general idea in quantum cosmology that anything that CAN happen given the physical preconditions, WILL happen. Apparently this can be postulated fairly reasonably, though somewhat controversially.    So given the initial gravitational conditions, everything else would follow.   So if the universe was bound to ensue from the "original  realm of unrestrained quantam gravity" then that would somewhat answer Hawking's question "Why does the universe bother to exist?"  It bothers to exist because given the original laws, it was most probable that it would exist.... in fact, it almost couldn't have been any other way.  And this response is conveniently secular. 

I haven't read the book, obviously, since it will release tomorrow.  But it seems to me that Hawkings and Mlodinow are postulating something familiar to people who have been reading Hawking for some time.    This is a long quote, but even then it's too short to provide the whole explanation. 

In 1983, Jim Hartle and I, proposed that the state of the universe should be given by a Sum over a certain class of Histories. (cf  Feynman)  This class consisted of curved spaces, without singularities, and which were of finite size, but which did not have boundaries or edges. They would be like the surface of the Earth, but with two more dimensions. The surface of the Earth has a finite area, but it doesn't have any singularities, boundaries or edges. I have tested this by experiment. I went round the world, and I didn't fall off.

The proposal that Hartle and I made, can be paraphrased as: The boundary condition of the universe is, that it has no boundary. It is only if the universe is in this ``no boundary'' state, that the laws of science, on their own, determine the probabilities of each possible history. Thus, it is only in this case that the known laws would determine how the universe should behave. If the universe is in any other state, the class of curved spaces, in the ``Sum over Histories'', will include spaces with singularities. In order to determine the probabilities of such singular histories, one would have to invoke some principle other than the known laws of science. This principle would be something external to our universe. We could not deduce it from within the universe. On the other hand, if the universe is in the ``no boundary'' state, we could, in principle, determine completely how the universe should behave, up to the limits set by the Uncertainty Principle.
He goes on to say that this hypothesis meets the standard for falsifiability, and that he has been working on it ever since, and so far it has not been falsified.

Relativity and quantum mechanics, allow matter to be created out of energy, in the form of particle/ anti- particle pairs. So, where did the energy come from, to create the matter? The answer is, that it was borrowed, from the gravitational energy of the universe. The universe has an enormous debt of negative gravitational energy, which exactly balances the positive energy of the matter. .... The debt of gravitational energy, will not have to be repaid until the end of the universe. 

 I am guessing that in the intervening 3 decades there has been more evidence that at least does not work against the original hypothesis.

The quantum theory of gravity has opened up a new possibility, in which there would be no boundary to space-time and so there would be no need to specify the behavior at the boundary. One could say: ‘The boundary condition of the universe is that it has no boundary.’ The universe would be completely self-contained and not affected by anything outside itself. It would neither be created nor destroyed. It would just BE.

His conclusion, even back then in 1988, was that it leaves a very tiny role for God in the universe as it exists.   The way I understand his reasoning, because the material universe incorporates time and space within it, it would be for that reason eternal and self-existent.   And because the universe "had to" be born, there was no necessity for God to turn on the light, so to speak. 

Aquinas apparently would have agreed with the bit about the possibility of an eternal material universe -- though he judged that it was not eternal.  According to this article by William Carroll., Aquinas actually didn't have a problem with the universe being eternal, with time basically enclosed within it,:

Aquinas saw no contradiction in the notion of an eternal created universe. For, even if the universe had no temporal beginning, it still would depend upon God for its very being. There is no conflict between the doctrine of creation and any physical theory. Theories in the natural sciences account for change. Whether the changes described are biological or cosmological, unending or finite, they remain processes. Creation accounts for the existence of things, not for changes in things.  

(I think this also helps with the idea of "cause" being inextricably associated with "time".  This argument is used by some, in combination with Hawking's theories, to say that there is no necessity for a First Cause because time is basically a part of the universe... so nothing has to proceed ultimately from Something Else.   But that is not a new idea and the philosophical idea of "cause" is not limited to quantifiable causes, no more than it is  inextricably linked with sequence.   In fact, given that time is enclosed by the universe, any Uncaused Cause would by definition be outside of time, which is a truism to theists). 

Back to Hawkings -- so, then, the ideas of a "no boundary" universe are nothing new for him, though most of the blogs are saying it is a change from his earlier statements about knowing the mind of God.   And the ideas are not a new surprise or a philosophical crusher to Catholics either, (or to Islam, apparently) since Aquinas and Avicenna were discussing the possibilities several centuries ago.

 I do think Hawkings is more firmly convinced than ever that there is no room for or necessity for a personal God, but this is an opinion or judgment on his part.  The physical evidence doesn't work for or against Revelation (almost by definition)  -- though the theory that a few simple truths could power all the seeming complexity of the universe does give an impression of sheer elegance, beauty and power that evokes awe in my mind. 

But Hawkings sees it differently than I do: 

Of course, God would still be free to choose the laws that the universe obeyed. However, this may not be much of a choice. There may only be a small number of laws, which are self consistent, and which lead to complicated beings, like ourselves, who can ask the question: What is the nature of God?
I wonder if it would be helpful here to make a distinction that has been made since Aristotle--  between metaphysical and physical necessity.    From that article:

The laws of nature, therefore, being subject to physical necessity, are neither absolutely necessary, as materialistic Mechanism asserts, nor merely contingent, as the partisans of the philosophy of contingency declare; but they are conditionally or hypothetically necessary. This hypothetical necessity is also called by some consequent necessity.
Given X and Y and Z preconditions, something can follow by consequent necessity.... like an "If .... then" statement in programming.   But the necessity is NOT necessarily absolutely necessary (can I use that word even more times if I keep this sentence going??).   It's sort of a retroactive necessity.   Given these conditions, the following will ensue.  If you drop salt in water, given the nature of salt and water and mixing, you will have a saline solution.   

Metaphysical or absolute necessity is somewhat more difficult.   It means what couldn't be otherwise by its very being, what doesn't depend upon something else to provide its origin.  Aristotle puts the existence of God in this category.    Some scientist/philosophers seem to say that physical law is an absolute or metaphysical necessity.     Here is where I'll stop because I don't want to get going on another big topic.   But I wonder if Hawking's theories on probability get into the necessity mix here -- they would almost have to in some way, I suppose.     That's something for me to think about while I'm making dinner and feeding my trio of flying squirrels.

1 comment:

I would love to hear your thoughts on this!