Posts Tagged ‘gravity’

God’s image

The universe is in God’s image: it has to be. In what other image could it be made? “Before the universe,” there was nothing, no image to copy, no starting point, no pattern. Serious “nothing” is much emptier than air and space.

Now, the image of God imprinted on the universe does not have the same aspect as the divine image that is imprinted upon us, because we are personal beings, and the universe is not. Let’s think about this a little before going on. When scripture says that we are made in the image of God, it uses a phrase that actually suggests sonship, the way that Adam’s children are in his image. The universe and its elements are not like that, and could not be.

Why not?

Take a minute to recognize that we ourselves could not be persons if our “parts,” – our hands, our feet, or our molecules – were other persons. Who would be in charge? Nor could we be persons if we were part of a planetary person, such as Gaia, because then the freedom to respond to destiny would either be located outside ourselves or else divided with others. That is what personal nature means: the capacity to seek a destiny with one’s whole being. It’s not about free will in the sense of trivial decisions, but about the capacity to seek our inwardly known destiny.

The universe cannot have this personal sense of destiny and still make room for our own. It is not part of God, and we are not part of it. But the universe does reflect the nature of God as the work of any artist reflects his nature and opinions, and for this reason it is always the case that new information about the universe, including new information from the natural sciences, can suggest new perspectives that are of interest to theologians, new ideas about God or deeper insights into his nature. These perspectives are just that, perspectives, not dogmas, and they do not excuse us from examining yet more of the universe. Each perspective has limitations; but each also has a new fund of truth.

But enough of abstractions. Let me give you an example of a perspective that was very quickly offered to counter the concept of an infinite universe which naturally arose in the wake of the Copernican insight that the universe was much, much larger than had been considered.

Olbers’ Paradox

If the universe were infinite, an infinite extension of space filled, or even just sprinkled, with an infinite number of stars, then the starlight converging on any given point of space would be infinite. For the light of an infinite number of stars, however weak, would add up to an infinite amount of light. Therefore the sky would not be black or even dark at any time, day or night.

You are thinking that if the stars were very far away, the light would not be infinite. That is an understandable objection, but it really depends on a sloppy concept of “infinite.” Infinite does not mean “really a lot” or “much more than usual.” It means there is no limit.

Somebody named Olbers pointed this out, and called it a paradox, meaning that he was surprised that these two statements should both be true: that the universe is infinite and that the night sky is dark. Actually, a paradox is only an apparent contradiction; this is a real one, meaning that one of the statements must be false. Since anyone can see that the night sky is dark, the universe must not be infinite.

There is a similar gravity paradox: If the universe had an infinite amount of matter, its gravity would be infinite, and it would disappear in a clap of thunder, or at any rate, a Great Collapse. Well, not even so; it could never break out in a Big Bang if the gravity were infinite. Again, the failure to understand this is the simple failure to understand the difference between “very large” and “infinite.”

One of the ways people try to get around these contradictions is to suggest that: in an infinite universe which is expanding (as ours is) some of the matter will expand so far away that it will move over the horizon of gravity. It will, in terms of relativity, apparently accelerate over the speed of light and its gravity will no longer affect what is left behind. But think about this. Even if gravity goes over such a horizon that it won’t affect you personally, it will affect something halfway between you and the horizon, something that does affect you. How does that work?

The answer is that it would work various ways at various times, and every so often, so much would be pulled together that it could not come apart, and over an infinite time, the Great Collapse would occur, perhaps in stages, but over an infinite time, there would be nothing left.

It could be worse: if the universe is expanding all the time, and if it is of an infinite age (infinite universes are always infinite in time as well as space) all the matter in the universe must already (in its infinite past) been completely scattered so that nothing but a tenuous puff of dust remains. How could there be a planet?

No, no, you say! The universe is constantly being created in the empty places, so its infinity keeps on going.

This is simply hilarious, and again, it is a failure of philosophy, a failure of thought, not of experiment. If the universe is self-generating in all the empty spaces, then there will be an infinite influx of matter coming towards us (towards any given point) from every horizon out there, and we will be crushed. Indeed, we will already have been crushed in the infinite past.

Stop thinking that infinite means “very big” and face it: the infinite is unimaginable. You need to think past your images; you need to use your reason all the way out to the end of the thought.

These two “paradoxes,” these twin impossibilities of infinite light and infinite gravity, were under discussion for hundreds of years, and it was a form of philosophical blindness for people to have gone on thinking the universe infinite. The progress of the natural sciences, which briefly suggested an infinite universe, very quickly turned around to demand a finite universe.

Gravity is not, as the ancients thought, just a condition of earthly things which seek the center of the earth; and light is not just a visually searchable property of celestial beings. Once these two material aspects of the physical universe were better known, once we understood that both gravity and light are law-abiding aspects of the material world and fully subject to mathematical laws, then the habit of assuming the infinity of the universe should have begun to collapse.

Instead, this habit persisted, and this was a religious and philosophical blunder. Indeed, it was a philosophical blunder whose persistence depended on the tenacity of religious unbelief and the consequent determination to avoid anything suggesting creation.

This is not to say that the finity of gravity and light prove the existence of God. We cannot jump from science to philosophy or theology in exactly that way; but the necessary finity of gravity and light do demand respect for the concept of a finite universe and attention to the implications of that finity. In that sense the face of God peers out from the mists of a dawn without a yesterday.

It is hard to be an atheist.

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Richard Bentley was a younger contemporary of Isaac Newton. After Newton had formulated his law of gravitation, he observed, in a letter to Richard Bentley, that if all the stars are drawn to each other by gravitation, they should collapse into a single point. One will be drawn to another; that star will grow and pull in still more and more. In time, everything must be drawn in.

How is the universe constructed so as to prevent this from happening?

It did not occur to Newton, or perhaps to anyone before the 20th century, that the universe is a changing space-scape. It has a history, at the start of which (in Big Bang theory) its matter was ejected apart; so far, it does not have the energy to re-gather everything in a universe-crushing event. Or maybe I should say that its momentum is still too great to be overcome by its gravity. Either way, it could face gravity collapse, but not yet.

Bentley’s Paradox (which maybe should be called Newton’s Paradox, since it is odd to name an insight after its first recipient, rather than its author) is similar to Olbers’ Paradox in that it does suggest a finite universe: an infinite universe would have infinite gravity and would certainly collapse.

Well, again, perhaps you’d have the Kelvin/Boltzmann suggestion of a universe with pieces far enough apart not to respond. But this suggestion only serves to indicate the distant (really distant!) possibility of a kind of multiverse. Unless it can be tested, it is not a scientific hypothesis, though it is an interesting thought experiment.

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