Is the Universe Large?

Is the Universe Large?

If you study astronomy, it will be impressed upon you that the universe is large—very very very large, unimaginably so. The galaxies, their number, the distance between them, the travel times (even for light)—the universe is an extremely big object, much bigger than you thought, much bigger than anyone thought until quite recently. A feeling of awe routinely follows. I am going to argue that this is not true: the universe is not extremely large—it isn’t even large simpliciter. This is not because I have discovered that cosmologists have got their measurements wrong and the universe is actually much smaller than they thought; it follows rather from the semantics of the word “large”, from its ordinary meaning. The sentence “The universe is large” is not true (nor is the sentence “The universe is small”). The argument is in fact quite simple and obvious. Consider “Jumbo is large” said of an elephant. This sentence is true if and only if Jumbo is large for an elephant.[1] To be large for an elephant is to be larger than most elephants (or the typical elephant, or a normal adult elephant, or some such). That is, there is a (non-empty) comparison class presupposed in the original sentence, viz. the class of elephants. That is why a large flea is smaller than a small elephant—different comparison classes. We can thus define the positive use of the adjective in terms of the comparative use (and the superlative use too—the largest elephant is larger than all elephants). Crucially, there is no sense in the positive use unless there exists a suitable comparison class. So, what is the comparison class for “The universe is large”? A large what, we must ask. A large universe, of course: This (pointing at our universe) is a large universe—the adjective now standing in attributive position. It is large for a universe—i.e., larger than most universes. But there aren’t any other universes! There is just this universe; there are no other universes hanging out in the wings. There are no other universes for ours to be larger than, some smaller, some larger. Of course, the universe (note the definite article) is larger than the solar system or the whole Milky Way or a cluster of galaxies; but it is not larger than some other universe. That is the sortal term we need to make sense of the original claim, not “galaxy” and the like. The universe is certainly much larger than the things contained in it, but it is not larger than the other universes, because there are none. Maybe it is larger than some other possible universes, but that is irrelevant, since a small elephant is not rendered large by the merely possible existence of yet smaller elephants (nor is a large elephant rendered small by the possible existence of still larger elephants). No, the universe can only be meaningfully described as large if there are actual universes smaller than it—but there are none such. It’s like saying the Eiffel tower is a large Eiffel tower when there is only one Eiffel tower. The universe is not larger than some other existing universe, so it makes no sense to speak of it as large—larger than what exactly? Other objects exist within a class of similar objects between which comparisons of size can be made, but that is precisely what cannot be said of the universe (everything that actually exists). If there were such co-existing universes, then it would make sense to say that this one is large by comparison with them (say, twice as far across), but that is what is signally lacking. Nothing is inherently large or small—a comparison class is needed for such judgments—so it is meaningless to suggest that the universe itself might be large (or small).

Why then do we insist on talking this way? The answer is that we are tacitly describing the universe subjectively, by reference to ourselves and our local environment. Yes, the universe is vastly larger than us or our particular neck of the cosmic woods, but it doesn’t follow that it is large in any objective sense. We tend to think anything larger than us is large in an absolute sense: to be larger than us is to be large, period. But that is an anthropocentric perspective: there is nothing intrinsically large about the spatial-material macro universe, as there is nothing intrinsically small about the micro world of atoms, quarks, etc. A possible world containing only free-floating atoms has nothing small in it, as a world containing many objects the size of our universe has nothing large in it. When we speak of such things as large or small tout court, we are thinking of them in comparison with our size, but really there is nothing to these descriptions, objectively speaking. The world does not come into existence containing small things and big things, only bigger or smaller things. The terms are completely relative, either to us or to suitable comparison classes. Things have shape and other qualities intrinsically, but their size is a relational matter. If I describe a mountain as huge, I am tacitly comparing it to my own body; compared to a whole planet it is a mere speck.

The same point applies to other attributive adjectives used in astronomy and cosmology and physics—“hot”, “heavy”, “fast”, “strong”, and their antonyms. The Sun is said to be extremely hot in its interior; some elements are described as heavy; the speed of light is said to be very fast; some forces are said to be strong. But none of these uses is truly objective: things are said to be “hot” or “cold” relative to normal human (or animal) temperatures, and the same for “heavy”, “fast”, and “strong”. These uses are subjective intrusions into our descriptions of nature, or else technical terms defined by objective relations between things. To say that light travels very fast can only mean much faster than we can or faster than other physical things. Nothing is inherently hot or heavy or fast or strong: there is nothing of our subjective nature in them, and they all come down to physical relations described in comparative terms. Gravity, say, is only described as a weak force in comparison with the electromagnetic force; it is not weak in any absolute sense. In a possible world in which things regularly travel faster than the speed of light, it could be correct to say that light travels slowly, even very slowly. That is just the logic of attributive adjectives (of this class). Semantically, light could be a slow mover and the Sun’s interior pretty cool and black holes quite light (weight-wise)—it all depends on what is true of other things that form the comparison classes for these attributions. We must not commit the fallacy of misplaced absoluteness. The language of astronomy, cosmology, and physics is logically misleading and could do with an overhaul. It needs de-subjectivizing.[2]

[1] Attributive adjectives like “large” are said to be syncategorematic, needing the appended noun in order to have meaning. The sentence “Jumbo is a large elephant” does not mean “Jumbo is large and an elephant”.

[2] There are even emotional connotations to these words that have no place in rigorous austere objective science: “hot” and “cold” evoke more or less hospitable environments; “heavy” suggests something hard to carry or potentially crushing; “fast” is something we like in ourselves but not in a predator; “strong” connotes an admirable quality. Such words humanize what should not be humanized, i.e., the physical universe. Even words like “attraction” and “repulsion” are suspiciously anthropomorphic. The constellations are clearly human projections not hard objective astronomical facts. The Sun and Moon have been personified since the dawn of man.

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4 replies
  1. Giulio Katis
    Giulio Katis says:

    We like to say it is a ‘wide world’ as well as “a small world after all”. Point taken. They can’t be exactly the same world. However, Hamlet hit something with “There are more things in heaven and earth….”

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