U.S. v. Causby
328 U.S. 256 (1946)

Justice William O. Douglas, who wrote this legal opinion, observed, “It is an ancient doctrine that at common law ownership of the land extended to the periphery of the universe. . . But the doctrine has no place in the modern world. The air is a public highway.”1 Indeed, if everyone’s property rights extended upwards infinitely, commercial aviation would be an impossibility, with lawsuits ensuing from every flight.

In this case, Mr. Causby was a chicken farmer whose property lay near the end of a Greensboro, North Carolina runway, where bombers and other military planes landed day and night, missing his chicken house by only 63 feet. It drove the birds crazy, and over half of them bashed themselves to death against the barn walls in a panic. The Causby family was driven to distraction as well, not only from the collapse of their business, but also from the exhausting noise and, at night, light. And so he sued to protect his to-the- heavens airspace . . . and lost.

Whatever the justice of it all, ancient doctrine citing “the periphery of the universe” raises the interesting metaphysical question of what shape that ownership might take. The full doctrine says property rights extend downward as well, so one can imagine something of an inverted cone or pyramid terminating at the center of the earth, where property lines from China would meet those from America, each coming to a fine point. But what about the other direction with its upward boundaries? Would it rise in the shape of a silo the width of the property on the earth’s surface? And how far would it go? The answers concern the metaphysics of space.

First, does the universe have a periphery? Say we go out a gazillion miles and hit some sort of terminus to what we view as outer space, the darkness from which the nebulae and constellations shine forth in the night sky. Do we hit a wall of sorts? If so, how thick is the wall? Isn’t it spatial as well? And, unless it’s infinitely thick, there’s something on the other side which continues the expanse. So shall we say that Causby’s property is infinitely large?

And what do we make of claims that space is “curved”? We get sort of statement from those who’ve imbibed Einstein’s relativity theorizing, with its talk of a “space-time continuum.” Textbook illustrations show a range of models, such as a steel ball resting on a flexible rubber sheet (the earth’s gravity bending light, whose speed is “the constant”) or something like a saddle-blanket draped over the back of an invisible horse. If space is really bent, then Causby’s “silo” could be curved rather than straight sided.

But those illustrations lie in the space of a book’s page, which strikes me as a better representation of space itself, with the curved illustration speaking more to the behavior of bodies within certain regions of space, and with the understanding that the page extends infinitely in not only two but three dimensions. The relativity math can be helpful, even indispensable, in sending out deep-space probes and such, but, in the end, they don’t give us the final word on capital-S Space. (And, incidentally, the speed of light — 186,000 miles per second — is not an absolute constant but a contingent one. It could be 220,000 mps, or 27 mps, depending on God’s good pleasure.) Science is good at helping us get around, but it’s not equipped to address ultimate realities.

Metaphysics is devoted to sorting out the reality beyond and behind appearances, and there are plenty of wacky appearances to get behind and beyond, e.g., mirages; the Doppler effect; the sense that you continue to spin after you’ve stopped; déjà vu; the impression that your train is moving when it’s actually the neighboring train. Similarly, the apparent curvature of space can be a useful, albeit puzzling, fiction (or a useful reality if you define ‘space’ a certain way), but it is ultimately nonsensical. We can’t think it, and so we shouldn’t say it, unless we’re doing something specialized, where an as-if claim can help our math.

Immanuel Kant had an interesting take on this. He called space and time “pure forms of intuition,” the theater, if you will, in which phenomena play, subservient to such “categories” as causality and plurality. On this model, space isn’t a thing but rather a perspective from which we see (touch, taste, smell, hear) all physical objects. It’s that by which we experience things and not a thing in itself.

Fortunately, the Supreme Court excused Causby from these ruminations and contestations. Otherwise, the case could have run on through the ages as the parties brought in rival “philosophically expert witnesses” (an oxymoron, I fear) to settle the matter. Meanwhile, Causby might have shifted his complaint from the Greensboro bombers to the Cassini-Huygens Saturn probe, dragging NASA into court.


1 The common law expression being Cujus est solum ejus est usque ad coelom, which Douglas quoted in the decision. He left off et ad infernos, which would make the sentence read, “Whoever owns the soil, it is theirs up to heaven and down to hell.” It was, indeed, a long-standing principle, applied for example in the 1587 British case, Bury v. Pope, where a homeowner protested, unsuccessfully, his neighbor’s decision to build a high structure which blocked out sunlight. The court ruled (citing “Cujus est solum . . .”) that he had the right to build as high as he wished on his own property.