The Legal Concept Of “Ad Coelum” Gave People Ownership Of?
Answer: The Sky Above Their Land
The legal principle of “ad coelum” is an old legal construct dating back to the medieval era that highlights how changes in technology force the legal system to adapt. The phrase is Latin and translates to “to the heavens (or sky)” and is an abbreviated version of the full phrase “Cuius est solum, eius est usque ad coelum et ad inferos”, or, “Whoever’s is the soil, it is theirs all the way to Heaven and all the way to Hell”.
The heart of the principle is that the owner of a piece of land is entitled to (and owns) all the space above and below the soil as well as any bounty found therein. Legal constructs like mineral rights, for example, where a land owner has rights to the bounty of the earth beneath their property, are extensions of this early concept.
While the principle is still largely in effect (it would be illegal in most places for another person to build a giant walkway over your backyard to a neighbor’s house or to dig under your property line and extend their basement), over time the concept has required a bit of refining. When the first hot air balloons took flight in France, for example, it became immediately apparent that the balloons drifting overhead (and their daring occupants) were trespassing, under “ad coelum” laws, on every parcel of land they crossed.
In the United States, the infinite-sky interpretation was officially shelved in 1946 when the Supreme Court ruled that an individual did not control the area above their property all the way out into the depths of space. The case was “United States v. Causby”, wherein the relevant federal party was the U.S. military and the other party was Thomas Lee Causby. The former was flying military aircraft low over the farm of the latter and killing so many of his chickens (who died of fright) that he was unable to continue farming. The Court ruled that while Causby did not, in fact, own the land up to the limits of the sky, he did, in fact, have a right to unimpeded light, air, view, or the safe and peaceful occupation and enjoyment of his land. The military was required to stay within the public easement recognized by Congress (365 feet and higher) and compensate Mr. Causby for trespass (and not, curiously, based on the damage to the chickens).
Photo courtesy of Oliver Dixon/Wikimedia.