An important discovery in physics was announced this past week at a meeting of the American Astronomical Society: gravity is not instantaneous, but acts at the speed of light. Using the radio waves emitted from a quasar (a galaxy with a black hole that emits huge amounts of radiation), physicists measured how the waves are affected by the gravity of Jupiter, the most massive planet in the solar system. Albert Einstein had theorized in his general theory of relativity that gravity would be propagated at the speed of light, contrary to Isaac Newton, who had thought gravity acted everywhere immediately, at an infinite speed.
Instantaneous gravity would present a puzzle, because that would be a force that acts faster than the speed of light, whereas known physics states that nothing can move faster than light. In Einstein's theory, gravity is caused by a warping or bending of space around an object. The more massive the object, the greater the warp and the stronger the gravitational attraction.
Just what it means for space to be warped is a mystery. Space seems to be a three-dimensional extent of nothing, yet mass bends it, so there must be something there to warp. The force of gravity is proportional to the product of the mass of the bodies affected, and inversely proportional to the square of the distance between them. That makes sense, because the warping of space proceeds in all directions from a body, like light from the sun, so it gets weakened as the force spreads out ever more thinly to more and more space.
That gravity moves at the speed of light implies that if the sun were to suddenly disappear, the earth would not immediately fly off into outer space, but would keep circling the sun for the eight minutes it would take for the unwarping of space to hit the earth, just as the light from the sun would keep shining on earth for those eight minutes.
Gravity is a free gift of nature that gives weight to mass so that we can walk around on the surface of the earth. Gravity makes the waters of the oceans sit there instead of flying off to space. But just because nature provides gravity free does not imply that we can use it gratis. Most folks have to pay a substantial amount in order to benefit from gravity. Because human beings exist in discrete locations with the three-dimensional surface of the earth, what matters is gravity at the locations we want to be in.
It's the same with sunlight. The biggest import into any country is not oil or food, but sunlight. Our economies import sunlight free from the sun. Yet we get charged for sunlight as well as for gravity. All the benefits of a location, both natural and human-made, become charged to the occupants as a rental payment for the use of the site. Where we live and work and travel, we are in space that is controlled by those having title, and these lords of the land charge for the use of the space. Rent is the price of using gravity, sunlight and other benefits in particular locations.
Much of the rental value of land comes from the civic goods in an area, the streets, parks, security, and services provided by government. We can get free light and gravity if we go to an empty desert with no roads, but that location has little human use. Many people want to be in the center of commercial activity, serviced by government-provided infrastructure, so the users bid up what they are willing to pay, establishing a market rent. We pay rent to use the air, gravity, and light where we want to be, and the financial benefits of gravity et al. go to the landowner, whose interests are protected and enforced by the state.
The odd thing is that even the services provided by government are not charged to the rent-taking landowner, but are instead forcibly paid for mostly by those engaging in labor. Not only do worker-tenants have to pay someone to use nature's gravity, they do not even receive the value of their time given up when they engage in labor. Landlords charge them for gravity, and the government taxes their time. Time and space! Free by nature, made unfree by government.
If gravity is a free gift of nature, then human equality requires that the benefits of gravity and all other natural gifts be shared equally. Civic services should be paid from the rent of land so that the landowners pay back the rental generated by the services and the rent generated by nature. Only when land rent is collected, shared, and used for public benefit, does gravity become a common economic benefit.
This article was originally published by The Progress Report and is reprinted by permission.
Progress & Poverty - Definitions - Capital - Law of Rent - Booms & Busts - The Remedy - Links