Einstein's Fridge: How the Difference Between Hot and Cold Explains the Universe

by Paul Sen

The earth, in other words, appears to measure the distance from its own center to every object nearby, as well as measuring the mass of all these objects. Then it has to calculate the exact amount of force to exert on each of those objects and the direction in which those forces must act. It then instantly transmits that force to all objects falling downward. It’s a preposterous idea. Indeed, the first person to point out quite how preposterous was Newton himself. In a letter shortly after he published his theory of gravity, he said, “That gravity should be innate, inherent, and essential to matter, so that one body may act upon another at a distance through a vacuum, without the mediation of anything else… is to me so great an absurdity that I believe no man who has in philosophical matters a competent faculty of thinking can ever fall into it. Gravity must be caused by an agent acting constantly according to certain laws; but whether this agent be material or immaterial I have left to the consideration of my reader.” It’s worth noting that no other force in nature acts like gravity. For example, a paper clip and a heavier object such as a bolt will accelerate toward a magnet at different rates. But if you drop the paper clip and the bolt, they will fall downward with exactly the same acceleration. The general theory of relativity is Einstein’s considered response to Newton. It dispenses with the absurd notion that objects such as the earth perform complex calculations an...