What would happen to the solar system if half of the universe disappeared? From Newton to Einstein, most experts have agreed that nothing much would happen except that the sky would have fewer stars. But now British Cosmologist Fred Hoyle says that the sun would shine 100 times brighter and burn the earth to a crisp.
Hoyle is a respected scientist, one of the originators of the theory of continuous creation, which holds that the universe is still being formed by particles that appear out of nothing in empty space. When he presented his new gravitation theory to a packed meeting of Britain’s venerable Royal Society, he modestly described his work, done in collaboration with Indian Mathematician Jayant V. Narlikar, as a slight extension of Einstein’s theory of general relativity. “We are clearly aware,” he explained, “that in putting forward still another idea we may be like small boys trying to steal apples.”
Splendid Parade. Far from a slight extension of Einstein’s work, Hoyle’s apple stealing is more ambitious larceny. His new theory stems from the Mach Principle, that the mass* of every object in the universe is affected by its interaction with every other object. Einstein tried to incorporate the Mach principle in his own scheme of the universe and admittedly failed. Hoyle claims to have succeeded.
Most of the Hoyle-Narlikar lecture consisted of what one Royal Society member described as “a parade of splendid mathematics”; it seems to have stunned to silence nearly all its hearers. Said Professor Brian Flowers of Manchester University: “If you give me three months to sit down and think about it, I might come up with something.”
For all its difficulties, several advantages are claimed for the new theory. It explains why gravity is always a force of attraction, never of repulsion. “We all know,” said Hoyle, “that the apple hit Newton on the head. It did not fly upward.” Einstein took account of this often-observed action by arbitrarily assigning a minus sign to a key quantity in equations. Hoyle demonstrates why the sign must be minus.
Hoyle’s theory also explains why galaxies in distant parts of the universe can, theoretically, move away from the earth faster than the speed of light—a limit that Einstein said could not be exceeded. Hoyle argues that it is wrong to compare the speed of light in one locality with the speed of an object in another locality. He believes that his theory makes it easier to explain in earthly terms events that occur in distant localities of the universe.
Hot, Heavy Sun. The most striking consequence of Hoyle-Narlikar gravitation is that it explains how the mass of every particle in the universe helps to create the mass of every other particle. As Hoyle and Narlikar see it, a universe with nothing in it is impossible. There must be at least two particles, each to give mass to the other.
The masses, and therefore the gravity, of the sun and the earth are partly due to each other, partly to more distant objects such as the stars and galaxies. According to Hoyle, if the universe were to be cut in half, local solar-system gravitation would double, drawing the earth closer to the sun. The pressure in the sun’s center would increase, thus raising its temperature, its generation of energy and its brightness. Before being seared into a lump of charcoal, a man on earth would find his weight increasing from 150 to 300 Ibs.
Hoyle is well aware that he will never be able to prove such ominous claims by experiment. He is hopeful, though, that someone, some time, will devise a practical way to test his theories.
* Mass is that property of a body which resists change of motion. On the surface of the earth, it is closely equivalent to weight. Austrian Physicist Ernst Mach (1838-1916), who gave his name to the principle, is better known today for Mach numbers, a method of measuring speed in multiples of the speed of sound.