Possibly misguided thoughts on the Universe.September 14, 2008
On a clear summer night, far from the obtrusive nighttime glow of cities’ sleepless lights, I sometimes wander out into the long grass of my open fields. I lie on my back, staring upward into the shimmering black sky in awe over the size of the Universe. I see so much with merely my eyes, from a pinprick of light slowly adjusting from white to blue to red to green, to a large sharp colored body of a planet.
Man has learned a staggering amount about these floating balls of mass over the past few hundred years, but what is this collection of stars and planets, asteroids and comets, galaxies and black holes part of? This Universe, impossibly enormous, gives us reason to stop and ponder how far it goes on.
Humanity has given the Universe’s size great thought, from Lucretius in ancient Rome, to Einstein in modern Austria and New Jersey. Poets and philosophers used to rule the arguments, being the men of knowledge and thought. Now theoretical physicists have the sway, using not equations of reason to form their opinion, but equations of quantum mathematics.
Speculations of ancient poets and philosophers, however limited in their scientific knowledge, are a good measurement of the laypersons’ perspective. They knew nothing of particle accelerators, massive orbiting telescopes, or spacecraft hurtling through deep void of space collecting stardust. They knew only what they saw, and could only speculate, like us, about the size of everything.
Lucretius, the ancient poet and philosopher, wrote an entire collection of books on the subject of atomic and astrophysics. A devotee of Epicurus and Democritus, the philosophers who first suggested atoms exist, Lucretius sought to prove the Universe as infinite. His work The Nature of the Universe, written in 55 B.C., to this day is thought of as a great feat of philosophy, no matter its obvious lack of credible science. He argues the Universe has to be infinite because of Epicurus’ view that the natural order of matter was to fall straight downward. One of Lucretius’ arguments from his monumental work is as follows:
If all the space in the Universe were shut in and confined on every side by definite boundaries, the supply of matter would already have accumulated by its own weight at the bottom, and nothing could happen under the dome of the sky — indeed, there would be no sky and no sunlight, since all the available matter would have settled down and would be lying in a heap for all eternity. As it is, no rest is given to the atoms, because there is no bottom where they can accumulate and take up their abode.
One can clearly see the faults in Lecretius’ argument, the notion of gravity as a force, not only near bodies of mass, but also everywhere, and in one direction. That was the world that they knew, the surface of the earth.
Today, we know so much more. Logical arguments of everything falling to the bottom of the Universe not only do not hold weight, but make us chuckle at the simplicity of thought surrounding the ancient world. However, it has taken countless people and arguments to come to view Lucretius as anything other than the holder of truth. It has been through hard science that we have come to the accepted opinion of the Universe as finite.
Einstein, whom many believe to be the greatest physicist of all-time, argued that the Universe was finite. He concluded the Universe was a spherical shape expanding outward from some point. There is two parts to Einstein’s conclusion. The first part is Mach’s principle, a mass of a body is finite, and that is determined by all the other mass in the Universe, therefore, the mass in the Universe is finite. In such a simplistic form, Mach sounds much like a philosopher, merely toying with logic arguments and supposition, yet this position led Einstein to create the General Theory of Relativity, the next part of his finite Universe conclusion.
The General Theory of Relativity suggests that space is warped by masses within it. Objects, bodies of mass, accelerate relative to one another, which is reminiscent of Mach’s beliefs of mass effecting other mass in the Universe. Space that is warping from bodies of mass, must eventually wrap around all mass, which was a finite amount. Einstein was forced to decide, through rigorous study of his own theory, the Universe had to be finite to satisfy relativity because of the curvature of space. This does not mean that finite space is bounded. Einstein and others since have argued the Universe need not be bound to normal confines to allow a finite Universe, strangely enough.
The thought of the Universe, spherical in shape, with no bounds, is a headache waiting to happen. The idea that everything, the sum of every bit of mass, every atom, every particle being both finite and having no boundary is tricky thinking. A way of thinking that must shed the normalcy of Lecretius’ world, and venture into the abstract.
Imagine the Universe as a giant kickball, one of those red textured bouncy balls that give infinite fun on the world’s playgrounds. The ball is finite. It has a beginning, and an end. Now picture yourself inside the ball, jetting across the air inside, from one side to another. The normal notion would be that once you reach the skin of the ball, the boundary that holds all that air in, you would need to turn around to continue. Match that up against Einstein’s theory of curved space. The two ideas are incompatible. To resolve this conundrum, allow yourself to pass through the rubber that entraps the air within the ball, but instead of continuing out into the playground, imagine that you come into the ball on the other side. This is the simple resolution to the problem. Other solutions may make more sense.
Take Einstein’s idea of curved space, by flying around his idea of space, you would never reach the edge, you would follow the curvature of space, much like someone going around the earth. You would eventually pass the same point from which you started, and possibly, every other point of space. For this idea, picture a torus, much like a doughnut. You could both follow a path for an infinite period of time, yet still be within a finite space. Dr. Max Tegmark, of the University of Pennsylvania, has suggested such a shape. We do not fear sailing off the edge of the earth any more than we fear being eaten by a dinosaur. Both ideas are extinct.
A recent study by NASA scientists, with French cosmologists, has given credence to the finite Universe. A spacecraft with a large microwave antenna has found hints at the cosmic radiation emitted from Alexander Friedmann’s theory of ‘The Big Bang’, the theory the Universe was created by the sudden expansion of extremely dense material. By studying the emissions, the team has found that the shape of the Universe may be close to spherical, as Einstein had predicted, with some alterations. The datum suggests at a dodecahedron, a twelve-sided shape, very close to a sphere.
The Universe may be enormous, it may be larger than a simple human mind can grasp in totality, but it can be limited in size. From Lucretius to Einstein, humanity has looked up into the sky and pondered the ends of it. From the great minds we have traveled from infinity to the finite, from spheres to dodecahedrons, yet we have not found a bounded Universe, we have found infinity within the finite. With more wonder than ever, I will look up into the shimmering night sky, and ponder the vast finite Universe.