Cosmogeny (as opposed to Cosmogony in the previous post) is the study of the birth or creation of the universe, and has long been accepted as a domain of philosophy, mythology and theology. Nowadays however, scientific enquiry intrudes upon this once sacred turf, and may even have something to contribute.
The universe is a unified four-dimensional continuum; why should it have a ‘beginning’ at an instant in time any more than a beginning at a point in space? The universe contains space and time, but is itself spaceless and timeless, and words such as ‘begin’ and ‘end’ seem inappropriate. Space and time are the most basic elements of the physical universe, and we must realize that it is created neither at a place in space nor at a moment in time (unless that place and moment are in the space and time of another universe occupied by the creating agent). We may say the universe began – in the sense of evolving – at the earliest moment in its time, but cannot say that it was created at that moment, or at any other moment in its time. Creation of the universe involves the creation of space and time including everything in space and time. The physical universe, if created, is created in one stupendous spaceless and timeless act. ~ Edward Harrison, Cosmology: The Science of the Universe
From the countless ancient mythologies that arose in various cultures around the world, to the many recent scientific hypotheses that attempt to provide naturalistic explanations, humanity has never stopped pondering about questions regarding our existence. One thing’s for sure, any cosmogenesis theory must also be able to explain why the universe seems just right for life. The laws of the universe, including the fundamental constants of nature (i.e. the gravitational constant, the speed of light, the charge and mass of an electron, the Planck constant) all seem incredibly fine-tuned for the development of intelligent life. Miniscule changes in any of these values would be disastrous – resulting in a universe totally devoid of life. What’s even more interesting is this:
The constants, when combined, yield dimensionless numbers that occupy two widely separated numerical groups: a ‘unity group’ (close to the value of 1) and a ‘large number group’ (close to the value 10^40). The observable universe is also 10^40 times larger than the characteristic size of an elementary particle. This coincidence between two very large and unrelated numbers is all the more striking because the ‘large number group’ values stay constant at 10^40, but the scale of the universe in subatomic units steadily increases, and now is 10^40. Robert Dicke showed that the present coincidence is the natural consequence of stellar evolution. Not until the first stars have evolved and synthesized and expelled into interstellar space elements, such as carbon, oxygen, and silicon, can planets form and life evolve. By that time, both numbers are in approximate agreement. ~ Edward Harrison, Cosmology: The Science of the Universe
The theistic explanation, is that God (or a bunch of gods and goddesses, depending on your beliefs) made it this way. For those who don’t like the notion of gods, there is absolutely nothing wrong in believing that the universe was created by extraterrestrial (or should I say, extra-dimensional) intelligent beings. Others, who subscribe to the weak anthropic principle, think that our universe could be only one of a multitude of universes in a multiverse, and we happen to live in one whose laws and constants are suitable for life. It is possible that our universe was spontaneously created out of quantum fluctuations in another universe, with a host of universes being created this way, but only some are able to harbour life. Or maybe, the constants of nature had to have these values, there was no other way the universe could have been, and science will find out why once we have an ultimate theory of the universe. Some cosmologists have even borrowed ideas from other fields, including natural selection – new universes are created in black holes, and therefore universes whose laws and fundamental constants favour the production of black holes will produce more offspring universes.
All these explanations run into the same problem – in providing an explanation for the birth of our universe, we end up with the need to provide an explanation for something else possibly even more complex. The point of terminus of our questioning has only been extended backwards by another step. If God created the universe, who created God? Why does God exist? What universe does He/She exist in? Where do some of these multiverses or transcendent universes come from, and what kind of universe do they exist in? Will such lines of questioning ever reach an end? Or will we eventually arrive at a closed causal loop in which the reason for the existence of the universe lies within the universe itself? Even if there is such a solution, we still have to contend with the question of why the universe exists at all. Why is there something rather than nothing?
If universes create universes, what created the multiverse that consists of a population of reproducing universes? Have we merely enlarged the scope of cosmologenesis and must now explain the origin of an indefinitely large number of universes? Notice that this question is similar in some respects to asking: If God created the universe, who created God? ~ Edward Harrison, Cosmology: The Science of the Universe