Genesis: The origin of the universe

National Forum, Winter 1996 by Wersinger, J-M

In summary, a model for the appearance of the universe out of the nothingness of vacuum is in the making. The model is highly speculative, and results from theoretical work are not corroborated experimentally. However, it is the first time in human history that science has come up with a theory of Genesis that does not have to rely on any supernatural intervention or on special initial conditions. Instead, it is entirely described by mechanisms rooted in the currently known laws of physics. A number of paradoxes and puzzling coincidences that the standard Big Bang model had to attribute to special initial conditions can now be resolved in terms of the mechanism of inflation.

The milestones of a plausible scenario for the appearance and evolution of our universe are the following. The universe appeared as a fluctuation of vacuum some 10 to 20 billion years ago. A microscopic bubble of space-time arose with a very high temperature. At the beginning there was one force and at most one type of fundamental particle. As the nascent universe emerged from the Planck time, the force of gravity separated from the superforce. A second separation of forces followed. However, during this second transition, supercooling occurred, and the universe found itself in a state of false vacuum. During its phase of false vacuum, the universe inflated at a dizzying rate, doubling in size every 10 sup -34 seconds. The entire observable universe grew from the size of a trillionth of a proton to the size of a beach ball during the incredibly short time of 10 sup -32 sec. At the end of inflation the strong force separated from the electroweak force and the energy locked up in the false vacuum was released, creating the particles and the radiation that make up the universe today. When the universe was 10 sup -10 seconds old, the weak nuclear force separated from the electromagnetic force. All currently known forces had appeared by then.

For the next few minutes, the universe was characterized by a complex era dominated by particle physics, which was not described in this essay. Four minutes after the initial explosion, the temperature had dropped to about a billion Kelvin, finally allowing for light nuclei of deuterium, helium, and lithium to be created by nucleosynthesis. This is the beginning of the era of nuclei. 100,000 years later, the temperature reached the 4,000K mark, and particles roamed around at low enough speeds to allow the electromagnetic force to keep electrons around nuclei. Atoms were born, and the universe became transparent to radiation. The radiation escaping the claws of matter at that time is the CBR that now fills the whole universe with its invisible glow of microwaves. Stars and galaxies had to wait about a billion years after the bang to form. Many billions of years later, in the Milky Way Galaxy, our solar system emerged from a dirty cloud of hydrogen. After several unsuccessful attempts over millions of years, life finally established itself on a small blue planet: Earth.