The commonly accepted model of the universe suggests that it began in an infinitely compact and singular state, enclosing a space even smaller than an atomic particle. The beginning of our universe then occurred when the compact particle -- the singularity -- grew not in a violent explosion (a "big bang") but rather through an incredibly rapid expansion -- an expansion so rapid that one could almost envision it as being a "creation."
While today scientists may feel relatively secure with the notion that the incredible expansion did occur, what they are not so secure about are some of the more troubling aspects surrounding the "scientific" explanations for how the incredible expansion occurred. Although the basic framework of the incredible expansion model has achieved wide acceptance, along with this acceptance has come an increased sophistication with regards to its shortcomings. As the potential for actually obtaining answers has improved, the questions have evolved from the "whats" and "wheres" to the "hows" and "whys".
Time, as we know it, began.
Up to 10–43 seconds after the Big Bang, the Planck Epoch began.
The Planck epoch is an era in traditional (non-inflationary) big bang cosmology in which the temperature is high enough that the four fundamental forces -- electromagnetism, gravitation, weak nuclear interaction, and strong nuclear interaction -- are all unified in one fundamental force. Little is understood about physics at this temperature, and different theories propose different scenarios. Traditional big bang cosmology predicts a gravitational singularity before this time, but this theory is based on general relativity and is expected to break down due to quantum effects. Physicists hope that proposed theories of quantum gravitation, such as string theory, loop quantum gravity, and causal sets, will eventually lead to a better understanding of this epoch.
In inflationary cosmology, times prior to the end of inflation (roughly 10−32 seconds after the Big Bang) do not follow the traditional big bang timeline. The universe before the end of inflation is a near-vacuum with a very low temperature, and persists for much longer than 10−32 second. Times from the end of inflation are based on the big bang time of the non-inflationary big bang model, not on the actual age of the universe at that time, which cannot be determined in inflationary cosmology. Thus, in inflationary cosmology there is no Planck epoch in the traditional sense, though similar conditions may have prevailed in a pre-inflationary era of the universe.
Between 10–43 seconds and 10–36 seconds after the Big Bang, the Grand Unification Epoch began.
As the universe expanded and cooled, it crossed transition temperatures at which forces separated from each other. These were phase transitions much like condensation and freezing. The grand unification epoch begins when gravitation separates from the other forces of nature, which are collectively known as gauge forces. The non-gravitational physics in this epoch would be described by a so-called grand unified theory (GUT). The grand unification epoch ends when the GUT forces further separate into the strong and electroweak forces. This transition should produce magnetic monopoles in large quantities, which are not observed. The lack of magnetic monopoles was one problem solved by the introduction of inflation.
In modern inflationary cosmology, the traditional grand unification epoch, like the Planck epoch, does not exist, though similar conditions likely would have existed in the universe prior to inflation.
Three forces began operating: electromagnetic, strong nuclear, and gravitational.
Weak interaction and electromagnetic force separated.
Between 10−36 seconds after the Big Bang to sometime between 10−33 and 10−32 seconds, the universe inflated at a rate faster than the speed of light.
The creative expansion of the universe was not an explosion in the classic sense. In our human experience with explosions, shrapnel like objects fly through a pre-existing space. However, with the expansion of the initial singularity, space itself was being created at the same time that time, matter, and even gravity were being formed. Indeed, at its beginning, the expansion of the singularity caused space to expand at speeds that, at times, exceeded the speed of light. This was possible because while light, energy and matter cannot exceed the speed of light, the expansion (the "creation") of space itself was not so restricted.
In physical cosmology, cosmic inflation, cosmological inflation or just inflation is the theorized extremely rapid exponential expansion of the early universe by a factor of at least 1078 in volume, driven by a negative-pressure vacuum energy density. The inflationary epoch comprises the first part of the electroweak epoch following the grand unification epoch. It lasted from 10−36 seconds after the Big Bang to sometime between 10−33 and 10−32 seconds. Following the inflationary period, the universe continued to expand, but at a slower rate.
The term "inflation" is also used to refer to the hypothesis that inflation occurred, to the theory of inflation, or to the inflationary epoch. The inflationary hypothesis was originally proposed in 1980 by American physicist Alan Guth, who named it "inflation". It was also proposed by Katsuhiko Sato in 1981.
As a direct consequence of this expansion, all of the observable universe originated in a small causally connected region. Inflation answers the classic conundrum of the Big Bang cosmology: why does the universe appear flat, homogeneous, and isotropic in accordance with the cosmological principle when one would expect, on the basis of the physics of the Big Bang, a highly curved, heterogeneous universe? Inflation also explains the origin of the large-scale structure of the cosmos. Quantum fluctuations in the microscopic inflationary region, magnified to cosmic size, become the seeds for the growth of structure in the universe.
While the detailed particle physics mechanism responsible for inflation is not known, the basic picture makes a number of predictions that have been confirmed by observation. Inflation is thus now considered part of the standard hot Big Bang cosmology. The hypothetical particle or field thought to be responsible for inflation is called the inflaton.
Quarks combined to form particles, including the "God" particle.
The Higgs boson or Higgs particle is an elementary particle initially theorised in 1964, and tentatively confirmed to exist on March 14, 2013. The discovery has been called "monumental" because it appears to confirm the existence of the Higgs field, which is pivotal to the Standard Model and other theories within particle physics, where it explains why some fundamental particles have mass when the symmetries controlling their interactions should require them to be massless, and—linked to this—why the weak force has a much shorter range than the electromagnetic force. Proof of its existence and measurement of its properties is expected to impact scientific knowledge across a range of fields, and should eventually allow physicists to determine whether the final unproven piece of the Standard Model or a competing theory is more likely to be correct, guide other theories and discoveries in particle physics, and—as with other fundamental discoveries of the past—potentially over time lead to developments in "new" physics, and new technologies.
The unanswered question ("Why do particles have mass?") in fundamental physics is of such importance that it led to a search of over 40 years for the Higgs boson and finally the construction of one of the most expensive and complex experimental facilities to date, the Large Hadron Collider able to create and study Higgs bosons and related questions. On July 4, 2012, a previously unknown particle was announced as being detected, which physicists suspected at the time to be the Higgs boson. By March 2013, the particle had been proven to behave, interact and decay in many of the expected ways predicted by the Standard Model, and was also tentatively confirmed to have + parity and zero spin, two fundamental criteria of a Higgs boson, making it also the first known scalar particle to be discovered in nature, although a number of other properties were not fully proven and some partial results do not yet precisely match those expected. As of March 2013 it is still uncertain whether its properties (when eventually known) will exactly match the predictions of the Standard Model, or whether additional Higgs bosons exist as predicted by some theories.
The Higgs boson is named after Peter Higgs, one of six physicists who, in 1964, proposed the mechanism that suggested the existence of such a particle. Although Higgs' name has become ubiquitous with this theory, the resulting electroweak model (the final outcome) involved several researchers between about 1960 and 1972, who each independently developed different parts. In mainstream media the Higgs boson is often referred to as the "God particle", from a 1993 book on the topic.
The first picosecond (10−12) of cosmic time. It includes the Planck epoch, during which currently established laws of physics may not have applied; the emergence in stages of the four known fundamental interactions or forces -- first gravitation, and later the electromagnetic, weak and strong interactions; and the accelerated expansion of the universe due to cosmic inflation.
[In physical cosmology, cosmic inflation, cosmological inflation, or just inflation, is a theory of exponential expansion of space in the early universe. The inflationary epoch is believed to have lasted from 10−36 seconds to between 10−33 and 10−32 seconds after the Big Bang. Following the inflationary period, the universe continued to expand, but at a slower rate. The acceleration of this expansion due to dark energy began after the universe was already over 7.7 billion years old (5.4 billion years ago).
Inflation theory was developed in the late 1970s and early 80s, with notable contributions by several theoretical physicists, including Alexei Starobinsky at Landau Institute for Theoretical Physics, Alan Guth at Cornell University, and Andrei Linde at Lebedev Physical Institute. Alexei Starobinsky, Alan Guth, and Andrei Linde won the 2014 Kavli Prize "for pioneering the theory of cosmic inflation". It was developed further in the early 1980s. It explains the origin of the large-scale structure of the cosmos. Quantum fluctuatons in the microscopic inflationary region, magnified to cosmic size, become the seeds for the growth of structure in the Universe. Many physicists also believe that inflation explains why the universe appears to be the same in all directions (isotropic), why the cosmic microwave cosmic background radiation is distributed evenly, why the universe is flat, and why no magnetic monopoles have been observed.
The detailed particle physics mechanism responsible for inflation is unknown. The basic inflationary paradigm is accepted by most physicists, as a number of inflation model predictions have been confirmed by observation; however, a substantial minority of scientists dissent from this position. The hypothetical field thought to be responsible for inflation is called the inflaton.
In 2002, three of the original architects of the theory were recognized for their major contributions; physicists Alan Guth of M.I.T., Andrei Linde of Stanford, and Paul Steinhardt of Princeton shared the prestigious Dirac Prize "for development of the concept of inflation in cosmology". In 2012, Guth and Linde were awarded the Breakthrough Prize in Fundamental Physics for their invention and development of inflationary cosmology.]
Tiny ripples in the universe at this stage are believed to be the basis of large-scale structures that formed much later. Different stages of the very early universe are understood to different extents. The earlier parts are beyond the grasp of practical experiments in particle physics but can be explored through the extrapolation of known physical laws to extreme high temperatures.
The nuclei of atoms formed.
The first true, complex atoms formed.
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