Below the UB quotes are the two scientific rationales for the big bang theory. They are the
expansion of the universe and the fact that space has a temperature above absolute zero (cosmic
background radiation--discovered in 1965--and worth a Nobel Prize). As the UB said (in 1955) they
both exist but are not related to a fictional big bang.
12.4.12 The present relationship of your sun and its associated planets, while disclosing many
relative and absolute motions in space, tends to convey the impression to astronomic observers that
you are comparatively stationary in space, and that the surrounding starry clusters and streams are
engaged in outward flight at ever-increasing velocities as your calculations proceed outward in space.
But such is not the case. You fail to recognize the present outward and uniform expansion of the
physical creations of all pervaded space. Your own local creation (Nebadon) participates in this
movement of universal outward expansion. The entire seven superuniverses participate in the two-
billion-year cycles of space respiration along with the outer regions of the master universe.
12.4.14 Although your spectroscopic estimations of astronomic velocities are fairly reliable when
applied to the starry realms belonging to your superuniverse and its associate superuniverses, such
reckonings with reference to the realms of outer space are wholly unreliable. Spectral lines are
displaced from the normal towards the violet by an approaching star; likewise these lines are displaced
towards the red by a receding star. Many influences interpose to make it appear that the recessional
velocity of the external universes increases at the rate of more than one hundred miles a second for
every million light-years increase in distance. By this method of reckoning, subsequent to the
perfection of more powerful telescopes, it will appear that these far-distant systems are in flight from
this part of the universe at the unbelievable rate of more than thirty thousand miles a second. But this
apparent speed of recession is not real; it results from numerous factors of error embracing angles of
observation and other time-space distortions.
42.4.6 Gravity presence and action is what prevents the appearance of the theoretical absolute
zero, for interstellar space does not have the temperature of absolute zero. Throughout all organized
space there are gravity-responding energy currents, power circuits, and ultimatonic activities, as well
as organizing electronic energies. Practically speaking, space is not empty. Even the atmosphere of
Urantia thins out increasingly until at about three thousand miles it begins to shade off into the
average space matter in this section of the universe. The most nearly empty space known in Nebadon
would yield about one hundred ultimatons — the equivalent of one electron — in each cubic inch.
Such scarcity of matter is regarded as practically empty space.
From Wikipedia, the free encyclopedia
This article is about the cosmological model of the Universe. For other uses, see Big Bang
(disambiguation) and Big Bang Theory (disambiguation).
According to the Big Bang model, the Universe expanded from an extremely dense and hot state and
continues to expand today. A common analogy explains that space itself is expanding, carrying
galaxies with it, like raisins in a rising loaf of bread. The graphic scheme above is an artist's concept
illustrating the expansion of a portion of a flat Universe.
The Big Bang is the cosmological model of the initial conditions and subsequent development of
the Universe that is supported by the most comprehensive and accurate explanations from current
scientific evidence and observation. As used by cosmologists, the term Big Bang generally refers
to the idea that the Universe has expanded from a primordial hot and dense initial condition at some
finite time in the past (best available measurements in 2009 suggest that the initial conditions occurred
around 13.3 to 13.9 billion years ago), and continues to expand to this day.
Georges Lemaître proposed what became known as the Big Bang theory of the origin of the Universe,
although he called it his "hypothesis of the primeval atom". The framework for the model relies on
Albert Einstein's general relativity and on simplifying assumptions (such as homogeneity and isotropy
of space). The governing equations had been formulated by Alexander Friedmann. After Edwin Hubble
discovered in 1929 that the distances to far away galaxies were generally proportional to their
redshifts, as suggested by Lemaître in 1927, this observation was taken to indicate that all very distant
galaxies and clusters have an apparent velocity directly away from our vantage point: the farther away,
the higher the apparent velocity. If the distance between galaxy clusters is increasing today,
everything must have been closer together in the past. This idea has been considered in detail back in
time to extreme densities and temperatures, and large particle accelerators have been built to
experiment on and test such conditions, resulting in significant confirmation of the theory, but these
accelerators have limited capabilities to probe into such high energy regimes. Without any evidence
associated with the earliest instant of the expansion, the Big Bang theory cannot and does not provide
any explanation for such an initial condition; rather, it describes and explains the general evolution of
the Universe since that instant. The observed abundances of the light elements throughout the
cosmos closely match the calculated predictions for the formation of these elements from nuclear
processes in the rapidly expanding and cooling first minutes of the Universe, as logically and
quantitatively detailed according to Big Bang nucleosynthesis.
Fred Hoyle is credited with coining the term Big Bang during a 1949 radio broadcast. It is popularly
reported that Hoyle, who favored an alternative "steady state" cosmological model, intended this to be
pejorative, but Hoyle explicitly denied this and said it was just a striking image meant to highlight the
difference between the two models. Hoyle later helped considerably in the effort to
understand stellar nucleosynthesis, the nuclear pathway for building certain heavier elements from
lighter ones. After the discovery of the cosmic microwave background radiation in 1964, and especially
when its spectrum (i.e., the amount of radiation measured at each wavelength) sketched out a
blackbody curve, most scientists were fairly convinced by the evidence that some Big Bang scenario
must have occurred.
The Cosmic Background Radiation
In every direction, there is a very low energy and very uniform radiation that we see filling the
Universe. This is called the 3 Degree Kelvin Background Radiation, or the Cosmic Background
Radiation, or the Microwave Background. These names come about because this radiation is
essentially a black body with temperature slightly less than 3 degrees Kelvin (about 2.76 K), which
peaks in the microwave portion of the spectrum. This radiation is the strongest evidence for the validity
of the hot big bang model. The adjacent figure shows the essentially perfect blackbody spectrum
obtained by NASA's Cosmic Background Explorer (COBE) satellite.
The following image was taken by COBE. It shows the temperature of the cosmic background radiation
plotted in galactic coordinates, with red cooler and blue and violet hotter (Ref). This dipole anisotropy
is because of the Doppler effect. If the Earth moves with respect to the microwave background, it will
be blue shifted to a higher effective temperature in the direction of the Earth's motion and red shifted
to a lower effective temperature in the direction opposite the Earth's motion.
The indication of the above image is that the local group of galaxies, to which the Earth belongs, is
moving at about 600 km/s with respect to the background radiation. It is not know why the Earth is
moving with such a high velocity relative to the background radiation.
Evidence for the Big Bang
The cosmic background radiation (sometimes called the CBR), is the afterglow of the big bang,
cooled to a faint whisper in the microwave spectrum by the expansion of the Universe for 15 billion
years (which causes the radiation originally produced in the big bang to redshift to longer
wavelengths). As shown in the adjacent intensity map of the background radiation in different
directions taken by the Differential Microwave Radiometer on NASA's COBE satellite, it is not
completely uniform, though it is very nearly so (Ref). To obtain this image, the average dipole
anisotropy exhibited in the image above has been subtracted out, since it represents a Doppler shift
due to the Earth's motion. Thus, what remains should represent true variations in the temperature of
the background radiation.
In this image, red denotes hotter fluctuations and blue and black denote cooler fluctuations around the
average. These fluctuations are extremely small, representing deviations from the average of only
about 1/100,000 of the average temperature of the observed background radiation.
Problems with the Uniformity
The highly isotropic nature of the cosmic background radiation indicates that the early stages of
the Universe were almost completely uniform. This raises two problems for the big bang theory.
First, when we look at the microwave background coming from widely separated parts of the sky it can
be shown that these regions are too separated to have been able to communicate with each other
even with signals travelling at light velocity. Thus, how did they know to have almost exactly the same
temperature? This general problem is called the horizon problem.
Second, the present Universe is homogenous and isotropic, but only on very large scales. For scales
the size of superclusters and smaller the luminous matter in the universe is quite lumpy, as illustrated
in the following figure.
FIGURE: Data from the survey of galaxies. The voids and "walls" that form the large-scale structure
are mapped here by 11,000 galaxies. Our galaxy, the Milky Way, is at the center. The outer radius is
at a distance of approximately 450 million light-years. Obscuration by the plane of the Milky Way is
responsible for the missing pie-shaped sectors to the right and left. Click on the image to get a larger
version. (Smithsonian Astrophysical Observatory, 1993. Northern data (top)--Margaret Geller and
John Huchra, Southern data (bottom)--Luiz da Costa et al. Quoted in Cosmology, a Research Briefing,
National Academy of Sciences.)
Thus, the discovery of small deviations from smoothness (anisotopies) in the cosmic microwave
background is welcome, for it provides at least the possibility for the seeds around which structure
formed in the later Universe. However, as we shall see, we are still far from a quantitative
understanding of how this came to be.
Discovery of Cosmic Background Radiation
In 1965 Arno A. Penzias and Robert W. Wilson of Bell Laboratories were testing a sensitive horn
antenna which was designed for detecting low levels of microwave radiation. They discovered a low
level of microwave background "noise", like the low level of electrical noise which might produce "snow"
on a television screen. After unsuccessful attempts to eliminate it, they pointed their antenna to
another part of the sky to check whether the "noise" was coming from space, and got the same kind of
signal. Being persuaded that the noise was in their instrument, they took other, more sophisticated
steps to eliminate the noise, such as cooling their detector to low temperatures.
Finding no explanations for the origin of the noise, they finally concluded that it was indeed coming
from space, but that it was the same from all directions. It was a distribution of microwave radiation
which matched a blackbody curve for a radiator at about 2.7 Kelvins.
After all their efforts to eliminate the "noise" signal, they found that a group at Princeton had predicted
that there would be a residual microwave background radiation left over from the Big Bang and were
planning an experiment to try to detect it. Penzias and Wilson were awarded the Nobel Prize in 1978
for their discovery.
By Paul Herrick