Big Bang theory
The Big Bang theory is a scientific theory used to account for the acceleration of matter throughout the Universe.
Big bang theories are actually a class of scientific models that describe the Universe as expanding from a very hot, dense state approximately 13.7 billion years ago (although this number has been revised several times throughout recent history). It was first proposed by the Catholic priest Georges-Henri Lemaitre and evidence for the expansion was observed by Edwin Hubble. Later George Gamow predicted that the Big Bang would leave an observable microwave background radiation (or CMBR). This radiation was discovered by Arno Penzias and Robert Wilson at Bell Labs; it was found to be close to that predicted by Gamow (Gamow predicted a background radiation level equivalent to a roughly 3 K black body object, and the observed level is that of a 2.725 K body).
The name "Big Bang Theory", first coined by steady state theorists is often mistakenly thought to imply an explosion of matter into pre-existing space, but the theory actually indicates that time began at that point and space expanded from then on, and more space is constantly created in the interstices between particles as the density of the universe falls. In other words, the Big Bang describes the expansion of space and time. Big Bang theorists state that the Hubble redshift is a consequence of this stretching of the fabric of space.
Observations of distant supernovae indicate that the Universe is actually undergoing accelerated expansion and galaxy surveys and recent observations of the microwave background have allegedly corroborated these claims. Atheists claim that the acceleration is caused by something called 'dark energy', for which there is only observational evidence but no experimental evidence. There is no viable naturalistic explanation of what dark energy is, which even a few atheists admit, yet they insist that dark energy is a naturalistic phenomenon.
Scientists refer to the theoretical exact moment the Big Bang supposedly began as t=0 ("t" standing for "time"). At this time, according to their theory all of the matter in the universe - in fact, the universe itself - was contained within a single point (a single point in mathematics is infinitesimally small). A burst of energy known as the Big Bang is claimed to have issued forth, and the universe began. 1.0×10-43 seconds later, the force of gravity separated from the other forces.
In 2006, researchers used the Wilkinson Microwave Anisotropy Probe (launched by NASA in 2001) to measure variations in the cosmic microwave background (a "faint glow which permeates the universe"). According to these measurements, the universe is estimated to be about 13.7 billion years old, "give or take a few hundred-thousand years".
Creationist and Theistic Evolutionary Views
The universe appears to be fine tuned for life to some contrary to more than 99.99...% of the universe having no life, suggesting that God set the laws of physics that allow the universe, complexity, and life to exist. Scientists have been baffled by these "coincidences" as they examine the parameters of the big bang and other physical constants.
Some creationists argue that the Big Bang theory is part of an effort to deny God's creation of all of existence. Christian physicists, such as Dr. John Hartnett, have claimed that the Big Bang theory was constructed to account for serious pitfalls to the theory of evolution, particularly the needed timescale of billions of years, amply contradicted by terrestrial and astronomical evidence. Thus, the big bang is trotted out by atheist evolutionists to silence creationist opponents.
Young earth creationist scientists contest the Big Bang Theory stating that it is scientifically unsound.   In addition, young earth creationism holds that the book of Genesis is historical in nature and that Bible exegesis warrants a six-day creation with each day being 24 hours.
Some Old Earth Creationists and Theistic Evolutionists argue that the Big Bang is in fact mentioned in the Bible.  Some Christian apologists who believe in an old earth, such as William Craig use the Big Bang as an apologetic, arguing that it proves that the universe had a beginning. 
He further discusses the many theories that have been proposed to counter the Big Bang Theory due to its conclusion that there is a beginning or origin of creation. These additional theories have been broken down to still revert to a beginning. This in essence tries to proves a divine power or creator, which frustrates the many atheistic scientists that are trying to prove that God does not exist, including well known physicist Stephen Hawking. 
It should be noted that the Big Bang theory has received criticism because it ignores the theory of an oscillating universe. Also, no first cause from the Big Bang has ever been successfully identified, although none is needed as the universe does not exist within time. Furthermore, critics of the Big Bang point out that not everything in the universe is actually moving apart from everything else as some galaxies have collided with other galaxies in the past, although this could be explained through understanding of classical mechanics.
The big bang theory is entirely unable to explain the matter-antimatter asymmetry. If the big bang theory did happen as they say, matter and antimatter would have been created in equal quantities. When antimatter was first discovered in the 1930's, scientists immediately began looking for traces of it in the universe. No traces have been found except what we produce in particle accelerators and positrons produced by a type of radiation called positron emission. This asymmetry means that the big bang theory would have had to violate the laws of physics, since matter would have had to be produced without its antimatter partner, which violates the laws of conservation of electric charge and mass. There was some excitement in the 1970's about electroweak symmetry breaking as a method by which the matter was "preferred" over antimatter, but the infrequency of the weak force made them conclude this was impossible.
Big Bang Theory Dissent Letter
Many have dissented from the theory, including the British astronomer Sir Fred Hoyle, the Nobel Prize winner Hannes Alfven, and astronomers Geoffrey Burbidge and Halton Arp.  It was Hoyle who sarcastically coined the term during a radio broadcast.
In 2004, an ‘Open Letter to the Scientific Community’ disputing the Big Bang theory was signed by 33 scientists and has been published on the internet and in the science journal New Scientist. 
The dissent letter has subsequently been signed by hundreds of individuals around the world.  Professional cosmologists are actively creating models (some of which contradict the Big Bang scenario) and collecting data that probe the specific nature of the earliest observable aspects of the Universe.
The Horizon Problem
The problem is this: even assuming the big bang timescale, there has not been enough time for light to travel between widely separated regions of space. So, how can the different regions of the current [cosmic microwave background] CMB have such precisely uniform temperatures if they have never communicated with each other? This is a light-travel–time problem.
Recognizing this difficulty, physicist Alan Guth conjured an explanation he named cosmic inflation. According to this claim, during the universe's first 10-35 of a second, a period of extremely rapid, exponential inflation occurred, expanding the universe by a factor of at least 1026. It would be the equivalent of taking a pea and expanding it to the size of our solar system in a time less than a millionth of a blink of an eye. If this occurred, it would mathematically allow for the uniformity of the CMBR - the vast distances were in thermodynamical contact before the rapid inflation. However, no naturalistic mechanism that would cause this sudden expansion is known, and inflation remains, at present, entirely speculative.
Other Criticisms of the Big Bang
- The Big Bang theory is unable to explain where the laws of gravity and inertia come from. It also cannot explain why the laws are consistent.
- Big Bang Theorists cannot explain where the matter arrived from in the first place. Also in order for the matter to move it requires energy and the Big Bang theory cannot explain its origins.
- In physics there is a law called the Conservation of Angular Momentum. If a spinning object breaks apart in a frictionless environment the pieces that lay off will be spinning in the same direction. If the Big Bang did happen then shouldn’t everything be spinning in the same direction? Galaxies and moons and planets spin in different directions. That doesn’t make sense according to the Big bang theory.
- If the Big Bang did happen then matter would be evenly distributed. Instead it is lumpy as there are clusters of stars and then great voids.
- WMAP Cosmology 101: Age of the Universe
- Hubble, E. Proceedings of the National Academy of Sciences of the United States of America, Volume 15, Issue 3, pp. 168-173.
- Riess, A. G., et al. The Astronomical Journal, Volume 116, Issue 3, pp. 1009-1038.
- Perlmutter, S., et al. The Astrophysical Journal, Volume 517, Issue 2, pp. 565-586.
- Sloan Digital Sky Survey
- Tegmark, M., et al. Physical Review D, vol. 74, Issue 12.
- Wilkinson Microwave Anisotropy Probe
- See, for example, http://arxiv.org/abs/astro-ph/0603449
- Thompson, Bert, Harrub, Brad, and May, Branyon The Big Bang Theory—A Scientific Critique Apologetics Press, May 2003 - 23:32-34,36-47.
- Brown, Walt, 2001, Big Bang?
- Days of Creation (CreationWiki).
- Genesis Questions and Answers (Answers in Genesis).
- Niessen, Richard, Theistic Evolution and the Day-Age Theory Impact 81, March 1980.
- Strobel, Lee. The Case for a Creator. Zondervan, 2004.
- Stephen Hawking, A Brief History of Time.
- Lisle, Jason, Light-travel time: a problem for the big bang, Creation 25(4):48–49, September 2003.
- Castelvecchi, Davide, The Growth of Inflation Symmetry, 1(2), December 2004, p.12-17
- Hinshaw, Gary, WMAP data put cosmic inflation to the test, 3rd May, 2006 (PhysicsWorld.com).