Explain the Big Bang

The Big Bang is the cosmological model of the initial conditions and subsequent development of the universe supported by the most comprehensive and accurate explanations from current scientific evidence and observation.[1][2] 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, and continues to expand to this day.

The scientist and Roman Catholic priest 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.[3] 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 phrase "Big Bang" during a 1949 radio broadcast, as a derisive reference to a theory he did not subscribe to.[4] Hoyle later helped considerably in the effort to figure out 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.

[1]^ Evidence for the Big Bang, www.talkorigins.org

[2]^ What is the evidence for the Big Bang?, UCLA Division of Astronomy and Astrophysics

[3]^ a b c d Hubble, E. (1929). "A Relation Between Distance and Radial Velocity Among Extra-Galactic Nebulae". Proceedings of the National Academy of Sciences 15: 168–173. doi:10.1073/pnas.15.3.168. PMID 16577160. http://antwrp.gsfc.nasa.gov/debate/1996/hub_1929.html.

[4]^ BBC News (2001). "'Big bang' astronomer dies". http://news.bbc.co.uk/1/hi/uk/1503721.stm. Retrieved on 2008-12-07.

Information from: http://en.wikipedia.org/wiki/Big_Bang

Another source describes the Big Bang as this:

One of the most persistently asked questions has been: How was the universe created? Many once believed that the universe had no beginning or end and was truly infinite. Through the inception of the Big Bang theory, however,no longer could the universe be considered infinite. The universe was forced to take on the properties of a finite phenomenon, possessing a history and a beginning.

About 15 billion years ago a tremendous explosion started the expansion of the universe. This explosion is known as the Big Bang. At the point of this event all of the matter and energy of space was contained at one point. What exisisted prior to this event is completely unknown and is a matter of pure speculation. This occurance was not a conventional explosion but rather an event filling all of space with all of the particles of the embryonic universe rushing away from each other. The Big Bang actually consisted of an explosion of space within itself unlike an explosion of a bomb were fragments are thrown outward. The galaxies were not all clumped together, but rather the Big Bang lay the foundations for the universe.

The origin of the Big Bang theory can be credited to Edwin Hubble. Hubble made the observation that the universe is continuously expanding. He discovered that a galaxys velocity is proportional to its distance. Galaxies that are twice as far from us move twice as fast. Another consequence is that the universe is expanding in every direction. This observation means that it has taken every galaxy the same amount of time to move from a common starting position to its current position. Just as the Big Bang provided for the foundation of the universe, Hubbles observations provided for the foundation of the Big Bang theory.

Since the Big Bang, the universe has been continuously expanding and, thus, there has been more and more distance between clusters of galaxies. This phenomenon of galaxies moving farther away from each other is known as the red shift. As light from distant galaxies approach earth there is an increase of space between earth and the galaxy, which leads to wavelengths being stretched.

In addition to the understanding of the velocity of galaxies emanating from a single point, there is further evidence for the Big Bang. In 1964, two astronomers, Arno Penzias and Robert Wilson, in an attempt to detect microwaves from outer space, inadvertently discovered a noise of extraterrestrial origin. The noise did not seem to emanate from one location but instead, it came from all directions at once. It became obvious that what they heard was radiation from the farthest reaches of the universe which had been left over from the Big Bang. This discovery of the radioactive aftermath of the initial explosion lent much credence to the Big Bang theory.

Even more recently, NASAs COBE satellite was able to detect cosmic microwaves eminating from the outer reaches of the universe. These microwaves were remarkably uniform which illustrated the homogenity of the early stages of the universe. However, the satillite also discovered that as the universe began to cool and was still expanding, small fluctuations began to exist due to temperature differences. These flucuatuations verified prior calculations of the possible cooling and development of the universe just fractions of a second after its creation. These fluctuations in the universe provided a more detailed description of the first moments after the Big Bang. They also helped to tell the story of the formation of galaxies which will be discussed in the next chapter.

The Big Bang theory provides a viable solution to one of the most pressing questions of all time. It is important to understand, however, that the theory itself is constantly being revised. As more observations are made and more research conducted, the Big Bang theory becomes more complete and our knowledge of the origins of the universe more substantial.

Information retrieved from: http://www.umich.edu/~gs265/bigbang.htm

Thank you for your very interesting answer. I understand the fact that the universe is expanding in all directions, which suggests a big explosion and that everything originated from a single point.  What I have a problem with is the assertion that everything originated from a single, tiny point smaller than a pin head. I can't even fathom squeezing something the size of a mountain into a pin head much less the entire universe.  That is just too bizarre.

The big bang has a cause and a mechanism.The cause is a big crunch in a Godel contradictory universe.It results in a contradiction of state force and energy.

Four states of matter are one.Four forces one and four energies one.

It starts with two dimensions one of time and one of space.

The energy is released 2+2=4 and changes from potential to kinetic that is the mechinism of the big bang.

13/APPLE+ 1/3 ORANGE+ 1/3 ORANGE= 1 APPLE/ORANGE.

The law of non contradiction states that two opposite particles X and Y cannot be in the same place in the same state at the same time.

The exception is prior to the big bang.

That's easy. U can't explain it cause it never happened. They think that the point spun so fast that it exploded. Scientificaly if it exploded then all the pieces would be spinning the same direction that it was (planets, moons, ect., ect.).....but not all of them r. There is only 1 plausible explanation....God. =)

per Eddie :
I don’t understand it too, I even don’t believe it. According to my unterstanding, the theory of BB (big bang) say’s:
1. before there was nothing
2. suddenly there was every thing but in rather squeezed condition
3. then it turned to distinguishable conditions and appeared as the „Standart Model“
For me it sounds like 1;2;3 and here we are!!!

A good thought-experiment is: Twist the time dimension and look, what would happend.
-     The movie goes backward, EVERY THING moves closer to each other.
-     But EVERY THING does have an own speed and direktion next to the move inward to the Center, what causes a momentum to the Center (Omega of BB).
-    As closer EVERY THING moves toward the Omega, as higher the effect of its momentum.
-    Close to Omega, the EVERY THING MOMENTUM (ETM) speeds up to C and energy becomes infinite.
-    Also next to the ETM is a momentum of matter in a subatomar scale what can’t exist in C. Before this, probably ETM becomes quantized energy.
-      From outside of our univers it might look like a bright shining sun with a certain size but from inside values turned to zero or infinite.
-      And this long before Omega is approached.

per aircloud:
I don’t understand the Apple/Orange/logic, but Gödel surely would.
I love the consideration of 4 states of matter, 4 (states of) forces, 4 (states of) energies.
I don’t think that energy changes from potential to kinetic, especially in BB energy was kinetic and in the deep meaning potential energy is kinetic too.
Gödel math would not help me to understand the BB, but could you show me how to use this math to describe the necessity of a previous universe with reversed values to make the logic complete. It would open a way, that ALL is a different state of ONE.

The energy prior to the big bang is potential..............

And the explosion of the BB converts potential to kinetic this is important the explain how Godels universe can be contracted to a big crunch that is contradictory and potential.

Contradictory force state energy must become non contradiction by explosion.

This is important to understand how Godel can become an eqaution for the big crunch.

Ponder something about Big Bang cosmology that you may not have seen on PBS.

We're talking about a simple explosive shock wave.  Before we go poking around in dimensional mechanics and other math that can fry MY brain, consider the mechanics of a simple stick of dynamite shot in a granite wall.  Everyday stuff, actually.

Prior to initiation, the dynamite has loads of chemical energy (to beat the metaphor to death, potential/chemical).  It will wait until the cows come home before it goes blam.  Then you hook up the shock tube, feed it into the hole, pack it with ANFO, set your delays, fill the rest of your holes, and retire to the safety line.  Screw in your earplugs, open your mouth, trip the cap, and wait for the shock wave to arrive.  Then spit, get off the floor, and think that the next time, you're going to go a little farther back even if you have to pay for the extra length of shock tube.

In a nutshell, that's it.  Then we must discuss zero-dimension/infinite-dimension, and lots else that actually simplifies Hubbell's work to something understandable.

I-1.  Initiation.  The compact form of the explosive (for the discussion, infinitely small -- not the size of a proton!) begins to expand.  It pushes the rock with about 1.35 X10^5 tons/CM^2.  The reason it expands so forcefully is that it is contained.  Unconfined explosives do not develop significant pressure.

I-2.  Wave initiation.  The explosive begins expanding, starting wave deflagration.  As the wave progresses, it cracks the nitrate ion from the monoglyceride molecule, causing further wave deflagration.

W-1.  The primary explosive has completed its reaction, cracking the rock.  But the rock does not move much. 

W-2.  The secondary explosive (anfo) begins uniform deflagration, causing the NH/4 to part from the 2-HNO/3, releasing 2H/2, 2N/2, 3O/2.  The lifting force pushes the cracked rock out of the hole at a prescribed uniform rate. 

W-3.  All deflagration has ceased, the shock wave has dissipated, flying rock will soon hit the floor.

So with our universe.  Taken as an ordinary explosive shock wave acting on space (no simple calculation, that) we see that space has a non-zero mass, is currently accelerating, and will continue until the explosive has completed its reaction.

The stars and galaxies we see are clumps of space smacked together by a huge, but well understood, shock wave.

Now, to convince the rest of the world that they're barking up the wrong theory . . ..