explain big bang theory?

Answer 1

Before the big bang, all the matter and energy in the universe was compressed in some matter.

This was then blown/expanded very quickly, during this period as identified in Einstien's equation E=MC2, matter and energy were interchangable due to the massive temparatures and pressures.

The universe then began to settle and as temperature decreased,matter began to distill out of the clouds of high energy plasma. Hydrogen clouds started to collapse on each other, forming stars, whose gravity caused hydrogen atoms to fuse creating stars and helium.

If a star was big enough it would supernova, and spread the helium and other elements.

Answer 2

"In physical cosmology, the Big Bang is the scientific theory that the universe emerged from a tremendously dense and hot state about 13.7 billion years ago. The theory is based on the observations indicating the expansion of space (in accord with the Robertson-Walker model of general relativity) as indicated by the Hubble redshift of distant galaxies taken together with the cosmological principle.

Extrapolated into the past, these observations show that the universe has expanded from a state in which all the matter and energy in the universe was at an immense temperature and density. Physicists do not widely agree on what happened before this, although general relativity predicts a gravitational singularity (for reporting on some of the more notable speculation on this issue, see cosmogony).

The term Big Bang is used both in a narrow sense to refer to a point in time when the observed expansion of the universe (Hubble's law) began — calculated to be 13.7 billion (1.37 × 1010) years ago (±2%) — and in a more general sense to refer to the prevailing cosmological paradigm explaining the origin and expansion of the universe, as well as the composition of primordial matter through nucleosynthesis as predicted by the Alpher-Bethe-Gamow theory.[1]

From this model, George Gamow in 1948 was able to predict, at least qualitatively, the existence of cosmic microwave background radiation (CMB).[2] The CMB was discovered in 1964[3] and further corroborated the Big Bang theory, giving it an additional advantage over its chief rival, the steady state theory.[4]"

Answer 3

An old story goes that if you look at the sky during a clear, crisp night, and challenge yourself in counting all the stars, when you will have counted them all, the spell says that this will bring you Death. Now we know that this is a rather accurate statement, since there are a few hundred billion sun-like stars in our own Milky Way (a galaxy, or group of stars) alone, and, by counting them one per second, it would take a few thousand years!


An image of globular cluster M13, containing perhaps more than 100,000 stars. It is about 25,000 light years from us.

If we look at the picture above, the famous Olber's paradox (1826) comes to mind. (Actually, the paradox was formulated before Kepler). The riddle goes like this: assume that the universe is uniform and infinite. Then, it should be as bright as our Sun, because it is filled with stars in all directions. It is true that distant stars look dim ( the intensity of light decreases as the square of the distance), but on the other hand, there are more distant stars than close ones (the number of distant stars grows with the square of the distance); thus the two distance dependencies cancel out, and one gets that the sky should be as bright as the Sun. Obviously it is not. What is wrong with the argument above

Answer 4

Big Bang Theory expalins the origin of life and universe.Scientists reveal that million years ago, all the matter in the universe gathered into a small mass.This mass then suddenly exploded sending its parts in all directions.these parts formed the modern-day planets, stars and other celestial bodies.

Answer 5

The BBT is the prevailing theory on when our known universe began and what event constituted that beginning. However, it fails to tell us how or why the BB occurred.

Prevailing theory posits our known universe is relatively flat, something like a pancake that is about 14 billion light years in radius around us. We are at the center of the visible, known universe only because the light that has reached us has reached us from all directions since the BB happened about 14 billion years ago. No one knows where the center of the BB is however. And no one knows how much farther beyond what we can see our universe goes.

The background noise in space is evidence of the BB. We can see that noise as "snow" in a badly tuned television for example. Hubble, for whom the space telescope was named, found that our known universe is expanding, something like how a balloon's surface expands when blown up.

Understand, it's the universe, not the stuff in it, that is expanding. The galaxies, for example, are staying the same size even though, on average, they are moving away from each other because the space between them is expanding.

After the BB, which inserted all the energy and mass that exists today, the universe began immediately to cool. As it cooled, the fundamental particles (quanta) of the universe began to sort-of gel out, like water freezes to form crystals called ice. Thus, quanta are like ice crystals in that they formed as the universe cooled down.

Just a few seconds after the BB, photons "crystalized" for example. Because the photons gelled out early, they've been traveling through space about 14 billion years, which is why observers on Earth can only see out that far...14 billion light years. [See source.]

No one knows why or how the BB happened. One guess, a spin off of string theory, is that there are parallel universes to ours but existing in other dimensions. The thought is that two of these universes collided, which would account for the unimaginable energy needed to create our known universe.

Answer 6

according to this theory this universe had been a big round ball and when it exploded it was broken into many small pieces some of which united to form planets, some formed galaxies.........etc and everything is moving far away from each other!
according to some scientists it must have happened around 15 million years ago and therefore our universe is 15 million years old!

Answer 7

The Big Bang theory is an effort to explain what happened at the very beginning of our universe. Discoveries in astronomy and physics have shown beyond a reasonable doubt that our universe did in fact have a beginning. Prior to that moment there was nothing; during and after that moment there was something: our universe. The big bang theory is an effort to explain what happened during and after that moment.

According to the standard theory, our universe sprang into existence as "singularity" around 13.7 billion years ago. What is a "singularity" and where does it come from? Well, to be honest, we don't know for sure. Singularities are zones which defy our current understanding of physics. They are thought to exist at the core of "black holes." Black holes are areas of intense gravitational pressure. The pressure is thought to be so intense that finite matter is actually squished into infinite density (a mathematical concept which truly boggles the mind). These zones of infinite density are called "singularities." Our universe is thought to have begun as an infinitesimally small, infinitely hot, infinitely dense, something - a singularity. Where did it come from? We don't know. Why did it appear? We don't know.

After its initial appearance, it apparently inflated (the "Big Bang"), expanded and cooled, going from very, very small and very, very hot, to the size and temperature of our current universe. It continues to expand and cool to this day and we are inside of it: incredible creatures living on a unique planet, circling a beautiful star clustered together with several hundred billion other stars in a galaxy soaring through the cosmos, all of which is inside of an expanding universe that began as an infinitesimal singularity which appeared out of nowhere for reasons unknown. This is the Big Bang theory.

Big Bang Theory - Common Misconceptions
There are many misconceptions surrounding the Big Bang theory. For example, we tend to imagine a giant explosion. Experts however say that there was no explosion; there was (and continues to be) an expansion. Rather than imagining a balloon popping and releasing its contents, imagine a balloon expanding: an infinitesimally small balloon expanding to the size of our current universe.

Another misconception is that we tend to image the singularity as a little fireball appearing somewhere in space. According to the many experts however, space didn't exist prior to the Big Bang. Back in the late '60s and early '70s, when men first walked upon the moon, "three British astrophysicists, Steven Hawking, George Ellis, and Roger Penrose turned their attention to the Theory of Relativity and its implications regarding our notions of time. In 1968 and 1970, they published papers in which they extended Einstein's Theory of General Relativity to include measurements of time and space.1, 2 According to their calculations, time and space had a finite beginning that corresponded to the origin of matter and energy."3 The singularity didn't appear in space; rather, space began inside of the singularity. Prior to the singularity, nothing existed, not space, time, matter, or energy - nothing. So where and in what did the singularity appear if not in space? We don't know. We don't know where it came from, why it's here, or even where it is. All we really know is that we are inside of it and at one time it didn't exist and neither did we.

Big Bang Theory - Evidence for the Theory
What are the major evidences which support the Big Bang theory?

First of all, we are reasonably certain that the universe had a beginning.
Second, galaxies appear to be moving away from us at speeds proportional to their distance. This is called "Hubble's Law," named after Edwin Hubble (1889-1953) who discovered this phenomenon in 1929. This observation supports the expansion of the universe and suggests that the universe was once compacted.
Third, if the universe was initially very, very hot as the Big Bang suggests, we should be able to find some remnant of this heat. In 1965, Radioastronomers Arno Penzias and Robert Wilson discovered a 2.725 degree Kelvin (-454.765 degree Fahrenheit, -270.425 degree Celsius) Cosmic Microwave Background radiation (CMB) which pervades the observable universe. This is thought to be the remnant which scientists were looking for. Penzias and Wilson shared in the 1978 Nobel Prize for Physics for their discovery.
Finally, the abundance of the "light elements" Hydrogen and Helium found in the observable universe are thought to support the Big Bang model of origins.

Big Bang Theory - The Only Plausible Theory?
Is the standard Big Bang theory the only model consistent with these evidences? No, it's just the most popular one. Internationally renown Astrophysicist George F. R. Ellis explains: "People need to be aware that there is a range of models that could explain the observations….For instance, I can construct you a spherically symmetrical universe with Earth at its center, and you cannot disprove it based on observations….You can only exclude it on philosophical grounds. In my view there is absolutely nothing wrong in that. What I want to bring into the open is the fact that we are using philosophical criteria in choosing our models. A lot of cosmology tries to hide that."4

In 2003, Physicist Robert Gentry proposed an attractive alternative to the standard theory, an alternative which also accounts for the evidences listed above.5 Dr. Gentry claims that the standard Big Bang model is founded upon a faulty paradigm (the Friedmann-lemaitre expanding-spacetime paradigm) which he claims is inconsistent with the empirical data. He chooses instead to base his model on Einstein's static-spacetime paradigm which he claims is the "genuine cosmic Rosetta." Gentry has published several papers outlining what he considers to be serious flaws in the standard Big Bang model.6 Other high-profile dissenters include Nobel laureate Dr. Hannes Alfvén, Professor Geoffrey Burbidge, Dr. Halton Arp, and the renowned British astronomer Sir Fred Hoyle, who is accredited with first coining the term "the Big Bang" during a BBC radio broadcast in 1950.

Big Bang Theory - What About God?
Any discussion of the Big Bang theory would be incomplete without asking the question, what about God? This is because cosmogony (the study of the origin of the universe) is an area where science and theology meet. Creation was a supernatural event. That is, it took place outside of the natural realm. This fact begs the question: is there anything else which exists outside of the natural realm? Specifically, is there a master Architect out there? We know that this universe had a beginning. Was God the "First Cause"? We won't attempt to answer that question in this short article. We just ask the question:

Answer 8

Big Bang Theory - The Premise
The Big Bang theory is an effort to explain what happened at the very beginning of our universe. Discoveries in astronomy and physics have shown beyond a reasonable doubt that our universe did in fact have a beginning. Prior to that moment there was nothing; during and after that moment there was something: our universe. The big bang theory is an effort to explain what happened during and after that moment.

According to the standard theory, our universe sprang into existence as "singularity" around 13.7 billion years ago. What is a "singularity" and where does it come from? Well, to be honest, we don't know for sure. Singularities are zones which defy our current understanding of physics. They are thought to exist at the core of "black holes." Black holes are areas of intense gravitational pressure. The pressure is thought to be so intense that finite matter is actually squished into infinite density (a mathematical concept which truly boggles the mind). These zones of infinite density are called "singularities." Our universe is thought to have begun as an infinitesimally small, infinitely hot, infinitely dense, something - a singularity. Where did it come from? We don't know. Why did it appear? We don't know.

After its initial appearance, it apparently inflated (the "Big Bang"), expanded and cooled, going from very, very small and very, very hot, to the size and temperature of our current universe. It continues to expand and cool to this day and we are inside of it: incredible creatures living on a unique planet, circling a beautiful star clustered together with several hundred billion other stars in a galaxy soaring through the cosmos, all of which is inside of an expanding universe that began as an infinitesimal singularity which appeared out of nowhere for reasons unknown. This is the Big Bang theory.

Big Bang Theory - Common Misconceptions
There are many misconceptions surrounding the Big Bang theory. For example, we tend to imagine a giant explosion. Experts however say that there was no explosion; there was (and continues to be) an expansion. Rather than imagining a balloon popping and releasing its contents, imagine a balloon expanding: an infinitesimally small balloon expanding to the size of our current universe.

Another misconception is that we tend to image the singularity as a little fireball appearing somewhere in space. According to the many experts however, space didn't exist prior to the Big Bang. Back in the late '60s and early '70s, when men first walked upon the moon, "three British astrophysicists, Steven Hawking, George Ellis, and Roger Penrose turned their attention to the Theory of Relativity and its implications regarding our notions of time. In 1968 and 1970, they published papers in which they extended Einstein's Theory of General Relativity to include measurements of time and space.1, 2 According to their calculations, time and space had a finite beginning that corresponded to the origin of matter and energy."3 The singularity didn't appear in space; rather, space began inside of the singularity. Prior to the singularity, nothing existed, not space, time, matter, or energy - nothing. So where and in what did the singularity appear if not in space? We don't know. We don't know where it came from, why it's here, or even where it is. All we really know is that we are inside of it and at one time it didn't exist and neither did we.

Big Bang Theory - Evidence for the Theory
What are the major evidences which support the Big Bang theory?

First of all, we are reasonably certain that the universe had a beginning.
Second, galaxies appear to be moving away from us at speeds proportional to their distance. This is called "Hubble's Law," named after Edwin Hubble (1889-1953) who discovered this phenomenon in 1929. This observation supports the expansion of the universe and suggests that the universe was once compacted.
Third, if the universe was initially very, very hot as the Big Bang suggests, we should be able to find some remnant of this heat. In 1965, Radioastronomers Arno Penzias and Robert Wilson discovered a 2.725 degree Kelvin (-454.765 degree Fahrenheit, -270.425 degree Celsius) Cosmic Microwave Background radiation (CMB) which pervades the observable universe. This is thought to be the remnant which scientists were looking for. Penzias and Wilson shared in the 1978 Nobel Prize for Physics for their discovery.
Finally, the abundance of the "light elements" Hydrogen and Helium found in the observable universe are thought to support the Big Bang model of origins.

Big Bang Theory - The Only Plausible Theory?
Is the standard Big Bang theory the only model consistent with these evidences? No, it's just the most popular one. Internationally renown Astrophysicist George F. R. Ellis explains: "People need to be aware that there is a range of models that could explain the observations….For instance, I can construct you a spherically symmetrical universe with Earth at its center, and you cannot disprove it based on observations….You can only exclude it on philosophical grounds. In my view there is absolutely nothing wrong in that. What I want to bring into the open is the fact that we are using philosophical criteria in choosing our models. A lot of cosmology tries to hide that."4

In 2003, Physicist Robert Gentry proposed an attractive alternative to the standard theory, an alternative which also accounts for the evidences listed above.5 Dr. Gentry claims that the standard Big Bang model is founded upon a faulty paradigm (the Friedmann-lemaitre expanding-spacetime paradigm) which he claims is inconsistent with the empirical data. He chooses instead to base his model on Einstein's static-spacetime paradigm which he claims is the "genuine cosmic Rosetta." Gentry has published several papers outlining what he considers to be serious flaws in the standard Big Bang model.6 Other high-profile dissenters include Nobel laureate Dr. Hannes Alfvén, Professor Geoffrey Burbidge, Dr. Halton Arp, and the renowned British astronomer Sir Fred Hoyle, who is accredited with first coining the term "the Big Bang" during a BBC radio broadcast in 1950.

Big Bang Theory - What About God?
Any discussion of the Big Bang theory would be incomplete without asking the question, what about God? This is because cosmogony (the study of the origin of the universe) is an area where science and theology meet. Creation was a supernatural event. That is, it took place outside of the natural realm. This fact begs the question: is there anything else which exists outside of the natural realm? Specifically, is there a master Architect out there? We know that this universe had a beginning. Was God the "First Cause"? We won't attempt to answer that question in this short article. We just ask the question:

Answer 9

There is nothing to explain, we assume that gases got together and provoked the big bang, but no one explains or proves where the gases came from to cause that bang.

Answer 10

TimmyD is right on with that answer. We don't know what caused the Big Bang. You can say it was God if you want.