by JOHN CARL VILLANUEVA
The Big Bounce is one of the scenarios predicted by scientists in which the Universe may end. To put it more accurately, it refers to the end of our universe but ushers in the beginning of another one. That is to say, you can think of both the Big Bang and the Big Crunch to simply make up a pair that mark the beginning and end, respectively, of one complete cyclical lifetime of the Universe.
A universe model made up of alternating Big Bangs and Big Crunches is called a cyclic or oscillatory model. In this model, a Big Crunch immediately followed by a Big Bang is more aptly called a Big Bounce. In a cyclic model, there is no such thing as an ultimate fate of the Universe since the Universe will simply collapse and expand alternately forever.
This model is generally at odds with the Second Law of Thermodynamics, i.e., that the entropy of an isolated system will always go by the direction of increasing entropy. The law instead favors the more popular model that details the possible ending of our universe – The Big Freeze.
For a Big Bounce to occur, the conditions that may result in a Big Crunch should first be present. For example, for the possibility of an eventual collapse to exist, the density of the Universe should be greater than a certain value, known as the critical density. Unfortunately, that is not so. In fact, recently gathered data indicate that the density is even much smaller than the critical density.
Furthermore, additional observations have also shown that the Universe is actually expanding at an accelerated rate. If the expansion continues in the way it is moving now, there is no reason to believe that it will collapse in the future. Hence, the probability of the Big Crunch, much less the Big Bounce is practically nil.
Central to the discussions that revolve around an ever expanding universe is the virtually unknown entity known as dark energy. It is believed to generate the force that leads to an accelerated expansion.
At first, the strength of the dark energy was believed to be increasing. This highly favored an extreme ending scenario known as the Big Rip. More recent developments however show that the strength of dark energy is not changing. However, this development still does not favor a Big Bounce. Until future observations can show that the dark energy may evolve into an attractive force, the Big Bounce must remain as the less popular theories.
The Big Bounce is one of the scenarios predicted by scientists in which the Universe may end. To put it more accurately, it refers to the end of our universe but ushers in the beginning of another one. That is to say, you can think of both the Big Bang and the Big Crunch to simply make up a pair that mark the beginning and end, respectively, of one complete cyclical lifetime of the Universe.
A universe model made up of alternating Big Bangs and Big Crunches is called a cyclic or oscillatory model. In this model, a Big Crunch immediately followed by a Big Bang is more aptly called a Big Bounce. In a cyclic model, there is no such thing as an ultimate fate of the Universe since the Universe will simply collapse and expand alternately forever.
This model is generally at odds with the Second Law of Thermodynamics, i.e., that the entropy of an isolated system will always go by the direction of increasing entropy. The law instead favors the more popular model that details the possible ending of our universe – The Big Freeze.
For a Big Bounce to occur, the conditions that may result in a Big Crunch should first be present. For example, for the possibility of an eventual collapse to exist, the density of the Universe should be greater than a certain value, known as the critical density. Unfortunately, that is not so. In fact, recently gathered data indicate that the density is even much smaller than the critical density.
Furthermore, additional observations have also shown that the Universe is actually expanding at an accelerated rate. If the expansion continues in the way it is moving now, there is no reason to believe that it will collapse in the future. Hence, the probability of the Big Crunch, much less the Big Bounce is practically nil.
Central to the discussions that revolve around an ever expanding universe is the virtually unknown entity known as dark energy. It is believed to generate the force that leads to an accelerated expansion.
At first, the strength of the dark energy was believed to be increasing. This highly favored an extreme ending scenario known as the Big Rip. More recent developments however show that the strength of dark energy is not changing. However, this development still does not favor a Big Bounce. Until future observations can show that the dark energy may evolve into an attractive force, the Big Bounce must remain as the less popular theories.
