What is this theory and how is it believed to have created the universe?
If you could also add points for and against and why scientists believe/disbelieve this theory that would be very helpful.
Thank you :)
If you could also add points for and against and why scientists believe/disbelieve this theory that would be very helpful.
Thank you :)
-
The initial thinking behind this is simple, all objects are moving away from us, at some point in the future, this expansion should stop, and the exp-ansion cease, inertia should take over and the gravitational pull of objects in the Universe should begin a process of contraction.
Objects moving away from us should be red shifted, in otherwords they should appear red in colour, objects moving toward us should be blue shifted, therefore appearing blue, therefore, if the process of contraction had begun, those galaxies furthest away from us that have been observed by such technology as the Herschel Space Observatory should show the most distant galaxies as blue shifted, as is the case with the Andromeda galaxy as this is moving twoard us. The problem is it doesn't, everything at or around 13.5billion light years is still expanding, it is red shifted.
Therefore the Universe is still expanding, this means that a number of things are happening, gravity is weaker than it should be, objects are moving faster than they should be, and there is more matter in the universe than we can detect, it may also mean that the universe is bigger than we currently think it is.
This is backed up by the speed of stars at the edges of galaxies, these are going too fast for them to be held by gravity being constant in proportion to the amount of matter, again this points to more matter being available, and by default more energy and therefore adds evidence to the idea of the existence of dark matter and with it, dark energy.
Added together this means that a cyclic universe, where everything expands to a point and then contracts to a 'big crunch' back to a state of singularity is unlikely, and becomes less plausible.
Simply for the amount of matter, with gravity being so weak, the expansion must continue into infinity, unless some factor in the future turns gravity from the weakest force to the strongest.
The majority opinion is now that the universe continues to expand to the point it simply becomes to diffuse and to cold to continue to exist, this is known as the 'big freeze'.
Objects moving away from us should be red shifted, in otherwords they should appear red in colour, objects moving toward us should be blue shifted, therefore appearing blue, therefore, if the process of contraction had begun, those galaxies furthest away from us that have been observed by such technology as the Herschel Space Observatory should show the most distant galaxies as blue shifted, as is the case with the Andromeda galaxy as this is moving twoard us. The problem is it doesn't, everything at or around 13.5billion light years is still expanding, it is red shifted.
Therefore the Universe is still expanding, this means that a number of things are happening, gravity is weaker than it should be, objects are moving faster than they should be, and there is more matter in the universe than we can detect, it may also mean that the universe is bigger than we currently think it is.
This is backed up by the speed of stars at the edges of galaxies, these are going too fast for them to be held by gravity being constant in proportion to the amount of matter, again this points to more matter being available, and by default more energy and therefore adds evidence to the idea of the existence of dark matter and with it, dark energy.
Added together this means that a cyclic universe, where everything expands to a point and then contracts to a 'big crunch' back to a state of singularity is unlikely, and becomes less plausible.
Simply for the amount of matter, with gravity being so weak, the expansion must continue into infinity, unless some factor in the future turns gravity from the weakest force to the strongest.
The majority opinion is now that the universe continues to expand to the point it simply becomes to diffuse and to cold to continue to exist, this is known as the 'big freeze'.
-
Basically, the cyclic universe theory postulates that the universe goes from singularity to big bang, where it expands until mutual gravity brings it all back to yet another singularity, where the process begins again.
It seems that dark matter and dark energy have put this theory to rest.
It seems that dark matter and dark energy have put this theory to rest.