I see that the Galaxies are concentrated in two parts of the sky, why are they thicker at those spots and why dont they appear to be distributed evenly throughout the sky? TEN POINTS TO THE FIRST GOOD ANSWER!
Galaxies aren’t evenly distributed because of tiny density variations in the earliest moments of the big bang. These initially tiny variations are believed to have been caused by small quantum fluctuations. The tiny variations were expanded by many orders of magnitude during the era of inflation with the result that the universe after the big bang was inhomogeneous on a large scale. Gravity then caused the denser concentrations of matter (especially dark matter) to collapse. The first stars formed out of the collapsing clouds, and stars were drawn into galaxies. Now, matter is distributed in a netlike array with fine filaments forming the net and the filaments separated by enormous voids. The filaments are composed of galactic super-clusters which in turn are composed of galactic clusters which are composed of galaxies. Some super-clusters are arranged in what is called "attractors," enormous concentrations of galaxies. However, the universal network of matter is not concentrated in any one part of the sky from the earth’s point of view. One looks out upon a series of filaments, the network, and those filaments exist in every direction. There are, however, nearby (relatively) dust lanes that obscure parts of the network as seen from earth.
February 16th, 2010 at 7:33 pm
Gravity. They are clumping together because they are each pulling towards each other.
References :
February 16th, 2010 at 8:08 pm
Think of them as tho they are molecules. Made up of atoms. For instance, the sun and its 8 planets would be an Oxygen atom. Our galaxy is a large molecule in a larger world, Say our known universe is a part of a granite rock. Or a tree. Our universe may be right at the edge of some structure.
References :
February 16th, 2010 at 8:53 pm
dark matter and dark energy.
Its not just gravity.
References :
February 16th, 2010 at 9:35 pm
Galaxies aren’t evenly distributed because of tiny density variations in the earliest moments of the big bang. These initially tiny variations are believed to have been caused by small quantum fluctuations. The tiny variations were expanded by many orders of magnitude during the era of inflation with the result that the universe after the big bang was inhomogeneous on a large scale. Gravity then caused the denser concentrations of matter (especially dark matter) to collapse. The first stars formed out of the collapsing clouds, and stars were drawn into galaxies. Now, matter is distributed in a netlike array with fine filaments forming the net and the filaments separated by enormous voids. The filaments are composed of galactic super-clusters which in turn are composed of galactic clusters which are composed of galaxies. Some super-clusters are arranged in what is called "attractors," enormous concentrations of galaxies. However, the universal network of matter is not concentrated in any one part of the sky from the earth’s point of view. One looks out upon a series of filaments, the network, and those filaments exist in every direction. There are, however, nearby (relatively) dust lanes that obscure parts of the network as seen from earth.
References :
February 16th, 2010 at 9:49 pm
Truth is, we’ve only done a detailed hubble deepfield analysis of about 2% of the sky. Just because it doesnt look perfectly even over this space we can see doesnt mean it won’t even out. It’d be a little odd if every galaxy was perfectly spaced and equidistant, wouldnt it?
Also, what you may be looking at are galaxy clusters. every galaxy pulls on the other with its gravity, and they group together just like any other objects do. They can get pretty massive.
References :
February 16th, 2010 at 9:59 pm
I don’t think that’s true, if you take the whole Universe into account. There are voids and clusters in every direction.
Over a short distance it is true: the Virgo cluster dominates. There is also an observer bias caused by the disk of the Milky way obscuring that part of the sky.
References :