Some physicists such as Max Tegmark believe the universe is actually infinite in size. If the galactic density of our own neighborhood is typical across this entire domain, and according to the data from the satellite COBE, then our bubble-universe should contain at least another 10 to the power 100 galaxies.

This is such a large figure, that it's difficult to explain it. So to give you an idea of how large a number this is, it's far larger the the number of atoms that compose every object in our own visible universe, which as you remember extends out 13.2 billion light years in every direction. This too is very difficult to conceptualize. So we'll have to scale down even further to a grain of sand.

The number of atoms composing a grain of sand is about 10 to the power 23 atoms, or 100 trillion trillion atoms for each grain of sand on a typical beach. And just think how many grains of sand are on your typical beach, let alone something the size of the Sahara. And that's just on the surface of the earth. All the sand in the world composes much less than 0.00001% of the mass of the earth. The number of atoms composing the Earth is about 10 to the power 60. And the Earth in turn is one tiny planet around a small star in an ordinary galaxy, among hundreds of billions of galaxies in our very local neighborhood, which we call the visible universe.

So 10 to the power 100 is a very very big number of galaxies! Adding it all together and you get more galaxies in our universe than there are atoms composing every object in our visible universe!!

The Coma cluster is one of the largest observed structures in the Universe,
containing over 10,000 galaxies and extending more than 1.37 billion light
years in length forming a wall like structure. Some of these elongated
super clusters have formed a series of walls, one after another, spaced
from 500 million to 800 million light years apart, such that in one direction
alone, 13 Great Walls have formed with the inner and outer walls separated
by less than seven billion light years.

According to scientists, our known Hubble length universe contains hundreds of millions of galaxies that have clumped together, forming super clusters and a series of massive walls of galaxies separated by vast voids of empty space.

The vastest structure ever is a collection of super clusters a billion light years away extending for 5% the length of the entire observable universe. It is theorized that such structures as the Great Wall form along and follow web-like strings of dark matter that dictates the structure of the Universe on the grandest of scales. Dark matter gravitationally attracts baryonic matter, and it is this normal matter that astronomers see forming long, thin walls of super-galactic clusters.

This isn't the only wall out there - others exist, all with far greater lengths than width or depth, actual sheets of galaxies forming some of the most impressive anythings there are. And these walls are only a special class of galactic filaments, long strings of matter stretched between mind-breaking expanses of emptiness.

Recently, cosmologists have estimated that some of these galactic walls may have taken from 80 billion to 100 billion, to 150 billion years to form in a direct challenge to current age estimates of the age of the Universe following the Big Bang.

Britain’s Astronomer Royal, Lord Rees, says some of the cosmos’s biggest mysteries, like the Big Bang , might never be resolved and that a correct basic theory of the universe may be just too tough for human beings’ brains to comprehend!

So the million dollar question is: Could all this matter have come out from a singularity? From a Big Bang? These walls of galaxies as scientists say, would have taken at least 100 to 150 billion years to form!

“Just as a fish may be barely aware of the medium in which it lives and swims, so the microstructure of empty space could be far too complex for unaided human brains."
Sir Martin Rees, Astronomer Royal, physicist, Cambridge University