- uploaded: Dec 13, 2010
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LARGE SCALE GLOBE OF THE UNIVERSE
THE BLACKNESS OF SPACE IS AN ILLUSION CREATED BY OUR OWN INSIGNIFICANCE AND OUR OWN PERCEPTIONAL LIMITS!!
The universe is very large and possibly infinite in volume. The region visible from Earth (the observable universe) is a sphere with a radius of about 46 billion light years, based on where the expansion of space has taken the most distant objects observed. For comparison, the diameter of a typical galaxy is only 30,000 light-years, and the typical distance between two neighboring galaxies is only 3 million light-years. As an example, our Milky Way Galaxy is roughly 100,000 light years in diameter, and our nearest sister galaxy, the Andromeda Galaxy, is located roughly 2.5 million light years away. There are probably more than 100 billion (1011) galaxies in the observable universe. Typical galaxies range from dwarfs with as few as ten million (107) stars up to giants with one trillion (1012) stars, all orbiting the galaxy's center of mass. Thus, a very rough estimate from these numbers would suggest there are around one sextillion (1021) stars in the observable universe; though a 2003 study by Australian National University astronomers resulted in a figure of 70 sextillion (7 Ã— 1022).