Astronomers Discover The Grand Barricade Of The Cosmos
Source: Open Talk Magazine 27/02/2011 01:04:00
The Great Wall of China is an impressive structure that presented the engineering wonders of ancient civilization. It was built for many centuries, and today it extends a total distance of 8,852 kilometers (5,501 miles). It is so long, that throughout the years there have been a few speculations about its visibility from outer space.
Sadly though, all speculations have been proven to be false. Even at low-Earth orbit, the wall is still difficult to see, and you need to use field glasses to even distinguish the structure within the mountainous regions of China. Even if the Great Wall of China seems large enough for us humans, it is still too small compared to the vastness of outer space. In fact, it is totally incomparable to one specific cosmic wall that stands mightily within the depths of outer space—the Sloan Great Wall.
The Sloan Great Wall is a massive array of galaxy clusters that form a natural structure in space and stretch across 13.7 billion light years of the known universe. There are around 10,000 galaxies clumped together within the Sloan Great Wall. A galaxy carries around 1 billion stars, so we can just imagine how small our planet would be compared to this astronomically gigantic wall of galaxies.
The entire structure is approximately 1 billion light years away from Earth. At that distance, recognizing the structure with the naked eye is outright impossible. In a way, like the Great Wall of China, it is invisible in outer space, not because it’s too small, but because it is too big for us to see the entire picture immediately.
The Sloan Great Wall was so named because it was discovered through the efforts of the Sloan Digital Sky Survey (SDSS). The SDSS is a project that aims to map all of the visible parts of the sky. The project started in 2000 and still continues today. The discovery of the Sloan Great Wall was announced by John Richard Gott and Mario JuriÄ‡’s team on October 20, 2003.
Before the discovery of the Sloan Great Wall, the CfA2 Great Wall was the largest known natural structure in the universe. It was discovered in 1989 by Margaret Geller and John Huchra, and is about one third the size of the Sloan Great Wall (approximately 500 million light years).
The gaps in each galaxy within the Sloan Great Wall were discovered to be on a runaway dash away from each other. It’s been found that the driving force behind the acceleration of each galaxy is dark energy. If the Sloan Great Wall continues to expand, within a few billion years future civilizations might see an even larger wall than we see today.
What are the implications of the Sloan Great Wall to our life? Knowing that there is a large structure 13.7 billion light years long in the universe probably won’t help you get a job, or get you something to eat. But the nourishment that it gives to our understanding of the universe soothes our curiosity, helps us understand our place in the cosmos, and prepares us for the next big step to the undiscovered frontier of outer space.