Who measured the size of the Universe?
You may have often wondered whether the universe can be measured. American astronomer Edwin Hubble also faced the same question. He was the first scientist who measured the distance to galaxies beyond the Milky Way, which is known as the Akash Ganga in Indian astronomy. Hubble suggested that the distant galaxies are receding from each other at greater speed than the closer galaxies. This is known as Hubble’s Law.
Hubble used the largest available telescope of the world (2.5 meters, on Mount Wilson, California) to try and measure the universe. He measured the separation of stars in the Andromeda galaxy. By measuring their brightness, he could judge how far away the stars actually are. Because of doubts about the brightness of stars, he obtained a result of 800,000 light years instead of the present two million light years.
According to Hubble’s law, the speed of the galaxies is closely related to their distance. This is the general picture of modern cosmology and it suggests that all galaxies were once close to each other, which in turn supports the Big Band theory.
During World War II, astronomer Walter Buade was able to make accurate measurements of galactic distances. He discovered that the observable universe is much larger than what Hubble had envisaged.
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