Astronomy

There is famous paradox in astronomy and cosmology: If this universe has unlimited broadness, we ought to will see the star in every sky corner, and thereby the whole skies should be bright. Then, why is dark area among the stars?

This paradox is conceived as the Olbers’ paradox, named after German astronomer and physics, Wilhelm Olbers, who has writing concerning this paradox at 1920’s. In fact, Olbers is not the first person who lifts this discourse. In early 17th, another German astronomer, Johannes Kepler, refer the same paradox to support his view concerning limited universe. On 1715, English astronomer Edmond Halley, after perceiving the very bright light footstep in the sky, raise his view that even universe not limited, but distribution the stars isn’t flatten.

Next, the Switzerland astronomer Jean-Philippe Loys de Chéseaux starts to study the paradox pursuant to Halley theory. He is concluded that either the universe is infinite, or brightness of starlight dimmer along with increasing of distance, possibility caused by light absorbent material in space.

This paradox starts to be comprehended widely from article published by Olbers at 1823. Olbers raise the theory that darkness of night sky caused by something in sky that hindering some of star lights to Earth (modern scientist now realize that the Olbers’ theory is impossible to be valid because if the items hinder the starlight really exist, hence he will continuous heating and at one time will transmit the light as bright as a star). Translation of Olbers’ article in English and France made his theory widely recognized. However, Olbers’ paradox never been expostulated again until more than a century later.

At 1948, this paradox returns to emerge. Now as reference to steady state theory, suggested by British astronomer, Hermann Bondi. Bondi raise the solution that as the effect of expansion of universe, the light we accept from the faraway object will seen squeeze, and thereby the amount of energy in each photon (light particle) is getting slimmer. This solution is valid also for big bang theory.

Latest understanding concerning Olbers’ Paradox with its solution just raised at 1960’s by American astronomer, Edward Harrison. Harisson indicate that the darkness of night sky caused of we cannot see the star from infinite distance. Harrison’s solution based from the expanding universe model. Because light transmitted by an object takes time to reach the Earth, hence seeing to deepness of space is same as seeing occurrences in past time.

On the other side, since the universe still expanded, stars and galaxies will progressively go away from time to time. Transmitted light from a galaxy today will pass through over further compared to the light transmitted million, or even one year before, because the distance dissociate us in Earth with pertinent galaxy continue to increase. The consequences are amount of energy that reaching us from faraway object will continue to decrease time to time. The farther a star, the red shift effect has smaller influence.

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