Light From Distant Stars example essay topic

"Why is the night sky dark?" (Hi enrich) For thousands of years this question, also known as Olber's paradox, has been asked. Astronomers are constantly growing closer to the answer but still no one has yet found a finite answer. As scientists relentlessly collect data hoping to find some clue as to the answer to this riddle we seem to realize that the answer may be because of something that is too mind blowing for us to comprehend. Several explanations have been considered over the years.

But as of right now only about two reasons seem to answer the question at hand. Here are several explanations, some of which have been scientifically accepted and others that just simply appear to be logical. The first explanation is that there is too much dusk in the universe to see the light from distant stars. This is obviously wrong. The dust does act as a shield, making some of the light harder to see from earth. But the amount of dust that it would take to completely block out all starlight would also block out light from the sun and this is clearly not happening.

A second explanation is that the Universe has a finite number of stars. Well, regardless of how finite the number of stars is, the reality is that the number of stars we do have would be enough energy to light up the entire sky. There is too much luminous matter in the Universe to allow this explanation to be correct. A third explanation is that the distribution of stars is such that some hind behind others and so the light from these stars can't be seen. This could be partially correct. If the stars were placed fractal ly (A geometric pattern that is repeated at ever smaller scales to produce irregular shapes and surfaces that cannot be represented by classical geometry) then there could be patches where the sky seemed to look empty, and in large areas appear dark.

Finally, the last two explanations seem to be the most correct. The first is that the Universe is expanding so distant stars are red-shifted into oblivion. According to the article by Ed Regis, astronomers searching for supernovas stumbled on the realization that the Universe is expanding. But the Cosmological Red-shift is needed to erase the star light form those distant stars. Together the expanding Universe and the redshift have proved that as the source of light moves away from us, the wavelength of the light increases making it harder to see.

This stretching of the wavelengths of the photons that are received owes to the expansion of the space. But the second good explanation, that the Universe is too young for distant star light to reach us also plays a big part in answering Olber's paradox. Our visible Universe is possibly only a small fraction of what is really out there. So, objects 20,000 thousand million years old are too far away to be seen by anyone on earth at this time.

If the Big Bang theory still holds true, then the Universe would have existed for only a finite amount of time, not allowing enough time for very distant starlight to reach us. 1. Heinrich Olber, 1823/26? 2. web Oden wald, Sten. Back to Astronomy Caf'e.