Discuss the difference between the Universe and the observable Universe
What will be an ideal response?
Today, cosmologists believe they understand why the sky is dark. Olbers's paradox makes an incorrect prediction because it is based on a hidden assumption. The Universe may be infinite in size but it is not eternal-that is, not infinitely old. That answer to Olbers's question was suggested by Edgar Allan Poe in 1848. He proposed that the night sky is dark because the Universe is not infinitely old but instead began at some time in the past. The more distant stars are so far away that light from them has not yet reached Earth. That is, if you look far enough, the look-back time is greater than the age of the Universe. The night sky is dark because the Universe had a beginning.This is a powerful idea because it clearly illustrates the difference between the Universe and the observable Universe. The Universe is everything that exists, but the observable Universe is the part that you can see. The Universe is 13.7 billion years old, and because of that, the observable Universe is limited by a light travel time of 13.7 billion years. We should not confuse the observable Universe, which is finite, with the Universe as a whole, which could be infinite.
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a. True b. False Indicate whether the statement is true or false
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a. does positive work b. increases the object's kinetic energy c. increases the object's potential energy d. None of the above choices are valid.