In this lesson, we will explore the concept of whether or not there is a "center" to the Universe.
Consider the following statements:
The Universe began with an explosion.
If the Universe began with an explosion, then the Universe must be expanding.
If the Universe is expanding, it has no center.
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Let E: The Universe began with an explosion.
Let A: The Universe is expanding.
Let C: The Universe has no center.
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1. ) Let us start with a one-dimensional view . Use the elastic bands with sequins from the Expanding Universe lesson. Pick a galaxy to be the "center". Stretch the band a little and measure how far all other galaxies are from it. Then stretch and measure again. What do you see? Pick another galaxy to be the center. Perform the experiment over. What happens this time? Given one more galaxy the honor of being the "center of the Universe" and repeat.
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2.) Two Dimensions now do the above procedure on a 2 dimensional surface like a balloon or a beach ball. Between your sets of measurements, blow up the balloon/ball a little more than it was.
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3.) Our Universe so what does all of this have to do with our perception of the Universe? Earth appears to be the center of the expansion of the Universe. After all, galaxies are moving away from us in all directions. However, this is an illusion. If we were in one of those other galaxies, we would think that there we were the center of the expansion. There really is no center, just like on the elastic band or the balloon surface, everything is moving away from everything else. Your teacher will now show you a visualization of this.
When you look at each image, is there an obvious "center" to the distribution?
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Once the sheets are overlaid, does a pattern emerge? Describe it.
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As the top sheet is shifted slightly up or to the right, what happens to the distribution? Describe what happens.
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How does this demonstration relate to what you have learned about the Universe?
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Describe what you would do so that ANY dot could appear to be the center of the expansion.
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