Recall that we have a baby picture of the universe from the cosmic microwave background, which shows us what the universe looked like the moment it cooled from a hot, charged plasma to mostly neutral gas. In that image, we see that the universe was smooth but not perfectly smooth. It has tiny ripples that represent the quantum fluctuations of the early universe. During the Big Bang, inflation stretched space tremendously and blew up those tiny ripples into huge wrinkles in the fabric of space and time. These wrinkles in space-time then created the clumps and hot spots of gravity that later led
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