Some astronomers - those who call themselves cosmologists ask similar questions about the universe. The scale that these scientists work at, of course, is much different. The universe is huge compared to a single planet, even a single galaxy, and its timeline is much, much longer. Because of this, cosmologists can't know with certainty how the Universe began or how it will end. They can, however, collect evidence, make educated guesses and establish theories. One such theory, concerning the future of the Universe, is playfully known as the "big crunch." According to this theory, the Universe will one day stop expanding. Then, as gravity pulls on the matter, the Universe will begin to contract, falling inward until it has collapsed back into a super-hot, super-dense singularity. If the theory holds true, the Universe is like a giant soufflĂŠ. It starts out small, then expands as it heats up. Eventually, however, the soufflĂŠ cools and begins to collapse. About 15 billion years ago, all matter and energy was bottled up in an incredibly small region known as a singularity. In an instant, this single point
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www.easyengineering.eu | March-April 2017