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Reality guide: The essential laws of cosmology

作者:都冉    发布时间:2019-02-26 06:03:06    

Millennium Simulation Project By Stuart Clark and Richard Webb The standard model of cosmology is our picture of the universe on a grand scale. Its basis is Einstein’s theory of gravity, the general theory of relativity, which he formulated almost exactly a century ago. To formulate the model, though, Einstein and others had to make some key assumptions about the way the universe ticks – laws that are the foundation stones of our cosmic understanding. Nothing can exceed this cosmic speed limit Back in the 1860s, James Clerk Maxwell was melding electricity and magnetism into one unified theory of electromagnetism. But however he sliced the equations, they only made sense if light travelled through space at the same constant speed, regardless of the speed of its source. This is odd. If someone fires a bullet from a moving car, to a bystander the bullet travels at the sum of its speed and the car’s speed. Yet when 20 years later US physicists Albert Michelson and Edward Morley were looking for the luminiferous ether, a medium supposed to carry light, they reached the same conclusion: however you look at it, the speed of light is a constant. Not only that, it is the ultimate cosmic speed limit. No influence – not matter, not information, not gravity or any other force – may travel faster than it. Reports of cosmic speed breakers, such as faster-than-light neutrinos announced in 2011,

 

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