That has an important but unavoidable consequence: it means the universe will expand forever. And a universe that expands forever is infinite and eternal.
Today, a group of physicists rebel against this idea. They say an infinitely expanding universe cannot be so because the laws of physics do not work in an infinite cosmos. For these laws to make any sense, the universe must end, say Raphael Bousso at the University of California, Berkeley and few pals. And they have calculated when that is most likely to happen.
Their argument is deceptively simple and surprisingly powerful. Here's how it goes. If the universe lasts forever, then any event that can happen, will happen, no matter how unlikely. In fact, this event will happen an infinite number of times.
This leads to a problem. When there are an infinite number of instances of every possible observation, it becomes impossible to determine the probabilities of any of these events occurring. And when that happens, the laws of physics simply don't apply. They just break down. "This is known as the "measure problem" of eternal inflation," say Bousso and buddies.
In effect, these guys are saying that the laws of physics abhor an eternal universe.
The only way out of this conundrum is to hypothesize some kind of catastrophe that brings an end to the universe. Then all the probabilities make sense again and the laws of physics regain their power.
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