2010 December 29 Wednesday
3.7 Billion Years To Last Restaurant At End Of Universe?

At UC Berkeley Raphael Bousso and some friends think the universe has to be of finite duration. Time to book a reservation.

There is a 50 per cent chance that time will end within the next 3.7 billion years, according to a new model of the universe

About that 5 billion year birthday party some of you have planned: Do you feel lucky?

An infinite universe is crazy because extremely low probability events can happen an infinite number of times?

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.

Just how many problematic extremely low probability events are there? Why wouldn't their probability drop to 0 at some point as the universe becomes too spread out?

From the abstract:

Present treatments of eternal inflation regulate infinities by imposing a geometric cutoff. We point out that some matter systems reach the cutoff in finite time. This implies a nonzero probability for a novel type of catastrophe. According to the most successful measure proposals, our galaxy is likely to encounter the cutoff within the next 5 billion years.

You can read the full PDF. One weirdness: if you ever find yourself falling toward a black hole time might end before you reach it. Not sure if that's a feature. They also discuss whether time ends sharply or in a smear.

By Randall Parker    2010 December 29 08:11 PM   Entry Permalink | Comments (7)
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