Our universe has existed for nearly 14 billion years, and as far as most people are concerned, the universe should continue to exist for billions of years more.
But according to a new paper, there's one theory for the origins of the universe that predicts time itself will end in just five billion years—coincidentally, right around the time our sun is slated to die.
The prediction comes from the theory of eternal inflation, which says our universe is part of the multiverse. This vast structure is made up of an infinite number of universes, each of which can spawn an infinite number of daughter universes. (Related: "New Proof Unknown 'Structures' Tug at Our Universe.")
The problem with a multiverse is that anything that can happen will happen an infinite number of times, and that makes calculating probabilities—such as the odds that Earth-size planets are common—seemingly impossible.
"Normal notions of probability—where you say, Event A happens twice and Event B happens four times, so Event B is twice as likely—don't work, because instead of two and four, you have infinity," said Ken Olum of Tufts University in Massachusetts, who was not involved in the study.
And calculating probabilities in a multiverse wouldn't just be a problem for cosmologists.
"If in?nitely many observers throughout the universe win the lottery, on what grounds can one still claim that winning the lottery is unlikely?" theoretical physicist Raphael Bousso of the University of California, Berkeley, and colleagues write in the new study.
Physicists have been circumventing this problem using a mathematical approach called geometric cutoffs, which involves taking a finite swath of the multiverse and calculating probabilities based on that limited sample.
But in the new paper, published online last month at the Cornell University website arXiv.org, Bousso's team notes that this technique has an unintended and, until now, overlooked consequence.
"You cannot use as mere mathematical tools that leave no imprint," Bousso said. "The same cutoff that gave you these nice and possibly correct predictions also predicts the end of time.
"In other words, if you use a cutoff to compute probabilities in eternal inflation, the cutoff itself"—and therefore the end of time—"becomes an event that can happen."
Our universe has existed for nearly 14 billion years, and as far as most people are concerned, the universe should continue to exist for billions of years more.
But according to a new paper, there's one theory for the origins of the universe that predicts time itself will end in just five billion years—coincidentally, right around the time our sun is slated to die.
The prediction comes from the theory of eternal inflation, which says our universe is part of the multiverse. This vast structure is made up of an infinite number of universes, each of which can spawn an infinite number of daughter universes. (Related: "New Proof Unknown 'Structures' Tug at Our Universe.")
The problem with a multiverse is that anything that can happen will happen an infinite number of times, and that makes calculating probabilities—such as the odds that Earth-size planets are common—seemingly impossible.
"Normal notions of probability—where you say, Event A happens twice and Event B happens four times, so Event B is twice as likely—don't work, because instead of two and four, you have infinity," said Ken Olum of Tufts University in Massachusetts, who was not involved in the study.
And calculating probabilities in a multiverse wouldn't just be a problem for cosmologists.
"If in?nitely many observers throughout the universe win the lottery, on what grounds can one still claim that winning the lottery is unlikely?" theoretical physicist Raphael Bousso of the University of California, Berkeley, and colleagues write in the new study.
Physicists have been circumventing this problem using a mathematical approach called geometric cutoffs, which involves taking a finite swath of the multiverse and calculating probabilities based on that limited sample.
But in the new paper, published online last month at the Cornell University website arXiv.org, Bousso's team notes that this technique has an unintended and, until now, overlooked consequence.
"You cannot use as mere mathematical tools that leave no imprint," Bousso said. "The same cutoff that gave you these nice and possibly correct predictions also predicts the end of time.
"In other words, if you use a cutoff to compute probabilities in eternal inflation, the cutoff itself"—and therefore the end of time—"becomes an event that can happen."
Genesis 1:14-19 And God said, Let there be lights in the firmament of the heaven to divide the day from the night; and let them be for signs, and for seasons, and for days, and years: And let them be for lights in the firmament of the heaven to give light upon the earth: and it was so. And God made two great lights; the greater light to rule the day, and the lesser light to rule the night: he made the stars also. And God set them in the firmament of the heaven to give light upon the earth, And to rule over the day and over the night, and to divide the light from the darkness: and God saw that it was good. And the evening and the morning were the fourth day.
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