Time Likely To End Within Earth's Lifespan, Say Physicists
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Time Likely To End Within Earth's Lifespan, Say Physicists
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Re: Time Likely To End Within Earth's Lifespan, Say Physicists
#2From the sounds of it, this is a far from accepted idea that's just now coming out in like it's first paper or something, so don't start planning your End of Time Party. There's still a lot of verification and research and math between this being published and it becoming the consensus among physicists.
Re: Time Likely To End Within Earth's Lifespan, Say Physicists
#3From the sounds of it, this is a far from accepted idea that's just now coming out in like it's first paper or something, so don't start planning your End of Time Party. There's still a lot of verification and research and math between this being published and it becoming the consensus among physicists.
From the comments it sounds like it's related to string theory, which itself is on shaky theoretical ground. Guess we have to think out the box to progress physics, just need these kind of articles to use appropriate language to give a good idea of how far off many of these types of theories are to being proven.
Re: Time Likely To End Within Earth's Lifespan, Say Physicists
#4Woit's take on the Not Even Wrong blog:
Re: Time Likely To End Within Earth's Lifespan, Say Physicists
#5This theory is well across the line from science and into religion.
How is this: "we'll run headlong into this catastrophe before we can observe its effects on anything else."
any different than this:
"But of that day and hour knows no man, no, not the angels of heaven, but my Father only." http://bible.cc/matthew/24-36.htm
Re: Time Likely To End Within Earth's Lifespan, Say Physicists
#6"If the universe lasts forever, then any event that can happen, will happen, no matter how unlikely."
That's just plain mathematically wrong. There are many kinds of infinity (http://en.wikipedia.org/wiki/Aleph_number), and the set of all possible events has a much, much higher cardinality than an infinite axis of time. This is similar to saying that, since the set of integers is infinite, it must contain Pi.
Re: Time Likely To End Within Earth's Lifespan, Say Physicists
#7> 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.
Umm... this does not follow. Their argument surely must be more convincing than this nonsense.
Re: Time Likely To End Within Earth's Lifespan, Say Physicists
#8From the sounds of it, this is a far from accepted idea that's just now coming out in like it's first paper or something, so don't start planning your End of Time Party. There's still a lot of verification and research and math between this being published and it becoming the consensus among physicists.
It's not even a paper, it's just a manuscript on the arXiv, yet to pass peer review, if indeed it ever will.
I had a quick skim of the manuscript, and remain skeptical... a bunch of it doesn't even seem to make sense:
If it does occur in Nature, eternal inflation has profound implications. Any type of event that has nonzero probability will happen infinitely many times, usually in widely separated regions that remain forever outside of causal contact. This undermines the basis for probabilistic predictions of local experiments. If infinitely many observers throughout the universe win the lottery, on what grounds can one still claim that winning the lottery is unlikely? To be sure, there are also infinitely many observers who do not win, but in what sense are there more of them? In local experiments such as playing the lottery, we have clear rules for making predictions and testing theories. But if the universe is eternally inflating, we no longer know why these rules work.
Re: Time Likely To End Within Earth's Lifespan, Say Physicists
#9"If the universe lasts forever, then any event that can happen, will happen, no matter how unlikely." That's just plain mathematically wrong. There are many kinds of infinity ( http://en.wikipedia.org/wiki/Aleph_number ), and the set of all possible events has a much, much higher cardinality than an infinite axis of time. This is similar to saying that, since the set of integers is infinite, it must contain Pi.
the set of all possible events has a much, much higher cardinality than an infinite axis of time.
Are you sure of that? How would you prove it?
It seems intuitively right, but intuition has a habit of being wrong, when it comes to infinities.
Re: Time Likely To End Within Earth's Lifespan, Say Physicists
#10I've skimmed the paper and it's quite readable. The problem arises because probability doesn't make sense in an infinite universe. To make sense of it the authors consider a small patch of finite size and then let that finite size go arbitrarily large. In this picture probability is well defined but our space and time will always have an edge. However this is just a model, not an expected version of reality. The same thing happens in quantum field theory where the theory doesn't make sense at arbitrarily high energy so we just impose a cut off and ignore energies above a certain scale. This doesn't mean we think physics just stops there. Instead, it's just a way to parameterise our ignorance about what comes beyond.