Argument From Infinity
post by DragonGod · 2017-06-05T21:33:25.054Z · LW · GW · Legacy · 19 commentsContents
NOTE: This post contains LaTeX; it is recommended that you install “TeX the World” (for chromium users), “TeX All the Things” or other TeX/LaTeX extensions to view the post properly. The Argument From Infinity If you live forever then you will definitely encounter a completely terrible scenario like being trapped in a black hole or something. I have noticed a tendency, for people to conclude that an infinite set implies that the set contains some potential element $Y$. Say for example, that you live f... Counter Argument. I shall offer an algorithm that would demonstrate how to generate an infinite number of infinite subsets from an infinite set. Pick an element $i$ in $N$. Exclude $i$ from $N$. You have generated an infinite subset of $N$.There are $\aleph_0$ possible such infinite subsets.Pick any two elements fro... Alternative Formulation/Charitable Hypothesis. This states a weaker form of the infinity fallacy, and a better argument. If you leave forever, the probability is arbitrarily close to 1 that you would end up in a completely terrible scenario. Let the set of events anathema to you be denoted $F: F = {y_1, y_2, y_3, …, y_m}$. We shall now attemp... Comment I cannot comprehend how probability works in the face of infinity, so I can’t respond to the above formulation (which if valid, I’ll label the “infinity heuristic”). Another popular form of the argument from infinity: If you put a million monkeys on a million type writers and let them type forever... None 19 comments
19 comments
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comment by entirelyuseless · 2017-06-06T01:42:43.844Z · LW(p) · GW(p)
Unless the probability of the terrible scenario (taken for example as an annual probability) is constantly decreasing, it will indeed happen almost surely.
Replies from: Lumifer↑ comment by Lumifer · 2017-06-06T14:38:41.184Z · LW(p) · GW(p)
Not true. For example, if the probability of the terrible scenario at some point drops to zero, that is sufficient.
Replies from: Manfred, entirelyuseless↑ comment by entirelyuseless · 2017-06-07T02:02:49.225Z · LW(p) · GW(p)
Yes, I was assuming that we are assigning reasonable probabilities.
Replies from: Lumifer↑ comment by Lumifer · 2017-06-07T04:22:50.310Z · LW(p) · GW(p)
What is the current probability of Nikita Khruschev ordering a nuclear strike on the United States? What was this probability 55 years ago and what happened to it?
Replies from: entirelyuseless↑ comment by entirelyuseless · 2017-06-07T13:56:59.214Z · LW(p) · GW(p)
The current probability is pretty low. It was higher before and dropped pretty dramatically in 1971. It is also currently getting lower since it is becoming more difficult to resurrect him. But it is nowhere near zero yet.
On the other hand, this may satisfy the condition of constantly getting lower, so it may never actually happen.
Replies from: Lumifer↑ comment by Lumifer · 2017-06-07T14:47:03.070Z · LW(p) · GW(p)
since it is becoming more difficult to resurrect him
Tell me more about this resurrection thing and why do you think it's becoming more difficult as time passes.
Replies from: entirelyuseless↑ comment by entirelyuseless · 2017-06-08T02:49:20.761Z · LW(p) · GW(p)
More scattering of information, presumably.
Replies from: DragonGodcomment by Onemorenickname · 2017-06-07T00:04:47.465Z · LW(p) · GW(p)
"summation of {i = 0} to n of (n combination i) = 2^n"
This is not a proof that "2^{aleph_0}" is the cardinality of the set of the subsets of natural numbers. You assume it works in the infinite cardinal case (without proving it), and then say that you thus proved it. You got confused by notation.
"I shall proffer a mathematical proof to show that for any infinite set of cardinality aleph_0 (the cardinality of the set of natural numbers) there are aleph_1 (2aleph_0) distinct infinite subsets."
No. 2^{aleph_0} is /by definition/ the cardinality of the set of the subsets of the natural numbers. It's named that way to allow the intuition of "summation of {i = 0} to n of (n combination i) = 2n" to work with cardinalities.
"aleph_1 (2^{aleph_0})"
aleph_1 = 2^{aleph_0} has been shown to be independent from ZFC. ie, if we haven't worked within inconsistent math for that past 60 years, what you just said is unprovable. You might have confused aleph and beth numbers.
Replies from: DragonGodcomment by AlexMennen · 2017-06-06T02:57:41.207Z · LW(p) · GW(p)
When K is a cardinal, 2^K is defined as the cardinality of the set of subsets of K (or alternatively, the cardinality of the set of functions from K into {0,1}, but it is easy to show that these are equivalent). Your "proof" of this is completely wrong. For any finite k, (aleph_0 choose k) = aleph_0, so the summation (k=0 to infinity) of (aleph_0 choose k) is (aleph_0)^2, which is also aleph_0. That's because you only added together the subsets with finite complement, of which there are only countably many. Also, aleph_1 is not necessarily the same as 2^(aleph_0). I'm also not sure why you even brought this up.
I don't think anyone has actually committed the fallacy that you describe, and when people say things like that, they mean something more like your alternative formulation (described more precisely by entirelyuseless).
comment by turchin · 2017-06-05T22:14:22.435Z · LW(p) · GW(p)
There is another fallacy: that an infinite path includes the infinite number of elements. However, we could imagine circular path, which has the finite number of elements. Eternal return by Nietzsche is a (wrong) example of such path.
It may help reject some false ideas about immortality and create the more positive image of it, without entrapping into black holes or need to remember infinite number of things.
Replies from: entirelyuseless↑ comment by entirelyuseless · 2017-06-06T01:39:36.162Z · LW(p) · GW(p)
It may help reject some false ideas about immortality and create the more positive image of it
I don't think that most people would think circular immortality is especially positive.
Replies from: turchin↑ comment by turchin · 2017-06-06T09:53:37.927Z · LW(p) · GW(p)
If we have linear and circular immortality, we could create morу complex constructions of pathways in the space of possible minds with merges, attractors, dead ends, two-dimensional figures etc. It completely dissolves fear of bad infinity associated with the naive understanding of immortality.
Replies from: entirelyuseless↑ comment by entirelyuseless · 2017-06-06T13:08:24.298Z · LW(p) · GW(p)
I don't see a convincing argument here. In fact, I don't see any argument at all, convincing or otherwise.
Replies from: DragonGod↑ comment by DragonGod · 2017-06-13T08:58:27.474Z · LW(p) · GW(p)
Do you think the argument from infinity is in fact a valuable heuristic?
Replies from: entirelyuseless↑ comment by entirelyuseless · 2017-06-13T13:37:54.658Z · LW(p) · GW(p)
It is not a heuristic; it is a mathematical proof, given the condition I mentioned (namely that the probability does not diminish indefinitely. A circular path which does not contain the element has a probability of zero for the element, but we have no reason to expect circular paths.)