[LINK] Too Soon for Doom Gloom?
post by shminux · 2012-12-24T21:14:52.081Z · LW · GW · Legacy · 11 commentsCame across this paper posted in gr-qc (General Relativity and Quantum Cosmology) of all places. Abstract:
The observation that we are among the first 10^11 or so humans reduces the prior probability that we find ourselves in a species whose total lifetime number of individuals is much higher, according to arguments of Carter, Leslie, Nielsen, and Gott. However, if we instead start with a prior probability that a history has a total lifetime number which is very large, without assuming that we are in such a history, this more basic probability is not reduced by the observation of how early in history we exist.
While I am skeptical of anything Don Page (Hawking's student and apparently an Evangelical Christian) writes on the topic of anthropics (he publishes stuff on Boltzmann Brains, for pity's sake), Stuart Armstrong and other resident experts in the area should be able to tell if this paper has any substance. If anything, it has a good list of references on the topic.
11 comments
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comment by CarlShulman · 2012-12-24T23:55:35.277Z · LW(p) · GW(p)
This sounds like old news: an SIA prior averts the SSA-style Doomsday arguments. However, it then creates a different Doomsday Argument by way of the Great Filter. It's all explained in Katja's thesis.
Replies from: shminux, torekp↑ comment by shminux · 2012-12-25T01:22:53.817Z · LW(p) · GW(p)
I'm wondering if there are multiple schools on this topic which do not read, interact or cite each other. If so, that would be a red flag of a diseased discipline.
Replies from: CarlShulman, DanielVarga↑ comment by CarlShulman · 2012-12-25T03:25:36.224Z · LW(p) · GW(p)
It's not so much different non-interacting schools defined by points of view on some question, it's that the same problems have come up in different places in philosophy and cosmology under various guises, and get hashed out in similar fashion in different places. The same families of responses get proposed and in none of the communities is there a decisive settlement of which principles to use. Eventually thee different literatures get connected together, you can chart out the connections with this bibliography.
Compare studies of publication bias: in many disciplines you get papers finding publication bias in the discipline, a standard back-and-forth takes place in the discipline's journals, similar to ones that had taken place in other fields.
↑ comment by DanielVarga · 2012-12-26T10:12:37.257Z · LW(p) · GW(p)
First, the cited paper is from 1994, and was updated 18 years later only to commemorate the Mayan calendar doomsday. Katja's thesis does indeed cite this paper, so the red flag of a diseased discipline can be safely lowered.
Second, it is the favorite hobby of many physicists to spot some place in another field (biology, sociology etc.) where some concept from physics (percolation, self-organized criticality etc.) can be applied, and rush there without reading any of the already existing literature. This habit of physicists can be annoying even in itself for the practitioners of the given field. But then another physicists comes by, finds that the physicists did not properly cite the literature, and deems the field a diseased discipline? Ouch, that must be painful to hear. :)
↑ comment by torekp · 2012-12-25T13:13:25.661Z · LW(p) · GW(p)
Ron Pisaturo claims to avoid both the SIA and the SSA. The argument snippet in the OP seems similar to Pisaturo's argument. The snippet does not commit to the SIA,
comment by JoshuaZ · 2012-12-25T15:03:39.410Z · LW(p) · GW(p)
he publishes stuff on Boltzmann Brains, for pity's sake
I must be missing something here, because this by itself doesn't seem to be a heavy criticism. (Nor for that matter does his being an evangelical Christian seem very relevant. Never underestimate compartmentilization.)
Replies from: Manfred↑ comment by Manfred · 2012-12-25T23:35:59.647Z · LW(p) · GW(p)
Not sure. Boltzmann brains are really cool, and at some point you realize that they're really a statement about entropy. At which point there's not much more to be said. So most of what can be said about Boltzmann brains will just be silly. Given this fact, we should assume any paper on Boltzmann brains will quickly degenerate into silliness.
EDIT: FYI: there's a joke here.
Replies from: Kaj_Sotala↑ comment by Kaj_Sotala · 2012-12-26T05:40:58.965Z · LW(p) · GW(p)
Can you elaborate on this, or provide a pointer to a discussion about it?
Replies from: Manfred↑ comment by Manfred · 2012-12-26T16:25:50.237Z · LW(p) · GW(p)
Well, you see, the vast majority of things that can be written about Boltzmann brains will be wrong. Therefore if we assume that a paper on Boltzman brains is pretty much average, it will be wrong.
Replies from: Desrtopa↑ comment by Desrtopa · 2012-12-26T16:44:49.400Z · LW(p) · GW(p)
That assumes that the average paper on Boltzmann brains will be saying things about Boltzmann brains at random. The "therefore" doesn't follow unless you assume there's no filter between possible things that could be said about them and things that actually would be said.
You could argue that the filters wouldn't be strong enough, but that's an argument that has to be made rather than assumed.
Replies from: Manfred