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entirelyuseless comments on Doomsday Argument Map - Less Wrong

6 Post author: turchin 14 September 2015 03:04PM

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Comment author: entirelyuseless 14 September 2015 04:21:13PM *  2 points [-]

While you didn't make any assumption like this in the post, it's a bit weird to talk about "Doomsday Argument" and "Solutions", as if we know in principle that the argument is wrong and we just have to find out why.

In other words, whether it is right or wrong, there isn't any special reason for the argument to be wrong just because people would like it to be wrong. Trying to get rid of the argument by looking for "solutions" is kind of like going out of your way to look for proofs for the existence of God, just because you want that to be true.

Comment author: turchin 14 September 2015 05:52:01PM *  2 points [-]

Solution are not only about research if DA is wrong, but about how we should live if it is true.

Personally I think that it is true and the doom is almost inevitable.

We should make some research to prove or disprove DA. The main line of such research would be to try similar to DA logic in other domains, starting from most mundane, like human age, and up to most complex and civilizational level ones.

For example, it is possible to measure size of the Earth using only Copernican mediocracy principle. All we need to know is distance from my birth place to equator, and assumption that human birth places are distributed on randomly distances from equator. I was born 6000 km from equator, and it may be used to conclusion that Earth's radius is around 7000 km which is almost true (real radius is near 6300) Exact calculations here should be more complex, as it must take in account spherical distribution of the observers and will result in bigger (edited) radius.

Comment author: Lumifer 14 September 2015 06:25:17PM 0 points [-]

and assumption that human birth places are distributed on randomly distances from equator.

Which is a pretty silly assumption that happens to be not true in real life.

Comment author: turchin 14 September 2015 07:03:33PM 3 points [-]

It's clear that this assumption may be refined in two ways: accounting for spherical geometry and accounting for agriculture conditions, both of which will result in higher density near equator and thus larger Earth radius in this calculation. But if we are interesting to estimate Earth's radius just up to order of magnitude, it will still work.

The main idea was to present another DA-style calculation and check if DA-logic works. It works.

Comment author: Lumifer 14 September 2015 07:34:50PM *  0 points [-]

Before accounting for agricultural conditions you probably should account for the distribution of land masses... But anyway, how is this a "DA-style calculation"?

Comment author: turchin 14 September 2015 07:42:35PM 3 points [-]

DA-style here means that my position is some set is used to estimate total size of the set, assuming that I random observer from this set. DA-style is also means that we ignore other available information about me, Earth etc, but use only my position in the set to get very rough estimate of total size of the set. The study of such DA-style predictions in known domains could help us estimate validity of DA in unknown domains.

Comment author: Lumifer 14 September 2015 09:14:49PM 0 points [-]

my position is some set is used to estimate total size of the set, assuming that I random observer from this set

Isn't this approach better known as "generalising from one example"?

Comment author: turchin 14 September 2015 09:17:52PM 2 points [-]

No, it is evidence, but very vague.

Comment author: Avo 14 September 2015 09:04:27PM -2 points [-]

I think it is an excellent idea to try DA logic in other domains.

Example: A a biologist prepares a petri dish with some nutrients, and implants a small colony of bacteria. The question is: will this colony grow exponentially under these conditions? According to DA logic (with a reference class of all bacteria that will ever live in that petri dish), the biologist does not need to bother doing the experiment, since it is very unlikely that the colony will grow exponentially, because then the current bacteria would be atypical.

To the best of my knowledge, this sort of DA logic is never used by scientists to analyze experiments of this sort (or to decide which experiments to perform). I believe this casts severe doubt on the validity of DA.

Comment author: turchin 14 September 2015 09:11:44PM 3 points [-]

Your example is not DA-style, because observer is not self-sampled here. Observer is not bacteria in this experiment. (By the way, most from all existing bacteria is not starters of exponential colonies)

I may suggest another experiment: you tell me your age and I will tell your life expectancy based on DA-logic.