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Comment author: Yosarian2 19 September 2017 02:00:04AM *  1 point [-]

Quantum mechanics is also very counterintuitive, creates strange paradoxes etc, but it doesn' make it false.

Sure, and if we had anything like the amount of evidence we have for antropic probability theories that we do for quantum theory I'd be glad to go along with it. But short of a lot of evidence, you should be more skeptical of theories that imply all kinds of improbable results.

As I said above, there is no need to tweak reference classes to which I belong, as there is only one natural class.

I don't see that at all. Why not classify yourself as "part of an intelligent species that has nuclear weapons or otherwise poses an existential threat to itself"? That seems like just as reasonable a classification as any (especially if we're talking about "doomsday"), but it gives a very different (worse) result. Or, I donno, "part of an intelligent species that has built an AI capable of winning at Go?" Then we only have a couple more months. ;)

It also seems weird to just assume that somehow today is a normal day in human existence, no more or less special then any day any random hunter-gatherer wandered the plains. If you have some a priori reason to think that the present is unusual, you should probably look at that instead of vague anthropic arguments; if you just found out you have cancer and your house is on fire while someone is shooting at you, it probably doesn't make sense to just ignore all that and assume that you're halfway through your lifespan. Or if you were just born 5 minutes ago, and seem to be in a completely different state then anything you've ever experienced. And we're at a very unique point here in the history of our species, right on the verge of various existential threats and at the same time right on the verge of developing spaceflight and the kind of AI technology that would likely ensure our decedents may persist for billions of years. isn't it more useful to look at that instead of just assuming that today is just another day in humanity's life like any other?

I mean, it seems likely that we're already waaaaaay out on the probability curve here in one way or another, if the Great Silence of the universe is any guide. There can't have been many intelligent species who got to where we are in the history of our galaxy, or I think the galaxy would look very different.

Comment author: turchin 19 September 2017 09:29:31AM 1 point [-]

I am a member of a class of beings, able to think about Doomsday argument, and it is the only correct referent class. And for these class, my day is very typical: I live in advance civilization interested in such things and start to discuss the problem of DA in the morning.

I can't say that I am randomly chosen from hunter-gathers, as they were not able to think about DA. However, I could observe some independent events (if they are independent of my existence) in a random moment of time of their existence and thus predict their duration. It will not help to predict the duration of existence of hunter-gathers, as it is not truly independent of my existence. But could help in other cases.

20 minutes ago I participate in shooting in my house - but it was just a night dream, and it supports simulation argument, which basically claims that most events I observe are unreal, as their simulation is cheaper. I participate during my life in hundreds shooting in dreams, games and movies, but never in real one: simulated events are much more often.

Thus DA and SA are not too bizarre, they become bizarre because of incorrect solving of the reference class problem.

The strangeness of DA appears when we try to compare it with some unrealistic expectations about our future: that there will be billion of years full of billion people living in human-like civilization. But more probable is that in several decades AI will appear, which will run many past simulations (and probably kill most humans). It is exactly what we could expect from observed technological progress, and DA and SA just confirm observed trends.

Comment author: Yosarian2 18 September 2017 08:57:32PM 2 points [-]

Let me give a concrete example.

If you take seriously the kind of anthropic probabilistic reasoning that leads to the doomsday argument, then it also invalidates the same argument, because we probably aren't living in the real universe at all, we're probably living in a simulation. Except you're probably not living in a simulation because we're probably living in a short period of time of quantum randomness that appears long after the universe ends which recreates you for a fraction of a second through random chance and then takes you apart again. There should be a vast number of those events that happen for every real universe and even a vast number of those events for every simulated universe, so you probably are in one of those quantum events right now and only think that you existed when you started reading this sentence.

And that's only a small part of the kind of weirdness these arguments create. You can even get opposite conclusions from one of these arguments just by tweaking exactly what reference class you put things in. For example, "i should be roughly the average human" gives you an entierly different doomsday answer then "i should be roughly the average life form" which gives you an entierly different answer then "I should be roughly the average life form that has some kind of thought process". And there's no clear way to pick a category; some intuitively feel more convincing then others but there's no real way to determine that.

Basically, I would take the doomsday argument (and the simulation argument, for that matter) a lot more seriously if anthropic probability arguments of that type didn't lead to a lot of other conclusions that seem much less plausible, or in some cases seem to be just incoherent. Plus, we don't have a good way to deal with what's known as "the measurement problem" if we are trying to use anthropic probability in an infinite multiverse, which throws a further wrench into the gears.

A theory which fits most of what we know but gives one or a few weird results that we can test is interesting. A theory that gives a whole mess of weird and often conflicting results, many of which would make the scientific method itself a meaningless joke if true, and almost none of which are testable, is probably flawed somewhere, even if it's not clear to us quite where.

Comment author: turchin 18 September 2017 09:28:49PM *  0 points [-]

It is not a bug, it is a feature :) Quantum mechanics is also very counterintuitive, creates strange paradoxes etc, but it doesn' make it false.

I think that DA and simulation argument are both true, as they support each other. Adding Boltzmann brains is more complicated, but I don't see a problem to be a BB, as there is a way to create a coherent world picture using only BB and path in the space of possible minds, but I would not elaborate here as I can't do it shortly. :)

As I said above, there is no need to tweak reference classes to which I belong, as there is only one natural class. However, if we take different classes, we get a prediction for different events: for example, class of humans will extinct soon, but the class of animals could exist for billion more years, and it is quite a possible outcome: humans will extinct, but animals survive. There is nothing mysterious in reference classes, just different answers for different questions.

The measure is the real problem, I think so.

The theory of DA is testable if we apply it to many smaller examples like Gott successfully did for predicting the length of the Broadway shows.

So the theory is testable, no more weird than other theories we use, and there is no contradiction between doomsday argument and simulation argument (they both mean that there are many past simulations which will be turned off soon). However, it still could be false or have one more turn, which will make things even weirder, like if we try to account for mathematically possible observers or multilevel simulations or Boltzmann AIs.

Comment author: Xianda_GAO 18 September 2017 06:37:32PM 1 point [-]

The doomsday argument is controversial not because its conclusion is bleak but because it has some pretty hard to explain implications. Like the choice of reference class is arbitrary but affects the conclusion, it also gives some unreasonable predicting power and backward causations. Anyone trying to understand it would eventually have to reject the argument or find some way to reconcile with these implications. To me neither position are biased as long as it is sufficiently argued.

Comment author: turchin 18 September 2017 07:41:34PM *  0 points [-]

I don't see the problems with the reference class, as I use the following conjecture: "Each reference class has its own end" and also the idea of "natural reference class" (similar to "the same computational process" in TDT): "I am randomly selected from all, who thinks about Doomsday argument". Natural reference class gives most sad predictions, as the number of people who know about DA is growing from 1983, and it implies the end soon, maybe in couple decades.

Predictive power is probabilistic here and not much differ from other probabilistic prediction we could have.

Backward causation is the most difficult part here, but I can't imagine now any practical example for our world.

PS: I think it is clear what do I mean by "Each reference class has its own end" but some examples may be useful. For example, I have 1000 rank in all who knows DA, but 90 billions rank from all humans. In first case, DA claims that there will be around 1000 more people who know about DA, and in the second that there will be around 90 billion more humans. These claims do not contradict each other as they are probabilistic assessments with very high margin. Both predictions mean extinction in next decades or centuries. That is, changes in reference class don't change the final conclusion of DA that extinction is soon.

Comment author: entirelyuseless 18 September 2017 02:03:52PM 0 points [-]

Exactly. My current age is almost exactly halfway through a normal human lifetime, not a millionth of the way through or 99.9% of the way through.

Comment author: turchin 18 September 2017 03:04:21PM 0 points [-]

However, if we look at Doomsday argument and Simulation argument together, they will support each other: most observers will exist in the past simulations of the something like 20-21 century tech civilizations.

It also implies some form of simulation termination soon or - and this is our chance - unification of all observers into just one observer, that is the unification of all minds into one superintelligent mind.

But the question - if most minds in the universe are superintelligences - why I am not superintelligence, still exist :(

Comment author: Xianda_GAO 17 September 2017 02:12:31AM 0 points [-]

The post specifically explained why your properties cannot be used for predictions in the context of doomsday argument and sleeping beauty problem. I would like to know your thoughts on that.

Comment author: turchin 18 September 2017 12:47:36PM 0 points [-]

I can't easily find the flaw in your logic, but I don't agree with your conclusion because the randomness of my properties could be used for predictions.

For example, I could predict medium human life expectancy based on (supposedly random) my age now. My age is several decades, and human life expectancy is 2 х (several decades) with 50 percent probability (and it is true).

I could suggest many examples, where the randomness of my properties could be used to get predictions, even to measure the size of Earth based on my random distance from the equator. And in all cases that I could check, the DA-style logic works.

Comment author: Yosarian2 17 September 2017 08:14:24PM 0 points [-]

I think the argument probably is false, because arguments of the same type can be used to "prove" a lot of other things that also clearly seem to be false. When you take that kind of anthropomorphic reasoning and take it to it's natural conclusion, you reach a lot of really bizzare places that don't seem to make sense.

In math, it's common for a proof to be disputed by demonstrating that the same form of proof can be used to show something that seems to be clearly false, even if you can't find the exact step where the proof went wrong, and I think the same is true about the doomsday argument.

Comment author: turchin 18 September 2017 12:42:59PM *  1 point [-]

I think the opposite: Doomsday argument (in one form of it) is an effective predictor in many common situations, and thus it also could be allied to the duration of human civilization. DA is not absurd: our expectations about human future are absurd.

For example, I could predict medium human life expectancy based on supposedly random my age. My age is several decades, and human life expectancy is 2 х (several decades) with 50 percent probability (and it is true).

Comment author: turchin 16 September 2017 08:03:28PM 1 point [-]

I think that most discussions about Doomsday argument are biased in the way that author tries to disprove it.

Also, it looks like that in the multiverse all possible observers exist, so the mere fact of my existence is non-informational. However, I could ask if some of my properties are random or not, and could they be used for some predictions.

For example, my birthday month seems to be random. And if I know my birthday month, but don't know how many months are in the year, I could estimate that they are approximately 2 times of my birthday month rank. It works.

The problem appears when I apply the same logic to the future of human civilization, as I don't like the result.

Comment author: Elo 15 September 2017 09:54:57AM 0 points [-]

An anecdata report of my experience of taking fish oil and having it mute the critical self-talk conversation in the mind. (short post)

Comment author: turchin 15 September 2017 07:26:12PM 0 points [-]

How much do you take of the fish oil?

Comment author: morganism 14 September 2017 07:20:52PM 2 points [-]

Was talking to these folks back before the Seasteading site and community was taken private. He has some solid ideas, but everyone likes floating cities, even with their weaknesses.



Comment author: turchin 14 September 2017 07:28:10PM 0 points [-]

Thanks, interesting!

Comment author: WalterL 13 September 2017 12:48:05PM 1 point [-]

Certainly, self replicating robots will affect our survival. I'm not sure it will go in the way we want though.

Comment author: turchin 13 September 2017 06:04:38PM 1 point [-]

It looks like that there is very thin time frame after we can build a self-sustainable base on Mars, but before the arrival of the self-replicating robots. I estimate it may be in 5-10 years.

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