trentmkelly/LessWrong-43k huggingface dataset:
Asymptotic Logical Uncertainty: A Modification to the Demski Prior
by Scott Garrabrant — 2015-08-23T20:47:14.000Z

Part of the Asymptotic Logical Uncertainty series. Abram Demski proposed a computably approximable coherent probability assignment in 2012. In this post, I will present a modification developed last year by Benja Fallenstein, Abram Demski, and myself, which samples Turing machines rather than logical sentences. I will further give a concrete computable approximation of it which is a logical predictor.

Fix a UTM U, which has a read only input tape with an infinite string of 0s and 1s, and a one way write only output tape which outputs a possibly infinite string of 0s and 1s and #s. We build a coherent probability distribution as follows.

Start with an empty set T of logical sentences. (Or a set containing some logical axioms you wish to start with.) One at a time sample a random infinite string w of 0s and 1s and use it as input for U. Interpret the output U(w) as a finite or infinite string of logical sentences separated by # symbols. If T is consistent with all the sentences in U(w) simultaneously, then modify T by adding in all the sentences in U(w). Resample and repeat infinitely many times.

The probability assigned to each logical sentence is the probability that it is eventually added to T in the above process. Let P(ϕ) denote the probability assigned to ϕ.

The step where we kept or threw out U(w) based on whether or not it was consistent with T required a halting oracle. However, we can approximate the above process. The following procedure M takes in an time t and outputs a list of sentences. It has the property the limit as t goes to infinity of the probability that M(t) outputs ϕ converges to P(ϕ).

On input t, sample 2t binary words w1,…,w2t. Run U for 2t time steps on each word to get 2t finite lists of sentences, ℓ1,…,ℓt.
Let K be a proof checker which takes a list of sentences and searches for contradiction in those sentences. Let T start as an empty set of sentences. For i=1,…,2t run K for 2↑↑t time steps on T∪ℓi. If it does not find a contradiction, modify T by adding in all the sentences in ℓi.

We make three assumptions about K. First, we assume that for any fixed list of sentences, K eventually finds a contradiction if and only if a contradiction exists. Second, we assume that for sufficiently large t, K observes any propositional contradictions in the time we give it. By propositional contradictions, I mean that K should observe a contradiction if

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Magic and the halting problem
by kingmaker — 2015-08-23T19:34:20.143Z

It is clear that the Harry Potter book series is fairly popular on this site, e.g. the fanfiction. This fanfiction approaches the existence of magic objectively and rationally. I would suggest, however, that most if not all of the people on this site would agree that magic, as presented in Harry Potter, is merely fantasy. Our understanding of the laws of physics and our rationality forbids anything so absurd as magic; it is universally regarded by most rational people as superstition.

This position can be strengthened by grabbing a stick, pointing it at some object and chanting "wingardium leviosa" and waiting for it to rise magically. When (or if) this fails to work, a proponent of magic may resort to special pleading, and claim that as we didn't believe it would work it could not work, or that we need a special wand or that we are a squib or muggle. The proponent can perpetually move the goalposts since their idea of magic is unfalsifiable. But as it is unfalsifiable, it is rejected, in the same way that most of us on this site do not believe in any god(s). If magic were to found to explain certain phenomena scientifically, however, then I and I hope everyone else would come to believe in it, or at least shut up and calculate.

I personally subscribe to the Many Worlds Interpretation of quantum mechanics, so I effectively "believe" in the multiverse. That means it is possible that somewhere in the universal wavefunction, there is an Everett Branch in which magic is real. Or at least every time someone chants an incantation, by total coincidence, the desired effect occurs. But how would the denizens of this universe be able to know that magic is not real, and that everything they had seen was by sheer coincidence? Alan Turing pondered a related problem known as the halting problem, which asks if a general algorithm can distinguish between an algorithm that will finish or one that will run forever. He proved that one could not for all algorithms, although some algorithms will obviously finish executing or infinitely loop e.g. this code segment will loop forever:

while (true) {

//do nothing

}

So how would a person distinguish between pseudo-magic that will inevitably fail, and real magic that is the true laws of physics? The only way to be certain that magic doesn't exist in this Everett Branch would be for incantations to fai...
Meetup : LW Canberra presents: Even More Zendo!
by Calien — 2015-08-23T14:12:33.944Z

Discussion article for the meetup : LW Canberra presents: Even More Zendo!

WHEN:
28 August 2015 06:00:00PM (+1000)

WHERE:
22 Albert St, Queanbeyan, NSW

I really enjoyed Zendo last time I played it so we're doing it again. The rules will be explained at the event, but in summary, one person is the 'Master', who has a secret rule in mind, and their 'Students' must guess the Master's rule in order to win. Further explanation is at the Wikipedia page.

If you're coming from Canberra proper, there is questionable bus service by Deanes over the state border, but you can't really catch one back at that time of night. I can't guarantee I'll be able to give anyone a lift but you're very welcome to ask.

Note that there are two friendly cats who shed.

As usual, vegan snacks will be provided.

Discussion article for the meetup : LW Canberra presents: Even More Zendo!
Rationality Compendium: Principle 1 - A rational agent, given its capabilities and the situation it is in, is one that thinks and acts optimally
by ScottL — 2015-08-23T08:01:08.021Z

A perfect rationalist is an ideal thinker. Rationality ↓, however, is not the same as perfection. Perfection guarantees optimal outcomes. Rationality only guarantees that the agent will, to the utmost of their abilities, reason optimally. Optimal reasoning cannot, unfortunately, guarantee optimal outcomes. This is because most agents are not omniscient or omnipotent. They are instead fundamentally and inexorably limited. To be fair to such agents, the definition of rationality that we use should take this into account. Therefore, a rational agent will be defined as: an agent that, given its capabilities and the situation it is in, thinks and acts optimally. Although it is noted that rationality does not guarantee the best outcome, a rational agent will most of the time achieve better outcomes than those of an irrational agent.

Rationality is often considered to be split into three parts: normative, descriptive and prescriptive rationality.

Normative rationality describes the laws of thought and action. That is, how a perfectly rational agent with unlimited computing power, omniscience etc. would reason and act. Normative rationality basically describes what is meant by the phrase "optimal reasoning". Of course, for limited agents true optimal reasoning is impossible and they must instead settle for bounded optimal reasoning, which is the closest approximation to optimal reasoning that is possible given the information available to the agent and the computational abilities of the agent. The laws of thought and action (what we currently believe optimal reasoning involves) are::

Logic ↓ - math and logic are deductive systems, where the conclusion of a successful argument follows necessarily from its premises, given the axioms of the system you’re using: number theory, geometry, predicate logic, etc.

Probability theory ↓ - is essentially an extension of logic. Probability is a measure of how likely a proposition is to be true, given everything else that you already believe. Perhaps, the most useful rule to be derived from the axioms of probability theory is Bayes’ Theorem ↓, which tells you exactly how your probability for a statement should change as you encounter new information. Probability is viewed from one of two perspectives: the Bayesian perspective which sees probability a

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Rationality Compendium
by ScottL — 2015-08-23T08:00:11.177Z

I want to create a rationality compendium (a collection of concise but detailed information about a particular subject) and I want to know whether you think this would be a good idea. The rationality compendium would essentially be a series of posts that will eventually serve as a guide for less wrong newbies that they can use to discover which resources to look into further, a refresher of the main concepts for less wrong veterans and a guideline or best practices document that will explain techniques that can be used to apply the core less wrong/rationality concepts. These techniques should preferably have been verified to be useful in some way. Perhaps, there will be some training specific posts in which we can track if people are actually finding the techniques to be useful.

I only want to write this because I am lazy. In this context, I mean lazy as it is described by Larry Wall:

Laziness: The quality that makes you go to great effort to reduce overall energy expenditure.

I think that a rationality compendium would not only prove that I have correctly understood the available rationality material, but it would also ensure that I am actually making use of this knowledge. That is, applying the rationality materials that I have learnt in ways that allow me to improve my life.

If you think that a rationality compendium is not needed or would not be overly helpful, then please let me know. I also want to point out that I do not think that I am necessarily the best person to do this and that I am only doing it because I don’t see it being done by others.

For the rationality compendium, I plan to write a series of posts which should, as much as possible, be:

Using standard terms: less wrong specific terms might be linked to in the related materials section, but common or standard terminology will be used wherever possible.

Concise: the posts should just contain quick overviews of the established rationality concepts. They shouldn’t be introducing “new” ideas. The one exception to this is if a new idea allows multiple rationality concepts to be combined and explained together. If existing ideas require refinement, then this should happen in a seperate post which the rationality compendium may provide a link to if the post is deemed to be high quality.

Comprehensive: links

...
Self-confidence and status
by  — 2015-08-23T07:36:49.113Z

I've seen the advice "be (more) confident" given so that the person may become more socially successful. For example self-confident get more raises. But I'm not sure if self-confidence is the cause of becoming more socially successful, or the result of it. I don't think self-confidence can be separated from social status. I see it more as an intersocial function that gives information to participants on who to follow or listen to, and you can't act fully confident in isolation with others and their feelings. Artificially raised confidence sounds really hard, and if possible it sounds more closer to arrogance or delusion and real confidence must have some connection to reality and knowledge of what kind of value you provide. I mean, delusion might work if those around you are delusional too, but that seems pretty risky and surer way is to just be connected to reality all the time. If what you're saying is not true or interesting, then it's hard to be confident when you're saying it and others will usually quickly notify in one way or another if what you're saying is not true or interesting. If the truth is that you can't really provide much value, then I can't see how you would be able to feel as confident as those who provide more value (note that value might sometimes be quite complex and not the first thing that comes into your mind, inept dictators might provide the kind of value that really makes sense in evolutionary context even though they seem to do nothing useful at all in reality)

So in short, self-confidence usually seems approximation of what kind of value you provide in the real world, where value is to be thought of as something that is beneficial in evolutionary context. There are some hacks to quickly raise your value, like dressing better or working out, but ultimately it comes down raising your value in the real world and confidence must follow that and not the other way around.

Thoughts? How does "fake it till you make it" strategy appears in this context?
Meetup : Rationality Reading Group (76-80)
by SeekingEternity — 2015-08-23T07:34:20.838Z

Discussion article for the meetup : Rationality Reading Group (76-80)

WHEN:
24 August 2015 06:30:00PM (-0700)

WHERE:
Paul G. Allen Center (185 Stevens Way, Seattle, WA) Room 503

Reading group for Yudkowsky's "Rationality: AI to Zombies", which is basically an organized and updated version of the Sequences from LW (see http://wiki.lesswrong.com/wiki/Sequences).

The group meets to discuss the topics in the book, how to apply and benefit from them, and related topics in areas like cognitive biases, applied rationality, and effective altruism. You can get a copy of the book here: https://intelligence.org/rationality-ai-zombies/

The reading list for this week is five topics from the "Against Rationalization" section of Book II, "How To Actually Change Your Mind". They are (actually 76-80, LW's auto-formatting is screwing it up):

Fake Justification

Is That Your True Rejection?

Entangled Truths, Contagious Lies

Of Lies and Black Swan Blowups

Dark Side Epistemology

We previously covered the "Map and territory" sequence (and previous parts of "How To Actually Change Your Mind"), but please don't feel a need to have read everything up to this point to participate in the group.

Event is also on Facebook: https://www.facebook.com/events/962791670440258/

We're meeting on the 5th floor. If you show up and the door into the room is locked, knock and look around for us elsewhere on the fifth floor if nobody answers. If the doors to the building are locked, try the other ones and see if you can tailgate in. If the doors are, in fact, locked, we'll try to have somebody to let people in.

There's usually snacks at the meetup, though feel free to bring something. We usually get dinner afterward, around 9PM or so.

Discussion article for the meetup : Rationality Reading Group (76-80)
Travel Through Time to Increase Your Effectiveness
by tanagrabeast — 2015-08-23T01:32:09.629Z

I am a time traveler.

I hold this belief not because it is true, but because it is useful. That it also happens to be true -- we are all time travelers, swept along by the looping chrono-currents of reality that only seem to flow in one direction -- is largely beside the point.

In the literature of instrumental rationality, I am struck by a pattern in which tips I find useful often involve reframing an issue from a different temporal perspective. For instance, when questioning whether it is worth continuing an ongoing commitment, we are advised to ask ourselves "Knowing what I know now, if I could go back in time, would I make the same choice?"1 Also, when embarking on a new venture, we are advised to perform a "pre-mortem", imagining ourselves in a future where it didn't pan out and identifying what went wrong.2 This type of thinking has a long tradition. Whenever we use visualization as a tool for achieving goals, or for steeling ourselves against the worst case scenarios,3 we are, in a sense, stepping outside the present.

To the degree that intelligence is the ability to model the universe and "search out paths through probability to any desired future" we should not be surprised that mental time travel comes naturally to us. And to the degree that playing to this strength has already produced so many useful tips, I think it is worth experimenting with it in search of other tools and exploits.

Below are a few techniques I've been developing over the last two years that capitalize on how easy it is to mentally travel through time. I fully admit that they simply "re-skin" existing advice and techniques. But it's possible that you, my fellow traveller, may find, as I do, that these skins easier to slip into.

Second Chances

There are those who tell you to live each day as if it might be your last. I prefer to live each day as if I'm doing it over.

These philosophies could not be more different. The first invites short-sightedness, and, if followed to its logical conclusion, results in each day being worse than the one preceding it, as you burn bridges and fail to act on any longer-term goals. The second philosophy, in contrast, invites you to optimize for mindfulness, growth, or productivity based on the circumstances of the day and its relation to all subsequent days.

I am doing today over. I trust that there is some reason I chose to go back ...
Instrumental Rationality Questions Thread
by NoSignalNoNoise — 2015-08-22T20:25:11.140Z

This thread is for asking the rationalist community for practical advice. It's inspired by the stupid questions series, but with an explicit focus on instrumental rationality.

Questions ranging from easy ("this is probably trivial for half the people on this site") to hard ("maybe someone here has a good answer, but probably not") are welcome. However, please stick to problems that you actually face or anticipate facing soon, not hypotheticals.

As with the stupid questions thread, don't be shy, everyone has holes in their knowledge, though the fewer and the smaller we can make them, the better, and please be respectful of other people's admitting ignorance and don't mock them for it, as they're doing a noble thing.

(See also the Boring Advice Repository)
A list of apps that are useful to me. (And other phone details)
by Elo — 2015-08-22T12:24:50.120Z

Edit: updated list http://lesswrong.com/r/discussion/lw/nh3/update_to_the_list_of_apps_that_are_useful_to_me/

I have noticed I often wish "Damn I wish someone had made an app for that" and when I search for it I can't find it. Then I outsource the search to facebook or other people; and they can usually say - yes, its called X. Which I can put down to an inability to know how to search for an app on my part; more than anything else.

With that in mind; I wanted to solve the problem of finding apps for other people.

The following is a list of apps that I find useful (and use often) for productive reasons:

The environment

This list is long. The most valuable ones are the top section that I use regularly.

Other things to mention:

Internal storage - I have a large internal memory card because I knew I would need lots of space. So I played the "out of sight out of mind game" and tried to give myself as much space as possible by buying a large internal card.

Battery - I use anker external battery blocks to save myself the trouble of worrying about batteries. If prepared I leave my house with 2 days of phone charge (of 100% use). I used to count "wins" of days I beat my phone battery (stay awake longer than it) but they are few and far between. Also I doubled my external battery power and it sits at two days not one (28000mA + 2*460ma spare phone batteries)

Phone - I have a Samsung S4 (android Running KitKat) because it has a few features I found useful that were not found in many other phones - Cheap, Removable battery, external storage card, replaceable case.

Screen cover - I am using the one that came with the phone still

I carry a spare phone case, in the beginning I used to go through one each month; now I have a harder case than before it hasn't broken.

MicroUSB cables - I went through a lot of effort to sort this out, it's still not sorted, but its "okay for now". The advice I have - buy several good cables (read online reviews about it), test them wherever possible, and realise that they die. Also carry a spare or two.

Restart - I restart my phone probably most days when it gets slow. It's got programming bugs, but this solution works for now.

The overlays

These sit on my screen all the time.

Data monitor - Gives an overview of bits per second upload or download. updat...
3AM stats quiz
by PhilGoetz — 2015-08-22T07:45:35.649Z

Because I'm tired and easily amused.

Consider two independent, normally-distributed variables X and Y, each with a mean of 0.

X has a standard deviation of 4.

Y has a standard deviation of 1.

Consider the probability distribution function (in two dimensions) for <X, Y>.

Imagine contour lines on the PDF connecting points of equal probability density. These would be a series of concentric ellipses.

Draw the contour line that is tangent to the line X = 4.

What values of Y does it pass through when X = 0?

Post your answer.

Run this R code to plot the contours:

library(mvtnorm)

bivn <- mvrnorm(100000, mu = c(0, 0), Sigma = matrix(c(4, 0, 0, 1), 2, 2))

bivn.kde <- kde2d(bivn[,1], bivn[,2], n = 100)

image(bivn.kde); contour(bivn.kde, add = T)
Meetup : Washington, D.C.: Chesterton's Fence
by RobinZ — 2015-08-22T02:13:42.324Z

Discussion article for the meetup : Washington, D.C.: Chesterton's Fence

WHEN:
23 August 2015 03:00:00PM (-0400)

WHERE:
National Portrait Gallery

Crossposted from mailing list. Meeting in courtyard, gathering from 3:00pm, hard start 3:30pm - until closing

We'll be meeting to talk about both the concept, and examples of, Chesterton's Fence. The caption of a picture on the Wikipedia article does a better job of explaining it than the original quote from G.K. Chesterton, so I'll use the caption to explain:

"Just because there doesn't seem to be a reason for this fence to be here doesn't mean there isn't one."

Side conversations welcome!

Upcoming Meetups:

Aug 30: Fun and Games (outdoors maybe)

Sep 6: What If

Discussion article for the meetup : Washington, D.C.: Chesterton's Fence