trentmkelly/LessWrong-43k huggingface dataset:
Are the bacteria/parasites in your gut affecting your thinking?
by witzvo — 2012-06-09T10:37:02.223Z

There is a variety of science going on, mostly in mice, about how intestinal microbiota (bacteria/parasites/fungi?) can affect behavior, emotion, and mental development (Review paper: The micro-biome gut-brain axis, 2011. Review paper 2009). Does any of it have relevance to those of us who'd like to be better rationalists? I'm just beginning to look into this and I'm not a biologist, so I could use help. I'll reference some interesting papers here and give interesting excerpts.

To start off with something easy to read, here is an excerpt from a press release for this 2011 paper about effects on mice:

Working with healthy adult mice, the researchers showed that disrupting the normal bacterial content of the gut with antibiotics produced changes in behaviour; the mice became less cautious or anxious. This change was accompanied by an increase in brain derived neurotrophic factor (BDNF), which has been linked, to depression and anxiety.

When oral antibiotics were discontinued, bacteria in the gut returned to normal.

"This was accompanied by restoration of normal behaviour and brain chemistry," Collins said.

To confirm that bacteria can influence behaviour, the researchers colonized germ-free mice with bacteria taken from mice with a different behavioural pattern. They found that when germ-free mice with a genetic background associated with passive behaviour were colonized with bacteria from mice with higher exploratory behaviour, they became more active and daring. Similarly, normally active mice became more passive after receiving bacteria from mice whose genetic background is associated with passive behaviour.

While previous research has focused on the role bacteria play in brain development early in life, Collins said this latest research indicates that while many factors determine behaviour, the nature and stability of bacteria in the gut appear to influence behaviour and any disruption, from antibiotics or infection, might produce changes in behaviour.

The writing in the abstract is a lot more abstruse, but perhaps substantially more accurate too. I'd be happy to know if anyone can translate it more accurately than this press release. (E.g. they didn't just transfer bacteria)

Naturally, the experimenters are doing things to the mice they'd never get away with on people, and so less is known about the relevance to humans. For example, norma...
[SEQ RERUN] Heading Toward Morality
by MinibearRex — 2012-06-09T05:41:45.225Z

Today's post, Heading Toward Morality was originally published on 20 June 2008. A summary (taken from the LW wiki):

A description of the last several months of sequence posts, that identifies the topic that Eliezer actually wants to explain: morality.

Discuss the post here (rather than in the comments to the original post).
This post is part of the Rerunning the Sequences series, where we'll be going through Eliezer Yudkowsky's old posts in order so that people who are interested can (re-)read and discuss them. The previous post was LA-602 vs RHIC Review, and you can use the sequence_reruns tag or rss feed to follow the rest of the series.
Sequence reruns are a community-driven effort. You can participate by re-reading the sequence post, discussing it here, posting the next day's sequence reruns post, or summarizing forthcoming articles on the wiki. Go here for more details, or to have meta discussions about the Rerunning the Sequences series.
Combining causality with algorithmic information theory
by  — 2012-06-09T01:31:59.979Z

Warning: maths.

Causal inference using the algorithmic Markov condition (Janzing and Schölkopf, 2008) replaces conditional independences between random variables, which define the structure of causal graphs, with algorithmic conditional independences between bit strings.

Conditional probabilities between variables become conditional complexities between strings, i.e. K(x|y) is the length of the shortest program that can generate the string x from y. Similarly, algorithmic mutual information I(x:y) is the amount of information that can be omitted in defining a string y given a shortest compressor for string x, I(x:y) = K(y) - K(y|x*). K(x,y) is the complexity of the concatenation of two strings x and y. These lead naturally to a definition of algorithmic conditional independence as I(x:y|z) = K(x|z) + K(y|z) - K(x,y|z) = 0 , where equality is defined up to the standard additive constant.

Then a lot of sexy, confusing proofs happen. When the dust settles, it looks like if you take some strings describing observations, interpret them as nodes in a graph, and "factor" so that a certain algorithmic Markov condition holds (every node string should be algorithmically independent of its non-descendant node strings given the optimal compressor of its parents' node strings), then every node can be computed by an O(1) program run on a Turing machine, with the node's parents and a noise term as input (with each node's noise string being jointly independent of the others).

Notably, this means that if we make two observations which were "generated from their parents by the same complex rule", then we can "postulate another causal link between the nodes that explains the similarity of mechanisms". They say "complex rule" because the mutual algorithmic information between simple information strings, like some digits of pi, will be swallowed up by additive constants. Which all seems very close to rediscovering TDT.

There's more to the paper, but that's the tasty bit, so the summary ends here.
Ask an experimental physicist
by RolfAndreassen — 2012-06-08T23:43:03.288Z

In response to falenas108's "Ask an X" thread. I have a PhD in experimental particle physics; I'm currently working as a postdoc at the University of Cincinnati. Ask me anything, as the saying goes.

This is an experiment. There's nothing I like better than talking about what I do; but I usually find that even quite well-informed people don't know enough to ask questions sufficiently specific that I can answer any better than the next guy. What goes through most people's heads when they hear "particle physics" is, judging by experience, string theory. Well, I dunno nuffin' about string theory - at least not any more than the average layman who has read Brian Greene's book. (Admittedly, neither do string theorists.) I'm equally ignorant about quantum gravity, dark energy, quantum computing, and the Higgs boson - in other words, the big theory stuff that shows up in popular-science articles. For that sort of thing you want a theorist, and not just any theorist at that, but one who works specifically on that problem. On the other hand I'm reasonably well informed about production, decay, and mixing of the charm quark and charmed mesons, but who has heard of that? (Well, now you have.) I know a little about CP violation, a bit about detectors, something about reconstructing and simulating events, a fair amount about how we extract signal from background, and quite a lot about fitting distributions in multiple dimensions.
Teaching Bayesianism
by JQuinton — 2012-06-08T20:18:35.085Z

I've had a bit of success with getting people to understand Bayesianism at parties and such, and I'm posting this thought experiment that I came up with to see if it can be improved or if an entirely different thought experiment would be grasped more intuitively in that context:

Say there is a jar that is filled with dice. There are two types of dice in the jar: One is an 8-sided die with the numbers 1 - 8 and the other is a trick die that has a 3 on all faces. The jar has an even distribution between the 8-sided die and the trick die. If a friend of yours grabbed a die from the jar at random and rolled it and told you that the number that landed was a 3, is it more likely that the person grabbed the 8-sided die or the trick die?

I originally came up with this idea to explain falsifiability which is why I didn't go with say the example in the better article on Bayesianism (i.e. any other number besides a 3 rolled refutes the possibility that the trick die was picked) and having a hypothesis that explains too much contradictory data, so eventually I increase the sides that the die has (like a hypothetical 50-sided die), the different types of die in the jar (100-sided, 6-sided, trick die), and different distributions of die in the jar (90% of the die are 200-sided but a 3 is rolled, etc.). Again, I've been discussing this at parties where alcohol is flowing and cognition is impaired yet people understand it, so I figure if it works there then it can be understood intuitively by many people.
Meetup : Pittsburgh - Past Wrongs
by KatjaGrace — 2012-06-08T19:22:58.835Z

Discussion article for the meetup : Pittsburgh - Past Wrongs

WHEN:
14 June 2012 06:00:00PM (-0400)

WHERE:
Eatunique, S. Craig street, Pittsburgh

What have you been most wrong about in the past? When have you changed your mind? Why were you wrong? How did you become right?

Bring a tale of giant belief updating (or else thoughts on why this has never happened to you!)

Eatunique serves salads, wraps, sandwiches, drinks, and that kind of thing. Call 412-304-6258 if you can't find us.

Our mailing list is at https://groups.google.com/group/lw-pgh?pli=1

NOTE THAT THIS IS ON THURSDAY, AN UNUSUAL DAY

Discussion article for the meetup : Pittsburgh - Past Wrongs
Weekly LW Meetups: Berlin, Buenos Aires, Cambridge MA, Pittsburgh
by FrankAdamek — 2012-06-08T14:17:10.725Z

There are upcoming irregularly scheduled Less Wrong meetups in:

Pittsburgh: Making Beliefs Pay Rent: 01 June 2012 06:00PM
Third Buenos Aires Meetup: 2 June 2012 4:00PM: 02 June 2012 04:00PM
First Berlin meetup: 05 June 2012 07:30PM
Phoenix, Arizona: 15 June 2012 07:00PM

The following meetups take place in cities with regularly scheduled meetups, but involve a change in time or location, special meeting content, or simply a helpful reminder about the meetup:

Less Wrong Cambridge (MA) first-Sundays meetup: 03 June 2012 02:00PM
Less Wrong Cambridge (MA) third-Sundays meetup: 17 June 2012 02:00PM

Locations with regularly scheduled meetups: Austin, Berkeley, Cambridge, MA, Cambridge UK, Chicago, Madison WI, Melbourne, Mountain View, New York, Ohio, Oxford, Portland, Salt Lake City, Seattle, Toronto, Waterloo, and West Los Angeles.

If you'd like to talk with other LW-ers face to face, and there is no meetup in your area, consider starting your own meetup; it's easy (more resources here). Check one out, stretch your rationality skills, and have fun!

In addition to the handy sidebar of upcoming meetups, a meetup overview will continue to be posted on the front page every Friday. These will be an attempt to collect information on all the meetups happening in the next weeks. The best way to get your meetup featured is still to use the Add New Meetup feature, but you'll now also have the benefit of having your meetup mentioned in a weekly overview. These overview posts will be moved to the discussion section when the new post goes up.

Please note that for your meetup to appear in the weekly meetups feature, you need to post your meetup before the Friday before your meetup!

If you check Less Wrong irregularly, consider subscribing to one or more city-specific mailing list in order to be notified when an irregular meetup is happening: Atlanta, Berlin, Helsinki, London, Marin CA, Ottawa, Pittsburgh, Southern California (Los Angeles/Orange County area), St. Louis, Vancouver, Washington, DC.

If your meetup has a mailing list that you'd like mentioned here, or has become regular and isn't listed as such, let me know!

Want to help out the common good? If one of the meetups listed as regular has become inactive, let me know so we can present more accurate information to newcomers.
Thoughts and problems with Eliezer's measure of optimization power
by Stuart_Armstrong — 2012-06-08T09:44:21.126Z

Back in the day, Eliezer proposed a method for measuring the optimization power (OP) of a system S. The idea is to get a measure of small a target the system can hit:

You can quantify this, at least in theory, supposing you have (A) the agent or optimization process's preference ordering, and (B) a measure of the space of outcomes - which, for discrete outcomes in a finite space of possibilities, could just consist of counting them - then you can quantify how small a target is being hit, within how large a greater region.

Then we count the total number of states with equal or greater rank in the preference ordering to the outcome achieved, or integrate over the measure of states with equal or greater rank. Dividing this by the total size of the space gives you the relative smallness of the target - did you hit an outcome that was one in a million? One in a trillion?

Actually, most optimization processes produce "surprises" that are exponentially more improbable than this - you'd need to try far more than a trillion random reorderings of the letters in a book, to produce a play of quality equalling or exceeding Shakespeare. So we take the log base two of the reciprocal of the improbability, and that gives us optimization power in bits.

For example, assume there were eight equally likely possible states {X0, X1, ... , X7}, and S gives them utilities {0, 1, ... , 7}. Then if S can make X6 happen, there are two states better or equal to its achievement (X6 and X7), hence it has hit a target filling 1/4 of the total space. Hence its OP is log2 4 = 2. If the best S could manage is X4, then it has only hit half the total space, and has an OP of only log2 2 = 1. Conversely, if S reached the perfect X7, 1/8 of the total space, then it would have an OP of log2 8 = 3.

The system, the whole system, and everything else in the universe

Notice that OP is defined in terms of the state that S achieved (for the moment this will be a pure world, but later we'll allow probabilistically mixed worlds to be S's "achievement"). So it give us a measure of how powerful S is in practice in our model, not some platonic measure of how good S is in general situations. So an idiot king has more OP than a brilliant peasant; a naive search algorithm distributed across the internet has more OP than a much better program running on Colossus. This does not seem...
[SEQ RERUN] LA-602 vs RHIC Review
by MinibearRex — 2012-06-08T04:33:33.855Z

Today's post, LA-602 vs. RHIC Review was originally published on 19 June 2008. A summary (taken from the LW wiki):

A comparison of LA-602, the classified report investigating the possibility of a nuclear bomb igniting the atmosphere and killing everyone, and RHIC, the document explaining why the LHC is not going to destroy the world. There is a key difference between these documents: one of them is a genuine discussion of the risks, taking them seriously, and the other is a work of public relations. Work on existential risk needs to be more like the former.

Discuss the post here (rather than in the comments to the original post).
This post is part of the Rerunning the Sequences series, where we'll be going through Eliezer Yudkowsky's old posts in order so that people who are interested can (re-)read and discuss them. The previous post was Ghosts in the Machine, and you can use the sequence_reruns tag or rss feed to follow the rest of the series.
Sequence reruns are a community-driven effort. You can participate by re-reading the sequence post, discussing it here, posting the next day's sequence reruns post, or summarizing forthcoming articles on the wiki. Go here for more details, or to have meta discussions about the Rerunning the Sequences series.
Debate between 80,000 hours and a socialist
by jefftk — 2012-06-07T13:30:01.258Z

The current issue of the Oxford Left Review has a debate between socialist Pete Mills and two 80,000 hours people, Ben Todd and Sebastian Farquhar: The Ethical Careers Debate, p4-9. I'm interested in it because I want to understand why people object to the ideas of 80,000 hours. A paraphrasing:

Todd and Farquhar
Choose your career to most improve the world. Focus on the consequences of your decisions.
Mills
80,000 hours says you must work a high paying but world-destroying career so you can give more money away. Then "your interests are aligned with the interests of capital" and you can't use political means to improve the world because that endangers your career.
Todd and Farquhar
Professional philanthropy is one option, but so are research and advocacy. Even if you go the high paying career route, you could be a doctor. Even if you take a people-harming but well paying job you're just replacing someone else who would do it instead. Engels was a professional philanthropist, funding Marx's reasearch.
Mills
"80k makes much of replaceability: 'the job will exist whatever you do.' This is stronger than the claim that someone else will become a banker; rather, it states that there will always be bankers, that there will always be exploitation." Engles took on too much by trying to be both a professional philanthropist and an activist which drove him to depression and illness.
Todd and Farquhar
Campaigning might be better than professional philanthropy, though you should consider whether you do better to get a well-paying job and fund multiple people to campaign. Replaceability means that a given job will exist whether you take it or not, but "there might be some things you could do that would cause the job to cease to exist; for instance, by campaigning against banking". "Even if you believe capitalism is one of the world's greatest problems, you shouldn't make the seductive inference that you should devote your energies to fighting it. Rather, you should work on the cause that enables you to make the biggest difference. There may be other very big problems which are more tractable."
Mills
"The language of probability will always fail to capture the possibility of system change. What was the expected value of the civil rights movement, or the campaign for universal suffrage, or anticolonial struggles for independence? As we have seen most recently with the Arab

...
Peter Thiel's AGI discussion in his startups class @ Stanford [link]
by Dr_Manhattan — 2012-06-07T12:27:48.075Z

http://blakemasters.tumblr.com/post/24464587112/peter-thiels-cs183-startup-class-17-deep-thought

Some perspectives on AI risk that might be interesting. Peter is (the primary?) donor for SI, and an investor in AGI startup Vicarious Systems.
[Link] Nerds are nuts
by  — 2012-06-07T07:48:26.973Z

Related to: Reason as memetic immune disorder, Commentary on compartmentalization

On the old old gnxp site site Razib Khan wrote an interesting piece on a failure mode of nerds. This is I think something very important to keep in mind because for better or worse LessWrong is nerdspace. It deals with how the systematizing tendencies coupled with a lack of common sense can lead to troublesome failure modes and identifies some religious fundamentalism as symptomatic of such minds. At the end of both the original article as well as in the text I quote here is a quick list summary of the contents, if you aren't sure about the VOI consider reading that point by point summary first to help you judge it. The introduction provides interesting information very useful in context but isn't absolutely necessary.

Link to original article.

Introduction

Reading In Spite of the Gods: The Strange Rise of Modern India, I stumbled upon this passage on page 151:

"...Whereas the Congress Party was dominated by lawyers and journalists, the RSS was dominated by people from a scientific background. Both groups were almost exclusively Brahmin in their formative years...three out of four of Hedegwar's [the founder, who was a doctor -Razib] successors were also from scientific backgrounds: M.S. Golwalker...was a zoologist...Rajendra Singh was a physicist; and K.S. Sudarshan...is an engineer...."

Some quick "background." The RSS is a prominent member of the Hindutva movement, roughly, Hindu nationalism. Some people have termed them "Hindu fundamentalists," suggesting an equivalence with reactionary religious movements the world over. There is a problem with such a broad brush term: some proponents and adherents of Hindutva are not themselves particularly religious and make no effort to pretend that they are. Rather, they are individuals who are attracted to the movement for racial-nationalist reasons, they view "Hindus" as a people as much, or more than, a religion. One could make an argument that the "Christian Right" or "Islamism" are not at the root concerned or driven by religious motives, but, members of both these movements would assert at least a pretense toward religiosity almost universally.
With that preamble out of the way, I was not surprised that the RSS had a core cadre of scientifically oriented leaders. This is a common tendency amongst faux reactionary movements wit

...
[SEQ RERUN] Ghosts in the Machine
by MinibearRex — 2012-06-07T04:51:33.768Z

Today's post, Ghosts in the Machine was originally published on 17 June 2008. A summary (taken from the LW wiki):

There is a way of thinking about programming a computer that conforms well to human intuitions: telling the computer what to do. The problem is that the computer isn't going to understand you, unless you program the computer to understand. If you are programming an AI, you are not giving instructions to a ghost in the machine; you are creating the ghost.

Discuss the post here (rather than in the comments to the original post).
This post is part of the Rerunning the Sequences series, where we'll be going through Eliezer Yudkowsky's old posts in order so that people who are interested can (re-)read and discuss them. The previous post was Grasping Slippery Things, and you can use the sequence_reruns tag or rss feed to follow the rest of the series.
Sequence reruns are a community-driven effort. You can participate by re-reading the sequence post, discussing it here, posting the next day's sequence reruns post, or summarizing forthcoming articles on the wiki. Go here for more details, or to have meta discussions about the Rerunning the Sequences series.
Is there math for interplanetary travel vs existential risk?
by DataPacRat — 2012-06-07T02:55:23.584Z

Can anyone recommend some resources, or provide actual examples, of any relevant evolutionary-biology-style equations which could describe what factors would most likely predominate to allow for the survival of sapience, given such factors as the ease which any given individual can acquire the means of killing large numbers of people, the scale of those means, the willingness o people to use those means, the ability of small groups to travel away from other groups, and so on?

Or, put another way - is there any way I can quantitatively check my intuition that a valuable way to avoid certain existential risks is to flee Earth?
Free Kindle Textbook: The Cerebellum: Brain for an Implicit Self (FT Press Science)
by buybuydandavis — 2012-06-07T02:43:19.652Z

**** DEAL OVER: As of 20120611.

Another free kindle I thought some might have interest in. I haven't read it, but the first review was glowing and looked relevant.

First Amazon Review:

> Five Star Final; Excellent; A "must read" for any "student" of brain-behavior relationships

http://www.amazon.com/gp/product/B005DKQQG4/

UPDATE: Still free at the US amazon at 2pm eastern time. Reports that it is not free at the UK site, which I verified. Since I can log in to the UK site from the US and see the price, I assume people in the UK could sign into the US site and buy it. If anyone gives that a try, let me know and I'll further update the top level.

UPDATE: Free at amazon.fr. Can buy at the US site from the Netherlands. Can't buy from FR or US sites from UK.
Mailing List for Digitized Belief Network Discussion
by avichapman — 2012-06-06T23:27:38.654Z

Hi all,

This is a follow-up to a previous post of mine - 'A digitized belief network?'.

I have now created a discussion group for anyone who wants to discuss the problems involved in creating a digital representation of a human's beliefs. Anyone who is interested in joining us can sign up here.

See you all around the list,
Avi