trentmkelly/LessWrong-43k huggingface dataset:
Logic as Probability
by Manfred — 2014-02-08T06:39:36.824Z

Followup To: Putting in the Numbers

Before talking about logical uncertainty, our final topic is the relationship between probabilistic logic and classical logic. A robot running on probabilistic logic stores probabilities of events, e.g. that the grass is wet outside, P(wet), and then if they collect new evidence they update that probability to P(wet|evidence). Classical logic robots, on the other hand, deduce the truth of statements from axioms and observations. Maybe our robot starts out not being able to deduce whether the grass is wet, but then they observe that it is raining, and so they use an axiom about rain causing wetness to deduce that "the grass is wet" is true.

Classical logic relies on complete certainty in its axioms and observations, and makes completely certain deductions. This is unrealistic when applied to rain, but we're going to apply this to (first order, for starters) math later, which a better fit for classical logic.

The general pattern of the deduction "It's raining, and when it rains the grass is wet, therefore the grass is wet" was modus ponens: if 'U implies R' is true, and U is true, then R must be true. There is also modus tollens: if 'U implies R' is true, and R is false, then U has to be false too. Third, there is the law of non-contradiction: "It's simultaneously raining and not-raining outside" is always false.

We can imagine a robot that does classical logic as if it were writing in a notebook. Axioms are entered in the notebook at the start. Then our robot starts writing down statements that can be deduced by modus ponens or modus tollens. Eventually, the notebook is filled with statements deducible from the axioms. Modus tollens and modus ponens can be thought of as consistency conditions that apply to the contents of the notebook.

Doing math is one important application of our classical-logic robot. The robot can read from its notebook "If variable A is a number, A=A+0" and "SS0 is a number," and then write down "SS0=SS0+0."

Note that this requires the robot to interpret variable A differently than symbol SS0. This is one of many upgrades we can make to the basic robot so that it can interpret math more easily. We also want to program in special responses to symbols like 'and', so that if A and B are in the notebook our robot will write 'A and B', and if 'A and B' is in the notebook it will add in A and B...
LessWrong Hamburg First Meetup Notes: Starting small
by Gunnar_Zarncke — 2014-02-08T02:20:46.279Z

Review of our LessWrong Hamburg First Meetup:

I arrived early and the location was somewhat crowded and the reserved table in the back had been replaced by a center table - but I managed to switch for a better one.

Then I put up some books and a sign and was quickly greated by the first LWer.

We started with smalltalk, finding common background quickly.

I had brought some books from the LW reading list I had in my collection and surprise: Half of them were recognized and the remaining quickly started a discussion (the Kahneman I later lent to C.F.).

Some friends trickled in and after some introduction we played Wits and Wagers and then Pandemic (without biasing because the game was new to most).

Summary: The Meetup was a success for me. We introduced some friends to LW ideas and we enjoyed a lively discussion not without controversy. I adapted to the Meetup format easily.

One idea I had was a Meetup Diary which I used to plan the Meetup and take notes in. I think it still beats digital for things like quick notes and diagrams. I had it handy to check our schedule, draw Bayes diagrams and write down a telephone number. I plan to have it around and maybe lend it to later Meetup organizers.

Outlook for the next Meetup: We planned it for Friday 21th in company offices somewhere in Hamburg, Altona (thanks to F.R. who will confirm the location later with a separate Post).

Topics will be then

Procrastination (I committed to read up and present some techniques in exchange for C.F. committing to use beeminder).

More discussion of LW topics, most likely: effective altruism

I will bring books and games again.

More Meetups will likely follow roughly every fourtnight and alternating Friday and weekends.
Preferences without Existence
by Scott Garrabrant — 2014-02-08T01:34:03.772Z

Cross-posted on By Way of Contradiction

My current beliefs say that there is a Tegmark 4 (or larger) multiverse, but there is no meaningful “reality fluid” or “probability” measure on it. We are all in this infinite multiverse, but there is no sense in which some parts of it exist more or are more likely than any other part. I have tried to illustrate these beliefs as an imaginary conversation between two people. My goal is to either share this belief, or more likely to get help from you in understanding why it is completely wrong.

A: Do you know what the game of life is?

B: Yes, of course, it is a cellular automaton. You start with a configuration of cells, and they update following a simple deterministic rule. It is a simple kind of simulated universe.

A: Did you know that when you run the game of life on an initial condition of a 2791 by 2791 square of live cells, and run it for long enough, creatures start to evolve. (Not true)

B: No. That’s amazing!

A: Yeah, these creatures have developed language and civilization. Time step 1,578,891,000,000,000 seems like it is a very important era for them, They have developed much technology, and it someone has developed the theory of a doomsday device that will kill everyone in their universe, and replace the entire thing with emptyness, but at the same time, many people are working hard on developing a way to stop him.

B:How do you know all this?

A: We have been simulating them on our computers. We have simulated up to that crucial time.

B: Wow, let me know what happens. I hope they find a way to stop him

A: Actually, the whole project is top secret now. The simulation will still be run, but nobody will ever know what happens.

B: Thats too bad. I was curious, but I still hope the creatures live long, happy, interesting lives.

A: What? Why do you hope that? It will never have any effect over you.

B: My utility function includes preferences between different universes even if I never get to know the result.

A: Oh, wait, I was wrong. It says here the whole project is canceled, and they have stopped simulating.

B: That is to bad, but I still hope they survive.

A: They won’t survive, we are not simulating them any more.

B: No, I am not talking about the simulation, I am talking about the simple set of mathematical laws that determine their world. I hope that those mathematical laws if run long enough...
White Lies
by ChrisHallquist — 2014-02-08T01:20:29.528Z

Background: As can be seen from some of the comments on this post, many people in the LessWrong community take an extreme stance on lying. A few days before I posted this, I was at a meetup where we played the game Resistance, and one guy announced before the game began that he had a policy of never lying even when playing games like that. It's such members of the LessWrong community that this post was written for. I'm not trying to encourage basically honest people with the normal view of white lies that they need to give up being basically honest.

Mr. Potter, you sometimes make a game of lying with truths, playing with words to conceal your meanings in plain sight. I, too, have been known to find that amusing. But if I so much as tell you what I hope we shall do this day, Mr. Potter, you will lie about it. You will lie straight out, without hesitation, without wordplay or hints, to anyone who asks about it, be they foe or closest friend. You will lie to Malfoy, to Granger, and to McGonagall. You will speak, always and without hesitation, in exactly the fashion you would speak if you knew nothing, with no concern for your honor. That also is how it must be.

- Rational!Quirrell, Harry Potter and the Methods of Rationality

This post isn't about HMPOR, so I won't comment on the fictional situation the quote comes from. But in many real-world situations, it's excellent advice.

If you're a gay teenager with homophobic parents, and there's a real chance they'd throw you out on the street if they found out you were gay, you should probably lie to them about it. Even in college, if you're still financially dependent on them, I think it's okay to lie. The minute you're no longer financially dependent on them, you should absolutely come out for your sake and the sake of the world. But it's OK to lie if you need to to keep your education on-track.

Oh, maybe you could get away with just shutting up and hoping the topic doesn't come up. When asked about dating, you could try to evade while being technically truthful: "There just aren't any girls at my school I really like." "What about _____? Why don't you ask her out?" "We're just friends." That might work. But when asked directly "are you gay?" and the wrong answer could seriously screw-up your life, I wouldn't bet too much on your ability to "lie with truths," as Quirrell would say.

I start with this example beca...
Meetup : London VOI meetup 16/2, plus socials 9/2 and 23/2
by philh — 2014-02-07T19:17:55.841Z

Discussion article for the meetup : London VOI meetup 16/2, plus socials 9/2 and 23/2

WHEN:
23 February 2014 02:00:00PM (+0000)

WHERE:
Shakespeare's Head, Africa House, 64-68 Kingsway, London WC2B 6BG, UK

The next not-purely-social London meetup will be on the 15th of February, on the subject of value of information calculations: what they are, when to do them, how to do them, things we've previously used them for (successfully or not), etc.

As usual, we'll be in the Shakespeare's Head from 2pm. If you have trouble finding us, you can reach me on 07792009646.

We are also continuing our regime of weekly meetings, with social meetups on the 9th and 23rd of February, at the same time and place. To avoid spamming the discussion list, I'm not posting them separately, but they will be happening. One of them is this Sunday! Come along!

Discussion article for the meetup : London VOI meetup 16/2, plus socials 9/2 and 23/2
MEETUP: February 9, Philadelphia
by NancyLebovitz — 2014-02-07T19:07:43.241Z

February 9th, Nam Phuong at 11th and Washington (a little south of the intersection) at 1PM.

The discussion prompt is Gwern's The Narrowing Circle.

"The “expanding circle” historical thesis ignores all instances in which modern ethics narrowed the set of beings to be morally regarded, and assumes its conclusion."

If you'd like to get email notifications, there's a forum with email sign-up here.
L-zombies! (L-zombies?)
by Benya — 2014-02-07T18:30:55.707Z

Reply to: Benja2010's Self-modification is the correct justification for updateless decision theory; Wei Dai's Late great filter is not bad news

"P-zombie" is short for "philosophical zombie", but here I'm going to re-interpret it as standing for "physical philosophical zombie", and contrast it to what I call an "l-zombie", for "logical philosophical zombie".

A p-zombie is an ordinary human body with an ordinary human brain that does all the usual things that human brains do, such as the things that cause us to move our mouths and say "I think, therefore I am", but that isn't conscious. (The usual consensus on LW is that p-zombies can't exist, but some philosophers disagree.) The notion of p-zombie accepts that human behavior is produced by physical, computable processes, but imagines that these physical processes don't produce conscious experience without some additional epiphenomenal factor.

An l-zombie is a human being that could have existed, but doesn't: a Turing machine which, if anybody ever ran it, would compute that human's thought processes (and its interactions with a simulated environment); that would, if anybody ever ran it, compute the human saying "I think, therefore I am"; but that never gets run, and therefore isn't conscious. (If it's conscious anyway, it's not an l-zombie by this definition.) The notion of l-zombie accepts that human behavior is produced by computable processes, but supposes that these computational processes don't produce conscious experience without being physically instantiated.

Actually, there probably aren't any l-zombies: The way the evidence is pointing, it seems like we probably live in a spatially infinite universe where every physically possible human brain is instantiated somewhere, although some are instantiated less frequently than others; and if that's not true, there are the "bubble universes" arising from cosmological inflation, the branches of many-worlds quantum mechanics, and Tegmark's "level IV" multiverse of all mathematical structures, all suggesting again that all possible human brains are in fact instantiated. But (a) I don't think that even with all that evidence, we can be overwhelmingly certain that all brains are instantiated; and, more importantly actually, (b) I think that thinking about l-zombies can yield some useful insights into how to think about worlds where all humans exist, but some of the...
Publication: the "anti-science" trope is culturally polarizing and makes people distrust scientists
by ancientcampus — 2014-02-07T17:09:59.692Z

Paper by the Cultural Cognition Project: The culturally polarizing effect of the "anti-science trope" on vaccine risk perceptions

This is a great paper (indeed, I think many at LW would find the whole site enjoyable). I'll try to summarize it here.

Background: The pro/anti vaccine debate has been hot recently. Many pro-vaccine people often say, "The science is strong, the benefits are obvious, the risks are negligible; if you're anti-vaccine then you're anti-science".

Methods: They showed experimental subjects an article basically saying the above.

Results: When reading such an article, a large number of people did not trust vaccines more, but rather, trusted the American Academy of Pediatrics less.

My thoughts: I will strive to avoid labeling anybody as being "anti-science" or "simply or willfully ignorant of current research", etc., even when speaking of hypothetical 3rd parties on my facebook wall. This holds for evolution, global warming, vaccines, etc.

///

Also included in the article: references to other research that shows that evolution and global warming debates have already polarized people into distrusting scientists, and evidence that people are not yet polarized over the vaccine issue.

If you intend to read the article yourself: I found it difficult to understand how the authors divided participants into the 4 quadrants (α, ß, etc.) I will quote my friend, who explained it for me:

I was helped by following the link to where they first introduce that model.

The people in the top left (α) worry about risks to public safety, such as global warming. The people in the bottom right (δ) worry about socially deviant behaviors, such as could be caused by the legalization of marijuana.
People in the top right (β) worry about both public safety risks and deviant behaviors, and people in the bottom left (γ) don't really worry about either.
New LW Meetup: Canberra
by FrankAdamek — 2014-02-07T17:01:52.119Z

This summary was posted to LW Main on January 31st. The following week's summary is here.

New meetups (or meetups with a hiatus of more than a year) are happening in:

Inaugural Canberra meetup: 12 February 2014 07:30PM
Meetup: First Meetup in Hamburg, Germany: 07 February 2014 07:00PM

Other irregularly scheduled Less Wrong meetups are taking place in:

Frankfurt meetup: 09 February 2014 02:00PM
Sydney Meetup: February: 26 February 2014 06:30PM

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

Austin, TX: 01 February 2020 01:30PM
[Berlin] Community Weekend in Berlin: 11 April 2014 04:00PM
Brussels: Morality - also cake: 08 February 2014 01:00PM
London - Paranoid Debating 2nd Feb, plus social 9th Feb: 02 February 2014 02:00PM
[Los Angeles] Virtual Evidence: 05 February 2014 07:00PM
[Melbourne] February Rationality Dojo: Planning Fallacy: 02 February 2014 03:00PM
Vienna: 15 February 2014 03:00PM

Locations with regularly scheduled meetups: Austin, Berkeley, Berlin, Brussels, Cambridge, MA, Cambridge UK, Columbus, London, Madison WI, Melbourne, Mountain View, New York, Philadelphia, Research Triangle NC, Salt Lake City, Seattle, Toronto, Vienna, Washington DC, Waterloo, and West Los Angeles. There's also a 24/7 online study hall for coworking LWers.

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, build community, and have fun!

In addition to the handy sidebar of upcoming meetups, a meetup overview is posted on the front page every Friday. These are an attempt to collect information on all the meetups happening in upcoming weeks. The best way to get your meetup featured is still to use the Add New Meetup feature, but you'll also have the benefit of having your meetup mentioned in a weekly overview. These overview posts are 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 notifie...
Jobs and internships available at the Centre for Effective Altruism
by tog — 2014-02-07T12:16:19.212Z

I work at the Centre for Effective Altruism, and thought some LessWrongers might be interested in applying for the jobs and internships that we're currently offering - or else know others who might be! CEA’s been discussed on LessWrong several times before, and is the umbrella organisation to which 80,000 Hours and Giving What We Can belong. We’re also starting to branch out into global prioritisation research (e.g. comparing the value of work on AI risk and on helping the global poor) and pure promotion of effective altruist ideas.

CEA is an exciting and inspiring place to work. You’re part of a focused team of intelligent, enthusiastic, driven colleagues; everyone involved is passionate about their work, making the office an inspiring place to be. We’re based in the centre of Oxford, where we share offices with the Future of Humanity Institute, and which is a global hub for the effective altruist community. For more, see this explanation of why working at CEA is an excellent opportunity.

The deadline to apply is 5pm GMT on February the 21st. To apply, or see more information about these roles, visit our careers page. If you know anyone who might be interested in these opportunities, do pass them on. Here is the full list of jobs and internships that are available:

Director of Development

We’re looking for a new staff member to lead our fundraising efforts. CEA is a young and rapidly growing charity, which has grown to a £300,000 annual budget over 18 months. In this role you’ll be fundraising for two exciting organisations that are part of the Centre for Effective Altruism - Giving What We Can and 80,000 Hours. CEA has a track record of incubating new charitable projects, and will continue to expand into new areas.

In order to meet its growth targets CEA has set the ambitious goal of raising an extra £150,000 over the next year. Currently, CEA is funded primarily by ‘high net worth’ donors, but also a number of medium-sized donors focussed on the effectiveness of their donations, and some grants. For this role we are interested in people with previous experience in fundraising. We would be willing to pay up to £40,000, dependent on experience.

Director of Community at Giving What We Can

Giving What We Can is looking for an exceptional candidate to lead its outreach to existing a...
[Link] Cause Prioritization - Paul Christiano 1:15h
by diegocaleiro — 2014-02-07T06:23:58.436Z

Paul Christiano speaks about cause priorization within Effective Altruism. Melbourne.
Cause Prioritization: Many effective altruists place a high degree of importance on working out what the most important cause to support is. This is one way that effective altruism is distinguishable from other traditional altruism or charity.
http://www.youtube.com/watch?v=uAloUCRVa5I
Expression of Interest: Brisbane LessWrong Meetup
by TRManderson — 2014-02-06T13:13:09.505Z

The new Canberra meetup has spurred me on to think about creating a Brisbane, Australia meetup for LessWrong. I would have posted this in the open thread, but this is significantly more likely to be seen by any potential attendees.

This post is obviously to see who, if anyone, would be wanting to attend a LessWrong meetup if one was to be started in Brisbane. I'm also curious to see how many LessWrongers also attend things like Brisbane Skeptics in the Pub (at the Plough Inn) or are members of UQ Skeptics etc (and if those people would be interested in a dedicated LW meetup nonetheless).

Comment away, Brisbane-ites!

EDIT: People of now, I'm not making any assumptions about upvotes so please comment if you're interested. Those of you who are upvoting anyway, thanks.

EDIT 2: People of the distant future, feel free to comment however old this post is when you stumble upon it.
True numbers and fake numbers
by cousin_it — 2014-02-06T12:29:08.136Z

In physical science the first essential step in the direction of learning any subject is to find principles of numerical reckoning and practicable methods for measuring some quality connected with it. I often say that when you can measure what you are speaking about, and express it in numbers, you know something about it; but when you cannot measure it, when you cannot express it in numbers, your knowledge is of a meagre and unsatisfactory kind; it may be the beginning of knowledge, but you have scarcely in your thoughts advanced to the state of Science, whatever the matter may be.

-- Lord Kelvin

If you believe that science is about describing things mathematically, you can fall into a strange sort of trap where you come up with some numerical quantity, discover interesting facts about it, use it to analyze real-world situations - but never actually get around to measuring it. I call such things "theoretical quantities" or "fake numbers", as opposed to "measurable quantities" or "true numbers".

An example of a "true number" is mass. We can measure the mass of a person or a car, and we use these values in engineering all the time. An example of a "fake number" is utility. I've never seen a concrete utility value used anywhere, though I always hear about nice mathematical laws that it must obey.

The difference is not just about units of measurement. In economics you can see fake numbers happily coexisting with true numbers using the same units. Price is a true number measured in dollars, and you see concrete values and graphs everywhere. "Consumer surplus" is also measured in dollars, but good luck calculating the consumer surplus of a single cheeseburger, never mind drawing a graph of aggregate consumer surplus for the US! If you ask five economists to calculate it, you'll get five different indirect estimates, and it's not obvious that there's a true number to be measured in the first place.

Another example of a fake number is "complexity" or "maintainability" in software engineering. Sure, people have proposed different methods of measuring it. But if they were measuring a true number, I'd expect them to agree to the 3rd decimal place, which they don't :-) The existence of multiple measuring methods that give the same result is one of the differences between a true number and a fake one. Another sign is what happens when two of these methods disagree: do...