trentmkelly/LessWrong-43k huggingface dataset:
Even if you have a nail, not all hammers are the same
by PhilGoetz — 2010-03-29T18:09:47.655Z

(Related to Over-ensapsulation and Subtext is not invariant under linear transformation)

Between 2004 and 2007, Goran Bjelakovic et al. published 3 famous meta-analysis of vitamin supplements, concluding that vitamins don't help people but instead kill people. This is now the accepted dogma; and if you ask your doctor about vitamins, she's likely to tell you not to take them, based on reading either one of these articles, or one of the many summaries of these articles made in secondary sources like The Mayo Clinic Journal.

The 2007 study claims that beta-carotene and vitamins A and E are positively correlated with death - the more you take, the more likely you are to die. Therefore, vitamins kill. The conclusion on E requires a little explanation, but the data on beta-carotene and A is simple and specific:

Univariate meta-regression analyses revealed significant influences of dose of beta carotene (Relative Risk (RR), 1.004; 95% CI, 1.001-1.007; P = .012), dose of vitamin A (RR, 1.000006; 95% CI, 1.000002-1.000009; P = .003), ... on mortality.

This appears to mean that, for each mg of beta carotene that you take, your risk of death increases by a factor (RR) of 1.004; for each IU of vitamin A that you take, by a factor of 1.000006. "95% CI, 1.001-1.007" means that the standard deviation of the sample indicates a 95% probability that the true RR lies somewhere between 1.001 and 1.007. "P = .012" means that there's only a 1.2% chance that you would be so unlucky as to get a sample giving that result, if in fact the true RR were 1.

A risk factor of 1.000006 doesn't sound like much; but I'm taking 2,500 IU of vitamin A per day. That gives a 1.5% increase in my chance of death! (Per 3.3 years.) And look at those P-values: .012, .003!

So why do I still take vitamins?

What all of these articles do, in excruciating detail with regard to sample selection (though not so much with regard to the math), is to run a linear regression on a lot of data from studies of patients taking vitamins. A linear regression takes a set of data where each datapoint looks like this:

Y = a1X1 + c

and a multiple linear regression takes a set of data where each datapoint usually looks like this:
Y = a1X1 + a2X2 + ... anXn + c
where Y and all the Xi's are known. In this case, Y is a ...
NYC Rationalist Community
by Cosmos — 2010-03-29T16:59:41.839Z

For those who don't yet know, there has been a thriving rationalist community in NYC since April 2009. We've been holding weekly meetups for the past several months now, and often have game nights, focused discussions, etc. For those of you who live in the area, and not yet involved, I highly encourage you to join the following two groups:

This Meetup group is our public face, which draws new members to the meetups.

This Google Group was our original method of coordination, and we still use it for private communication.

The reason I am posting this is because there has been interest by several members in sharing an apartment/loft, or even multiple apartments on a floor of a building if there are enough people. The core interest group is going to be meeting soon to figure out the logistics, so I wanted to extend this opportunity to any aspiring rationalists who either currently or would like to live in NYC. If you are interested, please join the Google Group and let us know, so that we can include you in the planning process. Additionally, if anyone has experience living with other rationalists, or more generally in a community setting, please feel free to share your knowledge with us so we can avoid any common pitfalls.
Highlights and Shadows
by Alicorn — 2010-03-28T20:56:19.473Z

Sequence index: Living Luminously
Previously in sequence: The Spotlight
Next in sequence: City of Lights
Part of a good luminosity endeavor is to decide what parts of yourself you do and don't like.

You may find your understanding of this post significantly improved if you read the fifth story from Seven Shiny Stories.
As you uncover and understand new things about yourself, you might find that you like some of them, but don't like others. While one would hope that you'd be generally pleased with yourself, it's a rare arrogance or a rarer saintliness that would enable unlimited approval. Fortunately, as promised in post two, luminosity can let you determine what you'd like to change as well as what's already present.
But what to change?
An important step in the luminosity project is to sort your thoughts and feelings not only by type, correlation, strength, etc, but also by endorsement. You endorse those thoughts that you like, find representative of your favorite traits, prefer to see carried into action, and wish to keep intact (at least for the duration of their useful lives). By contrast, you repudiate those thoughts that you dislike, consider indicative of negative characteristics, want to keep inefficacious, and desire to modify or be rid of entirely.
Deciding which is which might not be trivial. You might need to sift through several orders of desire before finally figuring out whether you want to want cake, or like liking sleep, or prefer your preference for preferentism. A good place to start is with your macro-level goals and theoretical commitments (e.g., when this preference is efficacious, does it serve your Life Purpose™, directly or indirectly? if you have firm metaethical notions of right and wrong, is this tendency you have uncovered in yourself one that impels you to do right things?).
As a second pass, you can work with the information you collected when you correlated your ABCs. How does an evaluated desire makes you feel when satisfied or unsatisfied? Does it cripple you when unsatisfied or improve your performance when satisfied? Are you reliably in a position to satisfy it? If you can't typically satisfy it, would it be easier to change the desire or to change the circumstances that prevent its satisfaction? However, this is a second step. You need to know wha...
The I-Less Eye
by rwallace — 2010-03-28T18:13:13.358Z

or: How I Learned to Stop Worrying and Love the Anthropic Trilemma

Imagine you live in a future society where the law allows up to a hundred instances of a person to exist at any one time, but insists that your property belongs to the original you, not to the copies. (Does this sound illogical? I may ask my readers to believe in the potential existence of uploading technology, but I would not insult your intelligence by asking you to believe in the existence of a society where all the laws were logical.)

So you decide to create your full allowance of 99 copies, and a customer service representative explains how the procedure works: the first copy is made, and informed he is copy number one; then the second copy is made, and informed he is copy number two, etc. That sounds fine until you start thinking about it, whereupon the native hue of resolution is sicklied o'er with the pale cast of thought. The problem lies in your anticipated subjective experience.

After step one, you have a 50% chance of finding yourself the original; there is nothing controversial about this much. If you are the original, you have a 50% chance of finding yourself still so after step two, and so on. That means after step 99, your subjective probability of still being the original is 0.5^99, in other words as close to zero as makes no difference.

Assume you prefer existing as a dependent copy to not existing at all, but preferable still would be existing as the original (in the eyes of the law) and therefore still owning your estate. You might reasonably have hoped for a 1% chance of the subjectively best outcome. 0.5^99 sounds entirely unreasonable!

You explain your concerns to the customer service representative, who in turn explains that regulations prohibit making copies from copies (the otherwise obvious solution) due to concerns about accumulated errors (the technical glitches in the early versions of the technology that created occasional errors have long been fixed, but the regulations haven't caught up yet). However, they do have a prototype machine that can make all 99 copies simultaneously, thereby giving you your 1% chance.

It seems strange that such a minor change in the path leading to the exact same end result could make such a huge difference to what you anticipate, but the philosophical reasoning seems unassailable, and philosophy has a superb track record of predictive acc...
Mental Models
by  — 2010-03-28T15:55:40.902Z

Related: Fake explanation, Guessing the teachers password, Understanding your understanding, many more

The mental model concept gets used so frequently and seems so intuitively obvious that I debated whether to bother writing this. But beyond the basic value that comes from unpacking our intuitions, it turns out that the concept allows a pretty impressive integration and streamlining of a wide range of mental phenomena.

The basics: a mental model falls under the heading of mental representations, ways that the brain stores information. It's a specific sort of mental representation - one who's conceptual structure matches some corresponding structure in reality. In short, mental models are how we think something works.

A mental model begins life as something like an explanatory black box - a mere correlation between items, without any understanding of the mechanism at work. "Flick switch -> lamp turns on" for example. But a mere correlation doesn't give you much clue as to what's actually happening. If something stops working - if you hit the switch and the light doesn't go on - you don't have many clues as to why. This pre-model stage lacks the most important and useful portion; moving parts.

The real power of mental models comes from putting something inside this black box - moving parts that you can fiddle with to give you an idea of how something actually works. My basic lamp model will be improved quite a bit if I add the concept of a circuit to it, for instance. Once I've done that, the model becomes "Flick switch -> switch completes circuit -> electricity flows through lightbulb-> lamp turns on". Now if the light doesn't go on, I can play with my model to see what might cause that, finding that either the circuit is broken or no electricity is being provided. We learn from models the same way we learn from reality, by moving the parts around and seeing the results.

It usually doesn't take much detail, many moving parts, for something to "click" and make sense. For instance, I had a difficult time grasping the essence of imaginary numbers until I saw them modeled as a rotation, which instantly made all the bits and pieces I had gleaned about them fall into place. A great deal of understanding rests in getting a few small details right. And once the basics are right, additional knowledge often changes

...
It's not like anything to be a bat
by Scott Alexander — 2010-03-27T14:32:52.050Z

...at least not if you accept a certain line of anthropic argument.
Thomas Nagel famously challenged the philosophical world to come to terms with qualia in his essay "What is it Like to Be a Bat?". Bats, with sensory systems so completely different from those of humans, must have exotic bat qualia that we could never imagine. Even if we deduce all the physical principles behind echolocation, even if we could specify the movement of every atom in a bat's senses and nervous system that represents its knowledge of where an echolocated insect is, we still have no idea what it's like to feel a subjective echolocation quale.
Anthropic reasoning is the idea that you can reason conditioning on your own existence. For example, the Doomsday Argument says that you would be more likely to exist in the present day if the overall number of future humans was medium-sized instead of humongous, therefore since you exist in the present day, there must be only a medium-sized number of future humans, and the apocalypse must be nigh, for values of nigh equal to "within a few hundred years or so".
The Buddhists have a parable to motivate young seekers after enlightenment. They say - there are zillions upon zillions of insects, trillions upon trillions of lesser animals, and only a relative handful of human beings. For a reincarnating soul to be born as a human being, then, is a rare and precious gift, and an opportunity that should be seized with great enthusiasm, as it will be endless eons before it comes around again.
Whatever one thinks of reincarnation, the parable raises an interesting point. Considering the vast number of non-human animals compared to humans, the probability of being a human is vanishingly low. Therefore, chances are that if I could be an animal, I would be. This makes a strong anthropic argument that it is impossible for me to be an animal.
The phrase "for me to be an animal" may sound nonsensical, but "why am I me, rather than an animal?" is not obviously sillier than "why am I me, rather than a person from the far future?". If the doomsday argument is sufficient to prove that some catastrophe is preventing me from being one of a trillion spacefaring citizens of the colonized galaxy, this argument hints that something is preventing me from being one of a trillion bats or birds or insects.
And this could be that animals lack subjective experience. This would ex...
Addresses in the Multiverse
by jimrandomh — 2010-03-26T23:02:28.384Z

Abstract: If we assume that any universe can be modeled as a computer program which has been running for finitely many steps, then we can assign a multiverse-address to every event by combining its world-program with the number of steps into the world-program where it occurs. We define a probability distribution over multiverse-addresses called a Finite Occamian Multiverse (FOM). FOMs assign negligible probability mass to being a Boltzmann brain or to being in a universes that implements the Many Worlds Interpretation of quantum mechanics.

One explanation of existence is the Tegmark level 4 multiverse, the idea that all coherent mathematical structures exist, and our universe is one of them. To make this meaningful, we must add a probability distribution over mathematical structures, effectively assigning each a degree of existence. Assume that the universe we live in can be fully modeled as a computer program, and that that program, and the number of steps it's been running for, are both finite. (Note that it's not clear whether our universe is finite or infinite; our universe is either spatially infinite, or expanding outwards at a rate greater than or equal to the speed of light, but there's no observation we could make inside the universe that would distinguish these two possibilities.) Call the program that implements our universe a world-program, W. This could be implemented in any programming language - it doesn't really matter which, since we can translate between languages by prepending some stuff to translate.

Now, suppose we choose a particular event in the universe - an atom emitting a photon, say - and we want to find a corresponding operation in the world-program. We could, in principle, run W until it starts working on the part of spacetime we care about, and count the steps. Call the number of steps leading up to this event T. Taken together, the pair (W,T) uniquely identifies a place, not just in the universe, but in the space of all possible universes. Call any such pair (W,T) a multiverse-address.
Now, suppose we observe an event. What should be our prior probability distribution over multiverse-addresses for that event? That is, for a given event (W,T), what is P(W=X and T=Y)?

For this question, our best (and pretty much only possible) tool is Occam's Razor. We're after a prior probability distribution, so we aren't going to bother incl...
Newcomb's problem happened to me
by Academian — 2010-03-26T18:31:43.355Z

Okay, maybe not me, but someone I know, and that's what the title would be if he wrote it. Newcomb's problem and Kavka's toxin puzzle are more than just curiosities relevant to artificial intelligence theory. Like a lot of thought experiments, they approximately happen. They illustrate robust issues with causal decision theory that can deeply affect our everyday lives.

Yet somehow it isn't mainstream knowledge that these are more than merely abstract linguistic issues, as evidenced by this comment thread (please no Karma sniping of the comments, they are a valuable record). Scenarios involving brain scanning, decision simulation, etc., can establish their validy and future relevance, but not that they are already commonplace. For the record, I want to provide an already-happened, real-life account that captures the Newcomb essence and explicitly describes how.

So let's say my friend is named Joe. In his account, Joe is very much in love with this girl named Omega… er… Kate, and he wants to get married. Kate is somewhat traditional, and won't marry him unless he proposes, not only in the sense of explicitly asking her, but also expressing certainty that he will never try to leave her if they do marry.

Now, I don't want to make up the ending here. I want to convey the actual account, in which Joe's beliefs are roughly schematized as follows:

if he proposes sincerely, she is effectively sure to believe it.

if he proposes insincerely, she will 50% likely believe it.

if she believes his proposal, she will 80% likely say yes.

if she doesn't believe his proposal, she will surely say no, but will not be significantly upset in comparison to the significance of marriage.

if they marry, Joe will 90% likely be happy, and will 10% likely be unhappy.

He roughly values the happy and unhappy outcomes oppositely:

being happily married to Kate: 125 megautilons

being unhapily married to Kate: -125 megautilons.

So what should he do? What should this real person have actually done?1 Well, as in Newcomb, these beliefs and utilities present an interesting and quantifiable problem…

ExpectedValue(marriage) = 90%·125 - 10%·125 = 100,

ExpectedValue(sincere proposal) = 80%·100 = 80,

ExpectedValue(insincere proposal) = 50%·80%&midd

...
The Shabbos goy
by PhilGoetz — 2010-03-26T16:16:55.362Z

Exodus 22:25, Leviticus 25:36, and Deuteronomy 23:20-21 forbid Jews from charging interest on loans to "your brother" (other Jews). (This is to me the most convincing argument against Judaism and Christianity, because it's too simple to argue around. That proscription is just wrong, in exactly the way you would expect laws written by uneducated tribal people to be wrong.)

Roman Catholics believe they must follow the Old Testament laws, except for the ones they don't have to follow; but during much of the middle ages in Western Europe, this was one of the ones they had to follow. They interpreted "your brother" as meaning "brother Christians". So Jews could lend to Christians with interest (and, presumably, Christians could lend to Jews). This was convenient for everyone. The Jews were necessary to work around an irrational moral prohibition of the Christians.

Of course, the Jews had to take on the guilt of violating the moral code, even though it was for the benefit of the Christians. (This was also convenient; it meant that after some Jews had loaned you an especially large amount of money, you could kill or expel them instead of paying them back, as the Spanish monarchy did in 1492).

Later on, some orthodox Jews hired goyim to turn lightswitches and other electric devices on and off for them on the Sabbath. They're called Shabbos goy, the Sabbath goy (thanks, Alicorn!).

JCVI is considering moving from an on-site hardware grid, to cloud computing. There are lots of reasons to do this. One is so that Amazon can be our Shabbos goy.

We develop lots of bioinformatics software that we're supposed to, and would like to, give out to anyone who wants it. But if you don't have 800 computers at home, connected using the Sun Grid Engine with a VICS interface and using a Sybase database, with exactly the same versions of C++ and Perl and every C++ and Perl library that we do, you're going to have a hard time running the software.

We can't put up a web service and let anybody send their jobs to our computers, because then some professor is going to say to their freshman class of 200 students, "Today, class, your assignment is to assemble a genome using JCVI's free genome assembly web service."

If we could charge users just a little bit of money, just a fraction of the cost of running their programs, we could pro...
Compartmentalization as a passive phenomenon
by Kaj_Sotala — 2010-03-26T13:51:08.199Z

We commonly discuss compartmentalization as if it were an active process, something you do. Eliezer suspected his altruism, as well as some people's "clicking", was due to a "failure to compartmentalize". Morendil discussed compartmentalization as something to avoid. But I suspect compartmentalization might actually be the natural state, the one that requires effort to overcome.

I started thinking about this when I encountered an article claiming that the average American does not know the answer to the following question:

If a pen is dropped on a moon, will it:
A) Float away
B) Float where it is
C) Fall to the surface of the moon

Now, I have to admit that the correct answer wasn't obvious to me at first. I thought about it for a moment, and almost settled on B - after all, there isn't much gravity on the moon, and a pen is so light that it might just be unaffected. It was only then that I remembered that the astronauts had walked on the surface of the moon without trouble. Once I remembered that piece of knowledge, I was able to deduce that the pen quite probably would fall.

A link on that page brought me to another article. This one described two students randomly calling 30 people and asking them the question above. 47 percent of them got the question correct, but what was interesting was that those who got it wrong were asked a follow-up question: "You've seen films of the APOLLO astronauts walking around on the Moon, why didn't they fall off?" Of those who heard it, about 20 percent changed their answer, but about half confidently replied, "Because they were wearing heavy boots".

While these articles were totally unscientific surveys, it doesn't seem to me like this would be the result of an active process of compartmentalization. I don't think my mind first knew that pens would fall down because of gravity, but quickly hid that knowledge from my conscious awareness until I was able to overcome the block. What would be the point in that? Rather, it seems to indicate that my "compartmentalization" was simply a lack of a connection, and that such connections are much harder to draw than we might assume.

The world is a complicated place. One of the reasons we don't have AI yet is because we haven't found very many reliable cross-domain reasoning rules. Reasoning algorithms in general are quickly subject to a combinatorial explosion: the reasoning system migh...