DuncanS

Karma: 594

DuncanS Oct 13, 2012, 10:30 AM
−2 points
on: A possible solution to pascals mugging.

If anyone accepts a pascals mugging style trade off with full knowledge of the problem,

Well, it’s very well known that Pascal himself accepted it, and I’m sure there are others. So, off you go and do whatever it is you wanted to do.

To be honest, your ability to come through on this threat is a classic example of the genre—it’s very, very unlikely that you are able to do it, but obviously the consequences if you were able to would be, er, quite bad. In this case my judgement of the probabilities is that we are completely justified in ignoring the threat.

DuncanS Oct 5, 2012, 8:30 PM
2 points
on: We won’t be able to recognise the human Gödel sentence
Actually human Godel sentences are quite easy to construct.

For example, I can’t prove that I’m not an idiot.

If I’m not an idiot, then I can perhaps make an argument that I’m not an idiot that seems reasonable to me, and that may persuade that I’m not an idiot.

However, if I am an idiot, then I can still perhaps make an argument that I’m not an idiot that seems reasonable to me.

Therefore any argument that I might make on whether I’m an idiot or not does not determine which of the two above states is the case. Whether I’m an idiot or not is therefore unprovable under my system.

You can’t even help me. You might choose to inform me that I am / am not an idiot. I still have to decide whether you are a reasonable authority to decide the matter, and that question runs into the same problem—if I decide that you are, I may have decided so as an idiot, and therefore still have no definitive answer.

You cannot win, you can only say “I am what I am” and forget about it.

DuncanS Oct 4, 2012, 11:02 PM
3 points
in reply to: Paul Crowley’s comment on: The Useful Idea of Truth
Although I wouldn’t think of this particular thing as being an invention on his part—I’m not sure I’ve read that particular chain of thought before, but all the elements of the chain are things I’ve known for years.

However I think it illustrates the strength of Eliezer’s writing well. It’s a perfectly legitimate sequence of thought steps that leads in a clear and obvious way to the right answer. It’s not new thought, but a particularly clear way of expressing something that many people have thought and written about in a less organised way.

To clarify—there are times when Eliezer is inventive—for example his work on CEV—but this isn’t one of those places. I know I’m partly arguing about the meaning of “inventive”, but I don’t think we’re doing him a favor here by claiming this is an example of his inventiveness when there are much better candidates.

DuncanS Oct 2, 2012, 10:23 PM
5 points
in reply to: Benquo’s comment on: The Useful Idea of Truth
It’s easy to overcome that simply by being a bit more precise—you are saying that such and such a proposition is true in geometry X. Meaning that the axioms of geometry X genuinely do imply the proposition. That this proposition may not be true in geometry Y has nothing to do with it.

It is a different sense of true in that it isn’t necessarily related to sensory experience—only to the interrelationships of ideas.

DuncanS Oct 2, 2012, 10:08 PM
3 points
in reply to: Sniffnoy’s comment on: The Useful Idea of Truth
I agree—atoms and so forth are what our universe happens to consist of. But I can’t see why that’s relevant to the question of what truth is at all—I’d say that the definition of truth and how to determine it are not a function of the physics of the universe one happens to inhabit. Adding physics into the mix tends therefore to distract from the main thrust of the argument—making me think about two complex things instead of just one.

DuncanS Oct 2, 2012, 9:39 PM
14 points
on: When does something stop being a “self-consistent idea” and become scientific fact?
Of course the limited amount of knowledge available to the primitive tribe doesn’t rule out the existence of George, but neither does it do much to justify the theory of George. What they know is that the ground shook, but they have no reasonable explanation of why.

There are, for them, many possible explanations they could dream up to explain the shaking. Preferring any one above the others without a reason to do so is a mistake.

At their postulated level of sophistication, I don’t think they can do much better than “The Earth shook. It does that sometimes.” Adding the bit about George and so forth is just unnecessarily multiplying entities, as Ockham might say.

DuncanS Oct 2, 2012, 9:28 PM
1 point
on: The Useful Idea of Truth

People usually are not mistaken about what they themselves believe—though there are certain exceptions to this rule—yet nonetheless, the map of the map is usually accurate, i.e., people are usually right about the question of what they believe:

I’m not at all sure about this part—although I don’t think it matters much to your overall case. I think one of our senses is a very much simplified representation of our own internal thought state. It’s only just about good enough for us to make a chain of thought—taking the substance of a finished thought and using it as input to the next thought. In animals, I suspect this sense isn’t good enough to allow thought chains to be made - and so they can’t make arguments. In humans it is good enough, but probably not by very much—it seems rather likely that the ability to make thought chains evolved quite recently.

I think we probably make mistakes about what we think we think all the time—but there is usually nobody who can correct us.

DuncanS Oct 2, 2012, 9:09 PM
0 points
in reply to: mbrubeck’s comment on: The Useful Idea of Truth
They are truisms—in principle they are statements that are entirely redundant as one could in principle work out the truth of them without being told anything. However, principle and practice are rather different here—just because we could in principle reinvent mathematics from scratch doesn’t mean that in practice we could. Consequently these beliefs are presented to us as external information rather than as the inevitable truisms they actually are.

DuncanS Oct 2, 2012, 8:49 PM
0 points
in reply to: Eliezer Yudkowsky’s comment on: The Useful Idea of Truth
Maps are models of the territory. And the usefulness of them is often that they make predictions about parts of the territory I haven’t actually seen yet, and may have trouble getting to at all. The Sun will come up in the morning. There isn’t a leprachaun colony living a mile beneath my house. There aren’t any parts of the moon that are made of cheese.

I have no problem saying that these things are true, but they are in fact extrapolations of my current map into areas which I haven’t seen and may never see. These statements don’t meaningfully stand alone, they arise out of extrapolating a map that checks out in all sorts of other locations which I can check. One can then have meaningful certainty about the zones that haven’t yet been seen.

How does one extrapolate a map? In principle I’d say that you should find the most compressible form—the form that describes the territory without adding extra ‘information’ that I’ve assumed from someplace else. The compressed form then leads to predictions over and above the bald facts that go into it.

The map should match the territory in the places you can check. When I then make statements that something is “true”, I’m making assertions about what the world is like, based on my map. As far as English is concerned, I don’t need absolute certainty to say something is true, merely reasonable likelihood.

Hence the photon. The most compressible form of our description of the universe is that the parts of space that are just beyond visibility aren’t inherently different from the parts we can see. So the photon doesn’t blink out over there, because we don’t see any such blinking out over here.

DuncanS Oct 2, 2012, 7:41 PM
7 points
on: The difficulty in predicting AI, in three lines
To summarise the argument further.

“A lot of people talk rubbish about AI. Therefore most existing predictions are not very certain.”

That doesn’t in itself mean that it’s hard to predict AI—merely that there are many existing predictions which aren’t that good. Whether we could do better if we (to take the given example) used the scientific method isn’t something the argument covers.

DuncanS Sep 7, 2012, 1:50 AM
0 points
in reply to: Mitchell_Porter’s comment on: Debugging the Quantum Physics Sequence
Thanks—I’ve amended the final paragraph to change ‘view’ to ‘outcome’ throughout—hope it helps.

DuncanS Sep 6, 2012, 4:29 PM
1 point
on: Debugging the Quantum Physics Sequence
This whole post seems to be a conjecture about what quantum mechanics really means.

What we know about quantum mechanics is summed up in the equations. Interpretations of quantum mechanics aren’t arguing about the equations, or the predictions of the equations. They are arguing about what it means that these equations give these predictions.

The important thing here is to understand what exactly these interpretations of quantum mechanics are talking about. They aren’t talking about the scientific predictions, as all the interpretations are of the same equations, and necessarily predict the same behaviour. By the same token they aren’t talking about anything we might see in the universe, as all the various interpretations predict the same observations.

Now sometimes people do propose new theories about the quantum world that lead to different predictions. These aren’t interpretations of quantum mechanics, they are new theories. Interpretations are attempts to talk about the current standard theory in the most helpful way.

As far as I can tell, creators of interpretations are looking at the elephant which is quantum mechanics, and discussing whether all angles from which to observe the elephant are equally good, whether some are better than others, or whether only the view we can actually see ourselves is the only one that truly exists.

Now it is useful to try and find new ways of looking at the elephant, as maybe some views are better than others, and someday we might have data that moves us to a new theory where viewpoints that seem equally good now are shown not to be. But right now there isn’t any such information, and so we can’t really say that one view is better than another. Saying that one answer is better than another, in the absence of relevant information, doesn’t seem helpful.

That’s the basis on which we prefer many worlds (all outcomes allowed by the equations exist) to collapse (there is only the outcome I can see). It’s part of the general principle of not making up complicated explanations on matters where evidence is lacking.

DuncanS Sep 4, 2012, 6:33 AM
2 points
in reply to: taelor’s comment on: Counterfactual resiliency test for non-causal models
The industrial revolution has some very tightly coupled advances, The key advance was making iron with coal rather than using charcoal. This reduced the price, and a large increase in quantity of manufacture followed. One of the immediate triggers was that England was getting rather short of wood, and the use of coal as a substitute started for iron-making and heating.

The breakthrough in steelmaking was initially luck—some very low sulphur coal was found and used in steelmaking. But luck arises often out of greater quantities of usage, and perhaps that was the key here. It certainly wasn’t science in the modern sense as the chemistry of what was going on wasn’t really understood—certainly not by the practitioners of the time. Trial and error was therefore the key, and greater quantity of manufacture leads to more trials.

DuncanS Sep 4, 2012, 2:50 AM
6 points
on: Counterfactual resiliency test for non-causal models
The model I have of human progress is this. Intelligence is not the limiting factor. Things are invented quite soon after they become possible and worthwhile.

So, let’s take the steam engine. Although the principle of the steam turbine is known to the Greeks, actual steam engines are only commercially viable from the time of Newcomen’s atmspheric engine. Why not earlier?

Well, there is an existing technology to displace, first of all, which is a couple of unfortunate animals walking in a circle driving an axle. This is far more fuel efficient than the steam engine, so it persists until coal mining comes along and provides fuel of a kind that can’t be fed to an animal. Of course coal mining exists for a long time before the industrial revolution, but as long as fodder is cheap enough compared to coal, the animals continue to win.

There is also a materials problem with steam. Wood is a terrible material for making steam engines, yet it’s cheap enough that it is used rather a lot in early models. Iron at the time is expensive, and of such terrible quality that it is brittle and quite unsafe as a means of making pressure vessels. There was no good way of making pressure vessels at all until the industrial revolution, along with good sliding seals, and initially there is great reluctance to use even moderate pressures due to the problems. The pressure to solve that set of problems was already faced by makers of guns. Essentially it was improving metallurgy that allowed the higher pressures that permitted the higher efficiencies that made steam engines more than a curiosity. Steam engines essentially couldn’t be invented earlier because the iron was too expensive and didn’t hold pressure well enough to allow the boiler to be made. As it was, burst boilers were not uncommon. Along with this there is a general problem of making anything with reasonable precision so that parts fit together in a reasonably airtight way.

Ditto the motor car. A motor car differs only from a steam engine in that it doesn’t run on a track—which isn’t really even an inventive step. So why didn’t people take steam engines off their tracks and run them on the roads? Well, steam engines were very heavy, and the roads were very bad. The idea is simple enough, but doing it with 1820′s technology isn’t really possible. Better metallurgy and better quality machining later allows light high speed engines that finally allow the horse to be displaced.

It’s an interesting counterfactual test. Pick any invention you like, and look into why it wasn’t done twenty years earlier. Usually the answer is that it couldn’t be done economically back then. The situation is usually more like the one with colour flat screen displays. It’s been considered a good idea for decades, but only actually became possible in the 1990′s. If you look at the details of how it was done in the 1990′s, you discover techniques that weren’t possible in the 1980′s.

It’s these changes in the surrounding technology that seem to me to govern progress, and these changes happen at a rate governed by as much by economics as anything else.

DuncanS Aug 16, 2012, 8:37 PM
2 points
in reply to: Jayson_Virissimo’s comment on: The weakest arguments for and against human level AI
Also the argument applies equally well to lots of non-intellectual tasks where a cheap human could well be a replacement for an expensive machine.

DuncanS Aug 7, 2012, 11:34 PM
9 points
on: Natural Laws Are Descriptions, not Rules
I haven’t put my finger on it exactly, but I am somewhat concerned that this post is leading us to argue about the meanings of words, whilst thinking that we are doing something else.

What can we really say about the world? What we ought to be doing is almost mathematically defined now. We have observations of various kinds, Bayes’ theorem, and our prior. The prior ought really to start off as a description of our state of initial ignorance, and Bayes’ theorem describes exactly how that initial state of ignorance should be updated as we see further observations.

Being ordinary human beings, we follow this recipe badly. We find collecting far too much data easier than extracting the last drop of meaning from each bit, so we tend to do that. We also need to use our observations to predict the future, which we ought to do by extrapolating what we have in the most probable way.

Having done this, we have discovered that there’s an amazing and notable contrast between the enormous volume of data we have collected about the universe, and the comparatively tiny set of rules which appear to summarise it.

There is quite a lot of discussion about the difference between fundamental and non-fundamental laws. This is rather like arguing in arithmetic about whether addition or multiplication are more fundamental—who cares—the notable factor is that the overall system is highly compressible, and part of that compression process allows you to omit any explicit stating of many aspects of the system. The rules that are still fairly explicitly stated in the compressed version tend to be considered the ‘fundamental’ ones, and the ones that get left out, non-fundamental.

You are of course right in saying that the universe often kind of simulates other rule systems within its fundamental one.

But I am suspicious that beyond that, this article is about words, not the nature of reality.

DuncanS Aug 6, 2012, 11:33 PM
10 points
on: The Doubling Box
Your other option is to sell the box to the highest bidder. That will probably be someone who’s prepared to wait longer than you, and will therefore be able to give you a higher price than the utilons you’d have got out of the box yourself. You get the utilons today.

DuncanS Aug 5, 2012, 12:16 AM
9 points
on: What are the optimal biases to overcome?
My top 2....

Looking at unlikely happenings more sensibly. Remembering that whenever something really unlikely happens to you, it’s not a sign from the heavens. I must remember to take into account the number of other unlikely things that might have happened instead that I would also have noticed, and the number of things that happen in a typical time. In a city of a million people, meeting a particular person might seem like a one in a million chance. But if I know a thousand people in the city, and walk past a thousand people in an hour, the chance of bumping into one of my friends is pretty good.

The other one? We’re all too optimistic about our own abilities. Most of the time that’s pretty benign, but it’s a good thing to remember when considering employing yourself as a stock picker, gambling advisor, or automobile driver. We’re actually much more average than we think, most of the time.

DuncanS Aug 5, 2012, 12:02 AM
0 points
on: Advice please: Cognitive distortion preventing me from accomplishing anything
This is a relatively common psychological problem. It’s a common reaction to stress. You need to take it seriously, though, because for some people it can be a crippling, disabling thing. But there is stuff you can do.

First of all, acknowledge the truth of what your fear is saying—sudden catastrophe could happen without warning. But the flip side is that worldwide the vast majority of deaths don’t come from sudden catastrophe. You should fear eating more than you fear such catastrophe—in terms of the real risk of it. It’s fear, but not reasonable fear—as it’s not sufficiently likely to happen to make it worth worrying about it. Particularly given that you can’t do much to avoid most such disasters in the first place !

Secondly, it’s OK to be irrationally afraid of something. All of us do it sometimes. What’s not OK is to let an irrational fear take away your right to do something. Right where you are now, you’ve probably lost some territories to the fear, and you need to identify some losses, and start taking them back. Choose some target territories and go. You will get used to being in the territory again, and you will progressively lose your fear of it each time you go. Don’t tackle everything at once, but start identifying territories and taking them back one by one. And don’t accept losing any others. Expect this to take some time to work through.

That’s all that CBT generally is—keep exposing yourself to circumstances that you’re irrationally afraid of until you learn from experience that actually nothing terrible happens. Start with something fairly easy, and make it really easy by learning it’s OK. Then move onto something a bit harder that just got easier because of your first victory, and do that until it’s no problem.

Rinse and repeat until your fears are all reasonable ones. Which may never happen. But you’ll get nearly all the territory back.

Make sure you talk to someone about this even if it isn’t a therapist. But I think a therapist might be good, as might something like Prozac—although on that matter you can’t simply base your view on a blog opinion.....

Finally, mental problems are essentially normal—all of our minds are capable of getting a bit weird, and it’s the responsibility of your rational brain to learn what sometimes go awry, spot it, and nudge you back in the right direction. You really can win this one yourself.

DuncanS May 18, 2012, 9:04 PM
0 points
in reply to: Xachariah’s comment on: Be careful with thought experiments
Well you could go for something much more subtle, like using sugar of the opposite handedness on the other ‘Earth’. I don’t think it really changes the argument much whether the distinction is subtle or not.