All of PeterDonis's Comments + Replies


Recommendation: Spacetime and Geometry

Author: Sean Carroll

This is an expanded version of Carroll's lecture notes on relativity, which he has used to teach courses and which are available for free online (see the "Lecture Notes" tab on the page linked to above). I find it to be an excellent introduction to the subject, which covers the mathematical tools used, the basics of the theory, and the most common applications, all in a straightforward fashion. I have recommended this text (or its corresponding lecture notes) many times on Physic... (read more)

Your R is actually the Ricci tensor, not the Riemann tensor. The Riemann tensor has four indices, not two. The Ricci tensor is formed by contracting the Riemann tensor on its first and third indices.

Whether that means 'out of the normal range' for any particular hormone, I don't know. Nobody seems to have the faintest idea what 'normal range' means for these things.

Yes, a better way to put it would be that the bloodstream levels of T3/T4 should be significantly higher when the person is treated and feels better than they were before treatment.

it should probably cause TSH suppression

That would be expected, yes.

What would be ideal would be to figure out the cause of the 'hormone resistance', and fix it, rather than trying to overwhelm it.

Yes,... (read more)

Agreed. All I'm really saying is "For God's sake, people, there's enough evidence here to have a look, surely?" We do have Broda Barnes' word that taking desiccated thyroid long-term isn't that bad for people. He really does seem to have put people on thyroid at the slightest excuse, and he reckoned that his patient records showed them being healthier than the general population, especially for things like heart disease. Which is kind of weird given that his patients were the sort of people who went to see a doctor and got put on lifetime medication. Maybe only the really healthy could survive his methods and everyone else scurried back to more conventional doctors who would sensibly tell them it was all their fault for fancying their parents? Increasingly I think that psychiatry has the same advantage as homeopathy, in that it can't possibly have any effect so they're not going to hurt people. I don't know how seriously to take Barnes. Originally I thought he must have been a bit of a lunatic, until I ended up coming up with the idea above, which pretty much makes his observations as predictions. Then I read his book, and it said exactly what I thought it would say. I disagree with his 'origin story', that the strange widespread hypothyroidism of modern times is because people aren't dying of infections any more. (He thought that hypothyroid children were prone to infections and so they'd have all died of tuberculosis before they became adults. I think that a 'genetic proneness to infection' would have bred out very quickly.) But again, if he was handing out thyroid meds to people who already had enough of the stuff naturally, that should have hurt them, not made them less prone to illness. He might have been a fraud, but it seems a weird thing to do..... Even if he was just disregarding his patients' complaints because he had given them thyroid and so they were damned well better, whatever they thought, he should have noticed them dying of heart attacks. Bu

Ok, so the "hormone resistance" hypothesis is really something more like: the rate of some key reaction involving T3/T4 is being slowed down by some unknown factor; since we don't know what the factor is, we can't fix it directly, but we can increase the reaction rate by increasing the concentration of T3/T4 in the bloodstream to above normal levels, to compensate for the damping effect of the unknown factor.

This hypothesis makes an obvious testable prediction: that when people with CFS/etc. who are treated with thyroid extract feel better, the T... (read more)

Absolutely, hormone levels would have to be higher than they were, in order to make any difference. Whether that means 'out of the normal range' for any particular hormone, I don't know. Nobody seems to have the faintest idea what 'normal range' means for these things. But if there are serious cases of resistance, the level of the thing resisted should have to be way high in order to make any difference. And it should probably cause TSH suppression. In my own case, I had TSH 2.51 when I first started complaining of symptoms, it was 4.06 when they came back, and with a tiny bit of thyroid which was nevertheless enough to get rid of all manifestations of CFS and cause some hyper symptoms it was 2.31, so looks like it pushed TSH down, but still not even as far as some people say is optimal. And all of that could be noise in the test. Circadian cycle means TSH results can vary by a factor of two depending on when the blood is drawn. Go figure! What would be ideal would be to figure out the cause of the 'hormone resistance', and fix it, rather than trying to overwhelm it. It might even be a bad idea to fix it, if it's performing some vital immune defence function.

I have a couple of questions about your hypothesis.

First, as I understand it, you are hypothesizing that there are people who have symptoms of CFS/etc. but normal blood levels of T3, T4, and TSH, who can nevertheless be helped by taking thyroid extract. And your hypothesized explanation for why these people are having symptoms of CFS/etc. is that, even though there are normal levels of T3 and T4 in their bloodstream, those hormones are not getting into their cells where they are actually needed. But if that is the case, how will putting more T3 and T4 into... (read more)

Hi Peter, I don't want to claim credit for this, it's mostly the work of John Lowe/Broda Barnes (and now Gordon Skinner). I've just put their ideas into what I think is a fairly compelling order, and connected them to some ideas of Greg Cochran and Sarah Myhill. I'm seeing myself more as a speaker for the dead. I was definitely starting off thinking about 'something wrong with those tests, a few cases missed, maybe', and I absolutely agree that if we take the anecdotal evidence that T3/T4/NDT help in CFS at face value, then this is definitely evidence for that. Two different hypotheses can make a similar prediction. I've ended up thinking about the 'hormone resistance' idea, because it seems like the sort of thing that might well be true, (once you've realised that it works that way in diabetes), and it's the simplest explanation for what's going on. Sometimes you'll see people with symptoms and a TSH of 2, sometimes you'll see people with a TSH of 30 (in whom something is obviously going wrong), but no symptoms at all yet. As for 'hormone resistance' as an idea, you're right that if the action of the hormones was completely blocked, adding extra stuff to the bloodstream wouldn't make any difference. And also, those people should be very ill indeed with really obvious hypothyroidism. (Severe cases are easy to recognise). But there's no reason why resistance should be an on/off thing. There are all sorts of chemical reactions taking place between hormones in the blood and their effect on the mitochondria. All it would need is for something to mysteriously slow one of the reactions down. John Lowe was forced into inventing the idea of 'peripheral resistance to thyroid hormone' by noticing that a lot (about 25%) of his patients didn't get better (or in fact notice) his attempts to fix them with T4/T3. They should have been made quite ill by this if hormone deficiency wasn't the problem. So he tried higher and higher doses of T3, and found that that worked. He neve

In this case, the Knighian uncertainty cancels out

Does it? You still know that you will only be able to take one of the two bets; you just don't know which one. The Knightian uncertainty only cancels out if you know you can take both bets.

Apologies for coming to the discussion very, very late, but I just ran across this.

If I saw no need for more power, e.g. because I'm already maximally happy and there's a system to ensure sustainability, I'd happily give up everything.

How could you possibly get into this epistemic state? That is, how could you possibly be so sure of the sustainability of your maximally happy state, without any intervention from you, that you would be willing to give up all your optimization power?

(This isn't the only reason why I personally would not choose wireheading, but other reasons have already been well discussed in this thread and I haven't seen anyone else zero in on this particular point.)

when it was realized in dath ilan that business cycles were a thing, the economists probably said "This is a coordination problem", the shadarak backed them, and the serious people got together and coordinated to try to avoid business cycles.

I think this is a feature of dath ilan, not a bug.

Among the serious questions, there are also some questions like this, where you are almost certain that the "nice" answer is a lie.

On the Crowne-Marlowe scale, it looks to me (having found a copy online and taken it) like most of the questions are of this form. When I answered all of the questions honestly, I scored 6, which according to the test, indicates that I am "more willing than most people to respond to tests truthfully"; but what it indicates to me is that, for all but 6 out of 33 questions, the "nice" answer was ... (read more)

Is that because you think it's necessary to Wei_Dai's argument, or just because you would like people to be up front about what they think?

(although of course I don't trust your rationality either)

I'm not sure this qualifier is necessary. Your argument is sufficient to establish your point (which I agree with) even if you do trust the other's rationality.

Personally, I am entirely in favor of the "I don't trust your rationality either" qualifier.

Sorry for the late comment but I'm just running across this thread.

demand for loans decreased and this caused destruction of money via the logic of fractional reserve banking

This is an interesting comment which I haven't seen talked about much on econblogs (or other sources of information about economics, for that matter). I understand the logic: fractional reserve banking is basically using loans as a money multiplier, so fewer loans means less multiplication, hence effectively less money supply. But it makes me wonder: what happens when the loan dema... (read more)

Sorry for the late comment but I'm just running across this thread.

Prices don't go up if all the new money just ends up under Apple Computer's proverbial mattress instead of in the hands of someone who is going to spend it.

But as far as I know the mainstream economists like the Fed did not predict that this would happen; they thought quantitative easing would start banks (and others with large cash balances) lending again. If banks had started lending again, by your analysis (which I agree with), we would have seen significant inflation because of the ... (read more)

Are there any theories about the mechanism involved here? I've done a fair bit of Googling about this but haven't found any discussion of underlying mechanisms, only the statistics. I know that CoQ10 is critical in the metabolic cycle that produces ATP, and therefore is involved in energy production everywhere in the body; but I'm not sure how to get from that to the specific result of lowering blood pressure (rather than something more general like "feel more energetic").

The fact that blood pressure is an independent predictor of mortality would imply it affects, and is most likely affected by, a lot of metabolic processes.

Sorry for the late comment, but I'm just running across this thread.

The question is not whether Google reinvests their producer surplus better than other monopolies. The question is whether Google reinvests their producer surplus more efficiently, i.e., for greater total benefit to society as a whole, than would all the consumers who would otherwise get that surplus as consumer surplus. That seems highly unlikely since the options for reinvestment open to even a large company like Google will cover a much smaller range of possibilities than the options ope... (read more)

Even if we had teleporters, would future Tyler Cowens be writing that they're not as innovative as the car - and would they be correct, in that a teleporter is just a more efficient way of solving a problem that cars and airplanes had already partially solved?

I don't think so, because there are threshold effects. For example, consider the airplane vs. the car: having airplane travel available doesn't just mean your trips are shorter; it enables many trips that otherwise would not even be considered, and therefore enables many kinds of activities that ot... (read more)

In this particular case, I agree with you that the weatherman is far more likely to be right than the person's intuitions.

However, suppose the weatherman had said that since it's going to be sunny tomorrow, it would be a good day to go out and murder people, and gives a logical argument to support that position? Should the woman still go with what the weatherman says, if she can't find a flaw in his argument?

Well, I wouldn't expect a weatherman to be an expert on murder, but he is an expert on weather, and due to the interdisciplinary nature of murder-weather-forecasting, I would not expect there to be many people in a better position to predict which days are good for murder. If the woman is an expert on murder, or if she has conflicting reports from murder experts (e.g. "Only murder on dark and stormy nights") she might have reason to doubt the weatherman's claim about sunny days.

The intelligent people are still humans, and can default to their intuition just like we can if they think that using unfiltered intuition would be the most accurate.

But by hypothesis, we are talking about a scenario where the intelligent person is proposing something that violently clashes with an intuition that is supposed to be common to everyone. So we're not talking about whether the intelligent person has an advantage in all situations, on average; we're talking about whether the intelligent person has an advantage, on average, in that particular ... (read more)

why should we stand by our intuitions disregard the opinions of more intelligent people?

Because no matter how intelligent the people are, the amount of computation that went into their opinions will be orders of magnitude smaller than the amount of computation that went into our intuitions, as a result of evolutionary processes operating over centuries, millennia, and longer. So if there is a conflict, it's far more probable that the intelligent people have made some mistake that we haven't yet spotted.

I am reminded of a saying in programming (not sure ... (read more)

Yes, but OTOH the “evolutionary processes operating over centuries, millennia, and longer” took place in environments different from where we live nowadays.
This doesn't make sense to me. The intelligent people are still humans, and can default to their intuition just like we can if they think that using unfiltered intuition would be the most accurate. And, by virtue of being more intelligent, they presumably have better/faster System 2 (deliberate) thinking, so if the particular problem being worked on does end up favoring careful thinking, they would be more accurate. Hence, the intelligent person would be at least as good as you. Moreover, if the claim "the amount of computation that went into their opinions will be orders of magnitude smaller than the amount of computation that went into our intuitions" actually implied that intuitions were orders of magnitude better, people would never use anything but their intuitions, because their intuitions would always be more accurate. This obviously is not how things work in practice. Not a good analogy, since the intelligent person would be able to write a program that is at least as good as yours, even if they aren't able to debug yours. It doesn't matter if the intelligent person can't debug your program if they can write a buggy program that works better than your buggy program.