Yes, I looked at that paper, and also Agreeing To Disagree: A Survey by Giacomo Bonanno and Klaus Nehring.

I agree about the issue of unresolved arguments. Was agreement reached and that''s why the debate stopped? No way to tell.

Particularly the epic AI-foom debate between Robin and Eliezer on OB, over whether AI or brain simulations were more likely to dominate the next century, was never clearly resolved with updated probability estimates from the two participants. In fact probability estimates were rare in general. Perhaps a step forward would be for disputants to publicize their probability estimates and update them as the conversation proceeds.

BTW sorry to see that linkrot continues to be a problem in the future.

Voted down for being off-topic. Feel free to delve into a deep discussion about the merits of doing this and what should be considered off-topic. Meanwhile, I'll say what I have to say anyway. Feel free to delve into a deep discussion about the merits of doing this as well.

The thing is, quantum mechanics looks like the Copenhagen interpretation. That's why Copenhagen hasn't been falsified. We've barely managed to produce any evidence against it. (I'm not considering its low-ish prior probability to be evidence, of course.) Therefore, if you want to explain an observed phenomenon, it's perfectly valid to explain it in terms of wavefunction collapse.

Note to self: ponder, and write something about, when it makes sense to explain something in terms of a mechanism you don't know exists.

Saying that a quantum algorithm is "simultaneously sampling all possibilities and choosing the best one" has always been, I've found, a strange way of putting it, since it suggests that quantum computing can do a lot more than it actually can. (Quantum superintelligence: simultaneously sample every possible process of reasoning and choose the most interesting one. Unfortunately, you can't actually do that.)

A quantum algorithm such as Grover's algorithm simply works by changing the probability amplitudes (i.e. the heights of the wavefunctions, the things that can interfere constructively and destructively, the things that determine the probability of each outcome) in such a way that the probability of the desired answer is much higher than the probability of any other answer. ("Probability" here is just a specific function of probability amplitude, which happens to be consistent with both quantum evolution and the laws of probability.) When you perform the observation, then, the majority of Bornstuff goes to the world where the answer observed is the desired one.

How does Grover's algorithm work, specifically? Well, there's a plane where one line is the algorithm's starting point, and another line is the correct answer; it uses reflections to rotate the point for a certain amount of time, until it's very close to the correct answer. I dunno. For details, see Wikipedia.

Here are the four papers relating to influence from the future and the LHC:

http://arxiv.org/find/physics/1/au:+Ninomiya_M/0/1/0/all/0/1

The basic idea is that these physicists have a theory that the Higgs particle would be highly unusual, such that its presence in a branch of the multiverse would greatly decrease the measure of that branch. Now I don't claim to understand their math, but it seems that this might produce a different result than the usual anthropic-type arguments regarding earth-destroying experiments.

The authors refer to an "influence from the future", and my reading is that the effect is that in a world where the future was very likely to produce a lot of Higgs particles, that would reduce the probability of that world existing (or being experienced, in the anthropic sense). Such an effect would not occur for an experiment which merely destroyed the world; such an experiment would not reduce the measure of the past. In a sense, Higgs particles destroy the past. (Keep in mind that this is a non-standard theory!)

Therefore I don't think their theory would predict our world, where it seems superficially quite likely that we will produce Higgs in the future. If the only thing that prevents it is unlikely events like the recent bird with baguette that Eliezer is riffing on, let along materializing tutued hamsters, then we are already on a branch of the multiverse whose future is full of Higgs. That should mean that our very branch is anthropically disfavored, and we should not be here.

Rather, we would expect to live in a world which never even seriously considers building an LHC. Either we would all be of a type which never developed technological civilization, or we would all be smart enough to deduce the danger of the Higgs before blundering forward and trying to build an LHC, etc.

The fact that we don't live in such a world would be an argument against the reverse-time effect, and in favor of the more conventional LHC world-destroying scenarios like black holes, strange matter, etc.

Wei, I understand the paper probably less well than you do, but I wanted to comment that p~, which you call r, is not what Robin calls a pre-prior. He uses the term pre-prior for what he calls q. p~ is simply a prior over an expanded state space created by taking into consideration all possible prior assignments. Now equation 2, the rationality condition, says that q must equal p~ (at least for some calculations), so maybe it all comes out to the same thing.

Equation 1 defines p~ in terms of the conventional prior p. Suppressing the index i since we have only one agent in this example, it says that p~(E|p) = p(E). The only relevant event E is A=heads, and p represents the prior assignment. So we have the two definitions for p~.

p~(A=heads | p=O) = O(A=heads)

p~(A=heads | p=P) = P(A=heads)

The first equals 0.6 and the second equals 0.4.

Then the rationality condition, equation 2, says

q(E | p) = p~(E | p)

and from this, your equations follow, with r substituted for q:

q (A=heads | p=O) = p~(A=heads | p=O) = O(A=heads)

q (A=heads | p=P) = p~(A=heads | p=P) = P(A=heads)

As you conclude, there is no way to satisfy these equations with the assumptions you have made on q, namely that the A event and the p-assigning events are independent, since the values of q in the two equations will be equal, but the RHS's are 0.6 and 0.4 respectively.

I think you're right that the descriptive (as opposed to prescriptive) result in this case demonstrates that the programmer was irrational. Indeed it doesn't make sense to program his AI that way, not if he wants it to "track truth".

Ugh. Deepest sympathies.

Your situation, and your reaction to it, highlight a great advantage of working within a knowledge profession - of identifying as what the LW community calls "rationalists". When learning about something like that, you can make plans to be not just a passive sufferer of the disease, but a researcher of it from the inside, actively helping in the fight against it.

You can plan to learn all you can about the causes and progression of the disease, and be prepared for your losses as they happen. You can plan to investigate related areas - you mentioned voice synthesis and Brain-Computer Interfaces also come to mind as a field that's been moving along lately; still quite slow from what I've seen, but improving. If you can use BCI to play a video game, it's not such a big stretch to think of it providing control of, say, a virtual avatar - the name "Second Life" takes an altogether different meaning there. Being a software developer would, at any rate, definitely be handy in that situation.

I didn't know about voice banking; that's a fascinating idea, with all sorts of interesting implications (would one want to record non-verbal things like laughter; is there some way to program voice synthesis for singing, etc.). Can you maybe post a link to whoever provides the free service you mentioned ? Especially if they can use financial support.

Best wishes.

I want to thank everyone for their good wishes and, um, hugs :)

As it stands, my condition is quite good. In fact at the time of my diagnosis two months ago, I was skeptical that it was correct. The ALS expert seemed rather smug that he had diagnosed me so early, saying that I was the least affected of any of his patients. Not only were my symptoms mild, I had had little or no progression in the three months at that time since I had first noticed anything wrong.

However, since then there has been noticeable progression. My initial symptoms were in my speech, a slight slowing and breathlessness; shortly after, my hands felt odd and a bit shaky while writing. This was stable as I said for a few months. But in the last two months my voice has gotten much weaker and softer, and somewhat more slurred; and my hands, especially my right hand, have lost strength. My right hand is now weaker than the left, and both are weaker than my wife's hands. At this point I'd say that I'm about 90% functional.

It is annoying and worrisome that my initial symptoms are showing up in my voice and hands, the two most used and highest bandwidth sources of output available. Everyone's progression is different with this disease, so I don't know what to expect in terms of rate of progress or degree of disability at various points in the future. My whole plan revolves around retaining some degree of outgoing communication, but I had hoped to be able to wait until near the end of the progression to be forced to rely on the more exotic technologies. I seem to recall hearing about a guy with ALS who moused, and maybe even typed, with his feet, so I want to check into that.

That is a good idea about brain computer interfacing. I've only started looking into it a little. There are clinical trials going on with highly disabled ALS patients where they are testing it out. I have looked at some of the gaming headsets, but it seems that they largely pick up muscle movements in the scalp and face. Still it might be a good place to start.

Thanks again for the comments and advice.

To what extent, if any, did your choice of signing up years ago modify the impact of the bad news ?

From a certain point of view, your diagnosis enhances the value of having purchased the cryonics option. You can be reasonably certain that when the end comes it will be predictable and you will be in an environment that makes suspension and transport easier.

Also I imagine that financing suspension with a life insurance policy becomes a different proposition, financially, after you've been diagnosed with ALS.

I've been putting it off, myself, for a bunch of reasons including the usual of looking like a very long shot and the social stigma, but mostly because at the moment it's such a US thing and there is so very little guidance to be had if you live elsewhere (I'm in France). Your example is making me rethink that. I suppose I should just fire off an email to Alcor and CI and see what they can tell me.

Are you signed up for cryonics?

Readers of Less Wrong may be interested in this New Scientist article by Noel Sharkey, titled Why AI is a dangerous dream, in which he attacks Kurzweil's and Moravec's "fairy tale" predictions and questions whether intelligence is computational ("[the mind] could be a physical system that cannot be recreated by a computer").

[edit] I thought this would go without saying, but I suspect the downvotes speak otherwise, so: I strongly disagree with the content of this article. I still consider it interesting because it is useful to be aware of differing and potentially popular perspectives on these subjects (and Sharkey is something of a "populist" scientist). I think the opinions it espouses are staggeringly ill-conceived, however.