Quantum Decisions

post by Alexei · 2014-05-12T21:49:11.133Z · LW · GW · Legacy · 20 comments

Contents

20 comments

CFAR sometimes plays a Monday / Tuesday game (invented by palladias). Copying from the URL:

On Monday, your proposition is true. On Tuesday, your proposition is false. Tell me a story about each of the days so I can see how they are different. Don't just list the differences (because you're already not doing that well). Start with "I wake up" so you start concrete and move on in that vein, naming the parts of your day that are identical as well as those that are different.

So my question is (edited on 2014/05/13):

On Monday, I make my decisions by rolling a normal die. Example: should I eat vanilla or chocolate ice-cream? I then decide that if I roll 4 or higher on a 6-sided die, I'll pick vanilla. I roll the die, get a 3, and so proceed to eat chocolate ice-cream.

On Tuesday, I use the same procedure, but use a quantum random number generator instead. (For the purpose of this discussion, let's assume that I can actually find a true/reliable generator. May be I'm shooting a photon through a half-silvered mirror.)

What's the difference? (Relevant discussion pointed out Pfft.)

20 comments

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comment by Pfft · 2014-05-13T17:11:50.829Z · LW(p) · GW(p)

I guess part of what you are asking about is the difference between using a quantum random number source, and using a deterministic pseudorandom number source (which happens to be inside your brain). Stuart Armstrong wrote Quantum versus Logical Bombs about one difference, suggesting that maybe risk-averse actors should prefer the quantum version (because then even if you make a bad decision, at least there will exist some multiple worlds in which you didn't...).

Replies from: Alexei
comment by Alexei · 2014-05-13T17:55:19.419Z · LW(p) · GW(p)

Yes! Thank you, Pfft, that's exactly what I was trying to get at. I'll go read the post right now.

comment by gjm · 2014-05-12T22:15:47.460Z · LW(p) · GW(p)

One obvious difference (which you may or may not have intended) is that on Tuesday, all your decisions need to be made consciously and with some explicit calculation. This makes the decision-making process more cumbersome, and also means you engage different bits of mental machinery from Monday, which will lead to decisions that differ in various ways.

I gravely doubt whether the Tuesday scenario is actually anything remotely like possible, but that may not matter.

All the above would be just the same if you were just rolling dice. Is the real point of the question something to do with the quantumness of the random number generator? If so, I think you need to be more explicit about what sort of difference you think there might be (or think that others think there might be).

Replies from: DanielLC, Alexei
comment by DanielLC · 2014-05-12T23:32:42.249Z · LW(p) · GW(p)

Hardware random number generators often use quantum effects for randomness. Though I agree that specifying quantum is pointless.

comment by Alexei · 2014-05-13T01:02:52.906Z · LW(p) · GW(p)

Yeah, that's not what I was getting at.

Not for every single decision, but let's say for 10 / day.

Yes, the quantumness is the point. Let's say I'm shooting photons through a half-silvered mirror or something like that.

By the way, "there is no difference" is a perfectly acceptable answer, if it's true.

Replies from: gjm
comment by gjm · 2014-05-13T20:18:41.710Z · LW(p) · GW(p)

I would be astonished if it made any difference. Not least because I bet your decisions already are well enough quantum-randomized: the universe is a quantum system, after all, and while maybe most everyday things can be adequately described as plus small errors, those small errors often grow exponentially over time.

comment by Shmi (shminux) · 2014-05-12T22:24:38.496Z · LW(p) · GW(p)

Why are you using the word "quantum" here? Do you expect any difference if you use a classical pseudo-random number generator... say, on Wednesday?

Replies from: Alexei
comment by Alexei · 2014-05-13T01:35:39.856Z · LW(p) · GW(p)

May be. That's the point of this question.

Replies from: shminux
comment by Shmi (shminux) · 2014-05-13T16:56:10.034Z · LW(p) · GW(p)

That's the point of this question.

I don't think it is the point at all, since the difference between quantum random and pseudorandom has nothing to do with making decisions. I think you are simply using a cool-sounding word "quantum" where "probabilistic" is what you really mean.

Replies from: Alexei
comment by Alexei · 2014-05-13T17:51:31.942Z · LW(p) · GW(p)

Sigh. No, I mean precisely quantum and not probabilistic. I'm wondering how it affects the "reality fluid", for example. I'll go and edit the question to make it more clear.

Replies from: shminux
comment by Shmi (shminux) · 2014-05-13T18:55:32.600Z · LW(p) · GW(p)

Ah, so you are taking the MWI ontology as if it were something testable. Gotcha. Let me just note that if your logic relies on untestables, it's not a good one. If the visible outcome changes when you replace "Everett branches" with "possible worlds", you are doing something wrong.

I'm wondering how it affects the "reality fluid", for example.

"Reality fluid" is EYspeak for "I have no clue", and he stated as much, though not in quite that way. It's not a good term, as it gives a false impression of explaining/modeling something. Don't use it.

Replies from: Pfft
comment by Pfft · 2014-05-15T01:59:44.235Z · LW(p) · GW(p)

The idea of the term is exactly to draw attention to the fact that it doesn't explain or model anything (by analogy with Phlogiston).

Replies from: shminux
comment by Shmi (shminux) · 2014-05-15T05:43:19.360Z · LW(p) · GW(p)

I don't think we disagree.

comment by Nisan · 2014-05-13T14:04:03.879Z · LW(p) · GW(p)

On Monday, I have to decide whether to eat ice cream or not. After a little thought, I decide it's all right to eat ice cream because . The reason is a lame reason that my mind came up with because it really wants ice cream.

On Tuesday I only eat ice cream with 50% probability.

Replies from: Alexei
comment by Alexei · 2014-05-13T18:26:51.055Z · LW(p) · GW(p)

Nisan, please see the revised version of the question.

On Tuesday, I'm still picking my threshold "manually". Let's say the quantum random number generator I use can give me a random 1-6 number, just like a 6-sided die, so I'm not stuck with 50/50.

comment by Dorikka · 2014-05-13T00:15:04.149Z · LW(p) · GW(p)

By Wednesday you're convinced that infinitely recursive strategies may not be as awesome as they originally seemed.

comment by DanielLC · 2014-05-12T23:34:09.607Z · LW(p) · GW(p)

People are underconfident when predicting their own decisions. As a result, I would expect that you will be more likely to go with the highest probability decision on Monday than Tuesday. I suspect it will tend to be the better decision.

comment by V_V · 2014-05-12T22:41:07.503Z · LW(p) · GW(p)

So on Tuesday you use mixed strategies, and on Monday you use...?

comment by ESRogs · 2014-05-13T00:05:13.086Z · LW(p) · GW(p)

Two questions:

  1. What kind of decisions do you have in mind? Presumably I'm not rolling each time I take a step (or not) while walking down the street, right?

  2. Is there any reason not to say 100% for all my decisions on Tuesday? (Assuming I don't happen to find myself in any adversarial interactions with Omega.)

Replies from: Alexei
comment by Alexei · 2014-05-13T01:04:08.758Z · LW(p) · GW(p)
  1. See my answer to gjm.

  2. Let's say I'm lazy, and I can't decide for sure if I want vanilla or chocolate. Rolling the quantum die seems easier.