I am going to be there.

Why do I think anthropic reasoning and consciousness are related?

In a nutshell, I think subjective anticipation requires subjectivity. We humans feel dissatisfied with a description like "well, one system running a continuation of the computation in your brain ends up in a red room and two such systems end up in green rooms" because we feel that there's this extra "me" thing, whose future we need to account for. We bother to ask how the "me" gets split up, what "I" should anticipate, because we feel that there's "something it's like to be me", and that (unless we die) there will be in future "something it will be like to be me". I suspect that the things I said in the previous sentence are at best confused and at worst nonsense. But the question of why people intuit crazy things like that is the philosophical question we label "consciousness".

However, the feeling that there will be in future "something it will be like to be me", and in particular that there will be one "something it will be like to be me"<1> if taken seriously, forces us to have subjective anticipation, that is, to write probability distribution summing to one for which copy we end up as. Once you do that, if you wake up in a green room in Eliezer's example, you are forced to update to 90% probability that the coin came up heads (provided you distributed your subjective anticipation evenly between all twenty copies in both the head and tail scenarios, which really seems like the only sane thing to do.)

<1> Or, at least, the same amount of "something it is like to be me"-ness as we started with, in some ill-defined sense.

On the other hand, if you do not feel that there is any fact of the matter as to which copy you become, then you just want all your copies to execute whatever strategy is most likely to get all of them the most money from your initial perspective of ignorance of the coinflip.

Incidentally, the optimal strategy looks like an policy selected by updateless decision theory and not like any probability of the the coin having been heads or tails. <a href="http://lesswrong.com/lw/17c/outlawing_anthropics_an_updateless_dilemma/13d7">PlaidX</a> beat me to the counter-example for p=50%. Counter-examples of like PlaidX's will work for any p<90%, and counter-examples like Eliezer's will work for any p>50%, so that pretty much covers it. So, unless we want to include ugly hacks like responsibility, or unless we let the copies reason Goldenly (using Eliezer's original TDT) about each other's actions as tranposed versions of their own actions (which does correctly handle PlaidX's counter-example, but might break in more complicated cases where no isomorphism is apparent) there simply isn't a probability-of-heads that represents the right thing for the copies to do no matter the deal offered to them.

The most effective version of this would probably be an iPhone (or similar mobile device) application that gives a dollar to charity when you push a button. If it's going to work reliably it has to be something that can be used when the beggar/cause invocation is in sight: for most people, I'm guessing that akrasia would probably prevent a physical box or paper ledger from working properly.

I recently visited Los Angeles with a friend. Whenever we got lost wandering around the city, he would find the nearest homeless person, ask them for directions and pay them a dollar. (Homeless people tend to know the street layout and bus routes of their city like the backs of their hands.)

Yes, we have a name from this, Religion

Agreed, but the fact that religion exists makes the prospect of similar things whose existence we are not aware of all the scarier. Imagine, for example, if there were something like a religion one of whose tenants is that you have to fool yourself into thinking that the religion doesn't exist most of the time.

• We actually live in hyperspace: our universe really has four spacial dimensions. However, our bodies are fully four dimensional; we are not wafer thin slices a la flatland. We don't perceive there to be four dimensions because our visual cortexes have a defect somewhat like that of people who can't notice anything on the right side of their visual field.

• Not only do we have an absolute denial macro, but it is a programmable absolute denial macro and there are things much like computer viruses which use it and spread through human population. That is, if you modulated your voice in a certain way at someone, it would cause them (and you) to acquire a brand new self deception, and start transmitting it to others.

• Some of the people you believe are dead are actually alive, but no matter how hard they try to get other people to notice them, their actions are immediately forgotten and any changes caused by those actions are rationalized away.

• There are transparent contradictions inherent in all current mathematical systems for reasoning about real numbers, but no human mathematician/physicist can notice them because they rely heavily on visuospacial reasoning to construct real analysis proofs.

I'm not sure the cost of privately held false beliefs is as low as you think it is. The universe is heavily Causally Entangled. Now even if in your example, the shape of the earth isn't causally entangled with anything our mechanic cares about, that doesn't get you off the hook. A false belief can shoot you in the foot in at least two ways. First, you might explicitly use it to reason about the value of some other variable in your causal graph. Second, your intuition might draw on it as an analogy when you are reasoning about something else.

If our car mechanic thinks his planet is a disc supported atop an infinite pile of turtles, when this is in fact not the case, then isn't he more likely to conclude that other things which he may actually come into more interaction with (such as a complex device embedded inside a car which could be understood by our mechanic, if he took it apart and then took the pieces apart about five times) might also be "turtles all the way down"? If I actually lived on a disc on top of infinitely many turtles, then I would be nowhere near as reluctant to conclude that I had a genuine fractal device on my hands. If I actually lived in a world which was turtles all the way down, I would also be much more disturbed by paradoxes involving backward supertasks.

To sum up: False beliefs don't contaminate your belief pool via the real links in the causal network in reality; they contaminate your belief pool via the associations in your mind.

Anyone who doesn't take truth seriously in small matters cannot be trusted in large ones either.

-- Albert Einstein

Those who can make you believe absurdities can make you commit atrocities.

-- Voltaire