Belief in the Implied Invisible

"The whole matter would be a lot simpler, admittedly, if we could just rule out the existence of entities we can't interact with, once and for all - have the universe stop existing at the edge of our telescopes. But this requires us to be very silly.

Why? If I believe that the universe doesn't exist outside my future and past light cones, then I don't expect any difference in experiences than you, so I really don't see what the point of arguing about it is.

"In Solomonoff induction, the complexity of your model is the amount of code in the computer program you have to write to simulate your model. The amount of code, not the amount of RAM it uses, or the number of cycles it takes to compute."

What!? Are you assuming that everyone has on the exact same data on the position of the quarks of the universe stashed in a variable? The code/data divide is not useful, code can substitute for data and data for code (interpreted languages).

Let us say I am simulating the quarks and stuff for your region of space, I would like my friend bob to be able to make the same predictions (although most likely they would be postdictions as I wouldn't be able to make them in faster than real time) about you. I send him my program (sans quark positions), but he still can't simulate you. He needs the quark positions, they are as much code for the simulator as the physical laws.

Or to put it another way, quark positions are to physics simulators as the initial state of the tape is to a UTM simulator. That is code. Especially as physics simulations are computationally universal.

I personally don't put much stock by occams razor.

This is what I thought at first, but on reflection, it's not quite right.

Could you explain a little more the distinction between the position preceding this remark and that following it? They seem like different formulations of the same thing to me.

Silly? That's an awfully subjective criticism.

Perhaps you could explain for us all what the difference is between 'destroying' a photon and causing it to become unable to affect you in any fashion.

To make it clear why you would sometimes want to think about implied invisibles, suppose you're going to launch a spaceship, at nearly the speed of light, toward a faraway supercluster. By the time the spaceship gets there and sets up a colony, the universe's expansion will have accelerated too much for them to ever send a message back.

Caledonian: the difference is that if you know that the photon was sent out, you have infinite computing power, and you want to know the exact subjective probability distribution you should hold for what a particular brontosaur ate for lunch 123 million years ago, you need to take that photon into account. You can then test that by looking for the fossilized dung in exactly the right set of places and you will probably find the relevant dung faster than your competition who started without knowledge of the photon in question.

Re: Vassar– that's not quite right, since Eliezer is proposing you knew about the photon being there when it was on Earth. When it leaves your light cone, you don't care about it, since it will never affect you and never affect any event that ever effects you.

Or if you are going to be on that spaceship, are you worried that the Earth will blip out of existence on your journey?

Dan: I'm not sure what exactly is being proposed. Actually I think that there is some confusion in the fundamental physics here, as well as in the positivistic assumptions being invoked by Caledonian. If physics is reversible I don't think that something can ever go from being part of my light cone to not being part of it. The photons future doesn't impact me past some point, but the past of the future of that photon does. I suspect that when you use causality diagrams, or just do the math, any confusion here goes away.

In Eliezer's example, the colony is in the future light cone of your current self, but no future version of you is in its future light cone.

One problem is that 'you' that can be affected by things that you expect to interact with in the future is in principle no different from those space colonists that are sent out. You can't interact with future-you. All decisions that we are making form the future with which we don't directly interact. Future-you is just a result of one more 'default' manufacturing process, where laws of physics ensure that there is a physical structure very similar to what was in the past. Hunger is a drive that makes you 'manufacture' a fed-future-you, compassion is a drive that makes you 'manufacture' a good-feeling-other-person, and so on.

I don't see any essential difference between decisions that produce 'observable' effect and those that produce 'invisible' effect. What makes you value some of the future states and not others is your makeup, 'thousand shards of desire' as Eliezer put it, and among these things there might as well be those that imply value for physical states that don't interact with decision-maker's body.

If I put a person in a black box, and program it to torture that person for 50 years, and then automatically destroy all evidence, so that no tortured-person state can ever be observed, isn't it as 'invisible' as sending a photon away? I know that person is being tortured, and likewise I know that photon is flying away, but I can't interact with either of them. And yet I assign a distinct negative value to invisible-torture box. It's one of the stronger drives inbuilt in me.

Should I believe that, in the moment where I can no longer interact with it even in principle, the photon disappears? No. It would violate Conservation of Energy. And the second law of thermodynamics. And just about every other law of physics. And probably the Three Laws of Robotics. It would imply the photon knows I care about it and knows exactly when to disappear.

1) The Second Law is a non-sequitur. It simply isn't relevant. The loss of a photon due to universal expansion does not violate that principle at all.

2) The First Law was formulated when we found that, in our attempts to examine situations where it was asserted substance was created or destroyed, substance was always conserved. It exists on empirical grounds; it's not some sacred revelation that cannot be questioned or even discarded if necessary. Citing the First Law against the idea that a bit of mass-energy could be destroyed is simply invalid, because if that substance could be destroyed, we'd have to abandon the Law.

3) The idea that "the photon knows when to disappear" is based on a mistaken understanding of existence. It is not an inherent property of a thing, but a relationship between two or more things. The photon doesn't keep track of how far it's gotten from Eliezer and then lose the "existence" property when it's distant enough. Its existence relative to Eliezer ends when it passes forever out of the universe in which things interact with Eliezer.

There is no difference between saying that a photon that travels far enough away from Eliezer is destroyed, and saying that a photon that travels far enough from Eliezer is no longer part of the set closed under interaction that includes him. Knowing the properties of the photon would no longer be necessary to completely represent Eliezer and the things that interact with him.

The photon is no more. It has ceased to be! Relative to Eliezer, at least. Whether it exists relative to other things is undefined - and utterly irrelevant.

1) The Second Law is a non-sequitur. It simply isn't relevant. The loss of a photon due to universal expansion does not violate that principle at all.

The photon had some entropy. If it vanishes with no effect, that entropy is gone.

Citing the First Law against the idea that a bit of mass-energy could be destroyed is simply invalid, because if that substance could be destroyed, we'd have to abandon the Law.

More than that, actually.

Let's drag this back to purpose. What's your answer to Eliezer's question at the end?

the colony is in the future light cone of your current self, but no future version of you is in its future light cone.

Right, and if anyone's still confused how this is possible: wikipedia and a longer explanation

There's an even simpler computer program that generates your present experiences: the program that runs all programs (each one a little bit at a time), the Universal Dovetailer. But this program does have the potential Occamian disadvantage of creating all possible universes, in addition to the one you see around you. Is this Multiplying Entities Beyond Necessity? Or merely a matter of more RAM?

Hal, some people make the argument that that is just more RAM, and therefore that Ockham's Razor requires that we assert that all possible universes actually exist; i.e. the simplest claim that will result in your experiences is that all possible experiences are real.

The problem with this is that one can disprove it empirically by anthropic reasoning. If all possible universes are real--i.e. including ones with special coding for specific miracles in the next ten seconds-- we should conclude with virtual certainty that the laws of physics will be violated in the next ten seconds. Since this does not typically happen, we can conclude that not all possible universes are real.

If all possible universes are real--i.e. including ones with special coding for specific miracles in the next ten seconds-- we should conclude with virtual certainty that the laws of physics will be violated in the next ten seconds.

"Virtual certainty" is a statement of probability, which can't be resolved without placing relative weights on different possible universes.

The photon had some entropy. If it vanishes with no effect, that entropy is gone.

So what? That has nothing to do with the Second Law, which describes how closed systems become disordered, probabilistically speaking.

The system Eliezer described 1) is not closed, 2) does not have an increase in order as a result of the photon disappearing. The amount of 'available work' in fact decreases as a result of that loss - which doesn't contradict the Second Law at all.

At Constant, Is there a 'natural' probability measure on the set of all possible existences? Otherwise it has to be included in the 'program' and not the 'RAM'.

To make it clear why you would sometimes want to think about implied invisibles, suppose you're going to launch a spaceship, at nearly the speed of light, toward a faraway supercluster. By the time the spaceship gets there and sets up a colony, the universe's expansion will have accelerated too much for them to ever send a message back. Do you deem it worth the purely altruistic effort to set up this colony, for the sake of all the people who will live there and be happy? Or do you think the spaceship blips out of existence before it gets there? This could be a very real question at some point.

I don't think it's possible to get outside Earth's light cone by travelling less than the speed of light, is it? I'm not well-educated about such things, but I thought that leaving a light-cone was possible only during the very early stages (eg., the first several seconds) after the big bang. Of course, that was said back when people believed the universe's expansion was slowing down. But unless the universe's expansion allows things to move out of Earth's light-cone - and I suspect that allowing that possibility would allow violation of causality, because it seems it would require a perceived velocity wrt Earth past the speed of light - then the entire exercise may be moot; the notion of invisibles may be as incoherent as the atomically-identical zombies.

I'm not 100% convinced - even after reading Eliezer's articles - that one interpretation of quantum mechanics is necessarily better than the other (my gut reaction would be to say "a plague on both your houses"), but this article looks like an argument in favor of many-worlds over Copenhagen.

In Copenhagen, the extra configurations "magically" collapse out of existence at some ill-defined point when the system decoheres to the point that we can't get to see them even in principle. In many-worlds, the macroscopic system decoheres instead. The existence of innumerable and undetectable "extra worlds" is not a violation of Occam's Razor as defined in this article: as long as it follows from just taking the laws of quantum mechanics to their logical conclusion, there is no extra information needed to describe this law, and the extra worlds are irrelevant to our description in the same sense as extra galaxies are, as it's only a question of extra RAM rather than extra meaningful information as long as they obey the same fundamental laws.

I'm pretty sure the spaceship doesn't actually seem to bleep out of existence. It's just that, from your point of reference, time passes slower and slower for it.

I could be wrong, though.

At first I was angry with myself for being afraid to say "Niblick"

but then when I said it I was angry with myself because Elizer had manipulated me into saying it via reverse psychology.

My human mind cannot resist something that you taboo so hard which is so easy to do! Damn it! Damn it all!

"Dur? What's that, God? Don't what? Eat the apples from the Tree of Knowledge!? Well, if you insist, I'd love to! OM NOM NOM NOM NOM NOM...."

I'M SO SORRY, ALL OF YOU 3^^^3 PEOPLE!

AND I APPARENTLY DOOMED MY DESCENDANTS WITH ORIGINAL SIN, TOO! WILL THE CONSEQUENCES OF MY ACTIONS OF A SINGLE AFTERNOON NEVER END!?

Why, oh god, whyyyyyy!?

Based on standard physics, in other words, I don't expect this photon to intercept anything on its way out.

If it has the wrong energy, it would veeery likely eventually interact with a photon from one of the diffuse radiation backgrounds into an electron-positron pair. A neutrino would be a much better example.

Conservation laws or not, you ought to believe in the existence of the photon because you continue having the evidence of its existence - it's your memory of having fired the photon! Your memory is entangled with the state of the universe, not perfectly, but still, it's Bayesian evidence. And if your memory got erased, then indeed, you'd better stop believing that the photon exists.

"So does it boil down to, “I believe the photon goes on existing as it wings
off to nowhere, because my priors say it’s simpler for it to go on existing than
to disappear”?
This is what I thought at first, but on reflection, it’s not quite right. (And
not just because it opens the door to obvious abuses.)
I would boil it down to a distinction between belief in the implied invisible,
and belief in the additional invisible."

Eliezer, what are these obvious abuses?