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Blueberry comments on Parapsychology: the control group for science - Less Wrong

62 Post author: AllanCrossman 05 December 2009 10:50PM

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Comment author: Blueberry 06 December 2009 08:34:14AM *  5 points [-]

You are going so far as to say that there is no possible way that there are hypotheses which have yet to be described which could be understood through the methodology of this particular subgroup. This exercise seems to me to be rejecting these studies intuitively,(without study) just from the ad hominem approach to rejection - well they are parapsychologists therefore they are wrong. If they are wrong, then proper analysis would indicate that, would it not?

This is exactly the point. Parapsychology is one of the very few things we can reject intuitively, because we understand the world well enough to know that psychic powers just can't exist. We can reject them even when proper analysis doesn't indicate that they're wrong, which tells us something about the limitations of analysis.

ETA: Essentially, if the scientific method can't reject parapsychology, that means the scientific method isn't strong enough, not that parapsychology might be legitimate.

Comment author: Yvain 07 December 2009 04:46:17PM *  17 points [-]

There are many other things that people have claimed can be rejected intuitively without study through the years.

In the 18th century, everyone knew that real scientific physics only permitted a body to act upon another body through direct contact. When Newton proposed his theory of gravity, many people rejected it as pseudoscientific or magical because it claimed the stars and planets could exert action at a distance, without saying how they did it.

In the 19th century, everyone knew that life was on a different order than mere matter, because obviously you couldn't produce the self-moving and self-regenerating qualities of life with just stuff like you get in rocks and sand.

In the 20th century, everyone knew that the mind was more than just the brain, since simple introspection could determine the existence of a consciousness inexplicable in simple material terms.

The absurdity heuristic is an okay heuristic, but I'd be really really careful before saying something is so absurd we can throw away any contradictory experimental evidence without a glance.

The possibility I give to some sort of psi effect existing (in a nice, scientific way that we can study once we figure out what form of matter/energy forms its substrate) is pretty low, but not zero. I'm not even willing to give it a tiny one in a bajillion probability - remember that people who say they're 99% sure of something are wrong 20% of the time, and that since this issue is "politically" charged, vaguely defined, and possibly affected by knowledge we don't have, this is exactly the sort of thing we'd be likely to be overconfident on. If this was some calibration test, I wouldn't feel too good about placing more than 95% or so on the nonexistence of psi.

And if you're a Bayesian, a couple of good studies should be able to start manipulating that 5% number upwards

Comment author: MichaelVassar 08 December 2009 03:38:08AM 16 points [-]

I used to think that way before I knew about Bayesianism. Once I learned about it I realized that the prior probability for psi was very VERY low, e.g. its complex and there's no reason to expect it so one in a bajillion, while the probability for the observed evidence for psi, given what we know about psychology, was well in excess of 50% in the absence of psi, so the update couldn't justify odds greater than two in a bajillion.

Comment author: Yvain 09 December 2009 06:50:16PM *  8 points [-]

You're right that I completely missed the Bayesian boat, and I'm going to have to start thinking more before I speak and revise my estimates down to <1%.

But I'm still reluctant to put them as low as you seem to. The anthropic principle combined with large universe says that whatever complexity is necessary for the existence of conscious observers, we can expect to find at least that level of complexity. Questions like consciousness, qualia, and personal identity still haven't been resolved, and although past experience suggests there is probably a rational explanation to this question, it isn't nearly dissolved yet. If consciousness really is impossible without some exotic consciousness-related physics (Penrosean or otherwise), then our universe will have exotic consciousness-related physics no matter how complex they need to be. And since evolved beings have been so proficient at making use of normal physics to gain sensory information, it's a good bet they'd do the same with exotic consciousness-related physics too if they had them...

...is a somewhat hokey argument I just invented on the spot, and I'm sorry for it. But the ease with which I can put something like that together is itself evidence that there are enough possible sides of the issue that hadn't been considered (at least I hadn't considered that one; maybe you've been thinking about it for years) that it needs at least a little more room for error than two in a bajillion (sorry, Alex).

I also disagree with your assessment of the amount of evidence. Have you ever read any good books by intelligent believers in the subject? It's not all John Edwards psychic chat shows. I also think you might be double-counting evidence against psi here - psi doesn't exist so we know any apparent evidence must come from human psychology, therefore there never was any apparent evidence in the first place. Or have you read the studies and developed separate explanations for each positive result?

Anyway, let's settle this the LW way. Give me your odds that psi exists, and we can make a bet at them. If it's one in a million, then I'll give a cent to your favorite charity on the condition that you give $10,000 to my favorite charity if psi's shown to exist within our lifetimes (defined however you want; possibly as evidence sufficient to convince any two among Randi, Dawkins, and Eliezer that psi is >50% likely).

Comment author: MichaelVassar 10 December 2009 07:20:33PM 10 points [-]

One problem with this argument is that if psi exists, we are very bad at using it, and we don't see other organisms using it well either. The world we see appears to be almost completely described by normal physics at worst.

I don't think that I'm double-counting evidence. I certainly know that there can be intelligent believers, after all, MANY intelligent people believe that one is compelled to accept the conclusions of the scientific method over those of the scientific community. Also, beliefs can be compelling for any variety of irrational reasons. The evidence I have seen though looks to me like exactly the evidence you would expect given known psychology and no psi. We can surely agree that there is a LOT of evidence that hyman psychology would create belief in psi in the absence of psi, can't we.

I would set my odds at "top twenty most astoundingly surprising things ever discovered but maybe not top ten". That seems to me like odds of many billions to one against, but not trillions. Unfortunately, the odds for almost any plausible winning conditions occurring without psi being real are much higher, making the bet difficult to judge. I have a standing 10,000 to one bet against Blacklight Power's "Hydrino Theory" with Brian Wang based on a personal estimate of odds MUCH less than 1-in-10K for "Hydrino Theory" and I'm happy to extend those odds when the odds are still more favorable, but psychotic breaks by two people in a group of three? If the odds per person are 1%, that gives odds of about 1:3300. I'm happy to give those odds on the Dawkins, Randi Yudkowsky bet and count "psi is actually real" as a rounding error.

Comment author: Yvain 11 December 2009 02:39:15PM 11 points [-]

Have donated $10 to SIAI (seemed less likely to lose you guys money in transaction fees than $1) with public comment about the bet . Will decide where you can donate your $33000 in the unlikely event it proves necessary.

Comment author: MixedNuts 13 July 2011 01:22:17PM 1 point [-]

I'd feel ridiculously overconfident stating a probability of less that 1e-6, yet I don't have the slightest hesitation to take that bet. (Brain sucks at small probabilities.) Condition is any two among {Randi, Dawkins, Eliezer, Vassar, me}, but if one is reported to have developed a new mental illness at least two months before they say psi is real, they don't count.

Also, let's make it purchasing power as of 2011, not dollar amount. Assuming scarcity lasts long enough.

Comment author: CarlShulman 11 December 2009 03:03:31PM 1 point [-]

What if they're dead?

Comment author: Yvain 11 December 2009 03:06:22PM 18 points [-]

Well, then I lose the bet...unless someone contacts their ghosts...in which case I win the bet!

Comment author: FeepingCreature 12 February 2012 03:10:54PM *  0 points [-]

Psi doesn't even explain consciousness or qualia.

[edit] Oops, necro. Disregard me.

[edit edit] okay! nevermind that then :D

Comment author: MC_Escherichia 12 February 2012 03:19:14PM 2 points [-]

I don't think there's a prejudice against replying to old posts around here...

Comment author: alexflint 08 December 2009 10:16:40AM 15 points [-]

One in a bajilion? Guys, the numbers matter. 10^-9 is very different from 10^-12, which is very different from 10^-15. If we start talking about some arbitrarily low number like "one-in-a-bajillion" against which no amount of evidence could change our mind, then we're really just saying "zero" but not admitting to ourselves that we're doing so.

Other than that, I agree with Yvain and have found this to be perhaps the most belief-changing so far on LW!

Comment author: Eliezer_Yudkowsky 11 December 2009 02:13:27AM 14 points [-]

It takes only 332 pieces of evidence with likelihood ratios of 2:1 to promote to 1:1 odds a hypothesis with prior odds of 1:googol, that is 10^-100, which would be the appropriate prior odds of something you could describe with around 70 symbols from a 26-letter equiprobable alphabet.

"A bajillion to one" are odds that Bayesian updating can overcome surprisingly quickly - it isn't anything remotely like "no amount of evidence can change my mind". Now odds of one to a googolplex - that might as well be zero, relative to the amount of evidence you could acquire over a human lifetime. But the prior probability of any possibility you can describe over a human lifetime should be much higher than that.

Comment author: roystgnr 09 February 2012 06:52:49PM 7 points [-]

A nitpick: it takes 332 pieces of all mutually independent evidence to perform that level of update.

More confusing, for these purposes the independence level of the evidence depends on what hypotheses you're trying to distinguish with it. E.g. if you're trying to distinguish between "that subject has ESP powers" and "that experiment was random luck" then 332 repetitions of the same experiment will do. If you're trying to distinguish between "that subject has ESP powers" and "that experimenter's facial expressions differ based on what cards he was looking at", then you can't just repeat it; you've got to devise new and different experiments.

Comment author: externalmonologue 27 November 2010 05:14:04PM 0 points [-]

One in a bajillion? You are saying you actually know how complex psi is without even saying what aspect of psi you are talking about.

We know biology is very complex. So when testing a supplement like creatine, the pseudoskeptic could say "biology is extremely complex. We do not know the mechanism that makes creatine work so I assign a very low bayesian probability. Today I feel like a hundred trillion to one".

Keep in mind this is after several studies have shown an effect in the predicted direction whose odds are not easily explained by chance. Indeed, there is nothing wrong with you assertion about complexity just the subjective part where you assign a number to a phenomena you are not very familiar with.

Comment author: wedrifid 27 November 2010 05:33:03PM 3 points [-]

One in a bajillion? You are saying you actually know how complex psi is without even saying what aspect of psi you are talking about.

Bajillion isn't exactly a precise measure. In this context it means 'lots'. That isn't hard to assign to the all aspects of psi.

Comment author: Sebastian_Hagen 07 December 2009 05:23:26PM *  10 points [-]

In the 20th century, everyone knew that the mind was more than just the brain, since simple introspection could determine the existence of a consciousness inexplicable in simple material terms.

No, they didn't. Superficial research indicates that serious materialism goes back to at least the Enlightenment in the 18th century. And the 20th century? That's not even plausible.

Comment author: nwthomas 04 July 2011 06:18:23PM 0 points [-]

Good point, with the qualifier that many people (including professional philosophers) presently find themselves unable to wrap their heads around the idea that they have no non-material consciousness. The "argument from absurdity" against materialism is alive and kicking.

Comment author: LauraABJ 06 December 2009 12:55:36PM 5 points [-]

Exactly! I guess Allan needs to explain further why parapsychology is bunk. As an example, a person 'reading the mind' of another person a mile away without the emission of any kind of detectable electromagnetic wave or signal capable of traveling that far is in violation of the laws of physics as we know them (and if people did emit such signals, it would be intensively studied). For this to be true, physics itself would need to be complicated on a level that would specifically allow this phenomenon to occur, which seems very, very unlikely. To quote Michael Vassar, "Magic is the hypothesis that physics is complicated."

We should expect positive results from the field of parapsychology, since so many people (in total over the years) are trying to prove it exists, and there is an extreme positive results bias. Thus by chance positive results will be obtained and published, while negative results are largely ignored or not even submitted (I assume a 'scientist' trying to prove parapsychology wants to do so, and so may only bother submitting a paper on the topic if the results are positive).

Comment author: Kaj_Sotala 07 December 2009 09:51:56AM *  3 points [-]

...Charles Honorton and his colleagues drew together all the forced-choice experimental precognition experiments reported in English between 1935 and 1987, publishing their findings in the December 1989 Journal of Parapsychology. The combined results were impressive: 309 studies contributed to by 62 senior authors and their associates, nearly two million individual trials made by more than 30,000 subjects. (In a properly conservative culling, all the experimental work of both Rhine's chosen but subsequently disgraced successor, Walter J. Levy, and S.G. Soal, once a famous specialist in time-displacement psi tests, was excluded; both were known to have cheated in at least some experiments.) Overall, the cumulation is highly significant - 30 percent of studies provided by 40 investigators were independently significant at the 5 percent level. Yet this was not due to a suspicious handful of successful researchers: 23 of the 62 (37 percent) found overall significant scoring.

By the same token, admittedly, this means 63 percent failed to show significant psi. But [...] [i]f one hundred studies are done, averaging as many as thirty-eight correct calls instead of the twenty-five due to chance, then, surprisingly, we should only expect to find among that one hundred "about 33 [statistically] significant studies ... and a 30% chance that there would be 30 or fewer!" Here's why: The scattergun variance that arises simply from chance would mask most of the extra correct calls. This fact would remain in force even if the responders were picking up their extra hits through hidden radio receivers rather than psi! It's just what happens with the statistics of phenomena that have low power. [...]

Well, could this 37 percent success rate be due to the "file drawer"? Hardly. Honorton's estimate required fourty-six unreported chance-level experiments for each of those in the meta-study, including those that themselves gave no significant support for the paranormal hypothesis. It seems highly unlikely that such a trove of dull experiments exists [...] Nor were the results due to an excessive contribution from a few specialist parapsychologists doing so many precognition studies that their non-scoring rivals were swamped. Strikingly, if all the investigators "contributing more than three studies are eliminated, leaving 33 investigators, the combined z [number of standard deviations found] is still 6.00" - with an associated probability of chance coincidence of somewhat more than one in a billion.

The individual effect sizes were all over the place, so Honorton and his coauthor, Diane C. Ferrari, unceremoniously threw out all the studies with unusually large deviations from the mean. [...] "Outcomes remain highly significant. Twenty-five percent of the studies (62/248) show overall significant hitting at the 5% level." Maybe the quality of studies explains the persistance of apparent anomalies? [...] if anything, the significance of the results climbed as quality improved. [...] What's more, the "effect size" had persisted over more than fifty years. This measure compensates for the different sample sizes in various studies: technically, it divides the z score by the square root of the number of trials in each study.

-- Damien Broderick, Outside the Gates of Science

Comment author: Jack 07 December 2009 10:14:25AM *  2 points [-]

Would it really surprise anyone here if, say, 10 percent of parapsychologists are either rigging experiments, hiding negative results or falsifying data? 20%?

Thirty-seven percent.

Comment author: Kaj_Sotala 07 December 2009 04:13:47PM *  4 points [-]

What would be the incentive? Forging results for highly public performances that allowed you to make money off people, sure. But for results published in obscure journals, when even academics in well-respected fields may need to fight tooth and claw for their next yearly funding? In a field that won't even get you the respect of most other academics, and might very well ruin your scientific reputation? Trying to prove a view that doesn't have powerful ideological backers pouring money into it the way creationists do? And with the number of fake researchers apparently staying roughly even for a period of fifty years, looking from the way the effect size hasn't changed?

Comment author: Jack 07 December 2009 05:50:18PM 6 points [-]

And with the number of fake researchers apparently staying roughly even for a period of fifty years, looking from the way the effect size hasn't changed?

That right there is a really good point I didn't think of. As for motive, my impression is that a lot of parapsychologists are trying to demonstrate the truth of beliefs that are incredibly significant to them-- their new age spirituality is at stake. For that matter, if they've dedicated their lives to the subject. If there are no psychic phenomena they have literally spent their lives studying nothing. You might as well ask why theologians never come up with arguments disproving the existence of God. But your point about consistency makes this all moot. I'll check out the book.

Comment author: AllanCrossman 07 December 2009 06:43:12PM 5 points [-]

why theologians never come up with arguments disproving the existence of God

Well if they do they get called philosophers of religion instead...

Comment author: CarlShulman 16 March 2012 12:49:31AM *  2 points [-]

What would be the incentive?

To get more funding for their work, more fame within the parapsychology community, and to make it more likely that the world at large will realize the truth via "fake-but-accurate" experiments. Some parapsychologists pay for their own experiments, using resources garnered from a "day job" in some other field, but many rely on donations from wacky psi-enthusiasts (people who also get excited about ghosts, "subtle energies" and so forth), or selling psi-controlled meditation lamps. Many others think that it's critically important for mainstream funding sources to provide grants to parapsychologists (such as themselves) to do the work they find interesting and important.

Under those circumstances, a psychic believer could come up with all sorts of justifications:

I have to publish these "fake but accurate" experiments to convince others of the effects that I KNOW are really there, and thus gain enough resources to get definitive proof. After all, surely those dishonest skeptics and materialists (who regularly misrepresent the existing literature, and deceive the broader scientific community about the great work done in parapsychology) are doing the same thing, and if only one side 'enhances' its data then the truth will lose out.

Comment author: CarlShulman 16 March 2012 01:24:02AM *  1 point [-]

Honorton's estimate required fourty-six unreported chance-level experiments for each of those in the meta-study, including those that themselves gave no significant support for the paranormal hypothesis.

Note that this is a bogus calculation: it says that if there was no publication bias, so that unpublished studies were just as likely to show positive results as published ones, then adding the stated number of chance studies would "dilute" the results below a threshold significance level. But of course the whole point of publication bias is the enrichment of the file-drawer with negative results. See this paper by Scargle. You need far fewer studies in the file-drawer given the presence of bias. Further, various positive biases will be focused in the published literature, e.g. people doing outright fraud will normally do it for an audience.

The number of studies needed also collapses if various questionable research practices (optional stopping, post hoc reporting of subgroups as separate experiments, etc) are used to concentrate 'hits' into some experiments while misses can be concentrated in a small file drawer.

Parapsychologists counter that the few attempts to audit for unpublished studies (which would not catch everything) have not found large skew in the unpublished studies, but these inflated "fail-safe" statistics are misleadingly large regardless.

Comment author: LauraABJ 07 December 2009 02:24:47PM 1 point [-]

"Honorton's estimate required fourty-six unreported chance-level experiments for each of those in the meta-study, including those that themselves gave no significant support for the paranormal hypothesis."

Why is this at all unlikely? This is a 52 year span of time, and who knows how many times each of these (only 62) 'scientists' ran the trials or tweaked the procedure before they decided they had a set of data worth submitting. Who knows how many people looked for these phenomena, didn't find them, and gave up without submission? Even without outright fraud (which I wouldn't doubt), people lie to themselves. I've worked with scientists who had evidence that their previously obtained results were bunk and submitted them anyway... 'maybe the retest was flawed...' The significant effect that was found may just be the threshold at which an investigator needs to see (or fake) results to submit a paper. There's the answer to the question Allan originally posed...

Also, on another note, not all 'forced choice' tests are conducted in the same way. Some of them involve the person looking at the card being in the same room as the guesser, and well, it's not hard to imagine ways of getting a score above chance like that.

Comment author: Kaj_Sotala 07 December 2009 04:05:01PM *  0 points [-]

Why is this at all unlikely? This is a 52 year span of time

309 times 46 is 14 214, which divided by 52 equals approximately 273 unpublished studies per year. I haven't seen any figures on how many studies were conducted for e.g. a specific experimental paradigm in psychology during that time, so I can't say for certain how plausible this is or isn't. It does sound a bit high considering that parapsychology hasn't exactly been the best-funded field around, though it might have had more money in the 1930's. Does anyone have numbers?

Comment author: LauraABJ 07 December 2009 07:13:53PM 2 points [-]

I'm not saying there were 14k unpublished completed full studies, I'm suggesting that what got published was already biased. There is room for selection bias at every level of a study, including which trials and which methods are finally taken, written up, and submitted. If the 'scientists' are trying to prove that psi exists, they can find it, one or another. Fraud isn't even required, just wishful thinking. The consistency of the effect is interesting, but may only be measuring the psychological phenomenon of deliberate self-deception.-- ah we've discovered the threshold deviation from chance at which people will believe their own crap hasn't been tampered by their own meddling.

Think about the alternative explanation: If the forced choice test is run properly- the subject guesses which order 5 symbols in a 25 card deck will appear before the deck has been shuffled. The deck is then shuffled by machine (or associate) in a different room, and the order of the cards are examined. Now, how do you propose the subject is entangled with the card shuffling machine and deck, without violating current physical law, such that he can predict the order? This is magical thinking, with no basis in reality as we know it. Unless there is a pattern in the card shuffling machine and some people are very aware of it due to practice with it... but that is hardly psi.

Comment author: Kaj_Sotala 07 December 2009 08:39:28PM *  2 points [-]

Think about the alternative explanation

I'm not saying that psi must be real, only that it seems to merit a closer look than most people in this thread have been implying. Yes, it does seem rather unlikely that psi would exist, which is why I'm still undecided myself. But the fact that we can't come up with any physical explanation for it doesn't mean that it couldn't be real. As Yvain pointed out, Newton's theories may at the time have seemed like magical thinking as well. There could be some physical mechanism we're just not aware of, but which the brain has nonetheless evolved to take advantage of.

Or then it might just be a sign of our statistical methods being flawed, made worse by psi researchers being insufficiently rigorous in their methods.

Comment author: LauraABJ 08 December 2009 01:30:23AM 6 points [-]

"I'm not saying that psi must be real, only that it seems to merit a closer look than most people in this thread have been implying."

I strongly disagree. Psi has been looked at very intensively for a very long time, and the best it can yield is that it's not completely statistically insignificant. No theories have been posed as to how it works, it hasn't been quantified (ie, how far away, in what time frame can the subject predict the future), and it cannot be demonstrated reliably and repeatedly from even a few individuals who could then be studied more elaborately. Even one person who could always predict the order of a deck of cards would be fascinating. At some point, you just have to say a line of research does not merit further study.

In the mean time, giving these theories credence wastes time and resources and leads people to think they can believe anything they want about the world, including the outstanding religious dogma, since, hey, you never know.

Comment author: scav 09 December 2009 01:30:52PM 0 points [-]

Here's a closer look: to accept psi, you would have to reject evolutionary biology.

It would be such a humungous advantage to communicate telepathically, see the future or remote locations, or manipulate the physical world by thinking, that there's no way evolution wouldn't have optimised the f* out of it by now.

We don't wonder whether birds have wings, or whether dogs have a sense of smell. That we can wonder whether we might have psychic powers means we DON'T, to a very high probability indeed.

Comment author: Kaj_Sotala 09 December 2009 04:00:52PM *  6 points [-]

Just because an ability would be useful doesn't mean that evolution could (or would, if reaching that ability required several intermediate steps with very low fitness advantages) optimize it without limit.

The ability to digest literally everything we put in our mouths would be useful as well, but the fact that we don't have that doesn't mean we need to reject evolution.

Comment author: scav 11 December 2009 04:07:06PM 0 points [-]

Voted up for making me think harder.

I'm not talking about an ability (like digesting cellulose) which would be really advantageous but we don't have and would require a lot of unlikely steps. The non-null hypothesis of human psychic powers is that we do already have them and ancient humans did too. Yet we don't seem to have evolved psychic abilities that are even detectable by now.

Compare: the abilies to cope with milk and beer in our diet have been evolving in humans since the invention of dairy farming and brewing (a few thousand years ago?) There is large population variation in these digestive abilities after that short time.

Would the selection pressure in favour of telepathy be that much less than for drinking beer?

Comment author: timtyler 09 December 2009 04:15:08PM 5 points [-]

Cellphones are advantageous too - yet their evolution seems to be currently in progress. That should be enough to indicate why this line of argument fails.

Comment author: Vladimir_Nesov 08 December 2009 10:33:13AM *  0 points [-]

I'm not saying that psi must be real, only that it seems to merit a closer look than most people in this thread have been implying.

This does mean estimating it to be much more probably real than seems reasonable at this point.

Comment author: Mitchell_Porter 06 December 2009 08:47:58AM 10 points [-]

Parapsychology is one of the very few things we can reject intuitively, because we understand the world well enough to know that psychic powers just can't exist.

Do you think it is possible that we are "living in the Matrix"? If so, then you should consider something functionally indistinguishable from psychic powers to be possible.

Comment author: bigbad 07 December 2009 11:24:43PM 4 points [-]

If we are, in fact, living in the Matrix, then science has already characterized the rules of the simulation rather well. Barring further interference by the sysadmin/God/whatever, it should continue to operate by mechanistic, semipredictable rules. Science has little to say about one-time interventions from outside observable reality, whether you call them "Matrix hacks", "miracles", or what you will. Regarding such matters, the null hypothesis has yet to be convincingly falsified, but absence of proof is not proof of absence.

Comment author: Strange7 05 February 2014 04:38:18AM 0 points [-]

It's a fairly common thing, in videogame design, to include "cheat codes:" obscure, highly specific, and seemingly useless in-game behaviors which produce otherwise impossible results.

Comment author: Pablo_Stafforini 06 December 2009 05:43:39PM *  0 points [-]

The hypothesis that we are living in the Matrix is best understood as a metaphysical hypothesis. The various claims made by parapsychologists, however, are not metaphysical claims about the nature of reality, but "scientific" claims about what goes on in reality. It is therefore unclear why such claims would be more probable on the assumption that the Matrix hypothesis is true.

Comment author: Psychohistorian 07 December 2009 04:08:19AM *  1 point [-]

I am not surprised when a video game character consistently summons balls of fire out of nothingness. I would be absolutely astounded to see an actual person do this. This is because the system of rules governing a video game and the system governing a deterministic universe appear to be very, very different.

If we were living in the matrix, this would not be the case. It would not mean that we are necessarily in the kind of video game where there are psychic powers, but it would provide a very clear mechanism through which psychic powers could act. Such a mechanism does not appear possible in a deterministic universe, or at least in the one we seem to occupy.

Comment author: Vladimir_Nesov 07 December 2009 05:48:27AM *  8 points [-]

Real world is uncaring, unsupervised. Magic is not just about the world being "complex", it's about the world containing mechanisms targeting specifically humans, and understanding the situation much like a human would. Being "deterministic" doesn't preclude anything, it's more of a way of seeing things than the way things are.

Comment author: wedrifid 07 December 2009 04:25:40AM 3 points [-]

This is because the system of rules governing a video game and the system governing a deterministic universe appear to be very, very different.

An artificial dichotomy.

Comment author: Zack_M_Davis 07 December 2009 04:46:22AM 1 point [-]

I don't think so. Video games are specifically programmed to create a particular experience for the user. If something goes over the horizon and won't be needed again, it just doesn't get computed. Whereas the real universe seems to be---just the same physics. Everywhere. No complicated ad hoc programming describing levels or characters or points, or translating keypresses into useful actions---no user input at all, come to think of it.

Comment author: SilasBarta 07 December 2009 07:59:36PM *  3 points [-]

If something goes over the horizon and won't be needed again, it just doesn't get computed. Whereas the real universe seems to be---just the same physics. Everywhere.

Not quite. That's what we assume happens -- justifiably! -- because it would be a far more complicated hypothesis to disbelieve in the implied invisible.

However, failing to see these implied invisibles is not itself independent evidence of universal law, just an inference from an Occamian prior. You would fail to see implied invisibles with equal probability whether or not the laws were fully universal.

Interestingly, I explored the question of whether it's possible, if the universe is a simulation, to shut it down by forcing it to do more and more computational work in order to keep fooling us. But, I argue, it turns out that the 2nd law of thermodynamics implies that no matter what observations observers choose to make, it requires no more storage capacity to continue fooling them.

Comment author: gwern 08 December 2009 04:22:58AM *  2 points [-]

But, I argue, it turns out that the 2nd law of thermodynamics implies that no matter what observations observers choose to make, it requires no more storage capacity to continue fooling them.

I read this, but I'm a little confused. Conceptually, as a closed system, the demand of universe is constant, sure, when I imagine it as something like the game of Life. Are you assuming that any simulator will be a full and perfect emulator, with no optimizations like caches?

Because if optimizations are applied, then it seems you can expand the necessary power by doing things that defeat the optimizations. Caches are ineffective if you keep generating intricately linked cryptographic junk, etc. One might think that no simulating agent would run a simulator whose worst-case requirements are beyond its abilities; but then, we humans routinely use QuickSort and don't mind our kernels over-committing memory...

(Incidentally, I made an estimation of my own for how small our substrate could be: http://www.gwern.net/Simulation%20inferences.html . I concluded that the simulating computer could be as small as a Planck cube.)

Comment author: SilasBarta 08 December 2009 05:02:33PM 1 point [-]

Are you assuming that any simulator will be a full and perfect emulator, with no optimizations like caches?

It doesn't rely on that assumption. It's just based on the fact that any time you destroy entropy by forcing some system, from your perspective, to be in fewer possible states, you also allow another system, from your perspective, to be in proportionally more possible states.

The more states something could be in, from your perspective, the less information the simulator has to store to consistently represent it for you.

Comment author: Tyrrell_McAllister 08 December 2009 07:29:38PM *  1 point [-]

You make an interesting observation. I'm still trying to think it through, so I might not yet be making sense. But, right now, I have the following difficulty with accepting your argument.

Any simulation has "true" physical laws. These are just the rules that govern how in fact the simulation's algorithm unfolds, including all optimizations, etc.

However, we expect, a priori, the ultimate laws of reality to satisfy certain invariances. For example, perhaps we expect the ultimate laws to work identically at different points in real physical space. The true laws of the simulation might not satisfy such invariances with respect to the simulation. For example, the simulation's laws might not work identically at different points in the simulated physical space. [ETA: Optimization makes this likely. The simulation could evolve in a "chunkier" way far from us than it does close to us.]

So maybe this is how we can define what it means to hide the simulated nature of our universe from us: "Hiding the simulation" means "making our universe appear to us as though its laws satisfy all the expected invariances, even though they don't".

Here's the issue that I hope you address:

I'm convinced by your argument that "any time you destroy entropy by forcing some system, from your perspective, to be in fewer possible states, you also allow another system, from your perspective, to be in proportionally more possible states."

Say that, when I start out, system A could be in any one of the states in some state-set X. Then I learn about system B, and so, as you point out, system A could now be in any one of the states in some larger state-set Y, as far as I know.

But what if the larger state-set Y includes states that do not obey the expected invariances? And what if, as I learn more about the universe, the state-set that A's state must be in grows, all right, but eventually consists almost entirely of states that violate our expected invariances?

Wouldn't that amount to discovering the simulated nature of our universe? To avoid this discovery, wouldn't the simulators have to put more resources into making sure that A's set of possible states includes enough states that obey the expected invariances?

Comment author: gwern 08 December 2009 07:00:49PM 1 point [-]

I vaguely see what you're getting at - every observation or interaction forces the simulator to calculate what you see, but also allows it to cheat in other areas. But I'm not sure how exactly this would work on the level of bits and programs?

Comment author: Jack 07 December 2009 09:30:18PM *  2 points [-]

When I was first introduced to quantum mechanics my professor taught us the Copenhagen Interpretation. I was immediately reminded of occasional moments in video games where features of a room aren't run until the player gets to the room. It seemed to me that only collapsing the wave function when it interacted with a particular kind of physical system (or a conscious system!) would be a really good way to conserve computing power and that it seemed like the kind of hack programmers in an fully Newtonian universe might use to approximate their universe without having to calculate the trajectories of a googolplex (ed) subatomic particles.

Can anyone tell me if this actually would save computing power/memory?

Comment author: SilasBarta 07 December 2009 09:48:49PM *  2 points [-]

The answer basically comes down to the issue of saving on RAM vs. saving on ROM. (RAM = amount of memory need to implement the algorithm, ROM = amount of memory needed to describe the algorithm)

Video game programmers have to care about RAM, while the universe (in its capacity as a simulator) does not. That's why programmers generate only what they have to, while the universe can afford to just compute everything.

However, I asked the same question, which is what led to the blog post linked above, where I concluded that you wouldn't save memory by only doing the computations for things observers look at: first, because they check for consistency and come back to verify that the laws of physics still work, forcing you to generate the object twice.

But more importantly (as I mentioned) because the 2nd law of thermodynamics means that any time you gain information about something in the universe, you necessarily lose just as much in the process of making that observation (for a human, it takes the form of e.g. waste heat, higher-entropy decomposition of fuels). So by learning about the universe through observation, you simultaneously relieve it of having to store at least as much information (about e.g. subatomic particles).

(This argument has not been peer-reviewed, but was based on Yudkowsky's Engines of Cognition post.)

Comment author: matt 07 December 2009 10:53:46PM 2 points [-]

googleplex = Google Inc's HQ

googolplex = 10^(10^100)

Comment author: Blueberry 08 December 2009 12:16:43AM -2 points [-]

It's truly sad now how people are less familiar with the original spelling and meaning of a googol. Now the first thing we think of is the search engine, instead of 10^100.

Comment author: pengvado 08 December 2009 06:59:36AM 1 point [-]

Assuming they don't make any approximations other than collapse, yes a classical computer simulating Copenhagen takes fewer arithmetic ops than simulating MWI. At least until someone in the simulation builds a sufficiently large coherent system (quantum computer), at which point the simulator has to choose between forbidding it (i.e. breaking the approximation guarantee) or spending exponentially many arithmetic ops.

Copenhagen (even in the absence of large coherent subsystems) does not take significantly less memory than MWI: both are in PSPACE.

Otoh, if the simulator is running on quantum-like physics too, then there's no asymptotic difference in arithmetic either. And if you're not going to assume that the simulator's physics is similar to ours, who says it's less rather than more computationally capable?

Comment author: Baughn 07 December 2009 07:43:44PM 3 points [-]

If you implemented the laws of physics on a computer, using lazy evaluation, then whatever is "over the horizon" from the observer process(es) would not be computed.

However, this would not in the least be observable from inside the system. If the observer moved to serve you, your past would be "retroactively" computed.

I'm not claiming this is very likely to be the case, since at the very least it requires an additional agent - the observer process - to cause anything to happen at all, but lazy evaluation isn't some weird ad-hoc concept; it's a basic concept in computer science that also happens to make programs shorter, a lot of the time.

Hopefully not sufficiently shorter that a universe using lazy evaluation with one random point in space somewhere as the observer is less complex than one using strict evaluation. That.. would be impossible for us to detect, of course, but I believe it'd still have consequences.

Comment author: NancyLebovitz 07 December 2009 10:58:03AM 2 points [-]

If the universe we're living in is a work of art or a game, it's made for minds with much greater processing power than we've got. It isn't obvious that they'd be satisfied with something as crude as a video game.

Comment author: Baughn 07 December 2009 07:46:07PM 4 points [-]

How about a video game where you attempt to control a pre-singularity global civilization by directly playing a few thousand randomly selected humans simultaneously, while not letting this fact be noticed by the NPCs?

It's interesting to wonder what sort of games post-humans might play, though I hope it won't be anything quite that ethically objectionable.

Comment author: wedrifid 08 December 2009 01:47:50AM *  1 point [-]

It's interesting to wonder what sort of games post-humans might play, though I hope it won't be anything quite that ethically objectionable.

Or, from the perspective of a pre-post-human, quite that dull. If I am going to play that kind of sim I'm going to pick the 'elves' faction.

Comment author: Baughn 10 December 2009 12:35:03PM *  1 point [-]

Considering that there exist fork-lift simulation games, I hesitate to claim that anything is too dull to be made.

Comment author: Lightwave 08 December 2009 09:35:49AM 1 point [-]

It could be that it was the elves who picked the 'humans' faction.

Comment deleted 07 December 2009 05:16:20AM [-]
Comment author: Pavitra 07 December 2009 05:22:15AM 0 points [-]

You mean, besides the predictive power of the mathematical formalizations of Occam's Razor, as opposed to a linguistic or pathetic formulation?

The universe looks very falsifiably like a computer program.

Comment author: Psychohistorian 07 December 2009 05:20:12AM 0 points [-]

If you can understand how the two are truly the same, you are far wiser than anyone I've ever met, and I would very much like to subscribe to your newsletter. I hope thefirst issue explains how this dichotomy is invalid.

Comment author: wedrifid 07 December 2009 05:37:59AM 3 points [-]

A video game can be deterministic or not in the same way any other kind of universe can. "Video game" vs "deterministic" is just a silly comparison. I don't know what word to use in place of 'deterministic', I just don't think that one is the right one.

Comment author: Blueberry 07 December 2009 06:40:08AM 2 points [-]

I'm thinking "algorithmic". That is, the universe, or a video game, follows a certain algorithm to determine what happens next, whether the algorithm is the laws of physics or a computer program. Algorithms aren't necessarily deterministic: we could have a step for "generate a truly random (quantum) number".

Comment author: Jack 06 December 2009 07:58:20PM 0 points [-]

Huh? "Metaphysics" refers to an incredibly wide variety of claims. But I'd say that metaphysics tries to answer questions about reality that aren't the kind of questions that can be answered by experimental science. Since we lack a good method for answering these questions our confidence in metaphysical claims is usually substantially lower than it is for empirical claims. But why should we think all metaphysical questions are radically different from scientific questions such that the answer to one can't influence our estimations of the other? Of hand I can't think of a number of metaphysical hypotheses that have been greatly effected by scientific knowledge and vice versa-- materialism, substance dualism, determinism and indeterminism, free will, eternalism and philosophies of time etc.

In this case it seems rather obvious that if we are "living in the Matrix" the probability that the basic laws of physics are complicated rather than simple is dramatically higher.

Comment author: Pablo_Stafforini 06 December 2009 11:25:32PM 0 points [-]

I never denied that a our assessment of an empirical claim may be influenced by the metaphysical views we hold. I simply noted that, once the Matrix hypothesis is understood as a metaphysical hypothesis, it is unclear why believing that we live in the Matrix should increase our credence in the various claims of parapsychology.

Comment author: Jack 06 December 2009 11:45:37PM 0 points [-]

I have no idea what your argument actually is. Why does it matter whether or not the Matrix hypothesis is a metaphysical hypothesis?

Comment author: Pablo_Stafforini 07 December 2009 12:24:17AM *  2 points [-]

My original comment was a reply to Mitchell Porter, who suggested that parapsychology would somehow receive support from the Matrix hypothesis. I replied by saying that this would not be true, or at least not clearly, if that hypothesis is understood as a claim about the ultimate nature of reality.

To take another example, suppose someone argued Berkeleyan idealists should be more open to psychic phenomena, since we are all ideas in the mind of God. I would reply that this is not so, since the fact that the world is ultimately made of mind has in itself no implications about whether certain kinds of mental phenomena take place within that world.

Comment author: Jack 07 December 2009 01:04:20AM 1 point [-]

The ability of certain collections of atoms to communicate large amounts of information to other collections of atoms over vast distances without there being any detectable emissions is an incredibly complex power. Complex entities are a priori improbable compared to simple entities. You need some kind of creation mechanism to make them probable... with biological systems we have evolution, with pocket watches and jet planes you have human inventors. If you accept a metaphysical hypothesis that involves an intelligence creating the universe-- programmers or God-- you have a mechanism for making complex entities probable. That is why the Matrix hypothesis makes psychic phenomena more likely

Comment author: wedrifid 07 December 2009 01:39:59AM *  2 points [-]

Complex entities are a priori improbable compared to simple entities.

This remains the case no matter what the universe is made of. All evidence suggests that psychic mechanisms are not available to us in our current mode of existence, whatever that may be. That evidence doesn't change until you get more.

At least, that seems to me to be the point ben is making.

Comment author: Jack 07 December 2009 01:58:16AM *  1 point [-]

Complex entities are a priori improbable compared to simple entities.

This remains the case no matter what the universe is made of.

Yes, but not no matter how the universe was created. The Matrix hypothesis includes a claim that the universe was created by some intelligence and that makes psychic phenomena substantially more plausible.

That doesn't mean all religious people have to believe in psychic phenomena or even that they should. If there is no evidence for psychic phenomena then there is not evidence for psychic phenomena. But if you think the universe was created claims of psychic phenomena should be less absurd on their face.

Comment author: Blueberry 06 December 2009 09:11:39AM 0 points [-]

Do you think it is possible that we are "living in the Matrix"? If so, then you should consider something functionally indistinguishable from psychic powers to be possible.

Yes, but then we would have to give up on the scientific method anyway, because the laws of physics would be whatever the adminstrators of the Matrix felt like changing them to.

Comment author: SilasBarta 06 December 2009 05:14:35PM 5 points [-]

What Jack said -- you can still notice regularities in the Matrix even if it's sometimes capriciously tampered with. That is, these overlords do not automatically make our universe a high-entropy white noise bath.

I discussed some of the implications of a simulated universe and the implications of the 2nd law of thermodynamics on it here.

Comment author: Jack 06 December 2009 05:06:33PM 3 points [-]

The universe being a simulation does not entail that the administrators of such a simulation are capricious. And that we have demonstrated the existence of a large number of natural regularities suggests they are not.

Comment author: Neil 06 December 2009 01:59:55PM 1 point [-]

If parapsychology is studying the patently non-existent, then the fact that parapsychologists don't typically spend their time debunking their own subject might suggest they are not up to par in some way, as a group, with "the rest of" science - unless you concede that other branches of science would also carry on in the face of total collapse in the credibility of their subject.

Comment author: Eliezer_Yudkowsky 06 December 2009 03:49:00PM 4 points [-]

The nonexistence of psychic powers is less patently obvious than the truth of many-worlds in physics, so there is no proof that parapsychologists are less rational than average physicists. They are studying a widely despised subject, but that if anything should raise our estimate of their level.

That said, it's entirely possible that, in reality, parapsychologists are lower-level. But we should not be so quick to assume this. And it remains that other sciences may also tend to contain some low-level people. Scientific protocols for saying when a theory has been verified are not supposed to rely on such things.

Comment author: alexflint 08 December 2009 10:25:14AM 2 points [-]

What is this "level" attribute you refer to? Does it mean intelligence or something more?

Comment author: Eliezer_Yudkowsky 08 December 2009 10:31:30AM 18 points [-]

Those little numbers that appear above people's heads. You can't see them?

Comment author: Strange7 05 February 2014 04:20:27AM 0 points [-]

Please record your "level number" observations so that we mere mortals can test whether they correlate with anything independently verifiable.