Are you living in a computer simulation? (Ipoteza vieţii în iluzie)

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Nu mai retin exact unde (ceva site sigur strainez dar coincidental si pe Evenimentul Zilei) dar am citit un articol ce m-a marcat profund. Am facut suplimentar si niste research-uri si va expun totul integrat in continuare, lasandu-va in sarcina sa trageti concluziile de rigoare. Si anume in anul 2001 Nick Bostrom, profesor de filozofie la Universitatea din Oxford, se întreba dacă noi, împreună cu realitatea inconjurătoare, nu suntem cumva o simulare de calculator. Oricât pare de absurd, Bostrom prezintă un raţionament coerent în sprijinul acestei idei, care începând de atunci este cunoscut ca fiind argumentul simulării (Simulation Argument). Argumentul simulării, aşa cum a fost definit de către Nick Bostrom, afirmă că cel puţin una dintre următoarele propoziţii este adevărată:

1)    Este foarte probabil că specia umană va dispărea înainte de a ajunge la un nivel de dezvoltare care sa ii permita sa efectueze simulari de lumi pe calculator
2)    Este foarte improbabil ca civilizatiile care ajung la un nivel post-uman să ruleze un număr semnificativ de simulări ale propriei istorii (sau variante ale acesteia).
3)    Noi insine trăim aproape sigur într-o simulare de calculator.

Filozoful René Descartes se întreba dacă nu cumva întreaga realitate, aşa cum o percepem prin cele cinci simţuri nu este altceva decât o înşelătorie bine pusă la punct. Plecând de la faptul că senzaţiile pe care le avem în vis par foarte reale, el specula asupra faptului că ceea ce percepem prin simţuri ar putea să nu fie realitatea înconjurătoare, ci doar o iluzie. În 1997, Hans Moravec estima (în conformitate cu legea lui Moore) că până în anul 2020 un calculator mediu va avea puterea de calcul şi memoria necesară pentru a egala performanţele intelectuale ale unui creier omenesc. La nivelul tehnologic actual nu ştim dacă un calculator, oricât de performant, ar putea simula o entitate conştientă. Dacă însă acceptăm acest lucru, atunci momentul în care dezvoltarea noastră tehnologică va permite crearea unei minţi conştiente într-un calculator nu este relevant pentru subiectul discutat. Ceea ce contează este doar că acceptăm acest lucru ca fiind teoretic posibil într-un viitor predictibil.Pentru a argumenta faptul că probabil noi trăim într-o simulare, Bostrom speculează că dacă urmaşii noştri („reali” sau doar simulări) vor avea suficientă putere de calcul să simuleze istoria (sau variante ale acesteia), atunci o vor face de un mare număr de ori (cu alte cuvinte, primele două propoziţii de mai sus nu ar fi adevărate). Considerând că personajele simulate ar putea fi conştiente, şi că numărul acestora ar putea fi mult mai mare decât a celor care rulează simulările, rezultă  că este mai probabil ca noi înşine să fim doar simulări.

Argumentând în continuare, Bostrom arată că tot aşa cum într-un viitor previzibili şi urmaşii noştri vor fi capabili să ruleze simulări, este foarte probabil ca personajele simulate să fie capabile la rândul lor să ruleze simulări; acest lucru creşte foarte mult numărul probabil de universuri simulate la un moment dat, ceea ce amplifică posibilitatea ca noi să trăim într-o simulare. În concluzie, se arată că dacă acest lucru este posibil, atunci numărul de simulări care rulează la un moment dat (în paralel, dar şi simulare în simulare) este atât de mare, încât şansa ca fiecare dintre noi să trăim într-o simulare este aproape o certitudine.

Argumentul moral: Este evident faptul că există multă suferinţă în jurul nostru. Dacă acceptăm faptul că realitatea care ne înconjoară este doar o simulare în memoria unui calculator, atunci se pune foarte serios problema moralei celor care rulează această simulare. Este de presupus că a produce atât de multă suferinţă unui număr atât de mare de fiinţe conştiente este profund imoral, cel puţin din perspectiva celor care suferă. Ar putea exista o raţiune superioară care să justifice acest lucru ? Există oare o perspectivă prin care suferinţa poate fi justificată, inclusiv din punctul nostru de vedere, al celor care suferă ? să sperăm că aşa este. Diversele religii, încercând să dea o explicaţie suferinţei, au recurs la răsplata de după moarte. Atât nirvana, cât şi veşnicele plaiuri ale vânătoarei sau paradisul promis celor mântuiţi poate fi un răspuns. Ceea ce merită însă observat este faptul că dacă trăim într-o simulare, este de presupus ca morala după care suntem judecaţi să fie una acceptată şi de către cei care controlează realitatea noastră. Dacă şi aceştia trăiesc la rândul lor într-o simulare, atunci şi lor li se aplică aceleaşi norme de evaluare, pe care ei ni le impun nouă. Din această perspectivă, şi pentru că nimeni nu poate fi sigur că se găseşte la nivelul de bază al realităţii, este probabil ca suferinţa din realitatea pe care o experimentăm să fie gratuită.

Bostrom presupune că simulările au ca scop analiza istorică; alte ipoteze vorbesc despre divertisment, iar Stephen King, în ultimul său roman (Under the Dome), propune ca explicaţie pentru suferinţa din lumea noastră joaca inconştientă a unor copii dintr-o realitate superioară. În sfârşit, există păreri că scopul civilizaţiei care a hotărât să simuleze întregul Univers în care trăim să fie dincolo de puterea noastră de înţelegere, iar suferinţa pe care o experimentăm să fie doar un efect colateral, sau care ţine de veridicitatea simulării. Chiar si noi avem o gramada de pograme pe calculator in care suferinta este la ordinea zilei.

Argumentul religios: Încă din 2001, când a prezentat argumentul simulării, Bostrom a vorbit despre unele implicaţii religioase ale teoriei sale. Se pare că pentru prima dată în istorie există o teorie care prezintă în termeni ştiinţifici argumente în favoarea existenţei unui Creator, lucru afirmat de majoritatea religiilor. Creatorul, în acest caz, este individul „în carne şi oase” care a scris primul program. În cazul în care acceptăm ipoteza că noi trăim într-o simulare, este posibil ca cei care au creat simularea în care trăim să trăiască la rândul lor într-o simulare şi aşa mai departe. Totodată, mai devreme sau mai târziu, chiar şi noi vom fi capabili să rulăm simulări populate de entităţi inteligente conştiente. Aşadar, realitatea ar putea conţine multe nivele incluse unul în altul.

Din perspectiva tulburătoare a vieţii într-un univers simulat, se poate vorbi despre puteri dumnezeieşti ale operatorului care controlează simularea; el este omnipotent pentru că poate interveni în universul simulat, chiar şi fără a fi obligat să respecte legile acestuia şi este omniscient, pentru că poate monitoriza orice loc şi orice moment al simulării. Ne-am putea chiar imagina acest operator creând din nimic, toate lucrurile văzute şi nevăzute, eventual pe durata a şase zile. Dacă acceptăm că trăim într-o simulare, atunci devine plauzibilă inclusiv prelungirea existenţei noastre după moarte, fie la un alt nivel al realităţii, fie în aceeaşi simulare. În funcţie de scopurile celor care realizează simularea în care trăim, este posibilă chiar şi existenţa unui sistem de recompensă şi pedeapsă, pe baza unui sistem moral.

***

ABSTRACT: This paper argues that at least one of the following propositions is true: (1) the human species is very likely to go extinct before reaching a “posthuman” stage; (2) any posthuman civilization is extremely unlikely to run a significant number of simulations of their evolutionary history (or variations thereof); (3) we are almost certainly living in a computer simulation. It follows that the belief that there is a significant chance that we will one day become posthumans who run ancestor-simulations is false, unless we are currently living in a simulation. A number of other consequences of this result are also discussed.

I. INTRODUCTION: Many works of science fiction as well as some forecasts by serious technologists and futurologists predict that enormous amounts of computing power will be available in the future. Let us suppose for a moment that these predictions are correct. One thing that later generations might do with their super-powerful computers is run detailed simulations of their forebears or of people like their forebears. Because their computers would be so powerful, they could run a great many such simulations. Suppose that these simulated people are conscious (as they would be if the simulations were sufficiently fine-grained and if a certain quite widely accepted position in the philosophy of mind is correct). Then it could be the case that the vast majority of minds like ours do not belong to the original race but rather to people simulated by the advanced descendants of an original race. It is then possible to argue that, if this were the case, we would be rational to think that we are likely among the simulated minds rather than among the original biological ones. Therefore, if we don’t think that we are currently living in a computer simulation, we are not entitled to believe that we will have descendants who will run lots of such simulations of their forebears. That is the basic idea. The rest of this paper will spell it out more carefully.

Apart from the interest this thesis may hold for those who are engaged in futuristic speculation, there are also more purely theoretical rewards. The argument provides a stimulus for formulating some methodological and metaphysical questions, and it suggests naturalistic analogies to certain traditional religious conceptions, which some may find amusing or thought-provoking. The structure of the paper is as follows. First, we formulate an assumption that we need to import from the philosophy of mind in order to get the argument started. Second, we consider some empirical reasons for thinking that running vastly many simulations of human minds would be within the capability of a future civilization that has developed many of those technologies that can already be shown to be compatible with known physical laws and engineering constraints. This part is not philosophically necessary but it provides an incentive for paying attention to the rest. Then follows the core of the argument, which makes use of some simple probability theory, and a section providing support for a weak indifference principle that the argument employs. Lastly, we discuss some interpretations of the disjunction, mentioned in the abstract, that forms the conclusion of the simulation argument.

II. THE ASSUMPTION OF SUBSTRATE-INDEPENDENCE: A common assumption in the philosophy of mind is that of substrate-independence. The idea is that mental states can supervene on any of a broad class of physical substrates. Provided a system implements the right sort of computational structures and processes, it can be associated with conscious experiences. It is nor an essential property of consciousness that it is implemented on carbon-based biological neural networks inside a cranium: silicon-based processors inside a computer could in principle do the trick as well.Arguments for this thesis have been given in the literature, and although it is not entirely uncontroversial, we shall here take it as a given.

The argument we shall present does not, however, depend on any very strong version of functionalism or computationalism. For example, we need not assume that the thesis of substrate-independence is necessarily true (either analytically or metaphysically) – just that, in fact, a computer running a suitable program would be conscious. Moreover, we need not assume that in order to create a mind on a computer it would be sufficient to program it in such a way that it behaves like a human in all situations, including passing the Turing test etc. We need only the weaker assumption that it would suffice for the generation of subjective experiences that the computational processes of a human brain are structurally replicated in suitably fine-grained detail, such as on the level of individual synapses. This attenuated version of substrate-independence is quite widely accepted. Neurotransmitters, nerve growth factors, and other chemicals that are smaller than a synapse clearly play a role in human cognition and learning. The substrate-independence thesis is not that the effects of these chemicals are small or irrelevant, but rather that they affect subjective experience only via their direct or indirect influence on computational activities. For example, if there can be no difference in subjective experience without there also being a difference in synaptic discharges, then the requisite detail of simulation is at the synaptic level (or higher).

III. THE TECHNOLOGICAL LIMITS OF COMPUTATION: At our current stage of technological development, we have neither sufficiently powerful hardware nor the requisite software to create conscious minds in computers. But persuasive arguments have been given to the effect that if technological progress continues unabated then these shortcomings will eventually be overcome. Some authors argue that this stage may be only a few decades away.[1] Yet present purposes require no assumptions about the time-scale. The simulation argument works equally well for those who think that it will take hundreds of thousands of years to reach a “posthuman” stage of civilization, where humankind has acquired most of the technological capabilities that one can currently show to be consistent with physical laws and with material and energy constraints.

Such a mature stage of technological development will make it possible to convert planets and other astronomical resources into enormously powerful computers. It is currently hard to be confident in any upper bound on the computing power that may be available to posthuman civilizations. As we are still lacking a “theory of everything”, we cannot rule out the possibility that novel physical phenomena, not allowed for in current physical theories, may be utilized to transcend those constraints[2] that in our current understanding impose theoretical limits on the information processing attainable in a given lump of matter. We can with much greater confidence establish lower bounds on posthuman computation, by assuming only mechanisms that are already understood. For example, Eric Drexler has outlined a design for a system the size of a sugar cube (excluding cooling and power supply) that would perform 10^21 instructions per second.[3] Another author gives a rough estimate of 10^42 operations per second for a computer with a mass on order of a large planet.[4] (If we could create quantum computers, or learn to build computers out of nuclear matter or plasma, we could push closer to the theoretical limits. Seth Lloyd calculates an upper bound for a 1 kg computer of 5*10^50 logical operations per second carried out on ~10^31 bits.[5] However, it suffices for our purposes to use the more conservative estimate that presupposes only currently known design-principles.)

The amount of computing power needed to emulate a human mind can likewise be roughly estimated. One estimate, based on how computationally expensive it is to replicate the functionality of a piece of nervous tissue that we have already understood and whose functionality has been replicated in silico, contrast enhancement in the retina, yields a figure of ~10^14 operations per second for the entire human brain.[6] An alternative estimate, based the number of synapses in the brain and their firing frequency, gives a figure of ~10^16-10^17 operations per second.[7] Conceivably, even more could be required if we want to simulate in detail the internal workings of synapses and dendritic trees. However, it is likely that the human central nervous system has a high degree of redundancy on the mircoscale to compensate for the unreliability and noisiness of its neuronal components. One would therefore expect a substantial efficiency gain when using more reliable and versatile non-biological processors.Memory seems to be a no more stringent constraint than processing power.[8] Moreover, since the maximum human sensory bandwidth is ~10^8 bits per second, simulating all sensory events incurs a negligible cost compared to simulating the cortical activity. We can therefore use the processing power required to simulate the central nervous system as an estimate of the total computational cost of simulating a human mind.

If the environment is included in the simulation, this will require additional computing power – how much depends on the scope and granularity of the simulation. Simulating the entire universe down to the quantum level is obviously infeasible, unless radically new physics is discovered. But in order to get a realistic simulation of human experience, much less is needed – only whatever is required to ensure that the simulated humans, interacting in normal human ways with their simulated environment, don’t notice any irregularities. The microscopic structure of the inside of the Earth can be safely omitted. Distant astronomical objects can have highly compressed representations: verisimilitude need extend to the narrow band of properties that we can observe from our planet or solar system spacecraft. On the surface of Earth, macroscopic objects in inhabited areas may need to be continuously simulated, but microscopic phenomena could likely be filled in ad hoc. What you see through an electron microscope needs to look unsuspicious, but you usually have no way of confirming its coherence with unobserved parts of the microscopic world. Exceptions arise when we deliberately design systems to harness unobserved microscopic phenomena that operate in accordance with known principles to get results that we are able to independently verify. The paradigmatic case of this is a computer. The simulation may therefore need to include a continuous representation of computers down to the level of individual logic elements. This presents no problem, since our current computing power is negligible by posthuman standards. Moreover, a posthuman simulator would have enough computing power to keep track of the detailed belief-states in all human brains at all times. Therefore, when it saw that a human was about to make an observation of the microscopic world, it could fill in sufficient detail in the simulation in the appropriate domain on an as-needed basis. Should any error occur, the director could easily edit the states of any brains that have become aware of an anomaly before it spoils the simulation. Alternatively, the director could skip back a few seconds and rerun the simulation in a way that avoids the problem.

It thus seems plausible that the main computational cost in creating simulations that are indistinguishable from physical reality for human minds in the simulation resides in simulating organic brains down to the neuronal or sub-neuronal level.[9] While it is not possible to get a very exact estimate of the cost of a realistic simulation of human history, we can use ~10^33 – 10^36 operations as a rough estimate[10]. As we gain more experience with virtual reality, we will get a better grasp of the computational requirements for making such worlds appear realistic to their visitors. But in any case, even if our estimate is off by several orders of magnitude, this does not matter much for our argument. We noted that a rough approximation of the computational power of a planetary-mass computer is 10^42 operations per second, and that assumes only already known nanotechnological designs, which are probably far from optimal. A single such a computer could simulate the entire mental history of humankind (call this an ancestor-simulation) by using less than one millionth of its processing power for one second. A posthuman civilization may eventually build an astronomical number of such computers. We can conclude that the computing power available to a posthuman civilization is sufficient to run a huge number of ancestor-simulations even it allocates only a minute fraction of its resources to that purpose. We can draw this conclusion even while leaving a substantial margin of error in all our estimates.

Posthuman civilizations would have enough computing power to run hugely many ancestor-simulations even while using only a tiny fraction of their resources for that purpose.

………………………………………………

VII. CONCLUSION: A technologically mature “posthuman” civilization would have enormous computing power. Based on this empirical fact, the simulation argument shows that at least one of the following propositions is true: (1) The fraction of human-level civilizations that reach a posthuman stage is very close to zero; (2) The fraction of posthuman civilizations that are interested in running ancestor-simulations is very close to zero; (3) The fraction of all people with our kind of experiences that are living in a simulation is very close to one. If (1) is true, then we will almost certainly go extinct before reaching posthumanity. If (2) is true, then there must be a strong convergence among the courses of advanced civilizations so that virtually none contains any relatively wealthy individuals who desire to run ancestor-simulations and are free to do so. If (3) is true, then we almost certainly live in a simulation. In the dark forest of our current ignorance, it seems sensible to apportion one’s credence roughly evenly between (1), (2), and (3).

Unless we are now living in a simulation, our descendants will almost certainly never run an ancestor-simulation.

***


[1] See e.g. K. E. Drexler, Engines of Creation: The Coming Era of Nanotechnology, London, Forth Estate, 1985; N. Bostrom, “How Long Before Superintelligence?” International Journal of Futures Studies, vol. 2, (1998); R. Kurzweil, The Age of Spiritual Machines: When computers exceed human intelligence, New York, Viking Press, 1999; H. Moravec, Robot: Mere Machine to Transcendent Mind, Oxford University Press, 1999.
[2] Such as the Bremermann-Bekenstein bound and the black hole limit (H. J. Bremermann, “Minimum energy requirements of information transfer and computing.” International Journal of Theoretical Physics 21: 203-217 (1982); J. D. Bekenstein, “Entropy content and information flow in systems with limited energy.” Physical Review D 30: 1669-1679 (1984); A. Sandberg, “The Physics of Information Processing Superobjects: The Daily Life among the Jupiter Brains.” Journal of Evolution and Technology, vol. 5 (1999)).
[3] K. E. Drexler, Nanosystems: Molecular Machinery, Manufacturing, and Computation, New York, John Wiley & Sons, Inc., 1992.
[4] R. J. Bradbury, “Matrioshka Brains.” Working manuscript (2002), http://www.aeiveos.com/~bradbury/MatrioshkaBrains/MatrioshkaBrains.html.
[5] S. Lloyd, “Ultimate physical limits to computation.” Nature 406 (31 August): 1047-1054 (2000).
[6] H. Moravec, Mind Children, Harvard University Press (1989).
[7] Bostrom (1998), op. cit.
[8] See references in foregoing footnotes.
[9] As we build more and faster computers, the cost of simulating our machines might eventually come to dominate the cost of simulating nervous systems.
[10] 100 billion humans50 years/human30 million secs/year[10^14, 10^17] operations in each human brain per second  [10^33, 10^36] operations.
[11] In e.g. N. Bostrom, “The Doomsday argument, Adam & Eve, UN++, and Quantum Joe.” Synthese 127(3): 359-387 (2001); and most fully in my book Anthropic Bias: Observation Selection Effects in Science and Philosophy, Routledge, New York, 2002.
[12] See e.g. J. Leslie, “Is the End of the World Nigh? ” Philosophical Quarterly 40, 158: 65-72 (1990).
[13] See my paper “Existential Risks: Analyzing Human Extinction Scenarios and Related Hazards.” Journal of Evolution and Technology, vol. 9 (2001) for a survey and analysis of the present and anticipated future threats to human survival.
[14] See e.g. Drexler (1985) op cit., and R. A. Freitas Jr., “Some Limits to Global Ecophagy by Biovorous Nanoreplicators, with Public Policy Recommendations.” Zyvex preprint April (2000), http://www.foresight.org/NanoRev/Ecophagy.html.
[15] For some reflections by another author on the consequences of (3), which were sparked by a privately circulated earlier version of this paper, see R. Hanson, “How to Live in a Simulation.” Journal of Evolution and Technology, vol. 7 (2001).

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7 răspunsuri to “Are you living in a computer simulation? (Ipoteza vieţii în iluzie)”

  1. Terese Chilinskas Says:

    Umm.. I can not read your post well. Font is a bit too small 🙂

  2. nbsh Says:

    Pai dupa ce scrii articolul asta ti se pare suspect ca unii se comporta ca niste vampiri, adica se folosesc de munca altora? Asta face media capitalista avida dupa subiecte si incapabila sa mai aduca ceva nou, cu toate diplomele lor (ce se mai lauda marie jenica rapita ca are o diploma de jurnalista…). Astia traiesc si din blogareala altora. Ei doar trebuie sa scrie un articolas sau sa dea o stire, ca blogerii le arata cum gandeste boborul. Apoi, daca le convine ce spune blogomanu’, ii preiau ideea.
    Ca sa nu fie probleme iti recomand sa pui „creative commons” pe blog, ce varianta iti convine. In caz ca cineva vinde articolul sau ideea originala poti sa le reprosezi cate ceva.

  3. Patratzel Says:

    frumos blog … si articole bune o sa te citesc in continuare .. am si eu o poza pentru Basescu cu dedicatie http://patratzel.com/neseriosu/2-lei/

  4. amycommunications Says:

    Stimat domn, eu nu sunt înregimentată politic precum sunteţi dumneavoastră d.e. şi este cel mai evident că îmi păstrez neutralitatea diplomatică, prin faptul că nu arăt greşelile unuia sau altuia, în special. Valoarea mea este morala legislaţiei (elveţiene şi americane dar şi..franceze?! d.e.) şi, fiind neutră d.p.d.v. politic, acest lucru îmi permite de a sesiza abaterile oricui . A-propos de ‘obtuzitatea tehnică de care vorbiţi, au trecut mai mult de 6 ani de cînd nu mai trăiesc în virtual şi am devenit extrem de diferită de majorităţi. dar şi de alţi şi alte prea mulţi indivizi…. . Nu mă înţelegeţi greşit: nu vă cunosc personal, aşa încît vă doresc succes!!

  5. dementor Says:

    Teoretic totul este posibil atat vreme cat nu cunoastem limitele de lucru ale creierului uman.Mi sa intamplat deseori sa cred ca la nivel universal suntem coordonati de un imens creier in stare metafizica…Abrodarea unui joc computerizat care sa imite realitatea inconjuratoare …,este o abordare mai mult decat realista este o posibilitate vizionara a ceea ce putem.Intr o alta ordine de idei…realitatea si visul se leaga intr o forma care devine posibilitatea intamplarilor reale constientizate la un moment dat.Computerul poate devenii sa zicem motivatia mintii umane in depasirea sinelui….insa realizarea imaginilot prezente trecute si viitoare tzine de starea chimica in care ne aflam acum…,iar chimia este stiintza realitati imediate

  6. amycommunications Says:

    Ai uitat de argumentul legal/juridic. Îl găseşti în unele cărţi de la edit. Polirom şi în majoritatea celor în edit. juridică C.H.Beck. Asta în cazul în care nu te îndrepţi spre alte teorii economico-matematice, mai implicate în viaţa de zi cu zi..Oricum, dă-ţi ochelarii jos şi poate veiîncepe să vezi. Mulţumesc-

    • SorinPLATON Says:

      @amy

      Stimata doamna,
      Despre ce ochelari vorbiti, ca nu reusesc sa ma dumiresc? Sugerati ca as fi obtuz in abordari … aplicand la toate fronturile, fara frica de consecinte?.. Ar fi multe de spus dar ma limitez. Poate ca v-am inteles gresit.

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