Let The Dice Play GodDamiano AnselmiDipartimento di Fisica Enrico Fermi, Università di Pisaand INFN, Sezione di Pisa,Largo B. Pontecorvo 3, 56127 Pisa, Italydamiano.anselmi@unipi.itAbstractWe dene life as the amplication of quantum uncertainty up to macroscopic scales.A living being is any amplier that achieves this goal. We argue that everything we knowabout life can be explained from this idea. We study a ladder mechanism to estimatethe probability that the amplication occurs spontaneously in nature. The amplicationmechanism is so sensitive to small variations of its own parameters that it acts as a bifur-cation itself, i.e. it implies that the universe is either everywhere dead or alive whereverpossible. Since the rst option is excluded by the existence of life on earth, we infer thatthe universe hosts a huge number of inhabited planets (possibly one per star on average).We also investigate models of conscious and unconscious learning processes, as well as thestructure of the brain and evolution. Finally, we address the problem of creating articiallife. 1 1 The denition of lifeThe problem of explaining life is extremely complex. As of today, an accepted denitionof life is still missing [1]. On the other hand, in the past century a huge progress has beenachieved, both in physics and biology. For a physicist, in particular, it must be possibleto understand life as a physical phenomenon. It is interesting to inquire whether theknowledge of the physical laws gathered so far is advanced enough to solve the problem ornot. In this paper we argue that it is.Although there is increasing evidence that the quantum phenomena play a non sec-ondary role in the biological systems, there is no general agreement on the importance ofsuch a role. That said, the starting point of the investigation we plan to carry out in thispaper is the idea that quantum phenomena are actually the essential features of the livingbeings. We provide four main reasons to support this position.The rst reason is intuitive. Most phenomena related to life, such as evolution, and thebehaviors of the living beings are not predictable, in contrast with the other phenomenathat occur around us, which are deterministic. It might be argued that the unpredictabilityin question is a blunder, due to the extreme complexity of the physical systems that areinvolved. However, we know that pure chance does exist in nature, due to the uncertaintyprinciple: at the microscopic level the output of a physical system cannot be predictedfrom the input, in general. Not only, but it is possible to amplify the eects of theuncertainty principle to large distances (which is what many experiments in quantummechanics do). Since the amplication is possible, there is a denite probability thatit may occur spontaneously in nature. It is scientically interesting to estimate such aprobability.Thus, we think that linking the unpredictability of the living beings to quantum uncer-tainty is a natural hypothesis. It suggests to dene life by means of quantum uncertaintyand view a living being as an amplier of quantum uncertainty up to the macroscopicrelative distances.The second reason we oer is encoded in the claim that everything we know about lifecan indeed be explained from this idea. Although the phenomena that have to do withlife are extremely involved, we believe that in the following pages we clarify several criticalissues and advance a lot in the direction of achieving this goal.The third reason is even stronger. We claim that we can validate the idea a posteriori,by building articial life along the guidelines that emerge from the investigation. Ratherthan plunging into a sterile and partisan discussion, we want to push for developing a new2 type of scientic research, whose nal goal is to build articially living creatures. We thinkthat once we will be surrounded by articially living companions  and it might not takeso long , any doubt about the ultimate nature of life will fade away.The fourth reason follows from a result that we obtain, which we anticipate below.Attempts to relate the uncertainty principle to biology or concepts like the so-calledfree will have appeared throughout the past decades. Although it is beyond the scopeof this paper to examine the literature on these subjects in depth, some mentions are inorder.Important roles have been attributed to chance and unpredictability in biology byscientists and philosophers even before the advent of quantum mechanics. Well-known isthe central role of chance in Darwin's theory of evolution, even if Darwin could not tellwhat the engine of chance was. For Maxwell, determinism was related to stability, whileunpredictability and free will were related to instability, which he dened as the conditionwhen an innitely small variation in the present state may bring about a nite dierencein the state of the system in a nite time. In other words, he thought that instability isthe watershed, where an imperceptible deviation is sucient to determine into which oftwo valleys we shall descend [2]. For Nietzsche there exists neither spirit, nor reason,nor thinking, nor consciousness, nor soul, nor will, nor truth: all are ctions that are of nouse [3]. On the contrary, it may be that our own voluntary acts and purposes are merelysuch throws of dice [4].After the discovery of quantum uncertainty, various scholars tried to link it to free will.Eddington thought that the new physics thus opens the door to indeterminacy of mentalphenomena, whereas the old deterministic physics bolted and barred it completely [5] andscience thereby withdraws its moral opposition to freewill [6]. Compton was convincedthat there are, however, conditions under which the uncertainty in a small scale eventmay result in an equal uncertainty in an event of great magnitude [7]. He thought that,as far as physics is concerned, a person's actions which we think of as free would thusappear to occur simply according to the rules of chance [8]. However, he also thoughtthat the principle of uncertainty was not sucient to prove freedom. He said that, instead,something additional to the physical phenomena is involved, because freedom does,however, involve the additional determining factor of choice, about which science tells usnothing [8]. Popper shared many of Compton's views. He admitted that it is conceivablethat something like the amplication of a quantum jump may actually happen in ourbrains if we make a snap-decision, but was against the doctrine according to which thealternative to determinism is sheer chance, stating that freedom is not just chance [9].3 More recent studies concentrated on human consciousness and the question whether it canbe explained by the physical laws as a weakly emergent consequence of the brain activityor it requires more [10].In our opinion, the main aws of these investigations and proposals are that theyare human centered, unsystematic and not particularly ambitious. They do not aim atunderstanding life, but focus on particular aspects of the human life. We would like topursue an investigation that is not inuenced by the existence of humans in the universe.In this spirit, we take a vow to basically ignore the human beings and their emotionalneeds and quests for moral principles, to concentrate on the possibility of developing anew science.To summarize, we view quantum uncertainty as the elementary bit of life. Precisely,a) life is the amplication of quantum uncertainty to macroscopic scales;b) a living being is any structure that amplies quantum uncertainty up to the macro-scopic scales.When the amplication occurs spontaneously in nature, it generates natural life. Whenit is produced by the human beings, it generates articial life.Among the other things, we study the probability that the amplication occurs spon-taneously in nature. It turns out that, without a ladder amplication mechanism (LAM),such a probability is so small that the universe would have to be everywhere dead. Sincewe exist, nature must be equipped with one or more ladder mechanisms that facilitate theamplication by subdividing the process into a sequence of reasonably small steps. Weshow that the LAM is so sensitive to small variations of its own parameters that it impliesthat the universe is either everywhere dead or alive wherever possible. Since, again, therst option is excluded by the existence of life on earth, we conclude that the universe musthost a huge number of inhabited planets. This result oers a fourth reason in support ofthe idea that life is the amplication of quantum uncertainty to macroscopic distances: areduced role of quantum uncertainty can be viewed as a huge variation of the parametersof the LAM, which would depress the probability of spontaneous life formation from onedown to zero.It may be observed that any device we build to make experiments of quantum mechan-ics, such as the Stern-Gerlach experiment, the double-slit experiment, or any quantumrandom number generator, amplies quantum uncertainty up to macroscopic distances.The denition of life we have given implies that such devices are alive, in the momentthey make measurements. This idea might sound unappealing to some people. However,4 we do not see a compelling reason to rene (and possibly burden) the denition of life toprevent this risk. A renement, even if well framed, could easily lead to a lack of clarity.Moreover, as explained already, what is unsatisfactory to humans is not going to inu-ence our investigation. After all, evolution tells us that we are descended from primatesand simpler species, so it should not be that upsetting to discover that we are actuallydescended from the atom.It goes by itself that we do not consider the reproductive ability a dening propertyof life. Indeed, a sterile living being must still be considered alive. Nevertheless, thereproductive ability is important to sustain and expand organic life, because generating alarge number of individuals rapidly enough makes it possible to have selection, adaptationand evolution. At the same time, there might be dierent forms of articial life and someof them may not need a reproductive ability. Certain types of articially living creaturesmay be practically eternal. They might learn how to produce other individuals (rather thanreproduce) or upgrade/evolve their own bodies. In that case, the number of individualsmight not be crucial to have evolution and/or prevent extinction.The paper is organized as follows. In section 2 we describe some basic quantum devicesand discuss how they can be combined. In section 3 we estimate the probability thatthe right combinations of quantum bifurcations form spontaneously in nature, with thehelp of a ladder amplication mechanism. In section 4 we investigate models of consciousand unconscious learning processes. In section 5 we study the structure of the brain andsome of its basic functions. In section 6 we describe the mechanisms of reproduction andevolution. In section 7 we address the problem of creating articial life. Section 8 containsthe conclusions.2 Chains of quantum bifurcationsBefore dealing with more complicated issues, it is convenient to describe some basic quan-tum systems and the simplest ways of combine them.Consider a spin-1/2 particle. Let s denote the spin operator and si its componentalong the ith direction. Let |+, i〉 and |−, i〉 denote the eigenvectors of si with eigenvalues +1/2 and −1/2, respectively. Let Q0 denote a device that measures the spin componentof input particles |+, x〉 along the z direction. The states of the output particles are |+, z〉and |−, z〉 with equal probabilities P+ = P− = 50%. We call this system a quantumbifurcation.Now, let α = (cosα, 0, sinα) denote the versor of the xz plane that forms an angle5 α with the x axis. Let |+, α〉 denote the eigenstate of the operator sα ≡ s * α witheigenvalue +1/2. For example, states |+, α〉 can be obtained from states |+, x〉 by lettingthe particles cross a uniform magnetic eld oriented along the y axis. Let Qα denote avariant of the system Q0 that measures the spin component of input particles |+, α〉 alongthe z direction. The outputs of Qα are still |+, z〉 and |−, z〉, but now their probabilitiesare P+α = (1 + sinα)/2 and P−α = (1 − sinα)/2, respectively. For example, α = 300 gives P+ = 75% and P− = 25%.A device H that is able to operate the modication Q0 → Qα is a simple tool that canbe used to ne tune the output probabilities to favor an output over the other output.Another elementary quantum device can be imagined as follows. Consider an atom Aand call E0 and E1 its rst two energy levels (which we assume to be non degenerate),corresponding to the states |0〉 and |1〉, respectively. Let τ denote the lifetime of the state |1〉. If A is isolated and its state is |1〉 at time t = 0, the probability that A decays to |0〉within an amount of time equal to t is p(t) = 1− e−t/τ . (2.1)Now, assume that the atom A is initially in the state |0〉 and interacts with a radiationof intensity I, with a spectrum of frequencies peaked around ω = (E1 − E0)/~. Theprobability that the atom is excited to the state |1〉 within time t is w(t) = BIτ ∗ ( 1− e−t/τ∗) , (2.2)where B is the Einstein coecient and τ ∗ = τ/(1 + 2BIτ).Build a quantum device, still denoted by Qα, as follows. Assume that A is in |0〉 at t = 0 and interacts with the radiation for an amount of time ∆t such that w(∆t) = w,for a given w. After that, the atom, if excited, goes back to the fundamental level withthe decay probability (2.1). Let ∆t = −τ ln(1 − p) denote the amount of time such that p(∆t) = p, for a given p. Assume that, if the atom does not emit a photon within ∆t,the device Qα discards the event and starts over. Instead, if the atom emits a photon, Qαrecords the answer yes, if the emission occurs before the threshold ∆tα = −τ ln ( 1− pP+α ) (2.3)[which is such that p(∆tα) = pP+α ] and no if the emission occurs after ∆tα. In the end,the output yes has probability P+α to occur, while the output no has probability P−α .Modifying α and the threshold ∆tα, the probability of outputs can be tuned to favor oneor the other answer. 6 The systems Qα are typical elementary quantum devices. What is interesting, now, isto inquire what happens when large numbers of them are combined into complex systems.It is not necessary to require that each unit Qα projects onto a pure state. Actually, it ismore interesting to have patterns of entangled devices, as naturally occurs in liquids.In simple terms, the microscopic quantum systems Qα can be combined in two basicways: at random or in ordered sequences. When they are combined at random, the eectsof the uncertainty principle average to zero and the result is an apparent determinism.When they are combined in an ordered sequence, the eects of the uncertainty principlecan be amplied at will to macroscopic scales. In simple terms, the random combinationsgive rise to the nonliving portion of the universe. The ordered combinations originate life.The random combinations, where the elementary systems are distributed with no par-ticular rule, are by far the most probable ones in nature. The simplest example is a systemmade of N copies of Q0, whose global output is the average of the Q0 outputs. If N islarge, the mean value of the z component of the spin of the output particles is equal tozero, with a normal probability distribution. This means that the system loses the abilityto make a decision.A combination in ordered sequence, on the contrary, is a conguration in which the out-come of a single quantum bifurcation aects the external world or the nearby bifurcations.For example, the output of a device Q0 can be used to modify the next device Q0 of thesequence by turning it into a Qα or a Q−α, where α is xed amount. Arbitrarily complexpatterns, chains, trees, or circuits, can be built, increasing the variety and complexity ofresponses at will.Locally, and in a very small fraction of cases, the microscopic quantum systems canspontaneously combine into ordered sequences, and amplify the eects of quantum un-certainty to macroscopic scales. We claim that the human beings, as well as the otherliving beings, animals and plants, are examples of such spontaneously formed quantumampliers. The rareness of life in the universe gives us an idea of how small the probabilityof spontaneous formation is. At the same time, the presence of life in at least one planetensures that it is nonvanishing. In the next section we estimate that probability and showthat interesting things come out from this kind of investigation.3 From atoms to cells: the LAMIn this section we study the probability that the right combinations form spontaneouslyin nature. 7 Let us begin by recalling a few numbers. The size of the atom is about 10−8cm. Itcan be taken as the microscopic scale of the quantum phenomena. A cell is already a wellorganized system, and in most cases a living being in itself. The typical size of a cell is 10−3-10−5cm in the case of prokaryotes and 10−3-10−2cm in the case of eukaryotes [11],which are made of about 1014 and 1011 atoms, respectively. We can take 10−5cm as ameasure of the macroscopic scales where organic life is present in form of cells. Eukaryotesare cells with nuclei, while prokaryotes are cells without nuclei. Various structures withoutcells are capable of replicating themselves, autonomously or non autonomously: the viruses(virions), which have a DNA; the viroids, which have an RNA but no DNA; the prions,which are just proteins. The DNA is a macromolecule made of about 108-11 atoms ineukaryotes, 107-8 atoms in prokaryotes and in viruses [12]. The DNA is organized inrelatively simple small units, the nucleotides, which contain about 35 atoms each. Thereare viruses with a DNA made of just 1821 nucleotides [13].The number of atoms in the observable universe is about NU = 1080, distributed inabout 1023 stars [14]. The universe contains also matter of dierent nature, like the darkmatter, which might also be able to form life of some type. Nevertheless, the dark matterin the universe is just 4-5 times more abundant than ordinary matter. For the purposesof this paper, including or neglecting the dark matter does not make a great dierence,since numerical factors of order 1 cannot be estimated anyway. Thus, a reasonable workhypothesis is that the matter of the universe is made of 1080 atoms in total.A typical star, like the sun, has 1057 atoms. The planet earth has 1050, while Jupiter has 1054. The amount of living matter on earth can be calculated as follows. Prokaryotes aremade of about 1030 cells [15], which means roughly 1041 atoms. The eukaryotes contributeby an amount that is similar to the one of the prokaryotes (with a predominant role ofplants), while the contribution of viruses is smaller by a factor one hundred [16]. Thus, wecan assume that life on earth is made of 1041 atoms in total. For comparison, the humanpopulation is around 6 * 109 people, which means 1023 cells, i.e. about 1037 atoms.Not all the atoms NU of the universe are in the condition to generate life. In particular,the four phases of matter, solid, liquid, gas and plasma, do not equally favor the formationof ordered sequences of quantum bifurcations. Solids are not dynamic enough, while gasesand plasmas are not stable enough. Liquids have the desirable properties to enhance thesearch for the right combinations, although they may not stabilize them once found. In thebody of a living being there are both liquid and solid phases, so it is reasonable to restrictto the portion of the universe where these two phases are in contact with each other.To estimate the fraction of atoms that can eectively generate life, we multiply by8 reduction factors that take care of various restrictions. First, we exclude the atoms thatmake the stars, as well as the gaseous or inhospitable planets. To do so, we multiply NU bya fraction equal to the ratio 10−7 between the number of atoms that make the earth andthose that make the sun. This corresponds to assume that there are roughly 1023 planetsearth in the universe one per star. We are not assuming that life is eectively present inall of them, at this level. After the reduction we get N ′U = 1073.Then, we multiply by the ratio 10−9 between the numbers of atoms of the earth andthe number of atoms contained in the bodies of the terrestrial living beings, which leadsto N ′′U = 1064 atoms of potentially living matter in the universe.Most parts of the body of a complex living being behave deterministically. Nevertheless,we have shown above that most living beings are unicellular, like the prokaryotes, so thereis no need of a correction factor for this eect. Moreover, it is reasonable to think that allthe cells of the living beings amplify quantum uncertainty to some degree, even those thatare part of organs that on average appear to behave deterministically.Let us now consider the combinations of atoms that amplify the eects of quantumuncertainty. For simplicity, we study one-dimensional sequences. The atoms must beappropriately oriented, because otherwise quantum eects average away. We call in seriesthe orientation that amplies the quantum eects and in parallel the orientation thatsuppresses them. Call p the probability that two close atoms are oriented in series. Then pN is the probability that a row of N atoms amplies quantum eects to the scale dN = N * 10−8cm.Assume that the atoms can be described as cubes. Two adjacent cubes have one face incommon and each cube can face the next one in 6 dierent ways. Thus, we take p = 1/6.Then, consider a row of N = 103, which is enough to cover the diameter of the cell of asimple prokaryote. The probability of formation of the ordered sequence is pN ∼ ( 1 6 )103 ∼ 10−778, (3.1)i.e. an unbelievably small number. If we take p = 1/2 the situation does not improvemuch, since we get pN ∼ 10−301.Assume that, since the birth of the universe all the atoms NU have been making at-tempts to search for the right combinations at a speed V of one billion attempts per secondper atom. This means that V TU attempts have been made so far by each atom, where TUis the age of the universe. We also assume that, once the right combination is found, itlasts forever. We round TU to 1017s (a quarter of the actual age), because we are interestedin orders of magnitude and also because 1017s ago is more or less when the earth formed9 and became inhabitable. Then, by now, we would have NU [ 1− (1− pN)V TU ] (3.2)right sequences of N atoms in the universe1. The formula gives 10−672 with N = 103 and p = 1/6. It does not make a big dierence if we use N ′′U instead of NU , or p = 1/2 insteadof p = 1/6, or 4TU instead of TU : the result is practically zero, so this kind of amplicationmechanism is just hopeless.The outcome changes a lot if we assume that there is a ladder amplication mechanism(LAM) in nature. More precisely, assume that the amplication eort is split into nseparate steps, or rounds, each of which takes an amount of time equal to TU/n. In therst round, atoms organize into structures s1 of ` atoms. In the i-th round (i = 2, . . . n), `copies, or versions, of the (i−1)-th structure si−1 combine into the i-th structure si. Then,after n rounds we have structures made of NC = `n atoms. More complicated LAMs canbe studied (for example, with dierent `is for dierent rounds), but here we just choosethe simplest option to prove the main point. We still assume that the right congurations,once formed, are stable. If V attempts are made per second per structure, the probabilityof nding the right combinations of NC atoms is P (Nc, n) = [ 1− (1− pN 1/n C )V TU/n ]n . (3.3)As said, we have assumed that the right combinations are stable, which is not soobvious. Actually, the most stable combinations are the wrong ones, those that makethe nonliving portion of the universe, which is made of NU − N ′′U atoms. An eectivestability for the right combinations can be achieved by means of reproductive mechanisms.We have to assume that, at some point, there appear combinations that can reproducethemselves suciently rapidly to ensure self-sustainment. Then, those combinations canbe assumed to last forever (in the sense that they generate a sucient number of similarnew combinations before the old ones die). In the simple model considered here, thisrequirement is incorporated in the probability p.1Formula (3.2) is obtained as follows. The factor NU is the number of sequences that can be built with N atoms. We can imagine, for example, that all the NU atoms are aligned along a circle. The factor 1− (1− pN )c is the probability that a sequence is right after c attempts. For c = 1 we have pN . For c = 2we have pN +(1−pN)pN , which is the sum of the probability to have it right after the rst attempt, whichis pN , plus the probability to have it wrong in the rst attempt and then right after the second attempt,which is (1− pN )pN . For c = 3 we have pN + (1− pN )pN + (1− pN)2pN , etc. For c generic (3.2) is easilyobtained. 10 If we take this into account, the probability of nding a living being made of Nc atomsis then P = ∑ Nc,n P (Nc, n)f(Nc, n), (3.4)where f(Nc, n) is 1 or zero, depending on whether the right combinations can reproducethemselves suciently rapidly or not. Ultimately, the correction just selects the right Ncand n (assuming that they exist). With those values the estimates obtained from formula(3.3) make sense.Another assumption tacitly made to derive (3.3) and (3.4) is that, once formed, thestructures si−1 are close enough to one another, so that they can eectively combine intothe i-th structures si. This assumption can be incorporated into corrections to the velocity V and/or the probability p. We can also justify the assumption a posteriori : if the nalprobability P turns out to be zero, the actual result cannot be worse than that. If P turnsout to be 1, it means that all the structures that can potentially form do form, so it isplausible that they are located at convenient distances from one another without havingto change V and p too much.With ` = 20 and n = 10 steps, `n is approximately the number NC = 1013 of atomsof a cell. If we assume that the velocity V is 1 per hour per atom, we get P = 10−31 for p = 1/6 and P = 1 for p = 1/2. With ` = 10 (roughly, the number of atoms of a base), n = 13 steps and the same velocity V , we get P = 1 for p = 1/6. With p = 1/6, ` = 10, n = 13 and V = 1 per year per atom, we get P = 80%. Probabilities equal to one or closeto one mean that all or almost all the N ′′U atoms that are eectively capable of generatinglife do achieve that goal, leading, on average, to about one inhabited planet per star.The probability of each step of the LAM is F (p, `, c) = 1− (1− p`)c,where c = V TU/n. The crucial quantity that controls F and the nal outcome P is χ = cp`,which we call root of the LAM. Since c is large, it is sucient to have χ & 1 to obtain F ∼ 1, P ∼ 1, because F = 1− ( 1− χ c )c → c→∞ 1− e−χ.On the other hand, if χ is small, then F ∼ χ, so P is also small.It is hard to have F and P reasonably dierent from zero if, say, ` > 20-30. Forexample, with the last used values for p, TU , n and V , F (p, `, c) is equal to 5 * 10−8 for ` = 20 and 2 * 10−23 for ` = 40. 11 We learn that the most important quantity is `, which should be reasonably small.Amplication steps of ` = 10 are aordable in nature, but bigger steps become problematic.On generic grounds, if even one step of the LAM requires an amplication factor ` greaterthan 20-30, then the probability P becomes too small to explain the appearance of life. Inthe alternative, p is also important. Instead, we cannot raise low values of F (p, `, c) toomuch by playing with c.The natural question is then: is organic life equipped with a suitable LAM? The ladderof organic life could be made of atoms, molecules, macromolecules, then (relatives, variantsor ancestors of) ribozymes, prions, RNA, virions, DNA and viruses, nally prokaryotes,unicellular eukaryotes, multicellular eukaryotes.It is enlightening to turn the argument around. There is no hope to explain the ap-pearance of the shortest known DNA (1821 nucleotides), or a combination of ` = 1000elements, or even a combination of just ` = 100 elements, by means of a single amplica-tion step (i.e. a jump from separate elements to a structure of 100 elements), not even byhaving each element make a billion trials per second for the whole lifetime of the universe.This means that nature must be equipped with the required ten or so steps with ` ∼ 10that make the amplication possible, otherwise life would have never appeared, not evenon a single planet in the whole universe. In conclusion, it might be early to identify theLAM of organic life with precision, but we know that it must exist.Moreover, we have seen that small variations of the input parameters of the LAM leadto huge variations of the outcome, which switches very quickly from a universe that iseverywhere dead to a universe that is alive wherever possible. Any intermediate situationis banned, because it would require very unnatural ne tunings. Basically, the LAM isitself a bifurcation, which allows only two outcomes: P = 0 and P = 1. Since the universeis not everywhere dead, because we exist, we can exclude P = 0. This leaves just P = 1,which means that the universe is alive everywhere possible.The conclusion is that there must be life on all the planets that permit it, which mighteven mean one planet per star on average. Even if it were just one planet per hundredthousand stars, there would still be billions of billions of inhabited planets in the universe.One may wonder whether something resembling life (say, an amplication of chancedue to thermal noise, chaotic systems, statistical uctuations and so on) might be achievedwithout quantum uncertainty, i.e. assuming that, for all the purposes of studying life(its functions, origin and evolution), we can treat the atoms and the molecules, as wellas the DNA, the cells and the living beings, as deterministic systems. In this scenario,what appears to be unpredictable about the phenomena of life is just a blunder, as in12 simulations due to pseudo random number generators. The strongest objection againstthis possibility comes precisely from the results we have just found. Indeed, we haveshown that a small variation of the parameters involved in the LAM can change theoutcome dramatically. Switching o quantum uncertainty, or downplaying its importance,is actually a huge variation of the parameters, since it implies that we must renouncethe discreteness of the energy levels, the metastability of the excited levels, the quantumtunneling and all the other properties that are helpful to the interlocking mechanismsinvolved in the amplication, and presumably play key roles in allowing for mutationsduring the DNA reproduction. Then, the most obvious conclusion would be a universethat is everywhere dead, contrary to observation.3.1 DeathThe formation of structures that amplify quantum uncertainty to macroscopic distancesrequires a huge number of trials. How stable the structures are, once formed, depends onmany variables. In a variety of circumstances, or after a sucient amount of time, theycan collapse back to disordered structures, which average quantum uncertainty away. Thisis death.We may want to identify life as a phase of matter, which is very unstable at the locallevel (which refers to a single individual), but may be more stable at the global level(thanks to reproduction). The nonliving portion of the universe is another, much morestable, phase of matter. Death is the phase transition from the living phase to the nonlivingphase.As a physical phenomenon, life does not admit states of equilibrium, or cyclic behav-iors. On the contrary, it can be stabilized only by means of a continuous renewal. Lifecan survive only if it has enough room to expand, grow, or evolve, which in most casesmeans explore new congurations and behaviors, using its built-in quantum trial-and-errorprocesses. However, expansion, growth and evolution are possible only by a mechanism oflearning and improvement, which in turn requires selection, which is possible only if thereis instability and death.Thus, the instability of quantum ampliers at smaller scales is what speeds up theprocess of growth to bigger scales. It makes the expansion possible and ultimately tendsto safeguard the existence of life for a longer period of time. There must be a sort of bal-ance between instability and growth, since stability is possible only through the strugglefor growth and growth is possible only through instability, by means of the reproduc-tion/selection/death mechanism. 13 4 Q-learning systemsIn this section we investigate models of conscious and unconscious learning processes. AQ-learning system L is a structure able toi) perceive from the outside world;ii) make choices of quantum nature;iii) act/react on the outside world;iv) compare perceptions and evaluate them according to criteria;v) modify itself;vi) keep memory.It may be helpful to imagine the Q-structure L as made of smaller interconnected Q-units U , which function in a similar way at a smaller level, and possibly play dierent roles.We can assume that each unit can modify itself and/or modify other units or be modiedby them. Together, the units can make arbitrarily large and complex Q-structures.For simplicity, let us assume that a Q-unit U can execute just two actions, a1 and a2, which are equally probable at the beginning. Briey, U perceives some signal s fromthe exterior world, decides a reaction r = a1 or a2 to s, perceives the consequences of itsreaction, in the form of another signal s′, evaluates whether the sequence srs′ is favorableor unfavorable, and nally modies the probability distribution of a1 and a2 according tothis judgment. Later, in a similar situation the same reaction will be more or less probable,according to the (supposed) advantage it brings to the Q-structure. This is how the systemlearns. At the level of the Q-structure L, the hardware modications Q0 → Qα can alsobe understood as a form of memory, or knowledge, or consciousness (see below).For example, we can imagine that the decision devices of point ii) are made of systems Q0, the actions a1 and a2 being triggered by the outcomes |+, z〉 and |−, z〉. Point v) canconsist in the modication of Q0 into a Qα, for a suitable α. Assume that the reaction is a1 and that its consequences are judged favorably, to the extent that α is tuned to 30o.The modied probabilities of the reactions a1 and a2 become 75% and 25%, respectively.Thus, when, at a later time, U perceives a similar signal s, it more probably executesthe same reaction a1. If the consequences are still judged favorably (which is not to betaken for granted, since the judgment process is also of quantum nature, see below), theprobabilities may become 90% versus 10%, etc. In this way, the unit U learns whether anaction is convenient or not.The judgment of point iv) occurs quantum mechanically, by means of other devices Qβ , which may be provided by other units U . The criteria used for the judgment can14 be of various types. An important role, for life, is played by the criteria that aim atself-preservation. However, since life admits no equilibrium state, the only way to havea chance of self-preservation is by aiming at expansion. Thus, most criteria of point iv)judge the situations/modications that lead to an increase of power favorably and all theothers unfavorably.Schematically, the learning system L must contain a body B, a hardware developer H , an evaluation center E and an action device A. The initial conguration of E may beinnate, but it can be modied by H . The body B is a set of quantum systems Qαi, oneor more than one for each type of known external signals, plus a number of unassignedsystems Q0 (or innately assigned systems Qβ inn) that are ready to be associated with newtypes of perceptions. The body is also the memory where the responses to known signalsand other informations are stored.We have the scheme s −→ B −→ A ↑ ; H ←− E ←− s′ (4.1)When a signal s is perceived from the outside world, it is sent to B, which checks if it is ofknown type. If it is, a piece of information is already stored in the memory, and used toforward the signal to the appropriate quantum device d(s). If s is of unknown type, it issent to an unassigned decision device, which becomes d(s). The outcome of the assignmentis stored in the memory.The device d(s) encodes the probability distribution of the quantum decision that isgoing to be made. The decision, in its turn, determines which action is executed by A. Callit a(s). When the selected action a(s) is executed, a corresponding information is storedin B. Then the learning system collects new external signals s′. If they are sucientlyclose in time to a(s), they are assumed to be responses to a(s) (but this call is actuallydemanded to another decision center and possibly another learning system). The sequence sa(s)s′ is sent to E for evaluation, to determine whether it is favorable or not. Finally,the hardware developer H modies the decision device d(s) of B to make sure that thereaction a(s) becomes more or less probable, depending on the result of the E evaluation.The data about the process are memorized in B.More generally, s can denote the context in which an initiative is taken autonomously,instead of an external signal of a specic type. In more sophisticated learning systems, H can modify also E. Alternatively, the modications of E, or its functions, may bedemanded to other interconnected learning systems.15 4.1 Consciousness and unconsciousIn this paper, thought and consciousness, and several related concepts, such as freedom,intent, will, etc., are understood to have quantum origins. In particular, they are notexclusive qualities of human beings. Being conscious of the meaning of perceptions meanshaving collected enough experiences to know how to react in order to produce favorableconsequences and/or avoid unfavorable consequences. It goes without saying that manyanimals have consciousness. A dog, for example, can associate specic actions to humancommands and other perceptions. When a dog becomes familiar with those perceptionsand the consequences of its actions, we can legitimately say that it is conscious of them, inthe sense that it knows which responses produce favorable consequences and which do not.At the same time, humans do not have consciousness in all the phases of their lives. Forexample, a newly born child is not conscious of the meanings of perceptions and actions. Ittakes months of work memorizing, associating and classifying, and executing actions andgenerating sounds autonomously, to reach a level where we can legitimately claim that thebaby has acquired knowledge of the meaning of sounds and other perceptions, and hasassociated perceptions to actions and consequences. At that point, the baby is consciousof such things.Thus, we can identify the learning scheme (4.1) as the conscious pattern. It can besummarized by the acronym SACEM (signal → action → consequence → evaluation →modication). Its main features are that it is local (we will understand in a minute whatthis means) and can be repeated an arbitrary number of times, to ne tune the probabilitydistributions as much as possible and improve the learning.Let us consider a large number n of SACEM units and equip them with a globalevaluation center E and a global hardware developer H. The set of individual bodies Bi,plus possibly other structures that we do not need to specify here, make the global body B.We obtain a pattern that, for the reasons that we are about to explain, can be describedas the unconscious pattern:     s1 −→ B1 −→ A1 ↑ ; H1 ←− E1 ←− s1 ′    ...     sn −→ Bn −→ An ↑ ; Hn ←− En ←− s ′ n                                ; E → H → B (4.2) 16 In what we are going to say, the local evaluation centers Ei and the local hardware de-velopers Hi do not play important roles and in most situations can actually be absent.Then the SACEM units simplify to SAC units (signal → action → consequence) and theunconscious pattern becomes [ s1 → B1 → A1 ; s ′ 1 ] [ s2 → B2 → A2 ; s ′ 2 ]... [ sn → Bn → An ; s ′ n ]              ; E → H → B (4.3) We can distinguish a local level, which is the level of each SAC unit, and a global level,which is the whole structure. Let us concentrate on a SAC unit for the moment. When asignal s is perceived, the memory stored in B is interrogated, after which s is forwarded toan appropriate or unassigned quantum device d(s) of B. Then d(s) determines an action a(s). After a(s) is executed by the action center A, its eects s′ are memorized in B. Asbefore, s can just be the context where an action a(s) is autonomously executed. Insteadof a trial-and-error mechanism, the SAC sequence describes a pure trial mechanism. Itdoes not let the individual learn from its actions a(s).The SAC units are part of a more complex structure (like the brain), which also includesa global evaluation center E, a global hardware developer H and a global body B. At theright moment, the evaluation center E is activated. It gathers informations coming froma large number of individual bodies Bi about their local experiences, occurred within acertain amount of time T . Then, it evaluates them at-large. On the basis of that evaluation, E instructs H to modify the probability distributions of the SAC units, or a large numberof them. The data about the whole process are stored in the global memory of B.The crucial novelty here is that the operations of evaluation are not performed locallyand instantaneously, as in the sequence SACEM, but on a collective scale, which meanson groups of numerous SAC patterns at once, and delayed to a later stage (as in thedreams, the night activities of the brain, and so on). The delayed process of evaluationat-large makes it impossible, for the individual, to keep track of what happens with enoughprecision to become aware of it. The individual does change, the change being enacted by H, but it has a hard time relating the change to its probable causes, so it perceives thechange as unconscious, not wanted, automatic.Despite the control we claim to have on our own lives, our conscious and unconsciousactivities presumably play equally important roles. What makes an activity conscious is17 that the evaluation of consequences occurs almost instantaneously, so it is possible to relatecauses and eects and repeat similar SACEM patterns an arbitrary number of times, torene the learning till it turns into an awareness. What makes an activity unconscious,on the other hand, is that the evaluation is delayed and performed on a much larger scale.This makes each unconscious decision essentially unique and unrepeatable, because it isalmost impossible to repeat the set of SAC patterns involved in it.For example, an individual cannot consciously evaluate, as a whole, the enormousamount of choices made during an entire day. That is part of the job done by the uncon-scious part of the brain during the night. Similarly, the individual cannot plan its ownchanges of life. A change of life is a typical example of a decision that just happensand has cascade eects on all subsequent ones. It cannot be experimented, repeated ortested, since it is impossible to change life a thousand times to evaluate the huge numberof available alternatives and develop a consciousness of what it truly means.4.2 RemarksQ-structures of arbitrary complexities can be built by combining the systems describedabove and create, for example, networks of interconnected Q-learning systems, where eachunit evaluates and modies the surrounding units. Such networks can collect, evaluateand memorize large numbers of experiences, and rapidly improve themselves by ne tuningthe probability distributions to the responses that produce more favorable consequences.Presumably, the structures should be semiliquid, to ensure a better and faster adaptability.At the same time, a learning process is so complex that it cannot be reduced to a smallamount of simple operations. A newborn baby takes months to learn how to grab an objectwith its own hands without shaking and years to calibrate the movements enough to writeand draw. This gives an idea of the challenges involved in the creation of articial life.In nature, learning and the ability of learning come with evolution, which is itself along, involved trial-and-error process. However, there are no absolute notions of errorand success: what is an error in a context or environment may be the right answer ina dierent context or environment. Lowering the probability of errors (i.e. downplayingthe role of quantum uncertainty in favor of more determinism), lowers the possibility ofadaptation. By the arguments of the previous section and the high sensitivity of the LAMto its own inputs, this can easily turn the probability of life formation and self-sustainmentfrom one down to zero.The main implication of these facts is that, in the quest for building articial life (seesection 7), the largest possible amount of functions of the Q-structures should be demanded18 s a s′ inner outer part part SACEM E H B s a s′ SAC Figure 1: Basic structure of the brainto quantum uncertainty, because a more deterministic structure may appear to be morepowerful in the short range and in a specic environment, but is doomed to get extinctquite easily.5 BrainAs said, arbitrarily sophisticated structures can be built, able to recognize perceptions,make decisions, elaborate actions, learn from the consequences of their own actions. Theoutcome is what we can call an organism, with a structure that is partly innate, due toevolution, and partly acquired by means of learning and experience, thanks to the internalmodications occurred during the course of life.A rich structure of elementary quantum bifurcations, ordered and hierarchically orga-nized, is the brain. We can imagine it as made of two main parts, as shown in g. 1.The inner part, which is unconscious, is mainly made of patterns of type SAC and hoststhe global evaluation center E and the global hardware development center H. The outer,conscious part is mainly made of patterns SACEM. The global body B is the union ofboth parts. Each part is hierarchically organized into levels, sublevels, and so on.The outer part of the brain receives signals from the external world as well as itself andperforms actions on the external world. The inner part, instead, receives signals from theouter part and performs actions on the outer part as well as itself (with some exceptions,considered below). The internal perceptions are the sensations of activities within the19 brain. They allow the inner part to perceive the outer part. They can also make dierentsectors of the outer part perceive one another.Basically, the actions of the inner part inuence or permanently modify the probabilitydistributions of the decision devices that are located in the outer part. They can recongureand reorganize the outer part to a high degree.The two-part structure of the brain, where only the outer part acts on the externalworld, lets the individual reach a considerable level of self control and enact smooth be-haviors, after a due amount of learning experiences. A child needs several years of adultsupervision and interactions with the external world to achieve this goal. Once the outerpart of the brain is well structured, the behaviors of the individual start to make sense.That said, they never become deterministic, since predicting a decision of a living beingremains impossible in principle due to its intrinsic quantum nature.In general, an external signal, once it becomes a perception, has the eect of proposing asort of question to the brain, and can reach a certain level or depth in its structure, whichdepends on the features of the signal, among which its intensity and duration. Decisionsof superior levels may have cascade eects on the inferior levels. If a signal has particularfeatures or is suciently strong (humor, fright, terror, adrenaline rush or excitement dueto gambling, extreme sports, etc.), or repeated and long (chronic pain, depression), itcan reach also the inner part, including its superior levels. Then its cascade eects onthe inferior levels and the outer part may generate decisions that are commonly ratherdisfavored, such as committing a suicide. In other situations they can lead to a change oflife.In pathological cases, adults may loose the ability to control their behaviors. Certainforms of mental problems are probably due to shortcuts in the brain structure, wherethe unconscious patterns of the inner part act directly on the external world, bypassingthe operations of ltering enacted by the outer part. The resulting behavior appearsinexplicable, possibly schizoid. In reality, it is just the consequence of randomly generateddecisions of quantum nature, whose probability distributions have remained at in largeregions, because they have not been ne tuned.5.1 WillThe brain considers an action a(s) as wanted, predetermined, intentional, when it hasalready been decided by the quantum systems d(s) assigned to it, but it has not beenexecuted, yet. This internal sensation is the will. It involves interconnected SACEMstructures in the outer part of the brain. 20 Previously, we used the symbol a(s) to denote both the outcome of the decision device d(s), located in the body B, and the consequent action executed by the action device A.We tacitly assumed that there was no time delay between the decision and the action. Inthe present discussion, such a delay plays a key role, in particular in the human being.We can dene the intentional action ain(s) as the outcome of the decision device d(s) anddistinguish it from the executed action a(s). The intentional action is stored in a suitablesector of the memory contained in B, till it is executed. Before that, a change of mind caninterfere and make the individual execute a completely dierent action.The will is the (internal) perception of the intentional actions ain(s) stored in thememory. Since there is no way to perceive a quantum process d(s) while it determines itschoice ain(s), the best the brain can do is associate an internal perception with a choicethat has already been determined. This is precisely the will. During the time interval thatseparates the quantum decision ain(s) from the eective action a(s), the decision ain(s) isclassied as intentional. After a(s) is executed, the brain continues to consider the actionas intentional, as long as it remembers that it was intentional. The time delay interposedbetween ain(s) and a(s) gives the illusion of awareness, intent, consciousness, control onthe actions.A decision may also be equipped with the internal perceptions of certain activitiesthat have contributed to shape the probability distributions that lead to it (such as thethoughts). It is nevertheless important to stress that will, free will, consciousness, aware-ness, intent, reason, intellect, etc., do not corresponds to elementary physical phenomena.They are not concurrent causes, or sources of a decision (because no such causes exist innature), although they are normally misunderstood as such. Instead, they are the results oflarge numbers of combined random processes, applied in various ways and dierent forms.Because the origin of such random processes is of quantum type, all decisions are ultimatelyconsequences of quantum uncertainty. Will and intent do not make decisions: they are therst internally perceived sensations after the decisions have already been made, quantummechanically, by the devices of the brain, before those decisions are turned into eectiveactions.5.2 Pain and pleasurePain is a compulsory distraction that prevents a living being from executing intentionalactions. When an individual hurts itself, superior levels of the brain, mostly unconscious,are activated. Their decision centers, characterized by peaked probability distributions,make certain reactions (like the reactions to a danger) almost compulsory, bypassing will,21 consciousness, intent and the whole outer part of the brain. Exceptionally, the inner part ofthe brain acts directly on the external world. In such a situation, all previously determined,intentional decisions are overruled. The individual is forced to suddenly turn its attentionfrom a wanted direction to a non wanted one. An individual that is subject to sucha distraction suers. Similarly, pleasure is the sensation associated with the presence ofanything that helps executing intentional actions.6 Reproduction, evolution, intelligenceThe ordered sequences of quantum bifurcations that amplify the eects of quantum uncer-tainty to the macroscopic scales are statistically disfavored, so the living phase of matteris intrinsically unstable and ephemeral. Reproduction is a possibility, presumably not theonly one, that can extend the duration of the living phase. The reproductive ability is oneof the rst consequences of evolution, in the known life forms, although it is not the engineof life.Evolution can be described by the unconscious pattern (4.3). The global body B isthe species and the global hardware developer H is reproduction. The global evaluationcriterion E is natural selection. Within the SAC units, the context si is (typically) theencounter of two individuals (the mother, the father), the action Ai is the mechanism ofDNA replication and the birth of new individuals, the consequence (new context) s′i is theset of parents and newborns, i.e. the family, the body Bi is the set of individuals interestedin the process (the parents at rst, the family at last).Evolution can also be viewed as a learning process. A new individual, whose innatestructure is dierent from the innate or improved structures of its parents, is a sort of trialof a trial-and-error mechanism. Many individuals turn out to be errors and the ttestones survive. This way, the mechanism of evolution allows the species to acquire a form ofknowledge of the surrounding environment. In the simpler species, this kind of knowledgeis gathered very quickly, as in bacteria and many insects, where few individuals are ablegenerate huge numbers of new individuals and so adapt quite rapidly. In more complexspecies the process of learning by evolution is much slower.In addition, the human beings have developed intelligence. Intelligence and evolutioncan be seen as two ways of learning, with similarities and dierences. In particular, theyare both trial-and-error mechanisms of quantum origin, in one case concentrated inside asingle individual, in the other case organized at the level of the species. We can associateintelligence with the conscious pattern (4.1), while, as said, evolution follows the uncon-22 scious pattern (4.3). Although intelligence plays important roles in several situations, wethink that it is a minor aspect of life, in the big picture, which is the reason we do notspend many words about it in this paper.7 Articial lifeThe living beings and the nonliving portion of nature are ultimately made of the sameingredients, dierently combined. It is conceivable that several types of life forms, besidesthe organic one, exist in the universe. It is also interesting to explore the possibilityof creating some new life forms articially, by amplifying quantum uncertainty to themacroscopic scales along the lines explained so far. The present knowledge and resourcesof the human species suggest that this task is within reach, although it may require aconsiderable collective eort. Learning how to build and work with liquid or semiliquiddevices is extremely helpful, as is arranging huge amounts of quantum random numbergenerators in tiny spaces. In a due amount of time, we might be able to equip the Q-beings or Q-droids with the ability to reproduce, or produce themselves. Once that goalis achieved, the Q-droids can proceed by themselves, through the mechanisms of selectionand evolution, and, if they are versatile enough, survive for a long time.The arguments of the previous sections have been phrased with an eye at the nalgoal we have in mind, which is precisely the creation of articial life. At this point, theconclusions are more or less straightforward.The program of creating articial life can proceed along three main directions. The rstdirection is to construct simple, possibly small, non specialized but very versatile Q-beings.At the beginning the Q-droids could be sold as Q-toys (Q-dolls, Q-worms, Q-tamagotchis, Q-pets, Q-companions, etc.). In passing, let us note that this business may turn into ahuge success, because it will likely help reduce the loneliness of people in our societies.The tiniest Q-beings could be even sent to explore the universe for us.The second possibility is to build more specialized Q-droids and equip them with agood deal of built-in knowledge, which might include the ability to produce other Q-droidssimilar to them. From their perspective, the built-in knowledge would be innate and wouldsave them a lot of learning eort. Their behaviors would look less erratic and much moreunder control from the beginning. These Q-beings will better t into the environment inthe short run, but will be less versatile and have fewer possibilities to adapt themselves inthe long run, when important changes will eventually occur. This direction for articiallife may have some interest if the Q-beings are built to be basically immortal.23 We mention a third, easier way to investigate the amplication of quantum uncertaintyto macroscopic scales, although it is of a rather dierent type: creating one-dimensional andtwo-dimensional Q-beings, such as sophisticated software programs for decision making,money investments, trading, politics, articial intelligence, etc.The creation of articial life is demanding also because it requires to break with somecommon ways of thinking. In particular, it is not supposed to make us humans morepowerful, or happy, or live longer, or be healthier. In some sense, it is meant to be a veryaltruistic research, directed to build life forms that can turn out to be more powerfulthan ours, compete with us for the control of the world and possibly overthrow theirown creators. Through evolution, many species have achieved the goal of creating morepowerful, tter species. However, none of them has done it intentionally, at least so far.The creation of articial life is the next step of the amplication of quantum uncertainty.Clearly, such a step does not easily t a LAM mechanism like the ones considered insection 3. Likely, most articial life forms to be created by us have no chance to appearspontaneously in nature. In a way, they belong to the class of impossible LAMs. However,nature seems to have found the way to bypass this diculty: create intelligent species oforganic life to take the plunge toward otherwise unreachable forms of life.8 ConclusionsAfter a century of research in quantum mechanics, we can fairly say that the phenomenathat take place at the atomic scales (and below those) have become familiar to us. Unlesssomething has escaped the scientic research, which is not plausible, the knowledge gath-ered so far must be enough to answer the questions: what is life as a physical phenomenon?how can we build articial life?The phenomena related to quantum uncertainty are the only unusual ones that wehave encountered at the atomic scales. There are no elementary phenomena that resembleconcepts such as those that we call will, free will, intent, consciousness, thought, intellect,intelligence, reason, intuition, emotions, feelings, or the subject, the I. Such notionscan be used as approximative descriptions of eects that involve collective phenomena.The overall picture that emerges from the investigation carried out so far is consistentand does indicate that life is the amplication of quantum uncertainty from the microscopicscales to the macroscopic scales. From this idea it is possible to explain everything we knowabout life and start the endeavor that will lead to the creation of articial life.In general, the degree of quantum uncertainty decreases from the microscopic to the24 macroscopic scales, where the eects of the uncertainty principle tend to average to zero.Exceptions are precisely the living beings, which behave non deterministically in a de-terministic environment. The amplication is possible only if nature is equipped with asuitable LAM, a ladder amplication mechanism, otherwise the probability is too small. Acrucial property of the LAM is that it is sensitive to the tiniest variations of its own param-eters, to the extent that it acts as a bifurcation, leaving just two possibilities: the universeis everywhere dead or alive wherever possible. Since (organic) life exists on earth, it mustbe equipped with a proper LAM and the universe must be alive everywhere possible.Moreover, similar initial or boundary conditions must produce substantially similarresults in comparable amounts of time, although the outcomes may dier in relativelyminor aspects. Thus, we expect that every planet that is inhabitable by organic life doesbecome inhabited in an amount of time comparable to the one taken by life on earth. Sincethe conditions for organic life are presumably met in a huge number of planets, we inferthat by now more or less one planet per star hosts life forms substantially similar to ours.The other inhabitable planets host life forms unknown to us, depending on the diversitiesof their conditions.The creation of articial life is a major step of a new type of LAM for quantum uncer-tainty. The main challenge humans face is building suciently complex (but not necessarilyspecialized) Q-droids that can develop, produce and evolve themselves so eciently to self-sustain and expand indenitely. Some bright side, in the short run, might be the possibilityto fund the research on the production and sale of relatively simple Q-toys for childrenand articial pets for companionship.We conclude with a few comments of broader interests. In a way, the uncertaintyprinciple implies that the world is (almost) everywhere free at small distances, while itis (almost) everywhere enchained (by determinism) at large distances. Instead of beingeverywhere predictable (which might also mean boring, to be taken for granted, etc.), theuniverse hosts an eternal conict between freedom and rule, with an apparent irreversibilityalong the direction of the relative distances: freedom decreases when the relative distancesincrease, while rule increases. The amplication of quantum uncertainty is an upstreamjourney against the current.But there might be more, with consequences that have yet to be fully appreciated.Indeed, quantum gravity predicts the violation of microcausality [17]. At scales that aremuch smaller than the atomic ones, but still much larger than the Planck length, whichmight mean around 10−24-10−27cm, the concepts of time, past, present and future, causeand eect lose meaning. It appears that these notions are not fundamental principles of25 nature, but eective descriptions that are good enough for a number of practical purposes.The breakdown of causality at small distances moves in a direction that is somewhat similarto the one opened up by quantum uncertainty: in some sense, it gives us another sign thatthe universe does not want to be subject to the chains we naively forged for it. One day,we might have to accept as a fact that the universe is indeed alive.AcknowledgmentsWe are grateful to U. Aglietti and A. Caricasole for useful discussions.References[1] See for example, C.P McKay, What is life  and how do we search for it in otherworlds?, PLoS Biol. 13 (2004) e0020302;D.E. Koshland, Jr., The seven pillars of life, Science 295 (2002) 2215;E.N. Trifonov, Vocabulary of denitions of life suggests a denition,J. Biomol. Struct. Dyn., 29 (2011) 259;E.N. Trifonov, Denition of life: navigation through uncertainties,J. Biomol. Struct. Dyn., 29 (2012) 647;C. Zimmer, Can scientists dene `life' ... using just three words?, NBC News (2012).[2] J.C. Maxwell, Does the progress of physical science tend to give any advantage tothe opinion of necessity (or determinism) over that of the contingency of events andthe freedom of the will? in L. Campbell and W. Garnett, The life of James ClerkMaxwell, MacMillan and Co., London (1882), Chapter XIV, essay I.[3] F. Nietzsche, The will to power, edited by W. Kaufmann, Vintage Books Edition, NewYork (1968), aphorism 480.[4] F. Nietzsche, The dawn of day, The MacMillan Company, New York (1911), apho-rism 130, Aims? Will?. The book is available at The Project Gutenberg (2012)Ebook 39955.[5] A.S. Eddington, The decline of determinism. Presidential Address to the MathematicalAssociation, 1932, The Mathematical Gazette 16 (1932) 66.26 [6] A.S. Eddington, The nature of the physical world, The MacMillan Company, NewYork (1928), p. 295.[7] A.H. Compton, The freedom of man, The Terry Lectures Series, Yale University Press(1935), pp. 48-49.[8] A.H. Compton and M. Johnston, The Cosmos of Arthur Holly Compton, Ed. Knopf,New York (1967), pp. 121-123.[9] K. Popper, Of clouds and clocks, an approach to the problem of rationality and thefreedom of man, inObjective Knowledge: An evolutionary approach, Oxford UniversityPress (1979). Sections X and XII.[10] See for example, D.J. Chalmers, Facing up to the problem of consciousness, J. Con-scious. Stud. 2 (1995) 200;D.J. Chalmers, The conscious mind: In search of a fundamental theory, Oxford Uni-versity Press, Oxford (1996);A. Kent, Quanta and qualia, Found. Phys. (2018) and references therein.[11] C. Rye, R. Wise, V. Jurukowski, J. DeSaix, J. Choi and Y. Avissar, Biology, OpenStax(2017), https://openstax.org/details/books/biology, p. 108.[12] M. Lynch, The origins of genome architecture, Sinauer Associates Inc., Sunderland,MA, Usa (2007).[13] C.L. Chen, P.C. Chang, M.S. Lee, J.H. 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