For example, there must be a reality where the maternity ward staff screwed up bigtime, gave another baby to your parents, and gave you to other parents coming from the other side of the world. Which baby is you? Which Mind casts which shadow? We are all essentially the same person, as suggested by Eastern spiritual traditions and the philosophy of Open Individualism.

Therefore, as I said, after death you will experience other times and other versions of your life.

## Selected Publications

But you will also experience other lives as other persons, which is equivalent to the traditional concept of reincarnation. Perhaps some memories leak through now and then. Cover picture from Pxhere.

- (PDF) Many-Worlds and Many-Minds Formulations of Quantum Mechanics | Jeffrey Barrett - teweepreli.ga!
- (PDF) Many-Worlds and Many-Minds Formulations of Quantum Mechanics | Jeffrey Barrett - teweepreli.ga.
- Children Reading Pictures: Interpreting Visual Texts.

Sign in. Get started. Giulio Prisco Follow. Turing Church Science and religion, spirituality and technology, engineering and science fiction, mind and matter. The splitting-worldstheory is perhapsthe most popularversionof the many-worlds formulation. The splitting-world formulation of quantummechanics assertsthat it makessenseto talk abouta statevector for the whole universe.

This statevector nevercollapsesandhencereality as a whole is rigorously deterministic. This reality, which is describedjointiyby the dynamicalvariables andthe statevector, is not the reality we customarilythink of, but is a reality composedof manyworlds. By virtue of the temporaldevelopmentof the dynamicalvariablesthe statevector decomposes naturally into orthogonal vectors,reflecting a continualsplitting of the universeinto a multitude of mutually unobservablebut equallyreal worlds, in eachof which everygood measurementhasyielded a definite result andin most of which the familiar statisticalquantumlaws hold.

## Quantum mind

The idea of slightly imperfectcopiesof oneselfall constantly spitting into further copies,which ultimately becomeunrecognizable,is not easyto reconcilewith commonsense. Here is schizophreniawith a vengeance. On the splitting-worldsformulation the universesplits wheneverone makesa measurement in sucha way that everyphysical possibleresult in fact determinatelyoccursin somefuture world. More specially,there is oneworld correspondingto eachterm in the expressionof the quantummechanicalstate whenwritten in the theory's preferredbasis. In choosingthe preferredbasis,one chooses a singlepreferredway from amongthe manydifferent, mathematicallyequivalent,ways of representingquantum-mechanical statesasthe sum of mutually orthogonalunit-length vectors.

A standardcomplaintis that the theory is ontologically extravagant. We presumablyonly ever needone physical world, our world, to explainfor our experiences. The reasonfor postulatingthe actual existenceof a different physicalworld correspondingto eachterm in the quantum- mechanicalstateis that is allows oneto explain our determinateexperienceswhile taking the deterministically-evolvingquantum-mechanical stateto be in somesensea complete andaccuratedescriptionof the physicalfacts. But againone might wonder whetherthe sort of completenessone getswarrantsthe many-worldontology.

Another problemwith the splitting-worldsformulation concernsstatisticalpredictionsof future events. The standardcollapseformulation of quantummechanicspredictsthat M will get the result "In NYC" with probability a-squaredandthe result "Not in NYC" with probability b-squaredin the aboveexperiment,andthis is what we observeasrelative frequenciesfor suchexperiments. Insofar astheir will be two copiesof M in the future, M is guaranteedto get eachof the two possiblemeasurement results. So, in this senseat least,the probability of M gettingthe result "In NYC" is one,which is simply not what we observe.

But that is the wrong answer. A principle of indifferencemight lead oneto assignprobability Y2to eachof the two possiblemeasurement outcomes. But not only would sucha principle be difficult to justify here,probability Y2for eachpossible outcomeis typically not what we observefor suchexperimentsasrelative frequencies. So while the splitting-worldsformulation explainswhy observersget detem1inate measurementrecords,it makesno empiricalpredictionsfor the likelihood of future events.

In orderto understandwhat onewould haveto addto the theoryto get the standard quantumstatisticalpredictionsfor future events,onemight notethat the question"What is the probability that M will recordthe result 'In NYC'? It is the fact that there is no rule telling us which worlds arewhich at different times that preventsthe splitting-worldstheory from making statisticalpredictionsconcerningan observer's future experiences.

And not being ableto accountfor the standardquantumprobabilities is a seriousproblemsinceit wasthe successfulstatisticalpredictionsof quantum mechanicsthat madequantummechanicsworth taking seriouslyin the first place. Another problemfor the splitting-worldsformulation of quantummechanicsconcernsthe way worlds are supposedto split.

In orderto explain our determinatemeasurement records,one must choosea preferredbasisso that observershavedeterminate measurementrecordsin eachterm of the quantum-mechanical statewhenwritten in the preferredbasis. This is the preferredbasisproblem. This problemis closelyanalogousto the original measurementproblemin the context standardcoI1apse formulation of quantummechanics.

### Many Worlds/Many Minds Interpretation of Quantum Mechanics

A popular strategyfor resolvingthe preferredbasisproblemis to try to find a criterion involving the interactionbetweena quantum-mechanical systemand its environmentthat would dynamically selecta preferredbasisfor a system. As a simple exampleof an environmentaldecoherencecriterion, one might takethe preferredbasisof a systemto be the onethat representsthe classicalproperty of the systemto which its environment becomesmost strongly correlated.

Insofar as measurementrecordsare easilyread,their environmentsbecomestrongly corralledwith them, so sucha criterion would canbe expectedselectthe determinate-record basisaspreferred. Oneproblemwith havingthe environmentof a systemselectthe preferredbasis,however,is that, at leasthere,one presumablyneedsa preferredbasisfor the entireuniverse,which doeshavean environment. David Albert andBarry Loewer's many-mindsformulation of quantummechanics providesanotherapproachfor interpretingEverett's relative-stateformulation of quantummechanics.

Everett saidthat his theory "is objectively continuousand causal, while subjectivelydiscontinuousandprobabilistic" , 9. Thus, philosophically, a theory like Bohmian mechanics achieves more than the MWI, but at the price of adding the non-local dynamics of Bohmian particle positions.

## Some Worlds of Quantum Theory

Another concept, which is closer to Everett's original proposal, see Saunders , is that of a relative, or perspectival world defined for every physical system and every one of its states provided it is a state of non-zero probability : I will call it a centered world. This concept is useful when a world is centered on a perceptual state of a sentient being. In this world, all objects which the sentient being perceives have definite states, but objects that are not under observation might be in a superposition of different classical states.

The advantage of a centered world is that a quantum phenomenon in a distant galaxy does not split it, while the advantage of the definition presented here is that we can consider a world without specifying a center, and in particular our usual language is just as useful for describing worlds that existed at times when there were no sentient beings. The concept of a world in the MWI is based on the layman's conception of a world; however, several features are different.

Obviously, the definition of the world as everything that exists does not hold in the MWI. The Universe incorporates many worlds similar to the one the layman is familiar with. A layman believes that our present world has a unique past and future. According to the MWI, a world defined at some moment of time corresponds to a unique world at a time in the past, but to a multitude of worlds at a time in the future.

I will correspond to them all. Every time I perform a quantum experiment with several possible results it only seems to me that I obtain a single definite result. Indeed, Lev who obtains this particular result thinks this way. However, this Lev cannot be identified as the only Lev after the experiment.

Although this approach to the concept of personal identity seems somewhat unusual, it is plausible in the light of the critique of personal identity by Parfit Parfit considers some artificial situations in which a person splits into several copies, and argues that there is no good answer to the question: Which copy is me? He concludes that personal identity is not what matters when I divide. Saunders and Wallace a argue that based on the semantics of Lewis one can find a meaning for this question.

We should not expect to have a detailed and complete explanation of our experience in terms of the wave function of 10 33 particles that we and our immediate environment are made of. We just have to be able to draw a basic picture which is free of paradoxes. A sketch of the connection between the wave function of the Universe and our experience follows. The basis for the correspondence between the quantum state the wave function of the Universe and our experience is the description that physicists give in the framework of standard quantum theory for objects composed of elementary particles.

Elementary particles of the same kind are identical.

Therefore, the essence of an object is the quantum state of its particles and not the particles themselves see the elaborate discussion in the entry on identity and individuality in quantum theory : one quantum state of a set of elementary particles might be a cat and another state of the same particles might be a small table. Clearly, we cannot now write down an exact wave function of a cat. We know, to a reasonable approximation, the wave function of some elementary particles that constitute a nucleon.

The wave function of the electrons and the nucleons that together make up an atom is known with even better precision. The wave functions of molecules i. A lot is known about biological cells, so physicists can write down a rough form of the quantum state of a cell.

Out of cells we construct various tissues and then the whole body of a cat or a table. According to the definition of a world we have adopted, in each world the cat is in a definite state: either alive or dead. Formally, the quantum state of an object which consists of N particles is defined in 3N dimensional configuration space. However, in order to make a connection to our experience it is crucial to understand the quantum state as an entangled wave function of N particles in 3 dimensional space.

Physical interactions are local in 3 dimensions and we only experience objects defined in 3-space.