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Reality or simulation?
Science & Vie echoes this month a quantum experiment “that can change everything”. The starting point is the simulation hypothesis. In 2003 Nick Bostrom, philosopher, notes that our descendants will have an exponential numerical power and draws 3 hypotheses: 1) Humanity will be extinct before being able to exploit it. 2) It will make the project to simulate its own evolution, in many forms and then it is likely that we are the actors of one of them. 3) Humanity will not be interested in such a project.
Simplistic? Very. It is assumed that future humans think like contemporaries. Let their curiosity no longer bother with ethics (they program abominable events). That the ‘hard problem’ of consciousness has been solved (a video game character is not supposed to experience consciousness). Do we really have to continue?
Let’s move on to the subsidiary questions: Simulation, so what? Don’t we live, think the majority of our contemporaries, in a simulation devised by God? Or, for scientists, in a simulation from the fundamental physical forces? Science already reduces the whole of reality to an information structure. The notion of substance is discussed. Why worry about attaching ‘simulation’ to ‘reality’ when it is so difficult to separate them? A lot of noise for nothing.
Does it take consciousness to make reality appear?
Let us now turn to the quantum experiment, the details of which I will give in a few moments. A team of physicists led by Tom Campbell “wants to give evidence that our reality is fundamentally virtual” and would only appear when a consciousness comes to discover it. This is an unsolved problem in quantum physics. Why do particles exist in a very large number of superimposed probabilities and we only see one? This reduction called ‘decoherence’ is not explained by quantum theory ( upward look). A paradigm shift is that consciousness chooses its reality (downward look). Head to tail for causality!!
For the journalist of Science & Vie, “reality would then only form when someone discovered it, just like a simulation does“. This sentence is particularly obscure. You could say it incoherent: the observer is not the programmer. But in the hypothesis of simulation, consciousness is the program. It was made (by our descendants, according to Bostrom), but it is it that manufactures its simulated reality. Moreover, the rapprochement with Matrix is a gross error, since in the movie it is a superior AI that manufactures reality for human brains in stasis (observer and programmer differ). As an aside: the whole article shows a poor understanding of the subject and is probably not unrelated to the complete change in the editorial team of the journal, which has lost much of its previous fame.
For the simulation hypothesis to be reinforced by Campbell’s experiment, the author therefore assumes that consciousness fully programs its own reality and that it itself is artificial, created by an external intervenor. Great perversion for the mind. Which ignores boring questions: Why would simulation allow consciousness to discover its artificial character, through a badly screwed up quantum theory? Is the ‘consciousness’ program fundamentally neurotic? How do all our consciousnesses agree to fabricate the same reality? Why choose this one and not another? Why not prefer the ones they enchant in dreams? Consciousness hardly seems free and independent in its own world, which brings us back to the assumption that observer and programmer are not the same. And the scaffolding of the simulation/quantum rapprochement collapses.
Tom Campbell’s experience
The experiment uses the famous double slit fitting. A particle gun sends photons. They pass through two slits, where a 1st detector D1 is placed. A 2nd detector D2 records the figure of interference on the screen. Quantum theory indicates that the photon behaves like a particle when its passage is recorded at the slits; appears a unique impact on the screen. If the passage is not recorded the photon behaves like a wave; the screen displays an interference figure.
In the hypothesis that consciousness creates its reality, the photon becomes a particle only when the observer becomes aware of the measurement. Campbell’s assembly then consists of recording the measurements of D1 (slits) and D2 (screen) on two separate USB keys and then destroying the D1 key. The observer cannot see the measurement at the slits. 2 possible results on the D2 key: 1) The screen displays an impact (photon-particle having undergone decoherence); the observer is not taken into account; we are not in a simulation. 2) The screen displays interference; the presence of the detector is not sufficient to create decoherence; it is the consciousness of the observer that provokes it.
In summary, if Campbell obtains the result (2), material reality is entirely quantum (in the state of superimposed probabilities) as long as a consciousness has not become aware of it. To conclude that this is an argument for simulation is excessive, we have already seen some reasons for this. Here are others: the behavior of living beings without brains (bacteria etc.) shows that they evolve in a world subject to decoherence, without mental device. Where is the frontier of “consciousness” capable of creating its simulation? The only way out: the good old solipsism: my consciousness creates everything, including you, and the rest of the living, in the same way as matter. And this blog. You no longer exist. Well, I agree to write a few more lines for your non-existence…
If Campbell gets the result (1), to conclude that we are not in a simulation is also excessive. The simulation can be perfect. But as with solipsism, then Bostrom’s hypothesis is neither refutable nor decidable and offers no interest.
Place your bets
I safely predict that Campbell will get the result (1). I do this as the author of Surimposium, which defines the nature of consciousness, quantum decoherence, and the complex dimension separating them. While Bostrom and Campbell have no explanation for these phenomena. How to combine simulation, consciousness and decoherence when they do not know how to specify them beforehand?
Campbell’s project dates back to 2017 and was looking for funding, eventually obtained via Kickstarter. Was the journalist interested in the reasons for this lack of interest from official organs? What do physicists outside Campbell’s team think? I suspect that they are so rare to predict the result (2) that none of them volunteered to verify it. A career is not built on the most fragile speculations.
If you are passionate about the case, understand why the result will be (1) with these articles:
Quantum strangeness in Helgoland
Can we put an end to the debate on interpretations of quantum mechanics?
Quantum oddities under the double look
Dark Matter, a novel on the multiverse
But perhaps you will remain seduced by the result (2), like Blake Crouch, who associated this possibility with the hypothesis of the multiverse to create the fantastic scenario of his novel Dark Matter. Exceptional anticipatory thriller that keeps our curiosity in suspense until the last page. Not our scientific rigor though. The number of inexplicable shortcuts in this story borders on the infinite number of doors the hero can open in the multiverse. Occam would have cut his throat with his razor…
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