The Infinite Monkey Cage – How to Build a Universe. Robin Ince

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      There appear to be two problems with this description. Firstly, we need to be clear what we mean by ‘observe’. What is so special about observation that it reduces the linear superposition to the certainty of one outcome or another? Why does the strawberry’s experience not count as an ‘observation’ of whether the radioactive nucleus has decayed? What if we replaced the strawberry by Robin Ince? Would he remain in a superposition of alive and dead until we opened the box?

      Secondly, the idea that a strawberry can only be in some combination of alive and dead in such an experiment and not one or the other doesn’t correspond to our perception of reality; surely the strawberry cannot be simultaneously both alive and dead before we open the box?

      There is an interpretation of quantum theory known as the Many Worlds Interpretation that addresses both these issues. It is the simplest interpretation of the theory, and states that the superposition is never broken. All that happens when we open the box is that we enter a superposition with the strawberry and the nucleus. We might say that there are ‘worlds’ in which we see a vaporised strawberry and ‘worlds’ in which we don’t, but this language is really misleading. Reality is a superposition of all possibilities – and the interesting question becomes why our experience is of a reality consisting of only one set of possibilities. The answer is that the two ‘branches’ of reality following our interaction with the strawberry box evolve separately to each other; they do not interfere and nothing in the future of each branch is contingent on things happening in the other branch. In the Many Worlds Interpretation of quantum mechanics, however, both branches are equally real. The terminology that has developed is to refer to these branches as ‘different worlds’, but that’s misleading. There is only one ‘world’, and it is a world in which everything that can happen does happen and everything is in a superposition with everything else. There are parts of reality in which we opened the box and saw a strawberry, and parts of reality in which we opened the box and saw only vapour. The reason we are unaware of the true ensemble of alternative possibilities in practice is because they have no discernible influence on our experience in a particular branch.

      In response to the Great Dead Strawberry Debate, Monkey Cage regular Professor Nick Lane sent us this contribution:

      Strawberries really are in a superposition of states, although unlike Brian I’m not thinking about quantum states: parts are alive and parts are dead. We tend to think of death as a digital process: we are either alive or dead. But even when a person dies, many of their constituent cells are still alive. These will die in time, because they don’t get the services they need to remain alive. Our cells need a lot of services because they have a lot to do – we are high-energy beings, so when the energy flow ceases, we die fast. Strawberries are not: their cells don’t have all that much to do, so they can persist much longer before being pronounced dead. The seeds themselves, nicely shrink-wrapped in their own personal ovaries, can persist for years because they’ve been practically switched off altogether. They’re dried out carefully – turned to glass! – without losing their nanoscopic structure. That means their metabolism – the process of living – can be kick-started again when they germinate. The Second Law itself is put on hold, for a while, because the shrink-wrapped state seriously restricts the number of alternative states that they are free to access. I hate to say it, but the chemistry trumps physics, if only for a while. As long as the seeds don’t lose their structure they can switch on again and grow when water is restored. So the most valuable parts of the strawberry are still alive and the rest is just a doomed vehicle at the service of the next generation. Aren’t we all?

      A Further Frog Footnote

      Zoologist Lucy Cooke, whose fruit work includes playing a dancing raspberry in the TV series The Smell of Reeves and Mortimer, was fascinated by poison frogs from an early age; in particular, the Golden Poison Frog. Appearing on a Monkey Cage about toxins, venom and poison, she told us of her quest to see one. Its poison, an alkaloid poison, is so powerful it will kill you in three minutes, and for the last minute, you’ll be in such a state of petrification you will look, to all purposes, to be quite dead already. You only need to touch it and your fate is sealed. While making a TV documentary, she finally came face to face with one. Heavily gloved and visored, she held one in her hand. The rush from her childhood desires being fulfilled, a tear came to her eye. As the frog departed her hand, she put her hand to her eye to wipe away the tear.

      NOOO!’ yelled the crew and she realised that she was millimetres away from joining those who have died for the love of a frog.

      Now Lucy lives her life wondering if it is better to live to old age or die young and be memorialised as a zoologist who died due to the overwhelming and potential toxicity of the natural world.

      Nick Lane: Without death there wouldn’t be evolution at all. All the magnificent things in this world are as a result of death, and without it they wouldn’t be here. From a non-religious point of view, it’s glorious because of death.

      Professor Sue Black: And if death is such a great thing, why are we so scared of it? I think it’s a wonderful thing. It’s the last adventure. No one knows what’s coming. Bring it on!

      Series 8, Episode 1 (24 June 2013)

      AN INTERLUDE

      Darwin’s worm

      ‘The sight of a feather in a peacock’s tail, whenever I gaze at it, makes me sick!’ wrote Charles Darwin in a letter to Asa Gray.¹ He went on to write that this was countered by Asa’s story of the black pigs of the Everglades that had evolved to be able to eat a plant root that made the hooves of all other coloured СКАЧАТЬ