Friday, 19 November 2010

Reading through Does God Play Dice?

After yesterday's meeting, I have begun to crack down on reading the remaining books and specifically picking out the parts that I believe will be most relevant to me. Chapter 16 of "Does God Play Dice?" by Ian Stewart is called "Chaos and Quantum" and may be exactly what I need to help me with understanding these 2 concepts for my project.

Ian Stewart discusses the 'cat in a box' experiment. I came across this experiment in the book Quantum by Jim Al-Khalili but I don't think I blogged about it:
"Imagine a box that contains a source of radioactivity, a Geiger counter to detect the presence of radioactive particles, a bottle of (gaseous) poison, and a (live) cat. These are arranged so that if a radioactive atom decays and releases a particle, the then Geiger counter will detect it, set off some kind of machinery that crushes the bottle and kill the unfortunate cat. From outside the box, an observer cannot determinw the quantum state of the radioactive atom; it may either have decayed or not. So [...] the quantum state of the atom is a superposition of 'not decayed' and 'decayed' - and so is that of the cat, which is part alive and part dead at the same time. Until, that is, we open the box. At this instant the wave function of the atom instantly collapses, say to 'decayed', and that of the cat also correspondingly collapses instantly to 'dead'.

This extract has helped me understand quantum theory a bit more. It shows that it is impossible to know what state something is in, and therefore it can be said that they are in both states.

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