Quantum guitar

 

I've been reading Jim Al-Khalili and Johnjoe McFadden's book on Quantum Biology. They use the idea of stringed instruments to highlight the difference between the classical and quantum understandings. I'm a guitarist - it's easy to hit the right note because there are frets. I can be a centimetre out with my finger and it doesn't matter. With a violin, slightly out means a slightly different note. There is continuous variation through the frequencies. This isn't true with the guitar. Only certain frequencies associated with the frets are allowed. That means the guitar is quantum and the violin is classical. That's appropriate, perhaps!