From Simon Burton
Are we all missing something obvious about the claims that Shahriar Afshar’s experiment violates Bohr’s principle (17 February, p 13)? This states that a single quantum can either behave as a particle or as wave, but never as both simultaneously.
The key word is “simultaneously”. Afshar’s experiment does not seem to me to achieve simultaneous measurement – it only detects photons after the light has passed the fringe detector grid, been focused through a lens and bounced off mirrors. The time taken to do this is a veritable age at light speed – and certainly doesn’t achieve the requirement of simultaneity.
Southampton, UK
