How do you observe the un-observable?
20 Mar 2009 by Evoluted New Media
Working on the border of philosophy is difficult for a physicist but it is a rare and exciting occasion when a fundamental thought experiment in quantum mechanics is demonstrated in a real experiment.
Working on the border of philosophy is difficult for a physicist but it is a rare and exciting occasion when a fundamental thought experiment in quantum mechanics is demonstrated in a real experiment.
Quantum physicists from Oska University and the CREST Photonic Quantum Information Project in Kawaguchi City, Japan have experimentally demonstrated a quantum conundrum that many have fought to overcome for decades.
The Japanese based researchers have put into practice Lucien Hardy’s quantum mechanics thought experiment, which follows the paths of two photons using interferometers, instruments that can be used to interfere photons together. Hardy’s paradox addresses the central question in quantum mechanics of how you can observe atomic and sub-atomic systems when just looking at them affects their behaviour. Although Hardy’s experiment is rarely contested, it was not until now that the experiment has been done in reality.
The researchers said: “Unlike Hardy’s original argument, our demonstration reveals the paradox by observation, rather than inference. We believe the demonstrated joint weak measurement is useful not only for exploiting fundamental quantum physics, but also for various applications such as quantum metrology and quantum information technology.”
By Leila Sattary
