Monday, September 1, 2008

Sending photons between 2 villages in Switzerland

We often imagine scientists hiding in the basement of some mysterious building, working with weird machines and not paying much attention of what happens outside. Wrong! A very curious experiment took place between two villages in Switzerland.
The experiment was conducted by five scientists named Daniel Salart, Augustin Baas, Cyril Branciard, Nicolas Gisin and Hugo Zbinden. It was published in Nature Aug. 14th 2008. The scientists used a network of optical fiber connecting two villages distant from 18 kms. They vehiculed light back and forth and verified a property called 'entanglement'. We won't go in detail about that phenomena here. We will focus on the geography of the villages.
Swiss villages Satigny and Jussy are aligned along the east-west direction. Why is that interesting? Well the earth rotates around the north-south axis in one day, as you know - that's why we have day and night every 24 hours, right! The scientists repeated their experiment throughout the day and verified they obtained the same result!
You are not surprised? No, we expect things to work the same regardless of the time of the day - our cell phones, cars, dish washers, etc. Most machines work regardless of their orientation in SPACE. The experiment verified it is also the case for 'entangled photons' with a very good accuracy. It showed that Albert Einstein's spooky action either does not exist or needs to be faster than 10,000 times the speed of light.
Do you know other weird experiments? I.e. experiments that require measuring small things between very weird or distant locations?