The unobserved tree makes noise

Two independent groups of scientists have recently confirmed that the universe does exist when we are not observing it.

The reality in question -- admittedly rather a small part of the universe -- was the polarisation of pairs of photons, the particles of which light is made. The state of one of these photons was inextricably linked with that of the other through a process known as quantum entanglement. The polarised photons were able to take the place of the particle and the antiparticle in Dr Hardy's thought experiment because they obey the same quantum-mechanical rules. Dr Yokota (and also Drs Lundeen and Steinberg) managed to observe them without looking, as it were, by not gathering enough information from any one interaction to draw a conclusion, and then pooling these partial results so that the total became meaningful.

That's a relief, although the head of one of the group called their results "preposterous", so perhaps we're still not really here.

Faster-than-light communication

In a Swiss experiment, two entangled photons 18 km away from each other were able to communicate with each other almost instantaneously.

On the basis of their measurements, the team concluded that if the photons had communicated, they must have done so at least 100,000 times faster than the speed of light -- something nearly all physicists thought would be impossible. In other words, these photons cannot know about each other through any sort of normal exchange of information.

Update: Hrm, the link above scampered behind Nature's paywall. Here's a post on the Scientific American blog instead.

Physicists at the University of Washington are

Physicists at the University of Washington are hoping to use entangled photons to send information back in time. "Here's where it gets weird."

Researching quantum honeybees

Researching quantum honeybees. Can bees detect quantum fields and use them to find food?

Brian Greene on Albert Einstein's miracle year,

Brian Greene on Albert Einstein's miracle year, his discovery of the photoelectric effect, and his uneasiness with quantum mechanics.