3rd place: Quantum effects seen in a visible object
In what is an important step towards testing Schrodinger's cat paradox, physicists at the University of California, Santa Barbara have bagged third place in our top 10 by observing true quantum behaviour in a macroscopic object big enough to be seen with the naked eye. Andrew Cleland and crew reduced the amplitude of the vibrations in a resonator by cooling it down to below 0.1 K. They were then able to create a superposition state of the resonator where they simultaneously had an excitation in the resonator and no excitation in the resonator. "This is analogous to Schrödinger's cat being dead and alive at the same time," says Cleland. This is the first time this feat has been achieved and it could shed light on the mysterious boundaries between the classical and quantum worlds.
To remind us non-physicists of the basics of Schrodinger's cat, we turn once again to Mark Rosengarten. His song "Schodinger's Cat Strikes Back" explains the paradox:
Of course, if you only play the song a single time without doing any additional reading, you might feel that the concept has been simultaneously explained and not explained. Quantum physics can be like that....