One of the most famous thought experiments in history might be carried out in the lab. Could Schrödinger’s Cat become Schrödinger’s virus? Discover's 80 Beats blog:
To take a step towards this logical impossibility, researchers propose in a paper
posted on the arXiv pre-print server that they start with a much
smaller living organism, a virus–although other researchers point out
that there is still debate over whether viruses
are truly alive. Still, the researchers say that since they think
they’ve figured out a way to conduct an experiment putting a single
virus in a superposition, it may as well be tried.
The proposed experiment would involve trapping a single virus in a
vacuum chamber, and then gradually cooling it and slowing it down until
it rests, motionless, in its lowest possible energy state. Finally a
single photon, a light particle, would be beamed into the chamber, and
as long as nobody peeked inside the chamber the virus would be placed
in a superposition of two states: both moving and not.
The story also points out that it should be possible in theory to put macroscopic items in superposition, an idea that was also suggested in the SEED article, Supersizing Quantum Behavior.
For physicists, proving that quantum and Newtonian physics are at work on the same scale would strongly suggest that we still lack a significant understanding of how the world is constituted.