JUST as the classic “two-slits” experiment shows that a beam of light is a
quantum wave, a team of researchers has now done the same trick with a flowing
liquid, showing that it, too, demonstrates quantum interference. Their
experiment is so sensitive it can easily sense the turning of the Earth.
In the classic demonstration of quantum interference, a light beam is split
in two and recombined. If the two waves line up peak to peak, the recombined
beam shines bright, but if peak lines up with trough they cancel out. Physicists
have shown this in light, electricity and neutron…
