Researchers build a working tractor beam, on a very small scale

We recently saw research that suggested negative radiation pressure in light could lead to a practical tractor beam. A partnership between the Czech Republic's Institute of Scientific Instruments and Scotland's University of St. Andrews can show that it's more than just theory: the two have successfully created an optical field that flipped the usual pressure and started pulling objects toward the light. Their demo only tugged at the particle level -- sorry, no spaceships just yet -- but it exhibited unique properties that could be useful here on Earth. Scientists discovered that the pull is specific to the size and substance of a given object, and that targets would sometimes reorganize themselves in a way that improved the results. On the current scale, that pickiness could lead to at least medicinal uses, such as sorting cells based on their material. While there's more experiments and development to go before we ever see a tractor beam at the hospital, the achievement brings us one step closer to the sci-fi future we were always told we'd get, right alongside the personal communicators and jetpacks.