The alyssum flowers pictured above aren't just pretty -- they're good for the planet, too. A recent study from the University of Warwick suggests that the common flowers and their relatives could help restore chemically poisoned land to a more livable state by leeching toxins from the ground. As an added bonus, researchers think they could one day harvest those same toxic chemicals -- now broken down to tiny nanoparticles -- for use in new technologies.
Though you might not know it by their day-to-day usage, metric units don't simply exist, but are actually determined in terms of the physical world. The International System of Units (SI) has used some clever tricks to precisely determine the definitions of many fundamental units: For instance, a second is defined as "the duration of 9,192,631,770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the caesium 133 atom," and a meter is defined as the distance light travels in a vacuum in 1 ⁄ 299,792,458 of a second. Compared to these, the definition of the kilogram seems surprisingly archaic: It's defined as the mass of a specific cylinder of platinum (technically, a 90% platinum / 10% iridium alloy) in a vault in Paris. Given that this particular cylinder gains about 50 micrograms per century and that it's a bit alarming to have so much of scientific measurement determined in terms of a physical artifact, some scientists hope to define the kilogram in more precise terms, and a study recently published on arXiv may point the way: