In the May 27 SN: Genetic intruders, seeing Chaco in a new light, an artificial womb, Mars’ origin revisited, domestication of the horse, glimpsing Earth’s glacial past, what’s in a fang blenny’s bite and more.
NUMBER SMARTS Cats show quantity-related abilities. Without training, cats can pick out differences between groups of a few small objects, such as 2 versus 5, but the felines may be using visual shortcuts.
TAKING MEASURE New units based on fundamental properties of the universe will make measurements more precise. A kilogram cylinder replica (left) is safeguarded under bell jars. Ultrasmooth silicon spheres (right) will soon be used to redefine the kilogram using the Planck constant — making the kilogram prototype obsolete.
epa european pressphoto agency b.v./Alamy Stock Photo