Ancient geographers listed many cities called Arsinoe, from Cyprus to Cilicia (in what is now southern Turkey), from Ephesus to the Gulf of Suez. Most of them were linked to the Ptolemies, the dynasty that ruled Egypt after the death of Alexander the Great. One, however, lies far from the Nile. It stood in the […]

In a lab at the Okinawa Institute of Science and Technology (OIST) in Japan, a slab of diamond smaller than a pencil eraser hangs from a carbon fiber rod about 5 centimeters (2 inches) long. The rod is attached to a graphite plate that floats in mid-air above four magnets. Nobody touches it. When a […]