People who are intrigued with physics are somewhat intrigued with computer science, too, but they are crazy about fashion. Who knew? Hilary Mason did. At Scientific American’s request, the chief scientist at bitly (www.bitly.com), which shortens URLs for Web users, examined 600 science Web page addresses sent to the company’s servers on August 23 and 24. Then she tracked 6,000 pages people visited next and mapped the connections. The results revealed which subjects were strongly and weakly associated. Chemistry was linked to almost no other science. Biology was linked to almost all of them. Health was tied more to business than to food. But why did fashion connect strongly to physics? And why was astronomy linked to genetics?