There's Alien Gas Flowing Through New York City's Subways
2nd Avenue Subway Station, Sans Gas Dan Nosowitz No need to fear, though: it's an experiment to see exactly how gases are dispersed through the hundreds of miles of New York City subway tunnels. Starting today, New York City authorities will be releasing perfluorocarbon gas into several subway stops, some above and some below ground. Sounds scary, but isn't: perfluorocarbon is a harmless gas, odorless and colorless, and it's being used in the largest airflow experiment ever undertaken. Perfluorocarbon tracers, or PFTs, are used because they're artificial and do not occur in nature, so a very small amount can be detected fairly easily. The work of detection will be done by a large team from three national labs: the Brookhaven, Argonne, and Los Alamos National Laboratories. About 100 interns in addition to professionals from the labs will be constructing and monitoring small black-and-grey boxes in dozens of locations all around the city,...