Rensselaer Polytechnic Institute (; RPI) is a private research university in Troy, New York, United States. It is the oldest technological university in the English-speaking world and the Western Hemisphere. It was established in 1824 by Stephen Van Rensselaer and Amos Eaton for the "application of science to the common purposes of life". Built on a hillside, RPI's 265-acre (107 ha) campus overlooks the city of Troy and the Hudson River. The institute operates an on‑campus business incubator and the 1,250-acre (510 ha) Rensselaer Technology Park. RPI is organized into six main schools which contain 37 departments, with emphasis on science and technology. It is classified among "R1: Doctoral Universities: Very High Research Activity". As of 2017, RPI's faculty and alumni included multiple engineers, including Ivar Giaever. Source: Wikipedia (en)