- Illinois (Wikipedia)
Illinois (/ˌɪləˈnɔɪ/ IL-ə-NOY) is a state in the Midwestern United States. Chicago is its largest city, and the state’s capital is Springfield; other major metropolitan areas include Metro East (of Greater St. Louis), Peoria and Rockford. Of the fifty U.S. states, Illinois has the fifth largest gross domestic product (GDP), the sixth largest population, and the 25th largest land area.
- Spacetime (Wikipedia)
In physics, spacetime is a mathematical model that combines the three dimensions of space and one dimension of time into a single four-dimensional manifold. Spacetime diagrams can be used to visualize relativistic effects, such as why different observers perceive differently where and when events occur.
