Gravitational lensing is useful to cosmologists because it is directly sensitive to the amount and distribution of dark matter. This is because the amount of light bending is sensitive only to the strength of the gravitational field it passes through*, which is mostly generated by the mass of the dark matter in the Universe.
Union City is a city in Wayne Township, Randolph County, Indiana, United States. As of the 2010 census, the city had a population of 3,584. Union City was a stop along the Pittsburgh, Cincinnati, Chicago and St. Louis Railroad, a forerunner of the Pennsylvania Railroad that connected Pittsburgh to Chicago and St. Louis.
Drained by the North Canadian and the Canadian rivers, which cross the county from northwest to southeast, the county consists of 905.17 square miles of land and water. In 2010 the incorporated towns included Calumet, Mustang, Okarche, Piedmont, Union City, Yukon, and El Reno (the county seat).