Eureka (word) "Eureka! Eureka!" after he had stepped into a bath and noticed that the water level rose, whereupon he suddenly understood that the volume of water displaced must be equal to the volume of the part of his body he had submerged. (This relation is "not" what is known as Archimedes' principle—that deals with the "upthrust" experienced by a body immersed in a fluid.) He then realized that the volume of irregular objects could be measured with precision, a previously intractable problem. He is said to have been so eager to share his discovery that he leapt out of his bathtub
Eureka, California the exception of Elk River and Freshwater, are shown to be part of the Eureka Urban Cluster. A 2011 community study performed by the St. Joseph Health System, projects increased growth of 20,000 to occur in the unincorporated communities (outskirts) located adjacent to Eureka. If that forecast is realized, Greater Eureka could achieve a population of at least 65,000, barring any increase within the city limits. Eureka is the largest city of the Eureka-Arcata-Fortuna Micropolitan Area, a construct of the U.S. Census Bureau, which is synonymous with the County of Humboldt. As of the census of 2000, there were 26,128