- The Central Intelligence Agency (CIA; /ˌsiː.aɪˈeɪ/), known informally as the Agency and historically as the Company, is a civilian foreign intelligence service of the federal government of the United States, officially tasked with gathering, processing, and analyzing national security information from around the world, primarily through the use of human intelligence (HUMINT) and conducting covert action through its Directorate of Operations. As a principal member of the United States Intelligence Community (IC), the CIA reports to the Director of National Intelligence and is primarily focused on providing intelligence for the President and Cabinet of the United States. Following the dissolution of the Office of Strategic Services (OSS) at the end of World War II, President Harry S. Truman created the Central Intelligence Group under the direction of a Director of Central Intelligence by presidential directive on January 22, 1946, and this group was transformed into the Central Intelligence Agency by implementation of the National Security Act of 1947.
- Why Bridges Don’t Sink (practical.engineering)
The essence of a bridge is not just that it goes over something, but that there’s clear space underneath for a river, railway, or road. Maybe this is already obvious to you, but bridges present a unique structural challenge. In a regular road, the forces are transferred directly into the ground. On a bridge, all those forces on the span get concentrated into the piers or abutments on either side. Because of that, bridge substructures are among the strongest engineered systems on the planet. And yet, bridge foundations are built in some of the least ideal places for heavy loading. Rivers and oceans have soft, mucky soils that can’t hold much weight. Plus, obviously, a lot of them are underwater.