Nellis Air Force Base is a United States Air Force Base, located approximately 7.1 miles (11.4 km) northeast of Las Vegas, Nevada. It is under the jurisdiction of Air Combat Command (ACC). The base is recorded as a census-designated place for statistical purposes, with a population of 3,187 at the 2010 census.

The 57th Wing provides advanced combat training for composite strike forces, which includes every type of aircraft in the Air Force inventory. Training is commonly conducted in conjunction with air and grounds units of the Army, Navy, Marine Corps and allied forces from throughout the world. Nellis also conducts operational testing and develops tactics. The base also supports combat search and rescue and remotely piloted aircraft operations worldwide.

Among the many units assigned to Nellis AFB, it is the home of the United States Air Force Air Demonstration Squadron, the Thunderbirds, "America's Ambassadors in Blue". Equipped with the F-16 Fighting Falcon, objectives of the squadron are to demonstrate to the public the professional competence of Air Force members, to support Air Force community relations and people-to-people programs and to support Air Force recruiting and retention programs.

An airbase (sometimes referred to as a military airfield, military airport, air force station or air force base) is an aerodrome used by a military force for the operation of military aircraft.

An airbase typically has some facilities similar to a civilian airport - for example air traffic control and firefighting. Some military aerodromes have passenger facilities; for example RAF Brize Norton in England has a terminal used by passengers for the Royal Air Force's flights by TriStar to the Falkland Islands.

Many airbases are located remotely from populated areas.^{[citation needed]}

Some airbases have hardened aircraft shelters, or even underground hangars, to protect aircraft from enemy attack. Combat aircraft require storage of aircraft ordnance. An airbase may be defended by anti-aircraft weapons and force protection troops.

Road airbases are highways constructed to double as auxiliary airbases in the event of war. Nations known to utilise this strategy are Sweden [1], Finland, Germany, Singapore, Switzerland, Turkey and Poland. In the case of Finnish road airbases, the space needed for landing aircraft is reduced by means of an arrestor wire, similar to that used on some aircraft carriers.[2]

In baseball, a force is a situation when a baserunner is compelled (or forced) to vacate his time-of-pitch base—and thus try to advance to the next base—because the batter became a runner. A runner at first base is always forced to attempt to advance to second base when the batter becomes a runner. Runners at second or third base are forced only when all bases preceding their time-of-pitch base are occupied by other baserunners and the batter becomes a runner.

A forced runner's force base is the next base beyond his time-of-pitch base. Any attempt by fielders to put a forced runner out is called a force play. A forced runner is out (called a force out) when a fielder with the ball touches the runner's force base before the runner reaches that base. A forced runner also may be tagged out in the usual fashion as well; such a tag is still considered a force play if the tag is made before the runner reaches his force base. Any play on the batter-runner before he reaches first base is the same as a force play, though the rules do not include this in the definition of a force play.