why do they call the clock big ben
Big Ben Big Ben is the largest of five bells and weighs 13.5 long tons (13.7 tonnes; 15.1 short tons).[1] It was the largest bell in the United Kingdom for 23 years. The origin of the bell's nickname is open to question; it may be named after Sir Benjamin Hall, who oversaw its installation, or heavyweight boxing champion Benjamin Caunt. Four quarter bells chime at 15, 30 and 45 minutes past the hour and just before Big Ben tolls on the hour. The clock uses its original Victorian mechanism, but an electric motor can be used as a backup.
Two-minute warning The origins are from the early years in the NFL when the official game time was kept by a member of the officiating crew, with the stadium clock being unofficial. Its purpose was a checkpoint to ensure that the teams knew how much time remained in the game. In the early 1960's the upstart American Football League made the stadium clock the official game time, a change followed later in the decade by the NFL. By then, television was an important factor in professional football, so the two-minute warning was retained as a commercial break and to serve as "tension building" time, and thus has become an important part of the game's flow.[3]