In education, a Grace Hopper nanosecond is a prop used by a teacher to help students understand an abstract concept. The teaching tool got its name from the foot-long lengths of telephone wire that Admiral Grace Hopper used to give out at lectures. Admiral Hopper used the wires to illustrate how in one billionth of second (a nanosecond ) an electronic signal can travel almost twelve inches. In addition to being a gifted programmer, Admiral Hopper was quite famous during her lifetime for her teaching skills. Admiral Hopper believed that by providing the learner with a concrete analogy already in their frame of reference, it was possible to absorb and even understand an abstract concept that might otherwise be too difficult to comprehend. Towards the end of her life, when asked which of her many accomplishments she was most proud of, Admiral Hopper replied, "All the young people I have trained over the years".