2007-05-27 23:50:24 · 5 answers · asked by Anonymous in Science & Mathematics ➔ Physics
Yeah, i know how, but WHY?
2007-05-27 23:57:26 · update #1
They've needed a more accurate standard as science and technology have progressed. Some measurements now days have to be accurate to withing parts per trillion, so a definition of the meter has to be extremely exact.
2007-05-28 03:03:07 · answer #1 · answered by Nomadd 7 · 0⤊ 0⤋
Historically, the metre was defined by the French Academy of Sciences as the length between two marks on a platinum-iridium bar, which was designed to represent 1/10,000,000 of the distance from the equator to the north pole through Paris.
Today, it is defined by the International Bureau of Weights and Measures as the distance travelled by light in absolute vacuum in 1/299,792,458 of a second.
2007-05-27 23:55:30 · answer #2 · answered by NoComment 2 · 0⤊ 0⤋
The platinum iridium bar cannot really give us an accurate measurement of one meter. It changes in length because of changes in temperature.
2007-05-28 01:55:09 · answer #3 · answered by spilledantidote 1 · 0⤊ 0⤋
The applications of dimension properties has changed these days. going to nanometer scale and astronomic space move us to find a new way to solve problems.
2007-05-28 00:03:24 · answer #4 · answered by Anonymous · 0⤊ 0⤋
old method is obsolute and requires too much caution and care. beside accuracy is more in new technique.
2007-05-28 00:30:39 · answer #5 · answered by Anonymous · 0⤊ 0⤋