Did they need to adjust it at all? My book says the uncertainty of the speed of light is 0. I find it hard to believe that the standard meter was exactly 1/299,792,458th already.
Was an adjustment of a few nanometers in one direction or the other required?
My brother wants to know, also.
2007-12-24 08:38:40 · 5 answers · asked by Anonymous in Science & Mathematics ➔ Physics
amansscientiae: That has nothing to do with anything. Where you came up with that conclusion, I have no idea.
2007-12-24 09:07:59 · update #1
No adjustment was required because the current definition was within the measurement error of the previous one. That's the point--- a more accurate meter was required. It's not that the previous meter was EXACTLY 1/299,792,458 of a second, but that value was within the error bars.
2007-12-24 08:49:15 · answer #1 · answered by Anonymous · 3⤊ 0⤋
That's an interesting question. I have a feeling that nine digits of precision was all that the previous definition had in it so that no fudging was needed, but it sounds like something to ask some standards lab people about.
The current definition defines the speed of light and the second, from which you can measure the length of a meter. The old definition defined the meter and the second, from which you could measure the speed of light.
The history of the changes in the definition of the meter is really interesting. There was a paper in the Am. J. of Physics several years ago that told the story (I think it's called "The Politics of the Meter Stick") of how a French surveying outfit lobbied for the original definition so they'd get the contract to carry out the measurement!
2007-12-24 16:51:12 · answer #2 · answered by Steve H 5 · 2⤊ 0⤋
The seventeenth meeting of the General Conference on Weights and Measures on October 21, 1983 replaced the definition of the meter with its current definition:
"The metre is the length of the path traveled by light in vacuum during a time interval of 1/299,792,458 of a second exactly."
2007-12-24 16:48:37 · answer #3 · answered by Charles M 6 · 1⤊ 0⤋
It's a definition. The new meter and the old meter are not exactly the same. The universe did not end.
After all, units of measure are arbitrary human choices and have no physical meaning. Looks like your science teacher never explained it properly.
:-)
2007-12-24 17:00:24 · answer #4 · answered by Anonymous · 1⤊ 3⤋
probably not...because the denominator is some wierd number you can tell that they weren't certain of it before...orignally, the meter was a fraction of the distance from the equator to the north pole.
2007-12-24 16:42:42 · answer #5 · answered by Anonymous · 0⤊ 1⤋