The whole idea of the meter is to establish a measurement based on some physical constant, rather than the arbitrary definitions of english standards like the inch or foot.Wikipedia:
To further reduce uncertainty, the seventeenth CGPM in 1983 replaced the definition of the metre with its current definition, thus fixing the length of the metre in terms of the second and the speed of light:
The metre is the length of the path travelled by light in vacuum during a time interval of 1 ⁄ 299,792,458 of a second.[1]
http://en.wikipedia.org/wiki/Meter
Check out this wikipedia article for some history.
My problem with the metric system is probably not the same problem that your grandpa has with the metric system.
The definition of the meter still seems arbitrary and awkward. I agree that it should be based on some physical constant, and the speed of light seems like a great contender. But the current definition of a meter is the distance traveled by light in 1 ⁄ 299,792,458 of a second in a vacume. That number, 299 million is based off a previous measurement of the wavelength of krypton, which is also a physical measurement of something which will not change, but the selection of krypton as the measure is itself ultimately arbitrary.
I propose that the standard measure of distance should be the light second. That is equal to 1Ls. A meter would then be =1Ls/100 million. So, 1 meter in this system is essentially 3 meters compared to the current system. That makes 1 centimeter = to approximately 3 current centimeters.
That is a good distance to work with and it is nicely framed in terms of "C", or the speed of light, and rooted in a cosmic constant.
So the new definition of a meter would be the distance light travels in 1/100,000,000 of a second. Much cleaner, much easier to teach, much easier to use in calculations, a nice round number that works well with our decimal system.
Any other nerds with an opinion on this? I can't get anybody i know in real life to have a reaction to this discussion, haha.