The Metre and Time

The development of measuring systems is a great human accomplishment. The early Egyptians created a unit of length, the cubit, based on the human forearm.
The English and others, used the human foot and grains of barleycorn to measure length. The metric system started with an fascinating attempt to define the metre using time. The metre evolved through a number of incarnations many involving distances taken from the planet. Today the meter is defined using the speed of light. This definition relies on a reliable means for measuring time. Time and space have been joined in our current definition of the metre.

Category:

Education

Tags:

• metric
• system
• metre
• meter
• foot
• French
• Revolution
• Einstein
• curriculum
• history
• measurement
• navigation
• physics
• math
• science

[ScienceOnline]

This re post of the video detailing the evolution of the metre corrects an error re. speed of light.

Thanks to "Oxydox".

[samten54]

Thank you

[5random1]

Excellent video. Great production qualities.

[compuholic82]

@beayn I realize it has been a while since the question has been asked. Maybe it is still of help. There is essentially two problems: 1. Somebody would need to control this official unit of length. 2. If you use a standard metal bar you would also need to define the temperature at which it has to be kept since metal can expand and contract.

Plus the relation of the units is the beauty of the metric system. Time defines length. Weight can be defined using length. All units are interrelated.

[Freakawn]

I have been looking for something like this for a while. Great thanks.

[RedWord]

@beayn because no matter how strong the metal or material, it will degrade over time. This way the definition is constant.

[MiKExAUS]

cheers mate, very good, interesting video.

[Anthonyk312]

@beayn Well who gets to make the bar? How long should the bar be in the first place? What if the bar is stolen? What if people don't agree with what the government decides is a length?

[sinupinginaaber]

in my school, they teach that 1 metre is 1 40millionth of a meridian.

[Tzimnewman3]

Thanks Bob

[111Yamato]

Yes thanks you for this vid.

[beayn]

Great vid but I don't get why it was such a huge dilema to define the length in relation to something else. Why not just pick a length, make a bar of metal to define the length and there you have it. That's the length.

[dgmcl3284]

i think it is so important that videos like this are out there, thank you!