Author Topic: British Definition of the Metre Amended.  (Read 1778 times)

ninthace

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British Definition of the Metre Amended.
« on: 18:02:12, 17/06/20 »
For those of us who walk in metres, I bet you missed this one:


The Weights and Measures Act 1985 has been amended to include a revised definition of the metre.
See http://www.legislation.gov.uk/uksi/2020/586/article/2/made
To save you the trouble the revised definition is as follows:


"for which the symbol "m" is used, is the SI unit of length, defined by taking the fixed numerical value of the speed of light in vacuum c to be 299 792 458 when expressed in the unit m/s, where the second is defined by taking the fixed numerical value of the caesium frequency ΔvCs, the unperturbed ground-state hyperfine transition frequency of the caesium 133 atom, to be 9 192 631 770 when expressed in the unit Hz, which is equal to s↑-1."


So now you know.  And for those of you who still walk in imperial - an inch is defined as 2.54 cm so you are walking in metric even if you didn't know it  O0
P.S.  If you are on a diet a kilogram is now:


“for which the symbol “kg” is used, is the SI unit of mass, defined by taking the fixed numerical value of the Planck constant h to be 6.626 070 15 x 10↑-34 when expressed in the unit J s, which is equal to kg m2 s↑1, where the second is defined by taking the fixed numerical value of the caesium frequency ΔvCs, the unperturbed ground-state hyperfine transition frequency of the caesium 133 atom, to be 9 192 631 770 when expressed in the unit Hz, which is equal to s↑-1.”


Isn't science wonderful?  :)

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pleb

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Re: British Definition of the Metre Amended.
« Reply #1 on: 19:30:13, 17/06/20 »
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SteamyTea

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Re: British Definition of the Metre Amended.
« Reply #2 on: 21:20:38, 17/06/20 »
Now explain, in clear English, why the derived units i.e. newton, pascal, joule
Are capitalised when abbreviated i.e. N, Pa, J.
But written in lower case when in long hand i.e. newton, pascal, joule.
Eventhough they are named after real people i.e. Newton, Pascal, Joule.


And why is the kilogram the odd one out?  It should be the gram.
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GinAndPlatonic

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Re: British Definition of the Metre Amended.
« Reply #3 on: 21:46:40, 17/06/20 »
Thanks for the heads up . !!

I just don`t know how I missed that . O0
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Mel

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Re: British Definition of the Metre Amended.
« Reply #4 on: 23:35:13, 17/06/20 »
Can I have some of what you're drinking Mr N?  Might help me understand that better  :D
Is the search over if you find nothing?
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ninthace

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Re: British Definition of the Metre Amended.
« Reply #5 on: 01:06:18, 18/06/20 »
Can I have some of what you're drinking Mr N?  Might help me understand that better  :D
It still does not explain how my out and back walk today was further in one direction than the other.  Perhaps I had a duff batch of caesium.  ;)
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Bigfoot_Mike

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Re: British Definition of the Metre Amended.
« Reply #6 on: 06:25:19, 18/06/20 »
Is it only the British versions of the metre and kg that are defined in this way? Am I a different height and mass if I travel abroad? If so, what happens to me while in transit, or does that depend on the nationality of the carrier?

SteamyTea

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Re: British Definition of the Metre Amended.
« Reply #7 on: 07:59:30, 18/06/20 »
Is it only the British versions of the metre and kg that are defined in this way? Am I a different height and mass if I travel abroad? If so, what happens to me while in transit, or does that depend on the nationality of the carrier?
The French use it, so you are safe there.
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richardh1905

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Re: British Definition of the Metre Amended.
« Reply #8 on: 08:45:30, 18/06/20 »
I struggle to see what this has to do with walking.  ::)
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ninthace

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Re: British Definition of the Metre Amended.
« Reply #9 on: 09:56:38, 18/06/20 »
Is it only the British versions of the metre and kg that are defined in this way? Am I a different height and mass if I travel abroad? If so, what happens to me while in transit, or does that depend on the nationality of the carrier?
Yet again, I think it is a case of HMG catching up with the rest of the world so I think your dimensions in transit will be ok, provided you travel at a sensible velocity.
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Bigfoot_Mike

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Re: British Definition of the Metre Amended.
« Reply #10 on: 18:58:50, 18/06/20 »
I struggle to see what this has to do with walking.  ::)
The distance we walk and the mass we carry are now different.  :)

SteamyTea

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Re: British Definition of the Metre Amended.
« Reply #11 on: 21:21:22, 18/06/20 »
The distance we walk and the mass we carry are now different.  :)
Or the same, but described differently.
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GoneWest

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Re: British Definition of the Metre Amended.
« Reply #12 on: 08:11:29, 19/06/20 »
Or the same, but described differently.


Indeed. It's all relative, after all.

myxpyr

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Re: British Definition of the Metre Amended.
« Reply #13 on: 16:00:37, 19/06/20 »
Well, I always know how many miles I've walked. Why would I want to know how many kilograms I've walked? ;D O0

ninthace

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Re: British Definition of the Metre Amended.
« Reply #14 on: 16:28:27, 19/06/20 »
Well, I always know how many miles I've walked. Why would I want to know how many kilograms I've walked? ;D O0
Depends on if you can walk fast enough - the faster you walk, the heavier you get.   O0

 
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