x404.co.uk
http://www.x404.co.uk/forum/

The Kilogram needs a diet and gets a suntan.
http://www.x404.co.uk/forum/viewtopic.php?f=19&t=18918		 Page 1 of 1
Author:  JJW009 [ Sat May 11, 2013 12:29 pm ]
Post subject:  The Kilogram needs a diet and gets a suntan.
http://www.eurekalert.org/pub_releases/ ... 010213.php

"The kilogram is one of the seven SI base units from which all other units can be derived and is the only one which is measured against a physical object – the IPK – all others are standardised against known constants."

I knew we had standard measures around the world, but it didn't occur to me that there wasn't a definition. Wikipedia says they're working on it though:

http://en.wikipedia.org/wiki/Kilogram

Quote:
After the International Prototype Kilogram had been found to vary in mass over time, the International Committee for Weights and Measures (CIPM) recommended in 2005 that the kilogram be redefined in terms of a fundamental constant of nature. At its 2011 meeting, the General Conference on Weights and Measures (CGPM) agreed in principle that the kilogram should be redefined in terms of the Planck constant, but deferred a final decision until its next meeting, scheduled for 2014.


Old news (January) but I don't remember reading it on here before.
Author:  cloaked_wolf [ Sat May 11, 2013 1:06 pm ]
Post subject:  Re: The Kilogram needs a diet and gets a suntan.
Quote:
"We're only talking about a very small change – less than 100 micrograms – so, unfortunately, we can't all take a couple of kilograms off our weight and pretend the Christmas over-indulgence never happened.


Surely if the kilo weighed less, we would all weigh more as a result?
Author:  JJW009 [ Sat May 11, 2013 1:20 pm ]
Post subject:  Re: The Kilogram needs a diet and gets a suntan.
Yes, but it weighs more. The research was about how to correct it.
Author:  cloaked_wolf [ Sat May 11, 2013 1:47 pm ]
Post subject:  Re: The Kilogram needs a diet and gets a suntan.
My point was only about a specific comment. If an object with a defined mass of 1kg (uncorrected), then surely (depending on density) it would measure more when corrected?

A bit like if you have a 100cm person measured against the ruler, and you realise the ruler has grown and is actually 110cm, then the person's height should have been measured at 110cm?

IIRC the standard unit of distance (the metre) is now a measurement of how far light travels over a particular time. Could they not do that with the kg? For example, you could invoke Avagadro's number and state that 1kg is the mass of x number of carbon atoms. Or something.
Page 1 of 1 All times are UTC
Powered by phpBB® Forum Software © phpBB Group
https://www.phpbb.com/