Physicists finally moving from SVN to Git.
An old artifact kept in a vault outside Paris is no longer the standard kilogram
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Re: An old artifact kept in a vault outside Paris is no longer the standard kilogram
#12Confused, so how do they measure 1 kilo of something now when they need to calibrate the most precise instruments? They count 10^40 photons? How? And how does that translate into a physical mass they want to carry around? Edit: Seems I completely missed a paragraph somehow. Thanks!
The term of art is "realisation". The article mentions two realisations but does not elaborate: "In practice, there are currently two known methods for measuring such masses with great precision. These are known as the Kibble balance and the single-crystal silicon sphere". You should be able to google from that.
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Re: An old artifact kept in a vault outside Paris is no longer the standard kilogram
#13I've always been mildly irritated that the name of the SI mass base unit has a prefix. Second, liter, meter, Newton, kilogram. Were I emperor of the world I would slide the name scale up so the mass equal to 2.205lbs was called a gram.
How about we keep the current name and use it as a basis for prefixing?
gram -> millikilogram
milligram -> microkilogram
metric ton -> kilokilogram
Re: An old artifact kept in a vault outside Paris is no longer the standard kilogram
#14Physicists finally moving from SVN to Git.
Git is fundamental now?
Re: An old artifact kept in a vault outside Paris is no longer the standard kilogram
#15Confused, so how do they measure 1 kilo of something now when they need to calibrate the most precise instruments? They count 10^40 photons? How? And how does that translate into a physical mass they want to carry around? Edit: Seems I completely missed a paragraph somehow. Thanks!
For most intents and purposes its OK if you are a bit inaccurate. The important thing is that we will never drift further and further away. In 1000 years time we will still have exactly the same kg as we have now.
Re: An old artifact kept in a vault outside Paris is no longer the standard kilogram
#16I've always been mildly irritated that the name of the SI mass base unit has a prefix. Second, liter, meter, Newton, kilogram. Were I emperor of the world I would slide the name scale up so the mass equal to 2.205lbs was called a gram.
How about we keep the current name and use it as a basis for prefixing? gram -> millikilogram milligram -> microkilogram metric ton -> kilokilogram ...never mind.
It's almost a crime that a metric ton isn't called a "megagram".
Aside, are the mega and giga prefixes ever used for anything except bits and bytes?
(Edit: OK, OK. I forgot about megaohms, megahertz, megawatts. Also megapixels and Megadeth.)
Re: An old artifact kept in a vault outside Paris is no longer the standard kilogram
#17Physicists finally moving from SVN to Git.
More like from JPG to SVG
Re: An old artifact kept in a vault outside Paris is no longer the standard kilogram
#18Re: An old artifact kept in a vault outside Paris is no longer the standard kilogram
#19laughs in imperial units
Re: An old artifact kept in a vault outside Paris is no longer the standard kilogram
#20Veritasium has a video back in 2017 explaining kibble balance
https://youtu.be/Oo0jm1PPRuo