Talk:2073: Kilogram - Revision history

172.69.55.112: E=γmc² pedantry

2019-09-11T22:56:05Z

E=γmc² pedantry

Nccsa186 at 19:29, 8 April 2019

2019-04-08T19:29:43Z

162.158.79.89 at 04:02, 29 December 2018

2018-12-29T04:02:00Z

162.158.94.2: Local gravity is measured with a gravimeter

2018-12-09T15:32:21Z

Local gravity is measured with a gravimeter

162.158.63.232 at 18:57, 30 November 2018

2018-11-30T18:57:48Z

162.158.63.232 at 18:54, 30 November 2018

2018-11-30T18:54:59Z

ProphetZarquon: Yup

2018-11-28T20:08:28Z

Yup

162.158.91.59: Mass wass defined by length via water

2018-11-22T12:57:51Z

Mass *wass* defined by length via water

108.162.238.59: a summary is a short synopsis of the content of a larger writing sample

2018-11-22T08:06:07Z

a summary is a short synopsis of the content of a larger writing sample

172.68.65.84 at 23:19, 20 November 2018

2018-11-20T23:19:33Z

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 ::The original proposition for a reproducible unit of mass (after the french Revolution, by Talleyrand) was that of the pound being the mass of a cubic foot of distilled water, Also the ''Grave'' (equal to our kilogram) was defined by the cubic decimetre of water by the French Commission of weights and measures in 1793. ("Le poid du pied cube d'eau étant ainsi connu, on a conclu celui du décimètre cube, ou la nouvelle unité de poids" https://books.google.nl/books?id=FufDNJHvgFEC p.274). So length and mass *were* interlinked by water.
 :Also, in E=mc², E is the energy '''at rest''' (for a stationary object of mass m), so your definition using the acceleration makes no sense.[[Special:Contributions/162.158.88.254|162.158.88.254]] 18:47, 16 November 2018 (UTC)
 Actually, for the new definition of the kilo using the Kibble balance you need to measure the gravity... [[Special:Contributions/162.158.134.16|162.158.134.16]] 17:34, 16 November 2018 (UTC)

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	I wish they ''had'' redefined the kilogram a little bit. It would have been neat if 1 kg was exactly the weight of 1 dm^3 (1 litre) of water under one atmosphere of pressure. Right now it's soooo close. It's a good enough estimate for simple maths, but whenever you tell people that a litre of water weighs one kilogram the pedants comes out of the woodworks... [[User:Kapten-N\|Kapten-N]] ([[User talk:Kapten-N\|talk]]) 16:50, 16 November 2018 (UTC)		I wish they ''had'' redefined the kilogram a little bit. It would have been neat if 1 kg was exactly the weight of 1 dm^3 (1 litre) of water under one atmosphere of pressure. Right now it's soooo close. It's a good enough estimate for simple maths, but whenever you tell people that a litre of water weighs one kilogram the pedants comes out of the woodworks... [[User:Kapten-N\|Kapten-N]] ([[User talk:Kapten-N\|talk]]) 16:50, 16 November 2018 (UTC)
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		+	:Having thought about it, therein lies much of the joke. Originally a kg was 1 dm^3 of water at stp. But it's no longer that, so it is essentially now an arbitrary value. And being an arbitrary value, there's really no principled argument not to just redefine it as a pound. The only argument against redefining it as a pound is practical, and sentimental.[[User:Nccsa186\|Nccsa186]] ([[User talk:Nccsa186\|talk]]) 19:29, 8 April 2019 (UTC)

	:You'll get pedants whenever you refer to a kilogram as weight; it's a mass. The difference is that stuff weighs less on the Moon - or on tall mountains - although the mass is the same. I think the article as I just read it gets away with this. And, sure, what is the standard kilogram but a weight, that you take and weigh... rja.carnegie@excite.com [[Special:Contributions/162.158.91.59\|162.158.91.59]] 23:57, 16 November 2018 (UTC)		:You'll get pedants whenever you refer to a kilogram as weight; it's a mass. The difference is that stuff weighs less on the Moon - or on tall mountains - although the mass is the same. I think the article as I just read it gets away with this. And, sure, what is the standard kilogram but a weight, that you take and weigh... rja.carnegie@excite.com [[Special:Contributions/162.158.91.59\|162.158.91.59]] 23:57, 16 November 2018 (UTC)

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	There is already one link to a Veritasium video on this subject a few coments above, and there was a new video out just before this vote, about the new units: [https://www.youtube.com/watch?v=c_e1wITe_ig The kg is dead, long live the kg]. --[[User:Kynde\|Kynde]] ([[User talk:Kynde\|talk]]) 15:57, 19 November 2018 (UTC)		There is already one link to a Veritasium video on this subject a few coments above, and there was a new video out just before this vote, about the new units: [https://www.youtube.com/watch?v=c_e1wITe_ig The kg is dead, long live the kg]. --[[User:Kynde\|Kynde]] ([[User talk:Kynde\|talk]]) 15:57, 19 November 2018 (UTC)
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		+	The title text actually made me scream in existential horror. [[Special:Contributions/162.158.79.89\|162.158.79.89]]Somebody who probably has an account here but can't be bothered to log in.

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 ::: No, it doesn't require an environment of precisely 1g, it relies on the fact that the effect of local gravity is well understood, can be measured precisely, and compensated for.  It's a fundamental aspect of the Kibble balance and you can rest assured that it hasn't been overlooked by the physicists designing it! [[Special:Contributions/162.158.134.34|162.158.134.34]] 16:38, 17 November 2018 (UTC)
 ::::Oh really? ''How'' would one precisely measure the local gravity? In kilograms of force? No, sorry. This is a bad method. It leads to an insoluble quandary & clearly either ''hasn't'' been thought through by its supporters, or is an intentional exploit. ''Actually'' fixing it to Planck's constant would be great, but a Kibble scale can't do that. Weighing mass against anything but another mass is foolish.[[User:ProphetZarquon|ProphetZarquon]] ([[User talk:ProphetZarquon|talk]]) 22:15, 19 November 2018 (UTC)
 :::I'm very happy that measuring a kilogram accurately now may require EM shielding.  EM shielding is far too rare nowadays, in this modern world of far-beyond-van-eck-phreaking.  Anything that makes shielding more prevalent and widely understood is sorely needed.  [[Special:Contributions/172.68.65.84|172.68.65.84]] 23:19, 20 November 2018 (UTC)

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		+	It's nothing short of a miracle that the US made it to the moon when the imperial system's so ingrained into our culture. Oh, wait, it was a bunch of German scientists who made that possible. Nevermind... Alex

	I didn't know that weights and currencies could be converted 1:1, that's cool! [[User:Fabian42\|Fabian42]] ([[User talk:Fabian42\|talk]]) 16:37, 16 November 2018 (UTC)		I didn't know that weights and currencies could be converted 1:1, that's cool! [[User:Fabian42\|Fabian42]] ([[User talk:Fabian42\|talk]]) 16:37, 16 November 2018 (UTC)

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	Ok, I'm going to point out something. What's a meter? 1000 milimeters. What's a milimeter? .....skipping the questions all the way to the end, the answer is "the wavelength of the color orange". Or at least that's what I read. So my question is: why orange? What's so special about orange? What as a species or as a solar system or as universe does the color orange have to do with anything? [[Special:Contributions/172.68.90.10\|172.68.90.10]] 21:50, 16 November 2018 (UTC) SiliconWolf		Ok, I'm going to point out something. What's a meter? 1000 milimeters. What's a milimeter? .....skipping the questions all the way to the end, the answer is "the wavelength of the color orange". Or at least that's what I read. So my question is: why orange? What's so special about orange? What as a species or as a solar system or as universe does the color orange have to do with anything? [[Special:Contributions/172.68.90.10\|172.68.90.10]] 21:50, 16 November 2018 (UTC) SiliconWolf
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		+	: Orange is my favorite color. Enough said. Alex

	: "The metre was originally defined in 1793 as one ten-millionth of the distance from the equator to the North Pole." That's why orange. Think of those lines from equator to pole... and how an orange is divided in segments beneath the peel. This is why the "Terry's Chocolate Orange" is so called, because it resembles the fruit orange. rja.carnegie@excite.com [[Special:Contributions/162.158.91.59\|162.158.91.59]] 23:51, 16 November 2018 (UTC)		: "The metre was originally defined in 1793 as one ten-millionth of the distance from the equator to the North Pole." That's why orange. Think of those lines from equator to pole... and how an orange is divided in segments beneath the peel. This is why the "Terry's Chocolate Orange" is so called, because it resembles the fruit orange. rja.carnegie@excite.com [[Special:Contributions/162.158.91.59\|162.158.91.59]] 23:51, 16 November 2018 (UTC)

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 ::::Oh really? ''How'' would one precisely measure the local gravity? In kilograms of force? No, sorry. This is a bad method. It leads to an insoluble quandary & clearly either ''hasn't'' been thought through by its supporters, or is an intentional exploit. ''Actually'' fixing it to Planck's constant would be great, but a Kibble scale can't do that. Weighing mass against anything but another mass is foolish.[[User:ProphetZarquon|ProphetZarquon]] ([[User talk:ProphetZarquon|talk]]) 22:15, 19 November 2018 (UTC)
 :::I'm very happy that measuring a kilogram accurately now may require EM shielding.  EM shielding is far too rare nowadays, in this modern world of far-beyond-van-eck-phreaking.  Anything that makes shielding more prevalent and widely understood is sorely needed.  [[Special:Contributions/172.68.65.84|172.68.65.84]] 23:19, 20 November 2018 (UTC)
 Up until 1964 a litre (and therefore actually the metre too) used to be defined as the volume that water with mass 1kg takes. But this is not good for exact measurements not only because you need exactly reproducable temperature, pressure (not so problematic, because you can measure them and then calculate the divergence) and gravity (not so easy to measure, because you need an exact mass and exact masses are impossible to keep the same), but also because you need pure water free of any polutions of other stuff (hard and expensive) and even free of tiny amounts of isotopes which are deuterium and tritium (even way more expensive).
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 :::: No longer necessary in modern life... Which is why we should all switch to base-10 units of time! [[User:ProphetZarquon|ProphetZarquon]] ([[User talk:ProphetZarquon|talk]]) 08:36, 17 November 2018 (UTC)
 ::::: Or we could change everything else to base 12... (I can dream, can't I?) [[User:Linker|Linker]] ([[User talk:Linker|talk]]) 18:45, 17 November 2018 (UTC)
 :::::: I would love a base-10 time system. Especially since time=money, and money is base-10. Color me surprised a while back when my research led me to find out this had been tried in the past. They had a whole calendar system designed to renumber minutes, hours, days and weeks. I think they went to a 10 day week. Would have worked, too, except for religion. Under the new system, too many people had problems keeping track of every seventh day. SO it was scrapped. --ElectroDFW-- [[Special:Contributions/108.162.238.59|108.162.238.59]] 08:06, 22 November 2018 (UTC)
 Ok, I'm going to point out something.  What's a meter?  1000 milimeters.  What's a milimeter?  .....skipping the questions all the way to the end, the answer is "the wavelength of the color orange".  Or at least that's what I read.  So my question is: why orange?  What's so special about orange?  What as a species or as a solar system or as universe does the color orange have to do with anything?  [[Special:Contributions/172.68.90.10|172.68.90.10]] 21:50, 16 November 2018 (UTC) SiliconWolf

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 :But how do you define/measure a Joule then? [[User:Fabian42|Fabian42]] ([[User talk:Fabian42|talk]]) 18:19, 16 November 2018 (UTC)
 :No, until 1964, meter and litre were totally independent, a meter has never been defined directly or indirectly in relation to a mass of water. It is only since 1964 that the liter is defined as a cubic decimeter.[[Special:Contributions/162.158.90.36|162.158.90.36]] 18:36, 16 November 2018 (UTC)
 :Also, in E=mc², E is the energy '''at rest''' (for a stationary object of mass m), so your definition using the acceleration makes no sense.[[Special:Contributions/162.158.88.254|162.158.88.254]] 18:47, 16 November 2018 (UTC)
 Actually, for the new definition of the kilo using the Kibble balance you need to measure the gravity... [[Special:Contributions/162.158.134.16|162.158.134.16]] 17:34, 16 November 2018 (UTC)

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 :::: No longer necessary in modern life... Which is why we should all switch to base-10 units of time! [[User:ProphetZarquon|ProphetZarquon]] ([[User talk:ProphetZarquon|talk]]) 08:36, 17 November 2018 (UTC)
 ::::: Or we could change everything else to base 12... (I can dream, can't I?) [[User:Linker|Linker]] ([[User talk:Linker|talk]]) 18:45, 17 November 2018 (UTC)
 Ok, I'm going to point out something.  What's a meter?  1000 milimeters.  What's a milimeter?  .....skipping the questions all the way to the end, the answer is "the wavelength of the color orange".  Or at least that's what I read.  So my question is: why orange?  What's so special about orange?  What as a species or as a solar system or as universe does the color orange have to do with anything?  [[Special:Contributions/172.68.90.10|172.68.90.10]] 21:50, 16 November 2018 (UTC) SiliconWolf
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 While it would be nice if the meter were equal to a yard, it would certainly be better if the meter were defined as 5.28 feet, so that kilometers and miles are the same.[[User:Mathmannix|Mathmannix]] ([[User talk:Mathmannix|talk]]) 13:54, 17 November 2018 (UTC)
 I'm guessing that they'll get around the varying g problem by defining the kg in terms of some standard acceleration equal to 9.81 m/s^2. Then when measuring an object's mass you would account for the difference between the local value of g and the standard one. This isnt a problem because we can measure gravitational acceleration quite precisely and it depends only on the units of length and time.