Today, in a landmark decision, representatives from 60 countries voted to redefine the International System of Units (SI), changing the world’s definition of the kilogram, the ampere, the kelvin and the mole, for ever.
The decision, made at the General Conference on Weights and Measures in Versailles, France, which is organised by the International Bureau of Weights and Measures (BIPM), means that all SI units will now be defined in terms of constants that describe the natural world. This will assure the future stability of the SI and open the opportunity for the use of new technologies, including quantum technologies, to implement the definitions.
The metric system – or, as it is known today, the International System of Units (SI) – is an amazing achievement of mankind. Save for a few archaic holdouts who still measure things by sheep intestines and cow brains, the entire world has standardized on this system, so that regardless of where you are, things innately make sense.
Thom Holwerda,
I see what you did there.
That is your problem and not one anyone in rational countries has to endure. :p
Actually these days, as I understand it, (almost ?) all non-metric system measurement systems are calibrated/defined by a conversion from the metric system in countries like the US. That’s the official way as they are defined.
So basically everyone is already using the metric system, just some do it indirectly.
Now I better get back to work screwing in those M6 screws in that 19″ rack.
Lennie,
I tell you what Lennie, I’m working on a robotic project where just about everything I buy online is from china and in metric and everything I buy in stores is in english units… the inconsistency absolutely sucks. We’ve got units like 5/8ths 5/32ths that don’t quite line up with metric parts. Homedepot, by far the biggest hardware store around, has an isle dedicated to english screws/bolts/etc, yet one small section for metric parts that is inadequately stocked. Say I need 8 M8 screws, well I’m screwed.
I’m almost of the mindset that someone should open up a “metric store”, but if it actually did well I know home depot would kill it off just like all the other local hardware stores. Mom & pop stores don’t survive in these parts, but that’s a different discussion.
Don’t go to Home Depot, or any of big stores.
Got an Ace Hardware near you? Every Ace I’ve been in has had a vastly superior selection of hardware available, or any smaller hardware store.
Drumhellar,
We used to have a local hardware store right in walking distance, it closed down some years ago. The closest ace hardware store, which was about 10 miles away, also closed down. This is one of my gripes with the US economy, small shops shutting down and big retailers taking over. And now even big retailers are shutting down and huge retailers are taking over. This is not the america I grew up in, not to this extreme anyways. Alas, this is the future, and I predict things will get worse for the middle class as we continue to elect con-men and swindlers into government, pushing the wealth gap even further. Anyways, I’m well off topic here; go metric!
American citizens have already lost the battle. Most people are either too ignorant of the cons they’re victims of, or they’re too engrossed in the tribalism, which is also a con, the fear mongers push. By the time enough people `wake up`, the plundering will be over and the fleecing of America will have been a tremendous success.
And none of this should come as a surprise to anyone because at the end of the day, we’re a country that was built from greed, violence, and corruption. Our demise will be as horrible as our beginnings because karma will always find balance.
Well, the problem with the middle class and small shops exist here too. That’s not an US economy problem.
That’s a technology problem. Internet is cheaper and has a bigger selection than small shops and it’s convenient to not have to leave the house/work to go to the shop. And globalization (again because of the Internet) broad down the wages of the middle class or at least stopped increasing them while things got more expensive.
Well, pretty much all in US politics now seem to be neo-con and I do mean neo-con in a way most would not mean.
Lennie,
Those aren’t mutually exclusive though. I say it IS an economy problem if technology produces more and more wealth for those at the top and less and less wealth for those at the bottom.
You could make the association between this view and that of Luddites, and you’d be right to do so. However there’s a big shift happening today in the type of changes automation is bringing. It isn’t just replacing physical work, but it is replacing human intelligence itself. Factory owners in the past fundamentally needed humans to operate the machines. In short they were dependent upon labor, and so it created an economy for laborers. However we’re at the cusp of creating entirely autonomous industries that have no labor. Whether it’s automated vehicles or grocery stores with no employees, that translates into a huge economic problem for the lower & middle classes who are loosing their jobs.
Some people say we need to retrain for high tech software jobs, which is a reasonable point. However unlike physical goods, the marginal cost to produce software is zero. These huge companies like facebook, amazon, etc can (and will) increase their markets across the globe, displacing thousands of other employers, but only replacing a fraction of the jobs. Sure they’ll hire some because they can, but when these mega-corps grow, there’s a huge net loss of jobs even for high tech software positions, which is an economic problem even for those with skills.
Personally I’m not anti-technology, becoming more efficient ought to be good for humans, however distributing the GDP gains across the economic spectrum is something we’ve largely failed to do in the past few decades. Consequently modern generations have less financial security, more debt, lower home ownership rates, fewer retirement assets, etc. Looking at the GDP figures alone seems to contradict this narrative and suggests we should all be doing significantly better than previous generations. It’s not until you recognize that all of these efficiency gains are going to the very top that we see why it’s leaving the lower & middle classes behind. So whatever else it is, it is also an economic problem and it will require economic fixes.
Unfortunately those with the power to fix the growing imbalance are beneficiaries of that very imbalance. By far and large they lead a privileged lifestyle.
Here are some stats for US government representatives:
https://ballotpedia.org/Net_worth_of_United_States_Senators_and_Repr…
Over half are millionaires, the average net worth of US senators and representatives is $14.0M and $6.6M respectively.
Edited 2018-11-18 23:16 UTC
It’s not as important how much money they have, it’s much more important how much money and benefits they receive from campaign funding, etc. Which should be exactly: 0. It’s pure bribery and it should be illegal.
Lennie,
Well, arguably it should be important to have families of lower means be well represented too. I think the average wealth of those in congress shouldn’t be too far off from the average wealth in society if we want fair representation. They live a privileged lifestyle. They don’t care about things like health care and social security precisely because of their own financial standing.
And this is supported by statistics.
For example I never understood why education is getting more expensive, teachers aren’t paid well and quality is going down. Something doesn’t add up.
[q]Well, arguably it should be important to have families of lower means be well represented too.[/]
Yeah, ‘not as important’ is all I said.
It should be about the right incentive.
People thought education is getting worse pretty much… since the beginning of education.
(also, sort of https://xkcd.com/603/ )
Someone (who I don’t remember right now) ones said:
A lot of politicians these days (at least in my country) are professional politicians (they might have studied politicology/political science), they’ve never been regular working people or union people like in the past.
Now, I don’t think it applies to the US in the same way, but it’s clear a lot of them have never been or at least for a long time not been regular working people.
So, yes, I agree about that, even although with a twist.
This again / you forgot about http://web.mit.edu/krugman/www/ratrace.html ?
People claimed that old times were better since forever… some ancient (Sumerian?) stone tablets had words about sure signs of closing doom of civilisation (also, sort of https://xkcd.com/603/ )
I will tell you one thing I miss, but it predates the large use of computers on stores (yes, I’m that old), wise and knowledgeable salesman. I could go to hardware shops, explain what I was trying to do and what solution I devised and talk to him and get good insights back. This is no more. Is this happening on USA too?
If the employee is 30’s or younger, he’s borderline useless. If he’s grandpa aged or older, he’s likely got some great feedback & ideas for you.
So it is about 16 km away.
cybergorf,
Yeah, I debated whether to covert it or not. I was trying to think of an explicit metric joke there, but the irony’s funny enough I suppose
Lowe’s & Home Depot must really suck where you live to make Ace Hardware stand out. My 2 local Ace Hardware’s rarely have something my local Lowe’s or Home Depot doesn’t – except higher prices on everything thanks to their franchise business model.
For hardware, i.e. nuts, bolts, hinges, stuff like that, the local Ace stores are vastly superior, or at least those near me.
Everything can be purchased individually. At Home Depot or Lowes, almost everything is in packs of 5 or 10 or more, with obscure sizes often only included in variety packs. And, even then, there isn’t as wide range a selection as the two Ace stores near me.
(emphasis mine) Isn’t that kinda the point? ;P
USA has been metric for years, since 1975 I believe.
So I guess they’re not going to standardize the kilogram on that perfect silicon sphere being made in Australia.
https://www.nist.gov/si-redefinition/kilogram-silicon-spheres-and-in…
But apparently that’s still being used to define the Avogadro’s constant, and it works as a check on the Planck constant kilogram too.
I guess the actual definition, and the practical application of those definitions, are two different things. You can’t calibrate a set of scales against a theoretical formula; at some point you need an actual physical object you can point at and say “That is precisely 1kg”
The upside with the Planck constant is that every country can create their own physical model without having to regularly go to Paris, which is important given how the platinum masses have diverged from each other.
Although I don’t suppose I’ll personally ever be directly affected by this (I never had to compare anything to Le Grand K in Paris, so I don’t suppose I’ll ever have to whip out my pocket Kibble balance either), it’s fascinating and exciting to live through the history. This is stuff that’ll make it into school text books for decades to come.
One part I’m curious about. The new definition of the kilogram is based on the Planck constant, which is measured using the Kibble balance (as described in other articles, although not mentioned directly in the one Thom linked to). But the Kibble balance relies on the definition g of gravity. Doesn’t that make the new definition of the kg dependent on where you measure it (or at least, dependent on being able to measure g accurately)? Asking as a lay person, not a pyhsicist, obviously!
Lets separate things a bit. One thing is how we define something and the other is with which technology we currently measure it. Clearly defining kg using h isolate any imperfections associated to using specific objects and, at same time, keep space to improve its accuracy whenever a new and or improved measurement method get developed.
Yes, that’s a fair point. But the two aren’t disconnected, and one of the factors when deciding to make this change was the ability to measure h consistently and accurately (“reaching the experimental accuracies” as the BIPM puts it). They also say “the Planck constant is ready for use everywhere and always”, and unless they just mean in theoretical calculations, this implies it can be measured in a location-independent way!
“Save for a few archaic holdouts who still measure things by sheep intestines and cow brains…”
I ran a metrology laboratory at an instrumentation maker that was a key supplier to NIST and Livermore, and I’d like to point out a couple of things:
First, the reason that fractional length units were preferred for so long is that the best way of making consistent calibration artifacts naturally resulted in fractional increments. That was true regardless of the units used, and it’s still true to some extent today.
You can lap two gauge blocks to an equal length and then wring them together and confirm that their combined length is identical to a standard (like the Meter Bar or your laboratory’s 1″ gauge block). If you try to do that in base-10 rather than base-2, the cleanliness and parallelism of the ends of the blocks becomes more critical.
The other thing I’d like to point out is that some of the changes made by BIPM and the WMO are more appropriate in a theoretical physics lab than in an applied metrology lab. For example, using a probabilistic definition of uncertainty is only elegant if the physical causes of that uncertainty can be expected to result in a normal distribution of error. That might be a good bet if you’re talking about quantum uncertainty in scanning electron microscopy, but it’s a really bad bet if you’re talking the geometric measurements that wafer fabs and disk drive manufacturers depend on.
Try cutting a gold coin into 10 equal parts with just a hammer and chisel.
The 19th century called. They want their monetary units and tools back
^ Too much Sagan and not enough Fermi.
You should get past the gee-whiz parts of science and learn more about the ones that actually make your world work.
Interferometric optical flats, lab surface plates and lots of similar artifacts are still hand-lapped because the thermal instability and elasticity of the materials require active intervention during lapping. You could automate it, but it wouldn’t save much money (if any) because the biggest delay is thermal equilibration, not processing. The cost of the artifact is high enough ($20k) that eliminating the tech wouldn’t make much proportional difference.
There’s a nice roundup of the changes on Wikipedia: https://en.wikipedia.org/wiki/Redefinition_of_SI_base_units
How long, I wonder, before the metric prefix system makes way for a binary (or something related like hexadecimal) system?
I’m willing to bet it’ll happen within the next 10 years (although I’m not going to tell you which base I’m using for my prediction!).
You mean like the current SI binary prefixes kibi- (KiB/kibibyte) or mebi- (MiB/mebibyte) that we already have?
Yes exactly. The standards are already in place, but whether in general or scientific use, it’s still unusual to see anything other than metric used except in a few narrow areas.
Allright, but it still also is SI (aka “metric”)
(and I do try to use in my posts on the internet the binary prefixes 
)
Unfortunately the understandable misuse of the decimal prefixes by the computing industry last century (like using k to mean 1024) has left things messy. I admire you for getting it right (I still often get it wrong myself).
I honestly believe there’s a possibility that we may move away from base 10 in the future, but given how difficult these changes are, I don’t see it happening in my lifetime.
in a world where you can translate between all the major languages in an instant, get real-time currency rates, or easily calculate time zone differences.. why is this such a big deal? not everyone is a physicist, so why should they give up their systems of measurement that they are used to? should different languages, societies and points of view should also disappear in the name of ‘progress’ (read rampant globalisation)?
sure, i’m exaggerating, and i’m definitely not against standars, but calling everyone a backward idiot for not using SI is a bit arrogant.. not to mention what happened to storage capacities because of this. xD
bamdad,
I’m not sure exactly how to dissect your comment. Most scientists and people around the world are already using metric, and for them nothing changes. They’re using the same units they are familiar with.
The problem being solved here is mostly one of definition. Historically units like length and weight had to be defined in terms of a physical object sitting behind lock and key. They created replicas as best they could, but one physical object could be authoritative by definition. This physical object defined what kg meant. If anyone in the world needs more accuracy, they’d need to travel to the authoritative object to make a more accurate copy.
This change in definition means the physical object is no longer the authoritative source of our units, but instead they can be derived from more fundamental properties of physics regardless of where we are on earth or even in the universe. By redefining our units in terms of universal physical properties, we can be confident in our units to arbitrary precision across time and space without being dependent on a single physical object to define what our units are.
I like the metric system, but I’m reminded of an old joke.
There are two kinds of countries:
Those who use the metric system, and those who have put people on the moon.
You mean those who have put people on the moon and use metric system internally? They even had some mishaps:
https://en.wikipedia.org/wiki/Mars_Climate_Orbiter
Having taken Physics and Chemistry in the U.S., both in the 80’s and, more recently, in the 2000’s, science in the U.S. uses the Metric System, in teaching and in practice. It’s the business and materials world that still uses the Imperial system.
Crazy posters don’t understand NASA wasn’t metric when they put people on the moon. They are now. Its still a good joke.
https://www.space.com/3332-nasa-finally-metric.html
Thank you! Jeez, I was beginning to think that nobody had a sense of humor anymore. Cranky old farts.
Von Braun probably thought in metric though.
https://imgur.com/gallery/bHA8OOQ
But seriously, while US got the “grand prize” of human Moon landing, almost all other “firsts” were done by the Soviet Union… (and the “first first”, of first human-made object in space, by Germany) Russia has maintained their flavour of presence in space for most of the past 40 years or so, perfecting ~tech needed for eg travel to Mars (but they have severe funds shortage). US did almost nothing with the Moon since Apollo…
I always forget; is it twelve sheep intestines in a chain, three chains in a cow’s brain, or the other way about?
…and the second will be second. I mean next.
i know this was supposed to be a joke, but actually the second was first here:
it is already redefined via atomic quantum-oscillations since 1967.