Earth now weighs six ronnagrams: New metric prefixes voted in
phys.org
phys.org
"(...) he had the idea for the update when he saw media reports using unsanctioned prefixes for data storage such as brontobytes and hellabytes. (...)" and "The only letters that were not used for other units or other symbols were R and Q"
So it seems the new prefixes are partly initiated by the exponential computer storage needs rather than scientific needs. So they might need to move again soon. However the SI has exhausted the available stock of letters. Maybe Greek letters next time like micro for 10^-6.
Anyway does it really matter for IT people? I have seen so many people mixing up bit and byte, milli- and mega- as well. There are countless usages of mb all over the Internet to express MB.
Eg: 1 QB (quettabyte) == 1,000,000 YB (yottabytes) == 1 MYB (mega-yottabyte)
Without the new prefixes, we could have gone to 1 YYB (1,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000, or 10^48 bytes)
That's definitely untrue. In my native language we never mix tens and hundreds, and it always takes me a moment to parse that "thirteen hundred" means one thousand and three hundred.
1e12 terabytes seems easier to digest than 1 whatever-the-hell-,-I-don't-know-what-this-unit-is-meant-to-represent-byte. Not to mention, easier to read.
Also: in the past 25 years, "tera-scale" (TB and TFLOP) went from a prognostication about future high-performance computing into something you find in affordable consumer products. When campus computing centers are now deploying hundreds of petabytes, it seems myopic to think the PB threshold is anything but a signpost flying by the window...
You mean 2 lakh USD?
:D
Every prefix up until now has been consistent about the first vowel mirroring the Greek word:
tetra -> tera
penta -> peta
hex -> exa
hepta -> zetta
okto -> yottaThe prefixes ronna and quetta represent 10^27 and 10^30, and ronto and quecto signify 10^−27 and 10^−30. Earth weighs around one ronnagram, and an electron’s mass is about one quectogram.
This is the first update to the prefix system since 1991, when the organization added zetta (10^21), zepto (10^−21), yotta (10^24) and yocto (10^−24).
How about 10^17 == "tenset", 10^27 == "venset", ...
Inspired by French vingt, from Old French vint, from Latin vīgintī.
Since the length of words (should) correspond to the frequency of usage, longer variants would be ok if not preferable too:
10^… == tento…
10^16 == tento-seize …
- decade
- century
- decagon
- centimeter
- decimal system
- decathlon
- centipede
edit: admittedly, hecto is pretty rare and centi is often used for both 1/100 and 100
> Centipedes (from New Latin centi-, "hundred", and Latin pes, pedis, "foot")
Hectolitres are commonly used in the food and drink industry. For example wineries and breweries typically measure their production in hectolitres.
Not exactly hecto but land, especially farm land is often measured in hectares. It is a non-SI metric unit equivalent to the square hectometer or 10000 square meters. We most likely kept the name because "hectare" sounds better than "square hectometer". As expected, 1 hectare is worth 100 ares, but ares and its other multiples are much less used than hectares.
2471 acres per hectare.
That may be in large part because of the unit prefixes we use. That is we think of these things in 3 orders of magnitudes because our unit prefixes come in three orders of magnitude but not the other way around. I think a much likelier explanation is the fact that many European languages (most importantly French and English) stop naming each decimal order after a thousand. If there was a word for ten-thousand—say fiorthom—but not a hundred-thousand (ten-fiorthom), surely these prefixes would map be multiples of 10⁴ as well.
... Or milliard, or giga
On paper, there are much larger units too, but they are never used.
10^6 is the same length as "mega".
10^9 is the same length as "giga".
Why is length suddenly an argument against new prefixes?
(A bit confusing since most sources list electron mass as 9x10^-31 kilograms, rather than 9x10^-28 grams.)
I think this is a error by nature.com, and Earth weighs around 5.97 ronnagram
The earth's mass may well be 5.97 ronnagrams.
The weight of the earth would be measured in newtons, yes?
The Earth has a mass, however.
> void of space, it is like a free falling apple
falling where in space??? =p ;)
[0]: https://www.bipm.org/documents/20126/64811223/Resolutions-20...
https://en.wikipedia.org/wiki/Unit_prefix#Unofficial_prefixe...
- At the beginning of a word, according to Byzantine convention, it is represented by an aspiration mark, discussed above. This can only occur if the word begins with a vowel, or with R. (All words beginning with R are aspirated.)
- Following a /p/, /t/, or /k/ sound, aspiration is represented by mutating the letter into an aspirated form. Unaspirated π becomes aspirated φ, τ becomes θ, κ becomes χ. By the time we're talking about Byzantine Greek, the "aspirated" letters have mostly mutated into other sounds. But for ancient Ancient Greek, they are aspirated forms.
- Doubled Rs have something special going on with them, and the Byzantines use a diacritic mark on the second R even though, obviously, it cannot occur at the beginning of a word. Again there is no contrast between "aspirated" and "unaspirated" double R; the aspiration is mandatory.
As you move into earlier stages of Greek, you lose the standardization of the alphabet; there are plenty of Greek inscriptions where the sound is represented by the glyph H.)
https://www.ismp.org/recommendations/error-prone-abbreviatio...
> Error-Prone Abbreviations, Symbols, and Dose Designations:
> µg
> Intended Meaning: Microgram Misinterpretation: Mistaken as mg Best Practice: Use mcg
I think older prefixes are just grandfathered in
My physics teacher always had a great way of drilling in these tidbits.
They also made things complex by then picking a unit of mass that’s inconsistent with that: a gram isn’t the mass of 1m³ of water, but of 1/10⁶ m³ of water (a cubic meter is 10³ liters, and a liter of water weighs 10³ grams)
Centimeter-gram-second (https://en.wikipedia.org/wiki/Centimetre–gram–second_system_...) really is superior in that sense (but of course, that’s relative to the arbitrary choice of using water to convert between mass and volume, and from that, length)
Exploring a bit, picking 4 times that, as an estimate of the circumference, would give us a basic length unit of 4 cm (a pretty reasonable unit—bit over an inch and a half, fits right in with the variety of Chinese cun standards, for example). Then our immediate volume unit is 64 mL, which seems kind of small (on the scale of 2 floces), but ten of them make a decent "pint", so I think it can work—it's ~13% bigger than an imperial pint instead of ~12% smaller. the corresponding mass unit, at ~64 g, which again seems a bit small but manages to line up an average person's weight right around 1 kilo.
Avogadro's number is close to 24!, so we could redefine our mass unit as exactly 24! hydrogen atoms (or 4!!) and that comes out to within about 3% of a gram while being significantly easier to communicate to an extraterrestrial civilization.
[1]: https://en.wikipedia.org/wiki/Earth's_circumference
[2]: https://en.wikipedia.org/wiki/Metre#Meridional_definition
>o their 1793 measurement of the distance from the equator to the North Pole was off by less than 2 km....
They spent several years making lots of smaller measurements that were added up.
Each measurement was done twice to ensure correctness. One of the distances had two conflicting measurements, but due to a war, they could not return to make a third measurement and had to just choose one of them (the wrong one).
They chose not to tell anyone because they feared politicians would use it to discredit the metric system.
For me, it's: Earth is a blue marble - in "Mega-view" (Mm zoomed to mm) - with a diameter of a baker's dozen Megameters. The volume of a ball is one half of its enclosing box, so that's ~(1E7)^3 or 1E21 m^3. Earth is rock (3 Mg/m^3) and iron (8 Mg/m^3) and averages 5 Mg/m^3. Or just bracket it - water,lead,gold is ~ 1,10,20 Mg/m^3). Giving an Earth mass of 5E24 kg. Actual value 6E24 kg. Brackets of water and lead give 1E24 to 11E24 kg.
> a great way of drilling in these tidbits
For me it's: Arm-sized, hand-sized, fingernail-sized, and "tiny"-sized, are 1000, 100, 10, and 1 mm. Zooming these by 1000^n gives scale-model "views". Mega-view with planet balls, kilo-view with cities in your palm, meter-view with buildings in hand, micro-view with red blood cell M&M's (yum), nano-view with virus balls (chewy shell, stringy inside), pico-view with H2O bumpy basketballs, femto-view with nuclei marbles. It's easier to remember how big things are, once they're toy-sized, and you've handled and played with them.
Just something I crafted years back. Resulting videos didn't seem to user test well. I was set to dust it off, doing rapid iterative development over gorilla street usability testing... in Spring 2020. Ah well.
“The SI has been adopted as the official system of weights and measures by all nations in the world except for Myanmar, Liberia, and the United States.”
> https://usma.org/laws-and-bills/metric-conversion-act-of-197...
> https://usma.org/laws-and-bills/executive-order-12770
The US government hasn't been great in converting US industry to metric. But ... it's a bit disingenuous to say we didn't even try.
At least if I have that right. A single Reagan's mass is from: https://www.celebheights.com/s/Ronald-Reagan-1750.html
Or, if you prefer, our sun as about 25 ronna-Reagans.
Upping the mass to the sun size would cause some interesting additional wrinkles because now we're talking about being large enough to have "problems" with the pressures in the middle being sufficient to start causing atoms to squish together, but it would take an astronomer to be clear on what happens next. My gut and layman's understanding says you might get a pretty big boom in a couple hundred thousand years or so, because you'd basically be building a sun that would be fairly far along its fuel consumption cycle.
By mass, the sun is 71% Hydrogen and 27.1% Helium, the last 1.9% or so being heavier elements (much of that being oxygen.
I’m no expert, but I suspect a mass of 25 ronna-Reagans would not make a very good star. I imagine it might collapse into a dense Oxygen and Carbon rich sphere, and in that environment various chemical reactions might turn it into some other kind of material.
But maybe I’m way off.
Even though we don't use metric directly in most cases in the US, the US customary units have long been rebased to be defined by metric units.
Inches and pounds are just centimeters and newtons walking around in a whacky outfit.
I think the point is that the US customary units are typically used in a very different way, with fractions being way more important than in metric. See the image in this [1] article that talks about drill sizes for DIY use, for instance. You guys go like "oh no the 5/16:ths hole is too small, I'll step up to 19/64ths that should do it". Over here in metric-world we go more like "oh no the 7.9 mm drill was too small, I'll step up to 8 mm".
Again, the fact that it's easy to convert the 5/16:ths to 7.9375 mm is not the point, the point is how the decimal/metric units are used in practice.
The US yard is exactly 0.9144m such a short decimal expansion is highly unlikely when selecting two random units of measurements. It is short because we defined the modern yard in terms of meters, selecting a short decimal expansion that was still "close enough" to the old definition to allow tooling to remain the same.
The units of the metric system are defined by physical properties that appear to be constant throughout the universe.
The units of the US customary system are defined as some exact number of equivalent metric units.
Still, I'm probably the 1% of 1% of Americans who uses Celsius in daily life, except where I cannot (my car won't let me do hybrid miles and Celsius, ugh).
As a practical matter, we use metric for many things in the US. The fact that we do not force everyone to change their customary units to metric really seems to irk some folks, but mostly outside the US.
And, the best, is “football pitches” which is often used by the news to describe large (but not too large) lengths.
For pints (only really used for beer and milk), we still use an imperial pint but it's officially specified in millilitres (568ml) and this will always be printed on packaging.
I think we'll soon be left with the only remaining imperial bits being speed, long distances, and pints of beer - none of which seem likely to go away any time soon
> U.S. customary units have been defined in terms of metric units since the 19th century, and the SI has been the "preferred system of weights and measures for United States trade and commerce" since 1975 according to United States law.[1]
[1] https://en.wikipedia.org/wiki/Metrication_in_the_United_Stat...
I haven't seen the official binary equivalents.
For example, we have "yotta" or "Y" for 10^24, and "yobi" or "Yi" for 2^80.
Are we going have "robi" and "quebi"? I presume the abbreviations will be "Ri" and "Qi".
(I guess we don't need fractional binary prefixes. There's not much use for nanobytes.)
Of course since this was just announced today, I'm not really complaining.
Considering Seagate is shipping only 155EB (=0.000000000155QB) of storage per quarter[0], reaching the QB scale seems a way off.
[0] https://www.forbes.com/sites/tomcoughlin/2022/08/21/c2q-2022...
In physics, in practice you either state the number in exponential notation and don't care abut it or for brevity introduce a more appropriate unit: barns (10⁻²⁸ m²) and electronvolts (10⁻¹⁹ J) in nuclear physics or solar mass (~10³⁰ kg) in astrophysics, etc.
CERN is at TeV ranges so yes, even in different units we use high prefixes. Might not come up in your every day small talk but they are used.
Why are these not serious usages? They are concepts that need to be communicated, that's what words are for.
But from Wikipedia:
> In the United Kingdom ... Demand for electricity in 2014 was 34.42 GW on average (301.7 TWh over the year) coming from a total electricity generation of 335.0 TWh.
We aren't there yet for power:
> The synchronous grid of Continental Europe is the largest synchronous electrical grid (by connected power) in the world. ... In 2009, 667 GW of production capacity was connected to the grid
This is from a Physics forum? Really?
No! The Earth does not have weight! It has mass. Weight is a force. It is a function of gravitational pull between two masses.
If you want to talk about force you have to use Newtown's Law of Universal Gravitation:
F = (G * m1 * m2) / r**2
I can't see how the concept of weight makes any sense when it comes to a planet. At all. Think of a hypothetical object in the middle of space with nothing whatsoever around it for millions of light years. No weight. Mass, of course.
You can't just use earth's 9.8 m/s*2 to convert from Kg to Newtons...that makes no sense at all in the frame of reference of any planet, even earth.
This isn't pedantic at all. Try to take a physic test anywhere and confuse these concepts, units of mass and force and see how well you do.
The word "weight" and its equivalents in other European languages, e.g. "poids", "pondo" etc., have been used for thousands of years principally to name the quantities measured by weighing with a balance, which are masses, not forces, and only seldom and mostly metaphorically and non-quantitatively to refer to a force. By etymology, such words derive in one way or another from the operation of using a weighing balance, e.g. "pound" means "hanging", from hanging objects on the weighing scales.
The word "mass" has been used for thousands of years only with a meaning that had nothing to do with a measurable quantity, but only to name some amorphous piece of some material, such as dough, clay, soil, rubble.
A wiser choice would have been to name as "weight" what is now named "mass" and to use a name such as "force of gravity" for what is now named "weight".
Such a terminology would have kept the continuity with the traditional meanings of the words and would not have offered opportunities for the majority of the people, who even today continue to use those traditional meanings in colloquial language, to be corrected by those who have made an arbitrary choice to assign new meanings to old words.
Unfortunately there exists a very large number of scientific or technical terms whose meaning has been changed some time during the last few centuries, sometimes intentionally, due to questionable decisions, but in many times due to various errors or misunderstandings.
Even when such names reflect very serious errors of those who have coined them, their meaning can no longer be changed, as too much new literature has accumulated, which uses the new meanings.
But the sun is 2000 quettagrams... looks like we need another higher prefix
My lab at the time slipped hella- into a few conference presentations here and there. We had to back our university. I always remember it getting a few chuckles.
Is it just people think that symmetry is a good thing, and for example they added 10^-30 despite the lack of demand? Or there is some deeper reason? Or it is more like one of those coincidences?
I mean. I use milli/micro/nano/pico as an electrical engineer every day, and it's so intuitive to me.
But why three orders of magnitude? Why not two orders, or five?
Sure if you grow up with it, you have that translation basically hard-coded but it’s still not ideal.
Really the worst system of the 3.
It's a rule that will tell you how to write "any number" equally, but it makes all the numbers inconsistent with each other.
My graduate advisor loved slipping it into papers just to show it off. I had to dissuade him at least once because it was in the middle of a table of percentages and who is going to that the 7th entry out of 12 has ‰ instead of %?
Never seen permyriads, though.
groups of 3 have first, middle, last - crucially _one_ middle digit, not 2+, which makes for quick comprehension.
Like in English 10000 is ten thousand, there is no new single word for it.
IMO most of it is momentum and convention, there is nothing inherently natural about grouping by every 3 digits.
She has 2 children according to that article.