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Earth now weighs six ronnagrams: New metric prefixes voted in

phys.org

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Re: Earth now weighs six ronnagrams: New metric prefixes voted in

#71

Post by SuoDuanDao »

jerf wrote: post #59
krallja wrote: post #54

Earlier quoted context omitted.

A ronna-Reagan is 10^27 Reagans.

One ronna-reagan is approximately 4% of the sun's mass: https://www.google.com/search?q=%28185+pounds%29+*+10%5E27+%... 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.

weird question for anyone with the relevant knowledge, would 25 ronna-Reagans in one place behave differently than our sun? I know that mass would be mostly oxygen, but at that scale does it matter?

Re: Earth now weighs six ronnagrams: New metric prefixes voted in

#72

Post by euroderf »

frob wrote: post #51
euroderf wrote: post #39

Earlier quoted context omitted.

Percentages lack sufficient granularity. Permillages would do the trick.

There's even an official per-mille symbol: ‰ 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 %?

Document UI design issue. Don't blame the promillages !

Re: Earth now weighs six ronnagrams: New metric prefixes voted in

#76

Post by Symbiote »

kyawzazaw wrote: post #63
NKosmatos wrote: post #25

From https://en.wikipedia.org/wiki/Metric_system : “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.”

We use the Metric System quite frequently in Myanmar.

If you can find official and unofficial references, it would be helpful to allow the article to be updated.

Re: Earth now weighs six ronnagrams: New metric prefixes voted in

#77

Post by burkaman »

rnhmjoj wrote: post #34

Is anyone seriously using prefixes above Giga, besides for counting bytes or boasting numbers in popular science articles? 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.

> counting bytes or boasting numbers in popular science articles

Why are these not serious usages? They are concepts that need to be communicated, that's what words are for.

Re: Earth now weighs six ronnagrams: New metric prefixes voted in

#78

Post by akavi »

argentier wrote: post #21
bjt2n3904 wrote: post #13

A question... Why do humans (or at least engineers) work so well in 1,000? 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?

Indians use lakh (100 000 -> 5) and crore (10 000 000 -> 7). They also group the digits differently.

And then combine them into lakh crore (1,00,000,00,00,000 -> 12)

Really the worst system of the 3.

Re: Earth now weighs six ronnagrams: New metric prefixes voted in

#79

Post by Symbiote »

rnhmjoj wrote: post #34

Is anyone seriously using prefixes above Giga, besides for counting bytes or boasting numbers in popular science articles? 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.

Electricity production for a country is reasonable measured in TWh, and I think I've seen this in newspapers discussing energy/gas in Europe.

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

Re: Earth now weighs six ronnagrams: New metric prefixes voted in

#80

Post by thrwaway298 »

divbzero wrote: post #60
opwieurposiu wrote: post #45

Earlier quoted context omitted.

Yes and the circumference of the earth is about 40 million meters. This is because a meter was originally supposed to be 1/10E6 the distance from the equator to the north pole through Paris.

Earth’s circumference around the poles is now given as 40,007.863 km [1]. So when the French Academy of Sciences defined the metre in the 1790s [2] the distance they measured from equator to North Pole was off by less than 2 km. [1]: https://en.wikipedia.org/wiki/Earth's_circumference [2]: https://en.wikipedia.org/wiki/Metre#Meridional_definition

I have read that the atronomers at the time actually knew that they were a bit off due to a mistake that was done by one of them.

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.

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