2500 miles * 2500 miles * pi = 19,630,000 miles squared
So that area represents about (19.63 / 57.51 ) 34% of the total world landmass. So 50% of humans live in 34% of the landmass. But harsh and relatively uninhabitable lands make up a large portion of the earth's landmass
So the habitable areas are 57.51 - 17.8 = 39.71 million miles squared.
So that circle represents ( 19.63 / 39.71 ) 49.4% of the habitable land.
So in the end, about 50% of the world population lives in about 50% of the world's habitable land.
Astounding huh? It's amazing what some math and common sense and understanding of geography takes away from a clickbait article based on a reddit post.
As others have noted, that area is also primed for human habitation due to tons of fresh water rivers flowing from the tibetan plateau and rich fertile land along with year-round planting seasons due to its proximity to the equator.
So that region is not more densely populated than the rest of the world? That makes me a bit skeptical of your math because it obviously is. For one, you are using habitable land mass for the rest of the world while the circled area is mostly sea water. I wonder how that comment got to the top.
The circle contains 1/3 ocean and ocean is not landmass. You'll have to revise your calculation. Also, since the circle contains Tibet, desert in Xinjiang and Mongolia, your assumption that all of that is habitable land is even more wrong.
It also clearly says "2500 radius circle" in the article title, and the submission title. The article is fast and loose with diameter vs radius later on as well. I can't blame the original commenter for using it as a radius when that's in the title.
But I agree, it's actually the diameter and changes the math a lot.
> Myers was amazed to find that a circle roughly 2,500 miles in diameter, when placed over the right part of Asia, could hold more than half the world's population.
The above is from the article. It says radius in the title and diameter in the article
A history of population within the circle would be interesting.
The population of China since 2000 years ago appears to have been a series of plateaus with brief periods of increase and a couple of brief decreases. The plateaus represent populations at the limit of agricultural systems. The increases are due to introduction of new systems, such as rice cultivation further north, double-cropping of rice and so forth. The decreases are periods of famine, disease and war. http://www.china-profile.com/data/fig_pop_0-2050.htm
Possibly other civilizations within the circle follow the same pattern of stability, innovation and crises.
If I recall correctly, rice can sustain a much greater number of people per unit of land than any other crop, and this explains why East Asia is more densely populated than any other part of the world.
The big difference with rice is that you aren't dependent on the weather nearly as much as you are with corn and potatoes. Corn and Potatoes put out more calories per acre when the rains fall at the right times in the right amounts, but rice puts out those calories regardless of the weather.
Ultimately you can only sustain a population as large as your food output at the end of a two or thee year long drought.
Sugar cane and sweet potatoes also produce similar calories per acre, depending on the soil, climate, etc. Sugar also has the advantage of being durable to ship. It could be produced in high volumes on tropical plantations and shipped to Europe.
Before bulk ocean shipping of food, population was generally limited by calorie production in the local area.
Until the industrial revolution, the human population everywhere was in equilibrium with agricultural technology. Improvements to technology would lead to population growth until wealth per capita reached the same old level and people stopped having as many kids. Check out the book "A farewell to Alms" for a solid 10 chapters of historical records on this from around the world.
The first person to notice this universal truth about the human population was Malthus. He had the misfortune to make the observation right on the eve of era when it stopped being true.
A universal truth doesn’t stop being true... So it’s probably better to revise it to say that it behaves that way under certain conditions and those conditions have changed.
52M km^2 of land on our planet is habitable, after forests, shrubs, rivers and lakes [0]. Total land mass is 149M km^2. So only 1/3 of the world's land is habitable. That's actually ~20M square miles. Your habitable land estimate is already nearly 50% off according to the source I found.
The circle covers 50.2M km^2 (4000^2 * pi). I'm going to assume the 2/3 land quotes are good enough an estimate. That makes the land mass inside the circle 33.5M km^2 (2/3 * 50.2). That means that the circle contains just 22.5% (33.5M/149M) of ALL land mass.
I couldn't find any quick data source on how much land inside the circle is actually habitable. So I'll apply a few ratios:
It's more than a third. Roughly half the circle is water. It also contains all of Tibet, the Hindu Kush and the Southeast Asian rainforest (except New Guinea). Furthermore it contains the highly mountainous islands of Japan, Taiwan, the Phillippines and Indonesia. Proclaiming that all or even most of this land is "habitable" is obviously silly if you just look at it:
This is definitely an interesting phenomenon and not just clickbait. The most likely explanation is that high rainfall in East Asia has allowed high-yield rice cultivation preceding the Green Revolution, allowing East Asia to support much higher population density in preindustrial times than any other region. Europe is too cold, Africa and West Asia too dry, and the Americas didn't have rice. (Although they did have the potato, but it didn't spread outside the Andes without European assistance.)
Fine. Thrown in the saraha desert and a few other inhospitable areas and it'll make up that third.
> And a significant amount of it is also Siberia and Mongolia.
Are we looking at the same map? Hardly any part of siberia is included ( maybe the a tiny portion of the russian far east ). Feel free to take out the mongolian landmass if you want.
| So in the end, about 50% of the world population lives in about 50% of the world's habitable land.
Your math may be accurate, but your assessment of habitable land-mass seems to be off.
I know and work with a number of people in Canada, and I've visited many, many times. I'd hardly consider the entire area of Canada "uninhabitable". (Per wikipedia [1], Canada has a total (non-water) area of 3,511,023 sq. mi.) 37 million people live Canada [1].
Also, just a quick visual check indicates that about 1/2 of the area within that circle is ocean. And, the population density of the Himalayas (which is in the circle) is arguably small as well.
Doesn’t almost all of the population of Canada live along the southern border? My understanding is that the northern ~80% of Canada is very sparsely populated.
That is correct. Pretty much the all of the major cities are right around that 100 mile mark. On the coasts that’s because of geography (Victoria, Vancouver, Toronto, Ottawa, Montreal, and the Atlantic provinces). In the prairies we generally have one major city close to the border (Calgary, Regina, Winnipeg) and one further north (Edmonton, Saskatoon, none in MB)
> 2500 miles * 2500 miles * pi = 19,630,000 miles squared
> So that area represents about (19.63 / 57.51 ) 34% of the total world landmass. So 50% of humans live in 34% of the landmass.
I've been telling myself that I have to teach myself Non-Eucledian Geometry, but lacking any real motivation, I've successfully procrastinated for 6 years.
The unfortunate itch to be pedantic on the internet will hopefully drive me to learn how to correctly calculate the area of a circle on a sphere.
"So that area represents about (19.63 / 57.51 ) 34% of the total world landmass."
1/2 of said circle is ocean, not land. And some of said land is 'uninhabitable' i.e Gobi Desert.
And Canada is 3.8 miles squared, implying that 3.5 of those are uninhabitable is rather off. By that calculation, you'd be excluding most of Quebec and Ontario, which are 'inhabitable' just sparsely populated, in which case much of Tibet and China would be comparably 'uninhabitable' as well.
While I live in Europe and I do agree, imagine how nice would it be if the entire world used the duodecimal system today for everything, i.e. 100 was preceded by BB (143). Greeks and Shumers were smart guys - 12 has 4 divisors (excluding itself and 1) while 10 has only 2. Same story with 100 and 144, etc.
Having spent a lot of time recently digging around memory dumps, I'm getting pretty good at hexadecimal mental arithmetic, and it certainly seems like a superior system.
Base 16 would be even worse than base 10. It isn’t a highly divisible number, so lots of common fractions aren’t clean hexadecimals. In base 12 you get 1/2, 1/4, and 1/8. Base 12 gets you 1/2, 1/3, 1/4, 1/6, 1/8, and 1/9.
But being a power of 2 I think has a massive advantage. There is also an advantage to have a chain of the square roots lead to 2. That leaves 4, 16, and 256.
16 seems most sensible of those.
You'd end up with a number system where everything is a sum of halvings and doublings, which is conceptually much simpler. Sure, you can't represent a third neatly, but I don't consider that a very important property.
I find it very interesting that a large portion of the UK uses yards to measure distances shorter than a few kilometers. I saw a sign that read "Exit - 500 yards" in London the other day.
You think that’s bad? Half the folks in this 2,500 mile radius are “laughing in their crores and lakhs”. Mildly infuriating for someone not used to arbitrary multiple names.
Well, sort of. It's a sometimes-1000-but-usually-100 based system. That's a significant conflict with the standard English assumption of a 1000-based system (which appears in the metric system as the widespread use of kilounits, megaunits, milliunits...).
Chinese uses a 10,000-based ("myriadic") system. Conversion is a gigantic pain. Calling these all "10-based" is more harmful, likely to confuse people, than helpful.
You might consider the powers of ten that get their own unit in each system:
[I had to look up if the official definition of trillion is 10^18 or 10^24. It looks like a nice question to get a good irrelevant discussion for the coffeetime after lunch, if you can collect a few mathematicians in a Spanish speaking country.]
It was also true in most of the English speaking world except for the US until relatively recently - some people still talk about "american billions" and "english billions" (the last being 10^12)
Being 10-based is already a big win (and it isn't harmful to say "10-based" as long as people know what it means). You need to only remember the name <-> power of 10 mapping, and the conversion amounts to adding or removing zeros. Beats having to multiply in your head by arbitrary, hard to remember fractional values.
Have you ever tried converting from one system to the other in your head? It basically can't be done. Conversion is an easy process if you're willing to use pencil and paper, but at that point you're most of the way to using arbitrary conversion factors.
I sometimes do between long and short scales (English uses one, Polish uses the other one). So to convert from Polish "bilion" to English, you go "bilion" -> 10^12 -> "trillion". Or, in the rarer case, "sextillion" -> 10^21 = 10^3 * 10^18 -> "tysiąc trylionów". Adding or subtracting the exponent of 10 is much easier than multiplying by random numbers (e.g. 5280 to get from miles to feet).
If you expand your definition of English to include the largest English-speaking population in the world, the existence of the Indian system leads to a nice property:
It should be noted that though "myriad" comes from a Greek word for 10,000, and this is why the term "myriadic" is used to describe a number system based on powers of 10,000, the word itself is common in English with no meaning other than "a lot", and can't be interpreted to mean 10,000.
‘I thought it looked a little queer. As I was saying, that seems to be done right—though I haven’t time to look it over thoroughly just now—and that shows that there are three hundred and sixty-four days when you might get un-birthday presents—’
‘Certainly,’ said Alice.
‘And only one for birthday presents, you know. There’s glory for you!’
‘I don’t know what you mean by “glory,”’ Alice said.
Humpty Dumpty smiled contemptuously. ‘Of course you don’t—till I tell you. I meant “there’s a nice knock-down argument for you!”’
‘But “glory” doesn’t mean “a nice knock-down argument,”’ Alice objected.
‘When I use a word,’ Humpty Dumpty said in rather a scornful tone, ‘it means just what I choose it to mean—neither more nor less.’
Of course, this is a famous example of an idiot who can't communicate. (Or, indeed, subtract 1 from 365.) Words mean what they mean by common agreement; your wish to use one inappropriately will not make that use appropriate.
> If I said there are five myriads of sand grains in an hourglass, what could this possibly mean but 50 thousand?
That you're given to poetic turns of phrase? That you're confused about how to refer to numbers in English? If I actually encountered this phrase, I'd lean heavily toward option one there. It would be much like saying the glass contained five times as many grains as the stars in the sky, instead of as many.
Nothing to apologize for. Try finding an example of sense 1. The dictionary you want to cite doesn't provide one.
By inspection, there are exactly zero such examples in the first 200 COCA hits for "myriad", of which there are about 4000 total.
There are 72 total hits for "myriads", of which exactly one is arguably using the sense of 10,000, but it is a translation of the foreign phrase 八百万の神, where 万 is literally 10,000. I don't know whether the number in the Japanese phrase is meant to be interpreted literally, but I doubt it. Even here, the translation given is "myriads of gods", not "eight hundred myriads of gods".
You don't seem to understand what linguistic prescriptivism means. Everyone agrees that there are rules determining what is and isn't valid in a language. Descriptivism is the approach of determining the rules from usage. Prescriptivism is the approach of postulating an authoritative source.
Descriptively, "myriad" cannot be used to indicate the quantity 10,000 in English, only to indicate a large but vague number.
> If you expand your definition of English to include the largest English-speaking population in the world
If you were trying to refer to India, you missed. They are estimated to have less than half the English-speaking population the US does. (And a negligible number of first-language speakers.)
They're different, and that is annoying, but it's hard to say exactly which is better or worse than any other. Indian seems to be the most useful, if you don't mind having a couple more words.
It's a 10 based system after the first 1'000. Hardly a "redeeming" feature considering numbers are always read/parsed right to left (Arabic) and given the first three digits separated for the thousands, the mind is already "trained" for the expected regular expression to parse. Booby trapped!
1 crore = 1,00,00,000 (written with accepted formatting). Which is 10'000'000 (formatted) - 10 million - for the rest of the world. Anyone used to the Western formatting will quickly get cockeyed seeing those numbers at a glance. I'd imagine it is just as jarring for the Indians seeing Western formats.
In the UK, yards are used almost exclusively for exit distance markers. I don't recall ever hearing/seeing them used for anything else in my entire life.
I guess the rules nowadays use metric, but many
parts of football fields originally were in yards/feet, and occasionally are still described that way (6-yard box, 18-yard box)
Indeed, you said "Distances longer than a few kilometers are measured in miles", which made it sound almost like someone starts a journey in km and then once it gets past say 10km switches to miles.
If you're pointing out the inconsistency of the UK using metric units for i.e. weight and then not for travel distances, I agree, its a bit of a schism.
"Distances longer than a few kilometers are measured in miles" was a direct reference to the OP's "yards to measure distances shorter than a few kilometers".
Exactly. And that's why the UK is especially stupid with units. At least in the US they are consistently idiotic with Fahrenheit and Miles and BTUs and so on. In the UK, they understand what a kilogram is, but measure weight in stones anyway. Fucking stones! And then this thing with yards and miles.
I don't see anything idiotic about Fahrenheit. With distances I can see why powers of ten make a difference, but we don't vary temperatures by orders of magnitude in regular life.
Nor do I spend much time around freezing or boiling water. Fahrenheit has 9/5th more specificity.
Is the point that it's different than the rest of the world? I can see that point, but am I missing anything particularly bad about the Fahrenheit scale?
> Is the point that it's different than the rest of the world? I can see that point, but am I missing anything particularly bad about the Fahrenheit scale?
Mainly that it doesn't make any sense. Why was 32F made the magical number for the freezing point of water? The "well known" temperatures like freezing/boiling points of water are based on observations after the scale was invented. The secrets to the F scale died with Fahrenheit and today nobody knows for sure what 0F actually means.
I wonder if they're keeping fixing this as a backup plan for a rainy day? Say one day UK's GDP goes down harder than they'd like, so in order to burn some money and boost it back without making it look obvious, they'll announce the country has made up its mind, and is switching to full and proper metric starting next year. Cue the economy going to overdrive, as everything and the kitchen sink has to be relabeled or replaced...
(And if that doesn't help for long, they can stimulate the economy further by changing the driving side to the right one.)
It’ll go the other way: the next time they need to leave something, they can have a referendum to leave the metric system, then go through a few governments to get it done.
Actually, I'm Indian, and we have our steering wheel on the right side, just like the Brits. It's one of the less fortunate things we picked up from them.
UK went a little crazy sometime after the American colonies split.
I mean, the US screwed up their fluid ounce / weight ounce so that a US fluid oz of water doesn't quite weight a US oz, but the UK redefined a hundredweight as 112 lbs to make it an even number of stones, and even though they kept their ounces correct, they redefined a pint to 20 ounces so now there's nowhere in the world a pint's a pound.
For the actual record, in the UK distances are measured in miles. This can be seen on road signage.
Speeds are measured in miles per hour. This can be seen when driving a car, and also on road signage.
It's basically a mix. Yards are not really used outside really by people, but you will find feet and inches being used (alongside metres and centimetres) often in commercial settings.
Other examples of finding both things in the wild in use by people and companies in the UK: pints and litres. pounds and kilograms
People's height in Feet
People's weight in Stones+Pounds
Beer in Pints (proper pints, not american tiny-pints)
Roads in Miles
Others are metric
Temperature in C
Milk in Litres
Petrol in litres, but we also use miles/gallon
Food in grams from shops, but oz when buying steak at a pub
Bottles and Cans in ml
Road distances on signs do tend to be yards rather than metres. Areas are often in acres, or square metres.
Milk is in pints. Some are sold in litres because you get less but it kind of looks the same: 1L < 2 pints. But people generally talk about milk in pints.
The supermarket branded milk that everyone actually buys is always in pints though. All of this filtered, UHT, skimmed business falls into the "things that aren't plain old milk" category
The USA, because of its size and remoteness from Europe and Asia, has relatively little international trade of goods (https://en.wikipedia.org/wiki/List_of_countries_by_trade-to-... has the USA sixth from the bottom) and didn’t, and, apparently, still doesn’t feel that pressure as much.
A major reason why the switch in the U.S. failed in the 70s was because the manufacturing sector revolted and didn't want to do the extra work to switch to metric.
I mean, what the hell, we are cutting their taxes to single digits anyway, might as well write this one off too.
The rest of the world has partially switched, but as long as people continue to use hours, days, weeks, months, years, leap years, and not kiloseconds and megaseconds, they don't seem to have switched completely either, but stopped at some point.
Even if you want to argue days and years are based on physical measurables, hours, weeks, and months are arbitrary and not based on 10.
Seconds (and thus all time units derived from them, e.g. hours, nanoseconds) are officially part of the metric system.
But yes, it is still worthwhile to keep in mind that despite nearly all countries officially adopting SI, a much lower percentage of humanity uses SI exclusively in their day-to-day life.
Seconds are indeed a fundamental unit of the metric system.
You can then use the standard multipliers and get things like kiloseconds and megaseconds, milliseconds and nanoseconds, some which are widely used, while some are not.
You the can also use legacy minutes and hours, which are based off the fundamental seconds unit, but that doesn't make them "metric", nor technically a SI unit (although it's accepted to be used alongside SI units. "Although not an SI unit, the minute is accepted for use with SI units" Source https://www.bipm.org/en/publications/si-brochure/)
The reason why you should do it is so that the rest of the world will understand what you are talking about, the cost is about 10 seconds with a calculator.
A litre of pure water weighs 1kg at sea level. A litre is 10cm x 10cm x 10cm. Water freezes at 0 and boils at 100. Volume, distance, temperature as wonderful easy to remember units.
I like the metric system and would love to see the US switch to the metric system, but this comment is just wrong on so many levels.
One litre of water only approximately weighs 1kg and density is relative to temperature and pressure. Further, the "standard pressure" density is measured in isn't equivalent to average sea level pressure. Celsius is as much a SI derived unit as Fahrenheit is. The official unit is Kelvin and water freezes at 273.15K. Not such a beautiful number, but still based on the scientifically more significant definition of temperature.
It's because fewer countries actually use the period as decimal separators. The English-speaking world (and its former colonies) and China use the period, which is probably why it's so widespread to. Other countries, while countries not originating in or heavily integrated into the English-speaking world use the comma. By count of governments, the comma is clearly winning as a decimal separator, though that doesn't say anything about usage in the global population of course.
There's no real reason why one is better than the other. They're both somewhat arbiratry and as far as separation goes, there's not even worldwide consensus about the amount of zeroes that are in front of a separator. As a European, I don't think I've ever been confused reading an English-style number because of the different separator. The only problem i can imagine is a number with three decimals (123.456) but with such many orders of magnitude in difference it should not be a problem to understand the right number based on context.
The character was chosen based on either practical reasons (the French already used a period for something else in maths) or because it made sense to use the system of countries around you or countries you were trading with a lot.
You can ask the same question about why some countries drive on the left and some on the right but in the end it's because you have to pick something and at that point you just pick what's practical. Or, you can ask why the American number system uses billion to mean 1e9 while in Europe it often means 1e12. It all comes down to what people are used to. Or why America has its date format unsorted (m/d/y vs d/m/y or y/m/d).
Furthermore, the whole world uses metric aside from three specific countries versus the much larger split of comma versus period. It's not really something that can go wrong much as long as you can understand some context (if you read a theoretical numbering system like 10-000-000'00 you'd still understand what the decimal point would be). Using two or four decimals clears up any confusion regardless of system.
> Or, you can ask why the American number system uses billion to mean 1e9 while in Europe it often means 1e12.
I'm gonna stick up for the American system here, because if "billion" doesn't mean 1e9 then the only way you can say that number is "thousand million", which is terrible. The long scale just sucks.
No, the way the UK used to say a thousand million is "milliard". You'll find that same term in a lot of European languages. Same with billiard, trilliard, etc.
The short scale is just another reason why European and American data sources get confused every now and then. I find it kind of strange that the UK switched to the American system despite having used the long scale themselves for quite some time. I suppose it was just a consequence of the US media getting influence in Europe after World War 2, but it couldn't have been an easy switch.
The history of this is that at some point, Arab mathematicians settled on a small pen stroke to separate decimals. When this got typeset, people found it convenient to just reuse the point or comma. Different countries made different choices, and now we have to deal with that.
Of course. When you're working mainly with one format, the other becomes a hassle. The point is that those two formats are pretty much equivalent, quality wise. One is not inherently better or worse than the other.
When it comes to imperial vs. metric, the systems are very much not equivalent, and you could argue that either of them is better. Of course, they're better at different things, so in the end it comes down to weighing their respecting strengths against each other - but at least there the discussion is somewhat meaningful. When it comes to dot vs comma, it's just an arbitrary choice, and too bad we didn't all choose the same.
I agree, it's quite annoying to see American style numbering everywhere.
An Intel driver program crashed at me because it stored its Window size American style while the system was set to a different locale.
This can easily be fixed by specifying the input and output locale in your code, which I'd something you should always do anyway if you're selling software to more than one country. There's more differences in internationalisation than just decimal separators and date formats. Using proper locale code will fix all of those for you so you don't have to deal with calls from customers.
JSON (and CSV for that matter) both use commas as list/column separators. So formatting floats using periods as the separator is much more compatible with these formats. Never mind that programming languages format their floats in this manner too.
Let's not kid ourselves, the comma representation does not play well with programming languages or common data formats, and for that reason shouldn't be used except at the very top level of the UI for formatting purposes when displaying for certain locales. You're needlessly making things a lot harder for yourself if you attempt otherwise.
Most of the CSVs I've encountered used the semicolon as a field separator, probably for exactly this reason, even ones from American sources. JSON has a standard format for writing numbers, which happens to be the American one, and I don't know what other data formats are sensitive to the comma.
I don't store floats in the users locale and I don't think anyone should, just like dates should be stored in UTC (timestamps, preferably) instead of in any local date format. However, many programmers seem to forget that if you don't specify a locale, the system will choose one for you and its probably the one the user set up while installing their system, just like what would happen with any date or time.
I'm not going to change the way I write numbers because some American programmer thinks it's too annoying to bother and neither are my customers. Localisation is important to remember because if you don't, you're going to be burned by it at some point. This is just another gentle reminder about that.
Other similar annoyances in US-centric front-end JS code :
- Numeric text fields filtering out all characters except figures + ".", even when the locale is set to something that should allow commas.
- Numeric text fields that expect a specific keyboard layout, for example numbers as the lower characters of the top keyboard row, filtering out anything else. In some layouts (like French), that's not the case : numbers on the top row are accessed with Shift, direct access is for symbols / punctuation. If the text field also disallows pasting, that makes it impossible to fill unless you switch layouts in the OS.
Part of the reason is the Ganges & YangTse river deltas are the most fertile on Earth. While other regions typically yield 2 crops a year, these deltas average 3 to 4.
Also, the climate is relatively moderate with no major high frequency calamities (like earthquakes and hurricanes).
The Deccan plateau is one of the world's most geologically inactive areas. The ring of fire goes through the circle but isn't a major component of the circle. There aren't even a remarkably high destiny of volcanoes.
Bonus points for whoever calculates the ratio of the surface areas for the two spherical caps that contain half of the human population. (The circle's radius is ~4,000 km)
> Bonus points for whoever calculates the ratio of the surface areas for the two spherical caps
Hmpf, I went to all the trouble of deriving the surface area of a spherical cap (it's really easy, as surface integrals go), and it's listed right there in the wikipedia page. A = 2πrr(1 - cos φ), where φ is the angle between the center of the cap and the edge (measured from the center of the sphere).
Assumptions:
1. The "radius" of the cap is 4000 km.
2. The "radius" of the cap is actually an arclength along a great circle of a sphere (the earth).
3. The radius (a real radius) of the earth is somewhere between 6300 and 6400 km.
The formula for arclength along a circle tells us that φ is somewhere between 40/63 and 40/64.
We can calculate the cap's percentage of the surface area of the entire sphere as (1 - cos φ) / 2. For an earth-radius of 6300km, this is 9.744%. For 6400km, this is 9.452%. For the smaller earth, the ratio of the cap's outside to its inside is 9.26:1; for the larger earth, it is 9.58:1.
Rounding to two significant figures, like we used for the size of the earth, the ratio should be between 9.3:1 and 9.6:1.
The ratio isn't really very informative, because the cap was drawn around where a bunch of people live, and "everything else" wasn't. This has artifactually put most of the ocean, where people cannot live, into "everything else". "Everything else" should probably be significantly deflated to adjust for this. The article messes up a similar point:
> The population density of Greenland, for example, is just 0.1/sq. mi—that is, one person living on every ten square miles of rock and ice. But it's a lot easier to find company in Manila, which is literally one million times as crowded: 107,000 Filipinos per square mile.
The population density of Greenland is mostly zero with some spikes. There's not a literal tenth of a person every square mile -- those people would all be dead. The population density in areas where local population density is more than zero is much higher. Manila is not actually one million times as dense.
It's more impressive to compare the area of the cap to the area of a flat circle of the same radius. The curvature really adds up -- the cap is under 40% of the circle.
Ah, the reason this was so impressive is that I mixed up the radius of the cap with the radius of the sphere on which it sits. In reality, this cap has 97% of the area it would if it were a flat circle of the same radius.
So, yes, good point. Let's start with assuming a perfect sphere, then oblate spheroid, then topography, then only land (not water), and however crazy this thread gets with whatever else we haven't thought of :)
Intestestingly in the original Reddit thread they were talking about epidemics as around that time (2014 was the post date) the influenza H7N9 was hitting China, which was also impacted heavily by Chinese new year travels. Smaller rates than Corona but it still hit 1223 people and had a 30-40% mortality rate:
From what I understand influenzas tend to be the scarier than Coronavirus types of viruses in most projected pandemic scenarios.
This is one of the downsides of high density areas, although for more cost effect for lower income people so density will only continue to grow in most of the world.
Beyond the factoid, the article unfortunately does not delve into why the population is concentrated in such region. Especially India, Bangladesh, Pakistan, that is most of the subcontinent has very uncomfortable weather, but still is highly populated, I wonder why? Why didn't people in the early ages decided to move to more temperate climes?
Uncomfortable, but not fatal. A human being can relax and turn down its metabolic needs when it's hot, find some shade, go for a swim. Also due to both climate and fertile soil, there is abundant growable food so humans will almost never starve (and even when food is low, metabolic needs are also low). It's possible to simply exist without trying too hard in those types of areas.
Contrast with areas such as NYC or Moscow, where it's almost impossible to simply exist for many months of the year.
It didn’t use to be so uncomfortable. Even just two generations ago, the weather was much milder and even when uncomfortable, only for a couple months.
Then everything got paved, all the trees were cut down so there’s no more shade, carbon emissions, population explosion, climate change etc. Even the cultural traditions which used to line up with seasons such as monsoons and spring don’t quite line up anymore.
Without artificial heating or cooling, it is far easier to survive India than many parts of say, US or Europe. So in terms of ancient civilization, India is the ideal climate
Mountains mean rivers, rivers mean agriculture, and agriculture means more people. The Himalayas are the largest mountains in the world, and the countries flanking them have always been the most populous.
Try an image search for "rivers of Asia" and you'll see a bunch of lines pointing near the center of that circle.
The DIAMETER of such an area is very roughly 12 percent of Earth's CIRCUMFERENCE. So you could (probably) lay 8 of these areas around the equator, give or take a a couple.
That should have been scaled by, at least, length of the circle of latitude (there are fewer people the nearer you go to the poles not only because it is cold there, but also because there’s less area), preferably also by land area on the circle of latitude.
Looking at the graph, I would guess that that combination explains quite a bit of the shape of the graph.
Note that the title is wrong. It's a circle on a map, not in real life and thus it's not a "2 500-mile radius". A sphere in real life would be distorted in the map. In fact, all the meridians and circles of latitude are circles in real life but on the map they don't show up as circles.
They don't talk at all about why it is so. Is it particularly fertile territory that can support this kind of density? Is there something about the geography of the area or the geography of the globe that makes it have so many more people than the rest of the world?
edit: The circle in the article has plenty of water. I'm not counting that. So maybe land area in that circle is 5% of world's total land area (not 10%).
I googled 'earth land area' and it showed ~196 million sq miles. And I used it without double check. (Google incorrectly reported the full surface area of earth.)
It's about 10% of the world's entire area, ocean included. It's much more than that of the land area. (But as you note, it includes water too. Not sure how much.)
It's centered on the island of Hainan. I want to know what the center of mass is for that picture, since the humans are not uniformly distributed in that circle.
Nobody lives in the Sahara, the population centers in Africa are in the tropical regions and the Mediterranean.
Africa will be the only continent experiencing population growth post-2050. Africa's largest economy, Nigeria, is expected to become the third most populous country in the world by 2050.
The effects of climate change on monsoon-dependent areas (the Mediterreanean coast of Africa and the semi-arid regions bordering the southern parts of the Sahara) are not well-understood and the effects are more complicated than everything will become a desert. For example, the Indian monsoon is expected to produce 10% more rainfall because higher temperatures allow the air to collect more moisture. This is going to be a huge boon for certain semi-arid regions of the country.
Hard to define, but not important for this stat, because the ancient global population of proto-humans was so small that it's not even a rounding error in 107BN (the estimated total humans to ever have lived)
I enjoyed this post on reddit explaining why China has such a large population [1]:
"You might be familiar with how the Nile River in Egypt works from school. If you aren't - for 9 months out of the year the Nile has a moderate flow rate that is sufficient to support human settlement and agriculture. For the remaining 3 months the Nile's flow rate increases dramatically and it floods a huge area around its river banks.
That flooding might sound bad but its not. Using soil for agricultural purposes will deplete it's minerals within about 100 years. That's a long time compared to a human life, but not compared to a civilization. When the soil runs out of minerals you can't grow anything in it anymore, and it turns out that this is the limiting factor for most civilizations. IE, a civilization will begin intensively farming its soil, deplete the soil, then starve to death.
In the modern world we're able to replenish the soil's minerals with fertilizer. They were sort of able to do this in the ancient world as well, but this involved transporting huge amounts of animal manure which is difficult to do and, in practice, if an ancient civilization had to manually fertilize the soil it would result in very low agricultural yields.
This is what makes the Nile's floods so good for the development of civilization - every time the Nile would flood it deposits a huge amount of new soil in the areas that got flooded. The source of that new soil was hills and mountains in Central Africa, so it was filled with minerals. Or to put it another way - every year the Nile naturally dumped a huge amount of fertilizer on Egypt.
This natural fertilizing allowed Egypt to be by far the most productive agricultural region West of India for thousands of years - everyone from the Pharaohs to Alexander the Great to the Roman Empire fed themselves using the food that the Nile was able to grow.
How does this relate to China? The Yellow River in China is the same type of river as the Nile. It spends most of the year with a moderate flow rate, then has massive floods for a few months that deposit a bunch of new soil along its banks.
Where the Yellow River is different from the Nile is in its size. The Nile is a single, small river with practically no tributaries or lakes. The Nile's floods only cover a small geographic area located immediately adjacent to it.
The Yellow River, on the other hand, is a massive system with hundreds of tributaries and lakes. When it floods, it covers almost the entirety of South East China - which is an area thousands of times the size of that covered by the Nile.
The Yellow River basin has been among for the most productive agricultural areas on Earth for much of human history. Because the only limiting factor to population size is a region's ability to produce food, this also means that the Yellow River Basin (and by extension, China) has managed to maintain a huge population for the entirety of human history."
Another point to add to this is that the Nile River is significantly easier to manage for the Egyptians than the Yellow River was for the Chinese. Unlike the Nile River that flows along the same path and floods the same areas every year, the Yellow River has a nasty tendency to change its mind about where it wants to flow into the sea, and it destroys all the farmland along its path when it shifts its outflow from the north side of the Shandong peninsula to the south and back again a few hundred years later. That widespread flooding and shifting of the rivers path makes the entire North China plain very fertile compared to a thin strip along the Nile, but it also causes widespread damage and casualties whenever a bad flood year shifts the Yellow River's path down the middle of a town.
https://en.wikipedia.org/wiki/List_of_countries_and_dependen...
2500 miles * 2500 miles * pi = 19,630,000 miles squared
So that area represents about (19.63 / 57.51 ) 34% of the total world landmass. So 50% of humans live in 34% of the landmass. But harsh and relatively uninhabitable lands make up a large portion of the earth's landmass
( antarctica - 5,400,000, siberia - 5,100,000, canada - 3,511,023, australia - 2,947,336, , greenland - 836,330) = 17.8 million square miles.
So the habitable areas are 57.51 - 17.8 = 39.71 million miles squared.
So that circle represents ( 19.63 / 39.71 ) 49.4% of the habitable land.
So in the end, about 50% of the world population lives in about 50% of the world's habitable land.
Astounding huh? It's amazing what some math and common sense and understanding of geography takes away from a clickbait article based on a reddit post.
As others have noted, that area is also primed for human habitation due to tons of fresh water rivers flowing from the tibetan plateau and rich fertile land along with year-round planting seasons due to its proximity to the equator.