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forum Content related discussions Populations (3 posts)
joined October 09, 2012
93 forum posts
pokelover218 - november 20, 2013


There is always debate on what seems to be the optimal population count for a space faring civilization, with powerful nations, such as the Canthin Khanate, having more than a trillion people. While this seems like a really big number, and is a really big number, a species dominating massive amounts of space would easily have a far larger population. For that example, lets look at a prime example of an issue like this: Coruscant in the Star Wars universe. (Note: all of the following was taken from to help express my point, and therefore is not my own original work)

"In the movies, the entire planet looks like it is covered by a continuous city. Also, the various on-line Star Wars resources indicate that at times: The entire surface of Coruscant was covered by sprawling kilometers-high ecumenoplis. (Wookieepedia, which provides references). The population is given as, variously, 1 to 3 trillion.

Let’s take that data and do some number crunching, something any worldbuilder or science fiction writer should consider doing. Coruscant is basically earth sized, which means we can use Earth data for surface area, and ect. We also have data from Earth that a skyscraper like the World Trade Center towers in New York City had about 20,000 people in them during the day. Let’s assume Coruscant has about 20,000 people in a 100x100m area, as a starting point. Now Coruscant probably has factories and various open spaces but it is supposed to be covered with “city” multiple kilometers thick so 20,000 people for the relatively short WTC tower is spread out over a taller Coruscant structure, as partial offset.

This would yield a population of: one million trillion people.

But maybe the poles aren’t necessarily populated and there was too little room for factories and such in the last calculation. But scale it back by 10 times or even 100 times, this is still one to ten thousand times higher population than per the Star Wars canon. One trillion people seems like a lot, but if spread over Earth, that’s about 2 people per square kilometer.

For comparison, Hong Kong has a population density of 6500 per square km and, if applied across the world, would result in a population of 3300 trillion. You can scale that back for a lower population density but to get to the stated population of Coruscant, you’d have to scale it back by 1500x which doesn’t really seem to qualify as “city-wide planet” since the state of Wyoming in the U.S. has a population density of 2.3 people per sq. km. and the only U.S. state less dense is Alaska, at 0.5."

Just to be clear, this is not something that I and M.Q. Allen (The one who wrote the article used above) are demanding science fiction writers address. Just, before saying that something like 1 trillion is impossibly too high for any species of aliens to attain to, consider the example of Coruscant, and how terribly small its population is.

My solar Systems: none
joined August 01, 2011
13 forum posts
manticore - november 24, 2013

I'm a little puzzled by Allan's math.

"20,000 people in a 100x100m area" == 2 people/m^2, right? Typical human resting metabolism is 50W or so, which yields 100W/m^2 for two people. Sunlight is roughly 1,000W/m^2 at the Earth's surface, so that's 10% of solar energy sunk right there. At 2,500W/person, the planet's population is consuming 5,000W/m^2, and the planet has a significant heat rejection problem. (It's late here, so apologies if I've blown this.)

Edit: NVM, I see what he means.

Edit 2: Looking at the picture he uses suggests that very low estimates of the average population are probably in order. The picture doesn't look much different from pictures of the dense areas of Europe or the US from orbit: lots of lights in the big cities, but still gaps between them. I'm too sleepy to do that math, it doesn't seem unreasonable to take the population of the US East Coast sprawl (northern VA to Boston, MA) and divide that by the area between the area between the mountains and the Atlantic to get a reasonable population density estimate of Coruscant, since the pattern of lights seems roughly similar. Wouldn't surprise me if that comes to a few thousand per square klick.

Message has been edited - november 24, 2013

joined June 01, 2008
2601 forum posts
thegreatpl - december 15, 2013

To be fair, if I ever wrote a trillion in regards to the Canthin Khanate population, it was most likely back when it was originally created, in which case, they would not be counting the slave races in that number. Plus, the Khanate is essentially, at its core, a warrior society. The population is spread out and it only owns so much territory because in the early days of FTL, it when on a conquering spree. It ended up fighting a costly war against the Ale-Turans, which would have knocked down the population, and then it spent the next 500 odd years fighting over the old Ale-Turan systems in the chaos wars.

Come to think of it, there are plenty of reasons to state why a trillion is not a low number. Lets start with the fact that the majority of settled planets in the galaxiki seem to be naturally uninhabitable. That means that any habitation is going to be needed to be built first. Sure, there are a few habitable worlds, but most of the empires seemed, to my recollection, to nab systems which were strategically placed, or nearby (and a community star). If you have to build all your habitation, that is going to limit your population right there. Also, you never know how much spread out the population is, and whether or not the planet is primarily agricultural in nature. At least one of the planets settled by the Children in there late stage colonization was settled to be a food production planet for the rest of the Children's Empire. Finally, the Dacor are nomads, and almost all their population lives aboard ships.

Now lets factor in the simple fact that in the last 1000+ years, most of the galaxiki nations who are in regular contact with each other have been engaging in war on a massive scale. The Core War alone almost wiped out the Umbrans and Riv, though that was a thousand years ago with plenty of time to recover since. At the same time, the Ale-Turans were involved in every single major galactic war since they overthrew the Kraznite Empire. The Ganites and Dacor also get involved in occasion. The Mananins and Zionites fight multiple wars against the Ale-Turans. The Children when they get in on the scene also follow suit and try to join every major conflict they can. Then the Ale-Turans Ascend, taking with them most of the galactic economy. That's going to cause a lot of civil unrest. Plus, the other 2 major superpowers of the time are having troubles as well, with the Children melting down into the Great Childrenic Empire and Dacor also destabilizing and withdrawing into themselves. Then the last 500 years have practically been one long drawn out period of warfare, with the Great Childrenic Empire fighting everybody (including, for the majority of the time, itself), and Zanta and the Khanate fighting over the Ale-Turan systems. War can be a huge drain to population. Really, the galaxiki universe is rather bad at the moment when it comes to the old nations. The Umbrans, Riv, and Ganites may have stayed out of it for the main, though their navy likely is fighting off incursions of Canthin pirates.

Of course, the Childrenic Empire's population is rather hard to quantify, since it is constantly fighting someone. Whether it is each other, invading Ale-Turan space (again) or just sending off fleets of it's excess population out into the galaxiki to go conquer, pillage, or more likely, die when the life support breaks down. However, despite all this for the last 500 years, they have somehow managed to expand their territories and number of systems through colonization. In fact, I would put their birthrate alone at at least a trillion a day. Considering how they have 32 elector systems alone, plus 8 other systems variously considered part of the empire, even that may be small estimate, I have not bothered to really do the math.

On the flip side, creating and supporting city planets in the galaxiki universe should be in the realms of plausibility. "A single Treagy plant can support 20 people a day", and the Treagy plant was used by the Ale-Turans and I have said in the past the Canthin ended up using them. Which means a lot lower farmland to population ratio than could have been said. Plus, the Riv have practically built a dyson sphere of solar panals and mirrors, which can easily be beamed down to a planet to power everything (though if they miss...).

My solar Systems: none
forum Content related discussions Populations (3 posts)

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