Worldhoppers- Where are they all coming from? How many exist?

[Soulgazer]

So I only recently got the Arcanum Unbounded and Oathbringer, and the info contained within is...confusing.  Up to this point, I had assumed that worldhoppers were exceptionally rare.  After all, most planets possess only one perpendicularity, often in difficult to use places, and about half of the currently named shardworlds are a mess in the cognitive realm or otherwise unavailable.  I had assumed that the interstellar community was limited to mostly Hoid, Khriss and the 17th Shard.  But wait, now there's a entire city in the Cognitive Realm with its own university?  There's factions like the Ire, and a functional interstellar economy that uses places like the Pits of Hathsin (a heavily guarded location in the Final Empire) as a trade route?  How many worldhoppers are there, and how are they moving between planets in any significant numbers without causing a fuss?  

[Farnsworth]

It makes sense that there would be many worldhoppers because there are many humans in the Cosmere. Let’s say there are 7 billion people on each populated planet in the Cosmere (approximate number of people on Earth). We have Roshar, Sel, First of the Sun, the two other planets in the Drominad system that Khriss says are inhabited, Vax, Threnody, Obrodai, Scadrial, Nalthis, Yolen, Taldain, and Ashyn. That’s 92 billion, and there are probably other habitable planets with perpendicularities we haven’t heard of. Let’s say it takes 5,000 people to make a smallish city like Silverlight. 5,000 people out of 92,000,000,000 people is one in every 18,400,000. So one in every 18,400,000 people becomes a worldhopper. That’s not too improbable. In addition, some people probably use life extending techniques like Hoid does,so the number of people joining their numbers exceeds the number of people dying. In the universe the size of the Cosmere, a city like Silverlight can easily be created.

Edited December 28, 2017 by Farnsworth

[kimni]

That doesn't change the fact that it doesn't take that many people from each Shardworld to establish a kind of worldhopping community. Also, once you've got a few thousand people hanging out in Silverlight, you're probably going to get new additions from children born there (does it count as Worldhopper if you're born in Silverlight?), not just "new" worldhoppers coming from the Shardworlds. A few thousand is enough to start a sustainable population, even without any influx from outsiders. And with people from the different Shardworlds joining them, I see no reason why Silverlight shouldn't be growing in population (assuming they've got enough soucres of food and water and so on, and since they established a city, I guess they do).

As for groups like the Ire, well, why wouldn't they exist? All it takes is one person discovering Worldhopping and instead of going off by themselves, starting a group.

But how they all manage not to be noticed by the people of the Shardworlds, I have no idea. Maybe most of them stay in the Cognitive Realm most of the time, and only a few people actually travel to different worlds (these would be the Worldhoppers we see), and the majority of Silverlight's inhabitants don't go running around on different Shardworlds, just like most inhabitants of Shardworlds never leave their home world.

[Hyarmenatan]

1 hour ago, Farnsworth said:

Let’s say there are 7 billion people on each populated planet in the Cosmere

I think you are overestimating the number of people on each planet. 7 billion is a number for modern era, developed societies, and planets of similar size to Earth, which I don't know if it's the case for Cosmere, isn't Roshar bigger than Earth? Also using Roshar as an example : Alethkar is one of the biggest kingdoms there and can only gather an army of ~100 000 soldiers. On earth, in Middle-age'ish or ancient times such numbers were achieveable for great empires, like Roman empire. In the 25B.C there were about 60 million people inhabitating the Empire and could equip ~150 000 - 300 000 soldiers at a time. Also, please keep in mind that Romans did not have the soulcasters which make feeding those massive hordes many times easier.  

My wild guess, basing on a number of soldiers purely and assumption that Soulcasters reduce the effort required for supporting an army let's say 5 times, I'd say that there were 10 million people in Alethkar tops. If we add the other kingdoms, maybe we can gather 100 million inhabitants of Roshar. This is based on speculations and arbitrary approaching the subject of soulcasters efficiency, so feel free to argue with me here. I bet someone has asked Brandon about it already.