Check these population/colonization calcs for me please

[Junghalli]

I'm trying to determine the size of the Human empire from a sci fi universe I'm working on. Please check my calculations if you have the time/inclination. Note that these are crude estimates.

I did some calculations for Earth's Navy at this time period and pegged it at a little less than three thousand ships. As a general rule of thumb every warship will use up two or three supply ships in the logistics chain. Moreover, for every one of those you're going to need a couple more to keep the general buisness of civilization running. So a total transport fleet of around 21,000 ships seems reasonable. Of these most of them will be bulk freighters, perhaps one in fifteen or twenty would be designed to carry people. So around 1,100 ships are free to move colonists. Each ship is capable of carrying 100,000 people, so this comes out to a total transport capability of 110 million people.

Now I'm assuming a "Gold-Rush" type period shortly after FTL becomes possible and passage becomes cheap enough to be within reach of the average citizen. I've used the immigration rates to the US during the "immigrant century" as a guideline here. They peaked at around one million, out of a population of (I think) about a billion worldwide. Earth as of the next century is projected to have a population of roughly 10.8 billion. So assuming that the fringe worlds are about as attractive proportionately as the US was during its highest periods of immigration that comes out to 10.8 million people per year as a high end. If you refer to the ship-space calculations above, this should be easily sustainable, but we'll err on the side of caution and assume the actual number is somewhat lower.
I'm assuming this emigration rate continues for roughly twenty-five years. So by the time this period is over (and the "storytime" part of the universe's TL starts) there should be. Note, habitable worlds are fairly common in this universe.

7-8 worlds with populations of 10-12 million
40 worlds with populations of 6-2 million
120 worlds with populations of 200-400 thousand

Does this sound about right to you?

[Ariphaos]

The world's navies right now are a couple thousand ships or so, including military support ships of various types. The world's merchant fleet (of 1,000 tonnes or higher) is some 30,000 ships, so with a navy of ~3,000 ships I'd expect more like 40-60 thousand massive transports of various types.

I tend to be of the opinion that humans will see an exponential growth in production capacity as time goes on. For Solar Storms, I extrapolated humanity reaching a Type II civilization in the 2270's or so (the year is 2208). That's a rather random figure, though.

This means that the number of ships is going to end up being truly mindboggling when humans actually start making regular trips to stars. At least in my mind, FTL or no (FTL doesn't even work yet in Solar Storms).

Regardless, I'd think the emigration rate would be even higher, perhaps as high as 3% or so, or roughly ~250 million people a year. A lot of people are going to want to leave, and if people are still fairly economically empowered, a lot of people are going to be able to, and Europe is no longer going to be the chief source, but rather the entire world population.

This all depends on the ease of FTL travel, how fast it is, and how common such worlds really are.

[Wyrm]

How's your Human empire's construction technology? Can the humans just sit back and let their machines industrialize their new home (and teach their children), or do the humans have to put in a bit of elbow grease?

[Lord Zentei]

The world's navies right now are a couple thousand ships or so, including military support ships of various types. The world's merchant fleet (of 1,000 tonnes or higher) is some 30,000 ships, so with a navy of ~3,000 ships I'd expect more like 40-60 thousand massive transports of various types.

I tend to be of the opinion that humans will see an exponential growth in production capacity as time goes on. For Solar Storms, I extrapolated humanity reaching a Type II civilization in the 2270's or so (the year is 2208). That's a rather random figure, though.

This means that the number of ships is going to end up being truly mindboggling when humans actually start making regular trips to stars. At least in my mind, FTL or no (FTL doesn't even work yet in Solar Storms).

Regardless, I'd think the emigration rate would be even higher, perhaps as high as 3% or so, or roughly ~250 million people a year. A lot of people are going to want to leave, and if people are still fairly economically empowered, a lot of people are going to be able to, and Europe is no longer going to be the chief source, but rather the entire world population.

This all depends on the ease of FTL travel, how fast it is, and how common such worlds really are.

3% and 250 million a year is a LOT of people.

Today, the human population growth of the Earth is around 1.5%, most of which is in the third world.

Anyway, I second the assertion that it neccesary to get more intel on the technological capabilities in the setting:

* How easy is it to leave the gravity wells of settled planets?
* What are the limitations of FTL (such as with regards to in-system jumping)?
* What are the resource demands of a jump capable ship as a fraction of GDP?
* What is the effective range of such jumps?
* How sophisticated are the construction techniques of the setting?
* How common are habitable planets (i.e. what is the mean distance between them)?
* How rapid is the terraformation technology?

[Ariphaos]

3% and 250 million a year is a LOT of people.

Yeah it is. We really don't have a relevant comparison, since the times before humans could build boats have little to tell tales by. And thinking in terms of modern production capacity seems to be a bit fallacious to me, is all.