Confusion over how quickly sunhearts run out

[pi4t]

Throughout this book, something bothered me: given the apparent population of Canticle, the amount of sunhearts used seems to be highly unsustainable.

On Canticle, each family seems to have their own ship. This is implied by the general descriptions, the fact that Elegy had a ship to herself, etc. It's also confirmed by the "flying over the mountains" sequence: When Beacon really squeezes, they fit a population of 135 (and essential infrastructure) onto eight ships, but it's a much tighter squeeze than normal. Thus each ship is normally occupied by significantly fewer than 135/8~=18 people.

How frequently do you have to sacrifice someone to run a ship? Well, Rebeke's mother sacrificed herself only two weeks ago (page 117) to power a single ship. By the time of the story, Beacon has essentially run out of fuel - they don't have enough to complete one more rotation around the planet. The Beaconites know that sunhearts can be split, so this implies (in particular) that Rebeke's mother's sunheart didn't have enough fuel left to get every ship around the planet once. Even assuming that there was one ship for every Beaconite, then, Rebeke's mother's sunheart doesn't have enough fuel left for 150 rotations. This means that a full sunheart, running a single ship, would last a maximum of 2 weeks and 150 rotations. Maybe a little more if it's just flying around the planet at a steady speed instead of being used for missions. Assuming the weeks on Canticle are actually somewhere around the 7-10 figure we see elsewhere in the Cosmere, that means each ship needs a new sunheart every 200 rotations maximum.

This is also confirmed by the fact that Beacon stopped the sacrifices less than two weeks ago (unless Rebeke's mother disobeyed orders) and is already running out, which indicates an even shorter figure. The fact that the Cinder King demanded a daily sacrifice from each of his vassal towns, and seems to need that many sunhearts to run the city (page 312: the workers are worried he'll start sacrificing them once he runs out of captives), also supports the idea.

So even with the most generous estimates possible, for every 18 people in your settlement you need to sacrifice someone (or steal a sacrifice from somewhere else) every 200 rotations. Which is way too fast to be sustainable. Unless you have all the women get pregnant as much as possible and sacrifice all their babies to the sun, but (thankfully) there's no indication that anyone has tried to implement that horrible idea.

[Shaukan-son-Hasweth]

I'm a little suprised nobody has replied to this. I haven't done the math but had a similar feeling.

Even though I liked the story, the worldbuilding of this book streches my suspension of disbelieve the hardest. Most other worlds while also not really possible feel way more coherent in how they work.
But there is something about Canticle that just seems like the society depicted would never hold up at all.
Somehow they are always at the brink of running out of energy needing to sacrifice people. But on the other hand there is also elderly people around.
Because not every person that dies is sacrificed to the sun. There has to be a decent part of the popluation dying in accidents, childbirth, desease etc. So all their souls are lost.
Also the general way in which they live seems a little to fast paced to maintain any sort of culture at all.

[AquaRegia]

Main reason for lack of response, I think... previous topic with plenty of math:

 

[drunkenbotanist]

The story says that a sunheart can power a ship for months, but that the cinderking has prevented them from picking up sunhearts at dawn, so their supplies have been dwindling 

[WandererNearby]

This is explained by the Cinderking knowing how to recharge sunhearts or by the Beaconites using their sunhearts up faster. I can come up with some reasonable guesses based the second alone. Lets say that every sunheart starts out with 200 BEU's. Beaconite usage requires permanently staying aloft in a thunderstorm so it uses 1 per day for flight, heating, lighting, and etc.. Normal usage requires less heating for the ships and much less flight time so it only uses .25 per day. At those rates, a regular city would need to produce a new sunheart for every ship every 800 days and Beacon would need one every 200 days. Assuming 18 people per ship and the older person dies every time this would mean about 39-40 years of life on a regular ship and about 10 years of life on the Beaconite ship. The regular life would be possible. It isn't fun but it's possible especially when you consider that they're are invested so disease is less of a worry and they have access to a lot of modern conveniences like indoor plumbing and heat. 

[drunkenbotanist]

On 2/2/2024 at 2:48 PM, WandererNearby said:

This is explained by the Cinderking knowing how to recharge sunhearts or by the Beaconites using their sunhearts up faster. I can come up with some reasonable guesses based the second alone. Lets say that every sunheart starts out with 200 BEU's. Beaconite usage requires permanently staying aloft in a thunderstorm so it uses 1 per day for flight, heating, lighting, and etc.. Normal usage requires less heating for the ships and much less flight time so it only uses .25 per day. At those rates, a regular city would need to produce a new sunheart for every ship every 800 days and Beacon would need one every 200 days. Assuming 18 people per ship and the older person dies every time this would mean about 39-40 years of life on a regular ship and about 10 years of life on the Beaconite ship. The regular life would be possible. It isn't fun but it's possible especially when you consider that they're are invested so disease is less of a worry and they have access to a lot of modern conveniences like indoor plumbing and heat. 

The 200 number I believe comes from this quote

 

"Hmmm… Aux said. I’d guess around two hundred BEUs in this one. Far less than what powers a full ship."

 

But the quote makes clear that a fresh or whole sunheart contains more than 200 BEUs.

Edited February 4 by drunkenbotanist

[Colors]

On 11/21/2023 at 3:53 AM, Shaukan-son-Hasweth said:

I'm a little suprised nobody has replied to this. I haven't done the math but had a similar feeling.

Even though I liked the story, the worldbuilding of this book streches my suspension of disbelieve the hardest. Most other worlds while also not really possible feel way more coherent in how they work.
But there is something about Canticle that just seems like the society depicted would never hold up at all.
Somehow they are always at the brink of running out of energy needing to sacrifice people. But on the other hand there is also elderly people around.
Because not every person that dies is sacrificed to the sun. There has to be a decent part of the popluation dying in accidents, childbirth, desease etc. So all their souls are lost.
Also thase we general way in which they live seems a little to fast paced to maintain any sort of culture at all.

One thing I'd point out is that just about anyone with a disease they didn't believe they'd recover from would likely volunteer to become a sun heart. With the speed at which rotations happen I don't think it would be often people would die from disease before sacrificing themselves. Being invested helps with disease too.