Random Worldbuilding Questions (Biology, Geography, Society, etc.)

[Yora]

Best is hydrogen, but that is extremely flameable.
Second best is helium, which is not flamable at all, so that's what is usually used.

Because of the atomic structure, there can be no gas lighter than these two. Unless maybe when you start going into quantum physics, but any devices would probably be quite huge and heavy.

Using helium baloons is probably the best estimate for how much gas you would need to lift a person, as the baloons and strings are as light as a container can get.

[Conners]

If you needed to float them in water, how larger would the balloon/whichever need to be?

[Yora]

To float in water, it could actually be much smaller. If you can lay still on your back and keep your face over the water, a human body will even float on water without any assistance. But if you are really fat, your center of gravity might move from your spine toward your belly, so floating on your back might result in your face being under the surface. And floating face down would have your face under the surface in either way.

If you have something large and lighter than water, you can even stay completely out of the water, like a raft.

And if you can keep water from going inside and replacing the air, even a metal object will float. Like an oil tanker.

If you want a human body to float in water below the surface, you actually need something to make him heavier.

[jseah]

You might like to reference my earlier 'calculations' about dragons and density.

Gas does not give you lift. Volume gives you lift (or more accurately, bouyancy). It doesn't matter what you use to fill the volume, if your total body density is less than the medium, you float.

Air density at sea level is about 1.2kg per cubic meter.
Water density is 1 gram per cubic cm (or 1 ton per cubic meter).


200 pounds is about 90kg, so about 75 cubic meters.
Of course, your balloon will add weight. You need to add the weight of the gas and the balloon to your calculations. Which is why Yora said hydrogen is best for lift because it is the lowest density. (of course, if you didn't need internal pressure and had a hard and light enough shell, vacuum is best)

[Andreaz]

Physically, a body floats if it's less dense than the fluid around it. Less mass per volume, same thing.
You end with an equation looking like this:

ρ1V1 + ρ2V2 + ρ3V3 <= ρ4(V1+V2+V3)

assuming ρ = density, V = volume and 1,2,3 your body, gas and container. To make a function out of it you'll dive into natural logarithms, which I'll presume is beyond what you are willing to do.

So just take some fixed values. All densities should be fixed (body, gas, environment, container), as well as the body and container's volumes. Throw it all on an excel sheet and the moment the first half equals the second half, any volume you add to the equation will generate buoyancy (at equality, the body's buoyancy cancels gravity, remaining wherever you put it)

[Yora]

Why build houses as longhouses?

I guess one reason would be that you don't need to learn any new tricks to make a roof. Just take the method for a small hut and keep going until you have enough space covered.
But skandinavian longhouses are often huge and very sophisticated, and the area is probably one of the best anywhere to get exactly the right size of post and beams for more extravagant constructions. Making the corners for the roof to build a square house with a central yard shouldn't have been any problem for them.

So why still longhouses?

[Ormur]

Why build houses as longhouses?

I guess one reason would be that you don't need to learn any new tricks to make a roof. Just take the method for a small hut and keep going until you have enough space covered.
But skandinavian longhouses are often huge and very sophisticated, and the area is probably one of the best anywhere to get exactly the right size of post and beams for more extravagant constructions. Making the corners for the roof to build a square house with a central yard shouldn't have been any problem for them.

So why still longhouses?

I'm not an expert but from what I know the wooden longhouse housed both animals and people in the same area for heat and the main space had a fireplace that ran the length of it with benches for sleeping and sitting on on either side. So I guess that was also for heat. Some houses had side rooms but they probably weren't fit for habitation in the winters as they were unheated, rooms like kitchens, pantry and smithy.

I know the development in Iceland best. The Norwegian settlers imported the wooden longhouse but as there was much less wood they built it mostly from turf and rock with only the roof being from wood. Eventually it developed into a very different kind of house with lots of corridors and different rooms only one of which was heated and housed the family. Probably to conserve heat and kindling in a deforested sub-arctic country.

[Beleriphon]

Why build houses as longhouses?

I guess one reason would be that you don't need to learn any new tricks to make a roof. Just take the method for a small hut and keep going until you have enough space covered.
But skandinavian longhouses are often huge and very sophisticated, and the area is probably one of the best anywhere to get exactly the right size of post and beams for more extravagant constructions. Making the corners for the roof to build a square house with a central yard shouldn't have been any problem for them.

So why still longhouses?

They're relatively simple to build by a fairly small population. A single family could put one up within a week if they worked quickly. The design is also easy to use, and has existed longer than the written word. There's a reason the basic setup is found in Europe, Asia and North America. Even as late as the 19th Century the basic design remained in use in Germany with German Low Houses.

[Yora]

Even as late as the 19th Century the basic design remained in use in Germany with German Low Houses.

I had to look that term up.
But yeah, those... They are all over the place where I am from.
Hadn't really considered them since they have almost all be converted on the inside with only the exterior left in the original state.

[Conners]

I've heard that as women get older, it gets more dangerous for them to have children (as in, the child will have things wrong with them). What sort of problems can arise, from this?

Also, what is the prime age for having healthy children?

[Jacob.Tyr]

I've heard that as women get older, it gets more dangerous for them to have children (as in, the child will have things wrong with them). What sort of problems can arise, from this?

Also, what is the prime age for having healthy children?

For part 2: Best before 30, problematic after 40.

Part 1: Autism, low birth way, premature birth, downs syndrom. Also, it's not just the mother. Risk of autism et al have also been linked to the age of the father. Iirc it's higher at young and old ages, highest before 20 and after 50.

[Conners]

So, the prime age for women is under 30--and men need to be at least 20 but under 50.

What is it exactly that causes the phenomenon? Is it the maturity or health of the parents? Or is it more complicated than that?

[Jacob.Tyr]

What options are there to treat the dead in a cold land without many trees?
Burning is out of the question since it's difficult to get the wood for a pyre. Burrial would be difficult with rocky ground that is often frozen. Tombs would probably be the best choice?

Also, does anyone know what nomadic people do with their dead?
The backstory is for a people that has moved a lot over the last centuries and is still occasionally relocating. They already switched to portable shrines for the spirits of the founders of their clan from worshiping the spirits of the land they live on, but what about the dead? Simply burrying them and leaving them behind when the clan relocates doesn't seem satisfactory. And carrying the bones of the whole clan with them every time also is not practical.
Any idea for methods to keep the spirits of the ancestors in contact with the living?

Cold land, few trees, nomadic people. Well, sounds like burying is out, cremating is out, I'd say eat them. Keeps their dead with them, and was a common practice in some cultures. No wasted resources and all that. Could throw in some ceremony, say the heart of a dead patriarch is eaten by his successor to give him the strength to lead etc.

Some cultures would also take it as a good omen to see vultures eating their dead, so they could just leave them for scavengers. Pretty viable if they're into some sort of nature worship, letting the body go back to the earth.

[Jacob.Tyr]

So, the prime age for women is under 30--and men need to be at least 20 but under 50.

What is it exactly that causes the phenomenon? Is it the maturity or health of the parents? Or is it more complicated than that?

http://en.wikipedia.org/wiki/Paternal_age_effect
That's for males, there's probably a corresponding article for females.
"A study of semen samples from 66 men published in 2003 demonstrated a correlation of increasing age with more DNA damage, less apoptosis, and lower sperm motility.[12] In 2006-2007 studies of sperm, age was again associated with DNA damage.[13][14]"
Damaged DNA in sperm->Damaged DNA in embryo->genetic abnormalities in offspring.

[Yora]

There are two types of aging.

One is maturing, which is developing the body until all bones, muscles, nerves, and organs have reached their final size and the building plan of the DNA has been completed. Which is roughly about 25 years.

After that, everything else is just wear and errosion, which becomes harder and harder for the body to repair. Because every time new cells are made there is a chance for mistakes in the replication of DNA which builds up an over time there are more and more cells that can't do their job properly. As long as there are still enough cells that can do their job more or less well, the organ still functions. But over time you have bone cells that don't properly bond with the rest of the bone, hair cells that don't produce pigment correctly, and skin cells that do not coordinate correctly with the rest of the skin. The body still tries to have everything to be exactly to match the blueprint in the DNA, but since all the cells have slighly different blueprints, the result becomes worse and worse. This makes the body more vulnerable to all kinds of accidents and diseases and even when everything works well, there's a point where the organs are in such a bad shape they just don't work anymore.
And since the cells for reproduction also have to copy the DNA from other other cells in the body, being old increases the chance that those cells will have some genetic defects.

Pregnancy might be difficult because the eggs are more likely to have such copy-defects in the DNA and also the reproductory organs, like all organs, are no longer working perfectly and there is a greater chance for complications.

In fictional races, you could easily have it that cell replication is less prone to errors and people stay young and fit for a longer time.

Interestingly, there are some simple animals that have an insanely good mechanism to check for errors in cell replication and correct such "typos". Which pretty much makes them immortal because the cells will always grow according to the genetic blueprint for a mature individuum.
There is some research to copy that mechanism and add it to other animals and eventually humans. In one scenario, the body would just freeze and the DNA would take no more damage and always repair the body to be just as it is now. Give it to a person who is not yet fully grown and the first maturing process will still go all the way to it's end, but after that there will be no dacay.
But there is even some indication that the mechanism might even be able to detect damages and repair them to recreate the original DNA. In that case, you would actually grow younger until the body has again reached the shape that is specified by the DNA to be the mature form. But it can't make you younger than 25, which actually is probably what almost anyone would want.

There is some reason to believe that this also does have advantages for the species. After all, these copy-errors are the main source of mutations and as such for new genes. For a species to evolve, you need to have some new genes. If everyone has genes for dark skin, the species can not evolve lighter colored skin. It first needs to have some individuals in which the skin color genes are slighly different. And when conditions change and the body needs more efficiency in absorbing sunlight, some of these genes can become very valuable to survival and as such spread through natural selection.
If you have a species in which there is no aging at all, then there is also almost no mutations and no new genes. And when something happens to the environment, there is no way to evolve. Big animals like humans live in environments that change a lot, so we needed a lot of mutation to get here. In the present, we no longer wait some dozens of generations to evolve, we just build machines and other devices that take care of the problem, like clothing. Because we have warm clothing, having more or less body hair doesn't change your chance to survive in cold climate, so no need to evolve.
Those animals that are naturally immune to aging and mutations are usually tiny and simple because the things they need don't really change. The deep oceans don't get warmer or colder regardless of what happens at the surface, and there is always the same amount of no light at all and they exist in such huge numbers that they don't care for changing predators as well. They can survive without evolving, so they can also survive without aging.

[Andreaz]

The eggs do not have such copy-defects: They are all already formed during the embryonary stage. The eggs deteriorate on their own.

[TheWombatOfDoom]

The eggs do not have such copy-defects: They are all already formed during the embryonary stage. The eggs deteriorate on their own.

I thought it was more that each woman has a certain amount, and once that amount is depleated...

[Ksheep]

I thought it was more that each woman has a certain amount, and once that amount is depleated...

Commonly held belief, but there is evidence that that is not the case.

[TheWombatOfDoom]

Learn something new every day! Health class from gradeschool fail.

[Yora]

School knowledge usually seems to go with "an explaination that is good enough to work with in most everyday situations".
Almost all science students I've ever talked with said something similar to "in the first two semesters, you have to forget everything you learned at school and start back at the very basics".

[Andreaz]

School knowledge usually seems to go with "an explaination that is good enough to work with in most everyday situations".
Almost all science students I've ever talked with said something similar to "in the first two semesters, you have to forget everything you learned at school and start back at the very basics".

Pretty much this in a lot of fields. As a physicist myself I'm finding the Major's barely putting me at a couple decades ago where the physics is.

[Ksheep]

Learn something new every day! Health class from gradeschool fail.

The thing is, most people still believe the old explanation. There has only been minimal research on the veracity of this, and I can only find one or two places that say "wait, this doesn't seem to be right". I remember first seeing the alternate theory in passing in an issue of Discover magazine years ago, and since then… almost nothing. I've found the above article and one or two others that say that new eggs may be produced naturally via stem cells, but nothing conclusive has been put forth yet.

Therefore, we are still taught an out-dated 60-year-old theory that isn't much more than a hand-wave.

[Yanagi]

What options are there to treat the dead in a cold land without many trees?
Burning is out of the question since it's difficult to get the wood for a pyre. Burrial would be difficult with rocky ground that is often frozen. Tombs would probably be the best choice?

Also, does anyone know what nomadic people do with their dead?
The backstory is for a people that has moved a lot over the last centuries and is still occasionally relocating. They already switched to portable shrines for the spirits of the founders of their clan from worshiping the spirits of the land they live on, but what about the dead? Simply burrying them and leaving them behind when the clan relocates doesn't seem satisfactory. And carrying the bones of the whole clan with them every time also is not practical.
Any idea for methods to keep the spirits of the ancestors in contact with the living?

Questions:

Most nomads follow seasonal, annual, or multi-annual circuits relating to the availability versus exhaustion and replenishment of resources. For foragers that mean bushfood and game, for pastoralists water and forage, horticulturalists the exhaustion versus replenishment of soil, and for peripatetics the saturation of a local market to which they have provided goods and services.

What's driving the movement of your group? Are your people migrating as a part of some kind of cyclic pursuit of resources? Do they return to places they've vacated?

I ask because it sounds like you're describing a cycle of settling and then being compelled to move, which is a different pattern than nomadism, and wouldn't develop the same understanding of location as part of ritual.

Another thing is: what's the structure of their ancestor veneration? I mean, most of the nomads I know have religious traditions where it's more important that a person be interred properly, which is a matter of process, not location. Keeping the bones with you is a pretty intense spiritual concept, but you don't see it much in cultures where people move around.

Also, what's their understanding of the dynamic between the body and the spiritual body, and how does that flavor ritual? Are bones ritually important, or just venerated because they're the most likely remainder? You're making it sound like the body is important not just to the individual deceased, but as a connection between deceased and living, and that's going to constrain options, particularly if their ritual calendar requires frequent to continuous as opposed to periodic contacts with the bodies/bones of the honored dead.

---

Given the constraints you're describing, here's a few tentative suggestions:

• They develop a tradition in which some part of the body can act as ritual proxy for the whole. An easy example being the idea that the skull contains that essence of the individual, so the cleaned skull becomes a portable object of veneration. But maybe even carrying skulls is too burdensome, and something smaller (and less pseudo-logical) is taken instead. Something easy to remove from the body, like the bone in the fingertip of the primary hand. Something tiny, because they have so many ancestors to carry--the angel bones in the ear, teeth, the patella. Something that can be crafted or transformed to make a better ritual implement: the cranial bones made into a shallow libation vessel, the femur into a scrimshawed icon or fetish. So the rest of the body is disposed of in some ritually-valid form: burning, burial, sky burial, exposure on platform. Or maybe the creation of the proxy nullifies the ritual sanctity of the corpse, and it can just be dumped.
  
• Ritual cannibalism means the loved one is always with the mourners. It's not as grim or gritty as it sounds...you're not chowing down to a full dinner. There are Amazonian peoples that cremate the dead and then ingest some of the ashes. In Papua New Guinea, the ritual used to involve eating a bit of brain matter. I don't think these fit very well, since you're describing a culture with a shrine-based complex.
  
• Eschewing the body and creating proxies. Fetishes, effigies, funerary tablets, memento mori. Another common venerative act, but kind of a dodge given what you've described.

[Conners]

If you had a Nutrients-Vampire, how would it get the most nutrients from a victim (aside from swallowing them)? I'm thinking the stomach would have the most nutrients, particularly with grazing animals. Are there any (other) high-nutrient parts of the animal or human body?

[Yanagi]

If you had a Nutrients-Vampire, how would it get the most nutrients from a victim (aside from swallowing them)? I'm thinking the stomach would have the most nutrients, particularly with grazing animals. Are there any (other) high-nutrient parts of the animal or human body?

What nutrients, specifically?

Fatty tissue -- Brain or Lungs, or, you know, body fat
Minerals and Vitamins -- Liver
Calcium -- Bones, obviously
Iron -- Blood
Protein -- Muscle tissue
Soluble Salt -- Kidneys

Otherwise we're a pretty homogenous blend of materials.

[Jeff the Green]

How much farmland does a city of n inhabitants need to feed it?

If I were building a fictional modern world, I'd look up productivity for modern farms, but the green and industrial revolutions had too big of an impact to make those figures relevant for a pre-industrial society.

Related, what would the ratio of farmers:burghers be?

[awa]

how much farmland required depends on a lot of things stuff off the top of my head in no particular order
population density,
quality of land, rain fall, pest control
productivity of the crops
any caloric supplements like fishing

[Ksheep]

How much farmland does a city of n inhabitants need to feed it?

If I were building a fictional modern world, I'd look up productivity for modern farms, but the green and industrial revolutions had too big of an impact to make those figures relevant for a pre-industrial society.

Related, what would the ratio of farmers:burghers be?

That depends greatly on diet, climate, and technologies used. You can feed many more people on an acre of rice, corn, potatoes, or wheat than you can with an acre of apple, orange, or olive trees, and those would take much less space than cows or other livestock (except maybe chickens). However, (if I recall correctly) rice is much more labor intensive than some of those others. As for technology, just look at Mesoanerica or SE Asia and their terraced farming, greatly increasing the yield of potatoes/corn. Also, if I recall, there isn't a linear relation to area needed per person, but I can't remember if it exponential or logarithmic (although that probably depends on tech as well: you can only support so much plantmatter per acre before you need to artificially add fertilizer.)

TL;DR; it depends on a LOT of factors.

[Jeff the Green]

how much farmland required depends on a lot of things stuff off the top of my head in no particular order
population density,
quality of land, rain fall, pest control
productivity of the crops
any caloric supplements like fishing

That depends greatly on diet, climate, and technologies used. You can feed many more people on an acre of rice, corn, potatoes, or wheat than you can with an acre of apple, orange, or olive trees, and those would take much less space than cows or other livestock (except maybe chickens). However, (if I recall correctly) rice is much more labor intensive than some of those others. As for technology, just look at Mesoanerica or SE Asia and their terraced farming, greatly increasing the yield of potatoes/corn. Also, if I recall, there isn't a linear relation to area needed per person, but I can't remember if it exponential or logarithmic (although that probably depends on tech as well: you can only support so much plantmatter per acre before you need to artificially add fertilizer.)

TL;DR; it depends on a LOT of factors.

Doy. Should have thought of that.

I suppose a better question would be "Given a climate, crop, and technology level, how can you figure out approximate yield?"

[Geostationary]

If you had a Nutrients-Vampire, how would it get the most nutrients from a victim (aside from swallowing them)? I'm thinking the stomach would have the most nutrients, particularly with grazing animals. Are there any (other) high-nutrient parts of the animal or human body?

First, is there a difference between a Nutrients-Vampire and a carnivore? Otherwise, a good thing to look at would be parasites. Why? They go where the food is, hence why the gastrointestinal tract (particularly the intestine) is a popular place to find them. The stomach itself is actually a pretty bad place for adult organisms due to the environment and unprocessed food (makes feeding harder), but some parasites actually have to pass through the stomach to mature. The blood is another good spot, as it distributes nutrients to the body directly from the digestive system, while the liver and other organs make excellent spots to live, dependent on the organism in question.

If this is a person who has rather specific nutritional requirements as opposed to something that can live in the host body, than you're best off eating select organs with high [desired compound] content. Is there a specific organ/compound you had in mind when doing this? "Nutrients" can refer to most anything in the human body, so specificity is helpful.