The Quick Questions About World Building Thread

Year length means the time it takes for the planet to run around the star. Day length means the time it takes for a planet to turn around itself. Tidally locked systems mean that both are the same. A red dwarf-orbiting planet can be not tidally locked if it's a) a double planet system, either a binary planet or a planet-moon system with a sufficiently large partner or b) if the planet entered that orbit fairly recently (in this case there will be substantial tidal heating).

A planet tidally locked to its star in a 365-day orbit would not experience seasons, since the sun would always be at the same angle at all points in the planet's orbit. Well, that's not quite true. Unless its orbit is perfectly circular, it would get more or less sunlight at different points due to varying distance, and so you'd have seasons of a sort. The effect of those seasons would be relatively trivial compared to the fact that one side would be permanently scorched and the other side permanently frozen.

A planet rotating such that the sun traverses the sky from any point on the surface in sync with its orbital period would be... unusual. That sort of arrangement probably wouldn't be stable in the long term, although the "long term" in this case is measured in millions of years. I suppose you could call the result "seasons", although the variation would be much more extreme. At any given point, almost half of the planet would be boiling and most of the other half freezing; the area in between would be a storm system of such ferocity as to make Earth's hurricane season look like a spring breeze.

Agriculture would be weird. Any given spot on the surface would have daylight for six straight months, followed by six straight months of night. Weather and temperature issues aside, any plant life would have to evolve to go dormant for the dark period, survive the below-freezing temperatures, germinate again once the sun started shining and everything melted, survive the hostility of the summer, and repeat the cycle.

Another problem is that a planet rotating that slowly wouldn't have much of a magnetic field, and so the solar wind would strip off its atmosphere over time. Any life on the surface would be exposed to hard radiation to a much greater degree than on Earth.

We could indeed discuss this more if you want to make a separate topic for it.

edited 25th Feb '18 6:54:39 PM by Fighteer

does the location of the magnetic poles actually matter?

i know the magnetic northpole is somewhere in canada atm, and ive heard its currently moving at a speed suggesting it could be in sibera in a couple of decades. ive also heard its entirely possible for the north and south pole to flip (albiet over the course of 100s or thousands of years)

but what ive not heard is the actual impact of the shifting magnetic pole. does it have any, beyond affecting compasses?

The position of the magnetic poles controls where the aurorae happen. It has little significance otherwise (other than for researchers who use archeomagnetic/paleomagnetic data; that's how the concept of seafloor spreading was discovered). Whether the strength of the magnetic field has much importance is debatable.

There's been a lot of pop-sci maundering about "shifting magnetic poles" and the havoc that would supposedly cause. There's no corresponding evidence in the geological record to support it.

The Earth's magnetic field deflects charged particles from the solar wind that would otherwise enter our upper atmosphere. Upon reaching it, these particles gradually erode that atmosphere by knocking bits of it off into space. (This is grossly simplified, but it'll do for purposes of the discussion.) It is currently believed that Mars lost most of its atmosphere because it lost its magnetic field, ages ago.

The magnetic field also protects us from the radiation flux of the solar wind, which would drastically increase the rate of genetic damage and mutation among Earth's organisms. Our atmosphere, guarded by the magnetic field, protects us from high-energy EM radiation coming in from space, such as X-rays and gamma rays, which would otherwise also cause serious damage to living organisms. Life, in turn, releases ozone which shields against UV radiation. It's a self-sustaining system driven in large part by the Earth's spin. Take that away...

edited 27th Feb '18 5:43:18 PM by Fighteer

So, I'm here again and I've got some more questions on figuring out some things relating to sci-fi planetary geography. You know how on City Planets, the 'streets' are quite often walkways built between very tall buildings and the typical visitor to such a planet will never actually walk on solid ground? Furthermore, if ground level is actually seen or visited, it's often perpetually dark even in the middle of the day, as the buildings simply cast that much shade (or, alternatively, the city is 'levelled' and as such the planet's actual surface is underground)? Would it be possible for plants or fungi to grow in these areas, and what would they look like? I'm not expecting full-on jungles between the skyscrapers, but I imagine if combined with waste from up top doing weird things to them, it might be interesting.

Well, assuming that we are talking about Earth or an Earth-colonized planet, plants would need starlight to grow. I presume that some plants may develop on concrete and building materials and would be fairly small. Fungi may look like a giant mould.

Fungi can grow without ultraviolet light, since they aren't photosynthetic. Most normal plants can't, though.

Not the original question-asker, but it does pique my interest... Can some form of plants and other photosynthetic life subsist on light emitted from large machinery that may very well exist at the bottom-most levels of such city planets - like some sort of reactor, furnace, or any other machine that could plausibly generate somewhat significant amounts of light as part of its normal activity? Or from lava flows that are both relatively "nearby" (that is, far enough to not burn anything with its steam alone, but "close" enough that it provides some degree of illumination) and practically a permanent fixture of the area?

edited 14th Apr '18 4:22:14 PM by MarqFJA

The kind of machinery that would radiate ultraviolet light as waste heat would be... inefficient, let's just say. Hell, our sun peaks in the middle of the visible spectrum.

Plants do not subsist on ultraviolet radiation. Some fungi can subsist on radioactivity and might also work with ultraviolet radiation.

Plants surely can live on artificial lights, yes. I've seen mosses and ferns growing in artificially illuminated caves. How effective it is would depend on the light spectrum among other things.

What could be the ecological consecuences of the extended presence of an island-sized rotting corpse half submerged in a shallow sea?

Umm, yeah, I knew that. Still, something glowing white in visible light from waste heat would be quite a bit hotter than plants like to live near. The question wasn't about deliberate illumination.

Unless the corpse were made of or contained something extremely toxic, there wouldn't be much of an ecological consequence at all. Nature's very good at decomposing animals of all sorts: small and large. Now, you probably wouldn't want to drink from the water without boiling it, but that's about the worst of it.

edited 17th Apr '18 8:05:38 PM by Fighteer

I didn't say that the light source would be glowing white and/or as bright as the Sun is in the sky. Think of something like this◊ placed so deep in this City Planet that sunlight is practically nonexistent, meaning it's the only source of light for the immediate locality.

edited 21st Apr '18 4:32:08 PM by MarqFJA

On a whim, I'm thinking of writing a handful of short stories involving a small mercenary band of four in an age where humanity has started colonizing the solar system (the wild west but RECYCLED IN SPACE). I have a vague idea of kind of characters they could be:

• leader person: very utilitarian, objective completion above all else, hardly expressive
• gun nut: lives in the moment, loud and proud, instinctive/emotional
• sneaky thing: crippling shyness, always seeks approval, pessimist/fatalist
• fourth ranger: no ideas I can think of

Should I continue with this or just leave it for someone else to pick up?

Ooh, is this a Firefly kind of deal?

I've never seen Firefly before, but I looked it up and they seem similar, so probably. I'll probably keep my setting within the solar system, though.

A kind of world-building question about the demographics of a Teenage Wasteland: Is there a way to relate the population doubling time of a country with its children/adult ratio?

Is there any countries where the head of legislature and the head of the cabinet are two different people?

The United States, for example. The legislature has its own leadership which has no overlap with the government.

Rice, wheat, maize, potato, barley, sorghum, cassava and soy. What are their pros and cons as staple food, and what kind of environment and society are they most suited for, respectively?

Got the answer at the humanities library. Cross-posting this one from the Random Questions Thread: Are there any colonial/modern landmarks in Latin America that incorporate a large degree of native influence in its architecture?

Is there anything that could cause a mass blackout across most of the world? If so, what would the immediate effects be on people?

A solar storm could do this.

How?