Geography
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[edit] World Building
It all starts with a world, a planet, a moon. Is it the same as on Earth? Is it different? If so, what aspects are different, for that will predetermine most of what you create afterwards if you want to do it with any consistency. Most of what you determine at this stage might never surface in the game, but it will be good to have it as an underlying principle.
If you decide to go for an historic time period you might think you can skip this phase, but think again. Merging this with the section on Science you should contemplate what is the truth and what people think is the truth. What have scientists perceived of the world? What do they understand, what do they not? This is the point to guard yourself against anachronisms by writing out what the worldview is of your setting. It will provide many powerful plothooks, so you can be assured it is not wasted energy.
Some details will be of interest only during a setting that is sci fi, but even in a fantasy environment you will want to know some of these questions.
[edit] Scientific Details of your World
- Planet Scientific Name - The name of the planet's star and the order it is in the system.
- Indigenous Name - This is the planet's common name according to the residents or local society.
- Orbital Radius - Firstly, you must decide if this planet can naturally support life. It is possible to have civilizations outside a star system's life zone, but they will have to be protected with biodomes or underground settlements. If you want your planet to be within a star's life zone, choose an orbital radius that falls within the star's "terrestrial equivalent" (a value you should have decided for the system's star during the Star Development process).
- Radius - Arbitrary, but use this scale to get an idea on how big a radius is relative to other planets. World Size:
- Micro (radius < 100 km)
- Small (radius >100 km, but < 5,000 km)
- Standard (radius > 5,000 km, but < 10,000 km)
- Macro (radius > 10,000 km, but < 50,000 km)
- Giant (radius > 50,000 km)
- Density - It is assumed your planet has an iron core. The density is relative only to how big you want the iron core to be and that will directly affect the planet's gravity. If you choose a core other than iron, it must be a realistic substance and you will need to track down the value of that element's density to determine your planet's density. You shouldn't have to be a chemist, but make it realistic given your limitation of resources. As a guide, remember that to get Earth's level of gravity, the density must be 5.52. Always measure density in grams per cubic centimeter.
[edit] Acceleration Due to Gravity
This is an important value when describing your planet because a society's architecture and lifestyle is greatly dependent on what the planet's gravity is. The Earth's gravity (9.8 meters per second per second) should be used as a guide. If your gravity is higher or lower than you like, you can adjust your planet's density and/or its radius to correct it. For ease of formula calculation you can simply compare your planet to Earth, to figure out its gravity.
Since we are simply comparing to Earth to make this calculation easier, you must first figure out what your planet's radius when compared to Earth is. Earth's radius is 6,378 kilometers. Divide your planet's radius in kilometers by Earth's. For example, if your planet's radius is 10,500, then divide 10,500 into 6,378, resulting in 1.64 (or in other words, your planet is 1.64 times the size of Earth). This is the value you will need to figure out your planet's gravity.
Divide the density of your planet by Earth's density (5.5 grams per cubic centimeter). Make sure that your density is converted to grams per cubic centimeter before figuring out this value. Take that result and multiply it by your planet's radius relative to Earth (the value you figured out in the previous paragraph). That value will be your planet's acceleration due to gravity in meters per second per second.
For example, if your planet's density is 3.5 and its radius compared to earth is 1.64, you would do the following: divide 3.5 into 5.5 resulting in .636. Multiply .636 by 1.64 resulting in a gravity value of 1.04 meters per second per second. Compared to Earth, that is almost 9 times less, so you can see how much an affect density has on gravity.
[edit] Mass
This is an arbitrary figure, but refer to the mass of planets in the Solar System for reference:
- Sun: 1.98892E+30 kg
- Mercury: 2.302E+23 kg
- Venus: 4.869E+24 kg
- Earth: 5.9742E+24 kg
- Mars: 6.4191E+23 kg
- Jupiter: 1.8987E+27 kg
- Saturn: 5.6851E+26 kg
- Uranus: 8.6849E+25 kg
- Neptune: 1.0244E+26 kg
- Pluto: 1.3E+22 kg
Keep your planet's mass some what relative to its radius.
[edit] Year Length
To figure out how long your planet's year is, you will need to do some math based on values you already have. For ease of math, you will be comparing your planet to Earth on this equation as well. Firstly, you must figure out how many AU's your planet's orbital radius is. Divide your planet's orbital radius by 149,598,000 kilometers (make sure your orbital radius is in kilometers). That is your planet's AU value. For example if your planet is 789,588,235 kilometers from the star, its AU is 5.27 (or 5 times farther from the star than Earth is).
Multiply the AU value three times (or cube the value). For example, if your planet's AU is 5.27, cube that to result in 146.36. Take the square root of that value, resulting in 12.09. This is 12.09 years SST.
If your planet is closer to the star than Earth, you will need to break down the resulting years into months and/or days. For example, if the AU of your planet is .021 you would do the following. Cube .021 resulting in .0000092 and then take that value's square root, resulting in .003 years SST. To convert that to months and days, multiply it by 365 to find how many days that is, 1.095 days. To convert even further, multiply .095 by 24 for hours, resulting in 2.26 hours and again multiply .26 by 60 to find the minutes, 15. This planet's year is 1 day 2 hours and 15 minutes.
- Length of Day - This is an arbitrary figure. It is unreasonable to have a day less then 8 hours or much more than the planet's year.
- Length of the Week, Month etc. - Again an arbitrary figure, determined by culture. Remember there must be a logic to it however. Why do we have a week of 7 days? Because this is determined in the bible. Why do we have 12 months? Again, there are historical reasons.
- Length of a Season - If there is even a season. This is very dependant on the climate, see below.
[edit] Axial Tilt
You will need to decide on this to determine your planet's climate patterns (if there is an atmosphere). A planet with a titled axis has seasons, because there are parts of the planet that are farther then the sun at varying times. The more the tilt, the more extreme and long the seasons are.
A planet with a vertical 90 degree axis receives direct light at the equator and all parts of the planet receive an equal amount of light, therefore there are no seasons. Although there are no seasons, the planet will have colder temperatures at the pole than at the equator. Additionally, if the orbit is elliptical (the farther into the system the planet is the more elliptical the orbit is), then it can have small, less extreme seasons. Days and nights would be equally lengthened.
A planet with a horizontal 0 degree axis would have half the planet constantly in sunlight and half the planet constantly in darkness. There would be no seasons and the sunny side would be extremely more hot then the dark side. Days and nights would be equally lengthened.
It is unrealistic for a planet to have the same temperature and/or climate globally, even on worlds with extreme distances, unless the planet is very small or asteroidal.
[edit] Moons
List all of your planet's moons and provide radius and orbital radiuses for them. You can world build them using this overall process when you are done with the planet. You need the radius and orbital radius values though, to create the planet's overall picture. Moons and rings are arbitrary and you can create as many as you want but with realistic sizes and distances. The moon's radius is arbitrary, but should be at least half the size of the planet (there are exceptions, e.g. Pluto and Charron).
You will also need to know the moon's density. Again, this is arbitrary, but assuming it has an iron core (most do), it's density directly affects the moon's gravity. Refer to the notes about figuring out the planet's density.
No matter what the radius or density is, the moon's orbital radius must fall outside the "Roche" limit on its orbital radius, otherwise the orbit is unstable and the moon would go crashing into the planet. To figure out the boundary outside which you can place the moon(s), do the following: take 2.423 and multiply it by the radius of the planet and then take that value and multiply it by the density of the planet. Divide that into the density of the moon. That is how many kilometers away you have to place the moon, at minimum, to avoid it becoming a massive meteorite. You can place the moon as far out as you want, within reason. At one point, the planet will lose it's gravitational affect of the moon.
Finally, you will want to calculate how long it takes for your moon to get around your planet. This could have a significant impact on your planet's society, so should be figured for every moon you have. It is easiest to figure this out by comparing your planet to the Earth.
First, figure out how far out the moon is in Earth's radii. Take the distance in kilometers out the moon (orbital radius) and divide it by the Earth's radius, 6,378 kilometers. For example if your moon's orbital radius is 12,600 kilometers, divide 12,600 into 6,378 resulting in 1.97 Earth's radii.
Next, figure out the mass of your planet relative to the mass of Earth by dividing your planet's mass by Earth's mass, 5.9742E+24. For example, if your planet's mass is 2.8E+24 then divide 2.8 by 5.9742 resulting in a relative mass of .47.
Take the Earth's radii equivilent (in our example, 1.97) and cube it. Our example of 1.97 cubed, is 7.64. Take this result and divide it by your relative mass. In our example we'll divide 7.64 by the relative mass of .47 resulting in 16.25. Square root that value, our example results in 4.0311. Now multiply that result by 1.4 and that is the time in hours it takes for the moon to go around the planet once, 5.6 hours in our example.
The formula for the prior calculation is Time is equal to 1.4 times the square root of radius cubed over mass.
[edit] Land Mass and Water
You can divide your planet into continents, where a continent is a large mass of land, or a piece of the crust of the planet, with water being between the continents (the oceans). A continent can be one land mass, an archipel or a collection of islands. Of vital importance will be the balance between land and water. For instance about 70% of the Earth surface is covered with water, and most of that is the ocean. Only a small portion of the Earth's water is freshwater.
A continent can be further divided into subcontinents or regions. Next try to imagine where you will place:
- volcanoes
- geysers and other hydrothermal vents
- hot springs
- mountain ranges including passes
- canyons
- cliffs
- glaciers
- rivers
- lakes
- reefs
- Lagune
Do not forget to make note of important seacurrents and travel routes. They may form the basis later of placing your cities and harbours.
[edit] Climate
By defining the scientific details above you have already accomplished much. Before you start drawing maps make a list of the climatezones and where they will be approximately. Research the effects of each climate zone carefully for they will give you an impact on culture and history.
The Köppen climate classification is one of the most widely used climate classification systems. It is based on the concept that native vegetation is the best expression of climate; thus, climate zone boundaries have been selected with vegetation distribution in mind. It combines average annual and monthly temperatures and precipitation, and the seasonality of precipitation.
- Group A: Tropical/megathermal climates - Tropical climates are characterized by constant high temperature (at sea level and low elevations) — all twelve months of the year have average temperatures of 18 °C (64.4 °F) or higher.
- Tropical rainforest climate - All twelve months have average precipitation of at least 60 mm (2.36 inches). No natural seasons, though there might be cycles to the availability of the water.
- Tropical monsoon climate - This type of climate, results from the monsoon winds which change direction according to the seasons. This climate has a driest month with rainfall less than 60 mm, and a wet "rainy" season with far more.
- Tropical wet and dry or savanna climate - These climates have a pronounced dry season, with the driest month having precipitation less than 60 mm
- Group B: Dry (arid and semiarid) climates (variations in temperature possible) - These climates are characterized by the fact that precipitation is less than potential evapotranspiration.
- Desert Climate - Deserts are defined as areas with an average annual precipitation of less than 250 millimetres (10 in) per year. Can be both hot or temperate.
- Steppe Climate - a biome region characterised by grassland plain without trees (apart from those near rivers and lakes). The prairie (especially the shortgrass prairie) can be considered a steppe. It may be semi-desert, or covered with grass or shrubs or both, depending on the season and latitude. The term is also used to denote the climate encountered in regions too dry to support a forest, but not dry enough to be a desert.
- Group C: Temperate/mesothermal climates - These climates have an average temperature above 10 °C (50 °F) in their warmest months, and a coldest month average between −3 °C (27°F) and 18 °C (64 °F).
- Mediterranean climates - These climates are in the polar front region in winter, and thus have moderate temperatures and changeable, rainy weather. Summers are hot and dry, due to the domination of the subtropical high pressure systems, except in the immediate coastal areas, where summers are milder due to the nearby presence of cold ocean currents that may bring fog but prevent rain.
- Humid subtropical climates - These climates usually occur in the interiors of continents, or on their east coasts. The summers are humid due to unstable tropical air masses, or onshore Trade Winds.
- Maritime Temperate climates or Oceanic climates - These climates are dominated all year round by the polar front, leading to changeable, often overcast weather. Summers are cool due to cloud cover, but winters are milder than other climates in similar latitudes.
- Temperate climate with dry winters- Winters are noticeable and dry and summers very rainy. In the tropics the rainy season is provoked by the tropical airmasses and the dry winters by subtropical high pressure. Temperate temperatures are the consequence of altitude which become cooler year-round.
- Maritime Subarctic climates or Subpolar Oceanic climates -poleward of the Maritime Temperate climates, and are confined either to narrow coastal strips on the western poleward margins of the continents, or, especially in the Northern Hemisphere, to islands off such coasts.
- Group D: Continental/microthermal climate - These climates have an average temperature above 10 °C (50 °F) in their warmest months, and a coldest month average below −3 °C (or 0 °C in some versions, as noted previously). These usually occur in the interiors of continents, or on their east coasts,
- Hot Summer Continental climates
- Warm Summer Continental or Hemiboreal climates -cold winters and long, warm (but not hot) summers, coniferous trees predominate.
- Continental Subarctic or Boreal (taiga) climates - long, usually very cold winters, and short, cool to mild summers. It is found on large landmasses, away from the moderating effects of an ocean
- Group E: Polar climates -- These climates are characterized by average temperatures below 10 °C (50 °F) in all twelve months of the year
- Tundra climate - Warmest month has an average temperature between 0 °C (32 °F) and 10 °C (50 °F). A biome where the tree growth is hindered by low temperatures and short growing seasons.
- Ice Cap climate - All twelve months have average temperatures below 0 °C (32°F).
[edit] Start Drawing Your Map
You now have the beginnings of a world. You can draw the shapes of the landmasses that form your continents, assign mountain ranges, rivers, lakes etc. Check for Natural Resources. Then decide where likely roads and harbours are. On the intersection of roads and other travelroutes you will find a few likely villages and towns, but there might be other probable locations as well. Hold off naming them till you have defined Languages and Culture.
Even if you only start in one single location with your game, it is good to realize what other areas are around because of the concept of Exported Content. In other words, other areas may influence your location and bring plothooks.
