The larger the world, the smaller the mountains should be, especially in proportion to world diameter. Water-saturated rocks have only so much strength (dry rocks are something else entirely; see Venus).
For any reasonable world size, I would expect that min and max are going to be pretty earthlike (-30000 to +30000 meters).
Posted By: AlricWhat's a reasonable world size? Traveller generates worlds from 1,000 to 10,000 miles in diameter.
Size for any world is a moot issue - it's DENSITY that counts - because density determines gravity, and gravity is a key factor in livability.
A planet can be twice the size of Earth - but if it has roughly from 0.86 to 1.4 times the gravity of Earth due to the density of it's mass, then technically / theoretically, it can have a gravitational pull tolerable to human life, and comparable to that of the Earth's - and could theoretically have an atmosphere like our own without either the atmosphere being too doped with raw hydrogen gas, or too dominated by CO2 (Carbon Dioxide). I weigh 212 lbs., on a world with 0.86 times the Earth's gravity - I would weigh 182.2 lbs.. On a world with 1.4 times the Earth's gravity, I would weigh 296 lbs..
As far as worlds go - it's density, not size. However - since most rocky terrestrial planets are roughly made of the same stuff, and packed together generally the same - then an "ideal Earth like" terrestrial world would probably be from 0.86 the Earth's diameter, to 1.4 times the Earth's diameter.
I'm not so much worried about if the planet can naturally sustain life, this is Sci-Fi after all. I just wanted to know if I needed to adjust the max and min elevations for realistic maps. Sounds like I don't really need to worry about that too much.
Posted By: AlricI'm not so much worried about if the planet can naturally sustain life, this is Sci-Fi after all. I just wanted to know if I needed to adjust the max and min elevations for realistic maps. Sounds like I don't really need to worry about that too much.
Nah - but if you make a world - say - three times bigger than Earth diameter wise - then unless it's a world that's density is only about 1.4 that of Earth's - your going to have a planet that has 3 times the gravity. You could pull that off if say - the world in question was honeycombed with so many subterranean cave networks that even though it was 3 times "bigger" than Earth - it only had enough "stuff" substance wise to be roughly equivalent to Earth's density / mass - and had an Earth sized molten core, as opposed to one that was three times larger ?
There is a sf story where a planet is huge. I forget how many times larger than the 'standard planet' it was. But here is the kicker. It was hollow, with a small, in mass, black hole in the center. The planet, which didn't appear to be a ring, was basically orbiting the black hole. I remember there being a map of the planet's surface in the book. I also remember, it has been years since I read it, mention that 'advanced technology' kept the black hole from swallowing the world. But the black hole did wobble. Making for interesting seasons and gravity changes.
Comments
For any reasonable world size, I would expect that min and max are going to be pretty earthlike (-30000 to +30000 meters).
A planet can be twice the size of Earth - but if it has roughly from 0.86 to 1.4 times the gravity of Earth due to the density of it's mass, then technically / theoretically, it can have a gravitational pull tolerable to human life, and comparable to that of the Earth's - and could theoretically have an atmosphere like our own without either the atmosphere being too doped with raw hydrogen gas, or too dominated by CO2 (Carbon Dioxide). I weigh 212 lbs., on a world with 0.86 times the Earth's gravity - I would weigh 182.2 lbs.. On a world with 1.4 times the Earth's gravity, I would weigh 296 lbs..
As far as worlds go - it's density, not size. However - since most rocky terrestrial planets are roughly made of the same stuff, and packed together generally the same - then an "ideal Earth like" terrestrial world would probably be from 0.86 the Earth's diameter, to 1.4 times the Earth's diameter.