Why Furaha is like Earth

Furaha is very much like Earth. The planet dies in fact differ from Earth in all aspects, but the departures are limited, so gravity, the temperature range and atmospheric composition are all close to those of Earth. 

I did not choose this similarity because I wanted the planet to be suitable for humans. The choice to add humans was made much later, and humans are simply there to add human interest and humour; few things are funnier that human behaviour, I think, even if you have to ignore stupidity and greed. The earlier choice to make the planet Earth-like did have a large effect on the human presence, as it meant that humans could mingle with the animals, fall into pools and could be stung, bitten and spat at by local spidrids, wadudu and kermitoids. In short, they could live on the planet, rather than be neutral observers isolated by space suits. 

 A big part of the attraction of speculative biology is that the animals, plants and other thingies are unearthly. If a high degree of unearthliness or alienness is the aim, shouldn't the environment itself be unearthly? Wouldn't an extremely low or high gravity, or temperatures hot enough to melt lead or cold enough to allow methane lakes evoke such alienness? I think the answer to that is 'yes'. But I chose otherwise. 

Mind you, extreme environments pose problems. One would be that there should a biochemistry that works in environments in which Earth creatures would freeze solid or burn to a crisp in seconds. But the purpose of The Book was to show life forms through paintings, and you do not see biochemistry on a painting. Well, indirectly you do, of course; if life forms need large areas for photosynthesis, that fact tells you something about photosynthetic efficiency; likewise, the presence of insulator coverings tells you something about metabolic temperature. But in such cases you only have to accepts that some type of biochemistry is behind what you see; you do not need details. 

Gravity wasn't the problem either, because gravity translates to mechanical stress, and designing appropriate mechanical adaptations is quite doable and can be represented well in paintings. 

Reflections off Titan. Click to enlarge. From here

The real problem is painting the mundane aspects of a creature's environment. Take a methane lake as on Titan. What colour is it? We know it is reflective, but is it transparent too? Do the degrees of reflection and of transparency depend on the angle of vision? I love painting water surfaces, so these things matter to me. On Earth, we are so used to all aspects of water, variable as they are, that I could show you a brownish flat surface with some reflexions on it and you would equate that with muddy water without even thinking about it. Staying with water, we are used to interpret wave amplitude ands wavelength, and immediately know whether a scene shows a stormy sea or ripples in a calm pond. Well, Titan's sease appear to be extraordinarily smooth (Wye et al 2009). There are waves on Titan, about 20 cm high for a wavelength of 4 meters (Lorenz and Hayes 2012). But even with that knowledge I would have to know much more about viscosity, foam, etc. before I could paint them. In fact, it would be nearly impossible to turn such data into any approximation of what the surface looks like; to do that, you need to see it. 

Use of atmospheric depth by Caspar David Friedrich, who really knew what he was doing

 

Rather less competent use of atmosperic depth in an old Furaha painting

Perhaps some planetary scientists have good ideas of what methane lakes really look like, but I do not. I guess painters have to see them before they can see them, and without close-up videos we have no idea. I could go on like this about rocks, soil and sand: does the wind produce ripples in the sand on the beach? The atmosphere is interesting too: are there clouds? What is their shape and colour? Any landscape teaching course class will introduce 'atmospheric (or aerial) depth'. That means that, if you wish to paint hills or mountains as if they are far away, you should make the colours pale, bluish, with little contrast and detail (at sunrise or sunset colours can become reddish rather then bluish). To which extent does aerial perspective apply to Titan? The physical mechanism behind it is Rayleigh scattering, and that probably works in the same way regardless of the composition of the atmosphere, but the effect may still be affected by the composition of the atmosphere. Some exoplanets may have blue skies, like Earth. This means it is reasonable to turn the colours of an alien atmosphere bluish near the horizon. But the sky right above you need not be blue itself, as we know from Mars, so the colour of the sky itself might be different. And that does not take the colour of the local sun into consideration, which might, for instance, cast such a red glow over the scenery that we would find it difficult to tell noon from sunset. 

The simple reason Furaha is so like Earth is that that choice allowed me to paint backgrounds and many details of Furahan landscapes without endless study and much uncertainty on my end. I feel that the uncertainty would also affect the viewing of the paintings. When I paint something that looks like a smooth reflective surface with some undulations, you might think it is viscous oil or even mercury, rather than what should show up as a nice refreshing Titan lake. It is much more helpful to fall back on people's expectations: when I paint a nice transparent aquamarine surface with the sun glinting off it, and if I manage to do that really well (which is not a given!) I would like people to wish they could jump into that nice tropical water. 

They shouldn't do that, of course, because of the sawjaws, but you get the drift. 

 

References

Lorenz RD, Hayes AG. The growth of wind-waves in Titan's hydrocarbon seas. Icarus 2012,  219: 468–475

Wye, L. C., H. A. Zebker, and R. D. Lorenz (2009), Smoothness of Titan’s Ontario Lacus: Constraints from Cassini RADAR specular reflection data, Geophys. Res. Lett., 36, L16201, doi:10.1029/2009GL039588.