On Creating Imaginary Worlds: Science Fiction

[Stephen4444]

You have plants but you also need to think about what type of light you have.

On earth, plants are green because of the light wave lenghts from our sun. Different suns/light and the plants will be a different colour, not green but brown and even black. This has been discussed before and Chrispy had great links, let me see if I can still find the thread.

WOW! never thought of different color plants... Black tomato plant...."Hmmm interesting."

 

[Stephen4444]

They also say that carrots and cucumbers don't do well underground.

I'm shocked that a root plant, (carrot,potato,etc,) does not do well underground. A life with low simple carbs, would mean the people who get sustenance from underground crops would be lean.

Do you think that would be the case?

 

[Ursa major]

Aren't they drilling through 3.4 kilometres of Antarctic ice to see whether life exists in one of the "underground" lakes, Lake Ellsworth? Unlike life at the ocean bottom, which can feed on detritus falling from above, the environment in the lake will have to be self-sustaining, as the light will likely not penetrate that far. (Or does it?)

 

[Abernovo]

Carrots get much of their energy from their leaves, though, as do potatoes. They need a good light source.

As to leanness from carbs, a former colleague of mine was always teased by his wife because of his 'rice belly'. They can give a spare tyre. He shook off the teasing and got round her by saying that her cooking was too good to refuse.

 

[chrispenycate]

Actually, I think your standard green is a way of getting rid of energy. The green light, which is the peak in our sun's spectrum, is reflected away, and the plants get their energy from the red and short wavelength infrared (you can actually persuade plants to grow with no visible light at all, but they don't enjoy it) and the blue and near ultraviolet, while wasting the richest region in the short yellows and greens. That means that plants could be far more efficient.

Plants evolved for low-light conditions, like african violets developed for the eternal shade under the jungle canopy, generally have darker green leaves, so as to use available resources as efficiently as possible.

And it's not as if chlorophyll was the only available photosynthetic chemical; even here on Earth cyanobacteria have one, if not two alternatives.

If you want a totally dark forest you could use microwave energy. I see the accretion disc of a black hole spitting out lethal particles and RF beams, diffracted along subterranean volcanic lava tubes; the closer to the entry you are, true more energy available, but the greater risk of mutation or cell destruction by ionising radiation, but in the deeper, cool darkness photosynthesis is slow, nothing has the energy to be in a hurry.

Umm – were you intending to have humans living here? They'd use up the available oxygen very fast, unless the population density was extremely low.

 

[JunkMonkey]

WOW! never thought of different color plants... Black tomato plant...."Hmmm interesting."

One of the things that endeared me to the late lamented Farscape was the fact that they tried to make their location shoots look alien planets by altering the colour of foliage so it wasn't just chlorophyll green.

(If you do a Google Image search for coloured leaves you'll find there are an awful lot of plants here on Earth that aren't green leaved, Copper Beech, Black-leaved Plum, Sambucus Nigra etc.)

 

[Stephen4444]

If you want a totally dark forest you could use microwave energy. I see the accretion disc of a black hole spitting out lethal particles and RF beams, diffracted along subterranean volcanic lava tubes; the closer to the entry you are, true more energy available, but the greater risk of mutation or cell destruction by ionising radiation, but in the deeper, cool darkness photosynthesis is slow, nothing has the energy to be in a hurry.

I think the "cell destruction" thing would be a no go for that idea. You couldn't get around that unless the skin melatonin or skin pigment protected the life.

 

[chrispenycate]

I think the "cell destruction" thing would be a no go for that idea. You couldn't get around that unless the skin melatonin or skin pigment protected the life.

Not near the entry, no. There life would be brief and violent, sprout, seed, die, and compost, all in the interval between those beams hitting. But deep in the caves, shielded by rock, even the secondary radiation hardly gets to you, just infra-red from the warmed rocks and the microwave background.

 

[Bowler1]

Not near the entry, no. There life would be brief and violent, sprout, seed, die, and compost, all in the interval between those beams hitting. But deep in the caves, shielded by rock, even the secondary radiation hardly gets to you, just infra-red from the warmed rocks and the microwave background.

Pop - tinkle. Ouch, me light bulb...

 

[nubins]

I did wonder if a planet is orbiting a young blue star, or an old red one, would plants and animals alter accordingly.

I didn't go for any science angle, but one of the planets in the story im writing orbits a bright blue star and subsequently it's plant life is primarily blue, rather than green. Scientifically, probably no ground for it, but I liked the idea of a world where the primary colour of nature was blue, not green

 

[chrispenycate]

It would take an awfully long time for a terrestrial plant to try something other than chlorophyll. But if the ecology had developed there, there's no reason that it wouldn't hve settled on phycocyanin as their photosynthetic chemical: it might have predated chlorophyll in oxygenating the reducing atmosphere of Earth, and there are organisms around now still using it after tens of millions of years, so it can't be that bad. That would give you a decent blue. And we all know about blooms of bright red algae; I don't know what chemical they use, but it probably isn't chlorophyll.

For the dim, red star chlorophyll would do fine, but due to lack of short wavelengths in the incoming light it would look brown. and quite possibly darken to grab all available energy.

 

[nubins]

Interesting about the phycocyanin, never heard of it. Thanks!

 

[Bowler1]

Is it possible to have plants any colour a writer wants. Or phrased another way, are there any light wavelenghts that will not produce food for plants.

I'm going to be focusing on light over the next few days, the odd paths of enquiry SFF has sent me down.

 

[chrispenycate]

Not in the visual spectrum, no. Any of the (at least three) chemical solutions found on Earth (two in bacteria, and it's strongly suggested that plant chloroplasts were once free-living organisms, so they've all had quite a bit of time to get established, probably billions of years) work on just about all visible frequencies, with different efficiencies. There might be a trough in their response (as in chlorophyll at the most common frequencies in sunlight) or even a notch – but unless you've got a star that lases at a particular frequency, how are you going to get that narrow an energy band (yes, I know, a greenhouse in the oort cloud, powered by a laser in close solar orbit. You can darn well tune the laser to something the plants like.)

In the long infra red you'd have to have a very cold environment to be able to get the energy, and quite possibly even then there wouldn't be enough to break the carbon/oxygen bond, while in the short ultraviolet and gamma region – well, you wouldn't have to worry about energy, but I wouldn't want to be the organism living there. Ozone depletion? That's more like growing up in a nuclear reactor. Fortunately there are a number of fluorescent chemicals you could put in the leaves to shift down the frequency; when you turned the lights out, the plants would glow for a while, but that's no problem.

So photosynthesis can be managed with any wavelength of the electro-magnetic spectrum, assuming the environment is cool enough to be able to absorb the waste energy.

(Did you manage to get a new lightbulb? These energy saving devices are just not rated for genius level ideas.)

 

[Bowler1]

Last question as you're being so helpful. I'm going to assume that most plants would be in the middle of the visual spectrum. A difficult question as we have never seen alien plants, but it would seem logical to me.

I have a new light bulb, another of the not so longer lasting energy saving ones. The next question that has me worried is age old, just how many people do I need to help me change the bulb?

 

[chrispenycate]

Logically, green would be the worst colour for plants on Earth, as they are wasting the best of the energy. But there were choices, as I pointed out, and evolution 'chose' the lowest efficiency as front runner. Which presumably means optimum energy transfer was not the defining factor. Perhaps ease of synthesis, or just you can't grow any quicker than chlorophyll will allow (look at how much carbon dioxide a sunflower can convert into cellulose in one season).

So I think you could get just about any coloured leaf under any lighting, or even have dual systems for different conditions if you decide to evolve under a binary star.

How many novelists does it take to change an idea? Only one, the rest are critics, agents, west coast under promotions men, line editors, rejection slip writers, proofreaders…

Who don't actually serve any direct purpose in the process, but are ever so encouraging.

 

[Bowler1]

http://www.bbc.co.uk/news/science-environment-19950923

Four suns and one little planet, real life has put my imagination to shame.

 

[JoanDrake]

If this is not the right way to do this I apologise. I will probably remain a noob here for some years.

I want a world which has ample water (enough to cover from 1/4 to 3/4 of the surface to an average depth of 2 miles, which is comparable to Earth) but having nearly all of it (some lakes up to the size of the Caspian sea are permitted but not a lot of them, no oceans) completely underground in vast aquifers, huge caves and giant underground rivers. Is that possible?

I'm thinking it might develop from an all water covered world where the oceans last long enough to form thick beds of limestone. Then the water dissolves holes in the rock and gradually drains underground as it dissolves more limestone.

There are two problems I can see immediately. How would the limestone form if the water was dissolving it? and even assuming it could, wouldn't the caves all collapse eventually?

Then again, worlds evolve, so could a world like this form at some stage of development.

You could, I suppose have less water and a few very deep lakes, but I don't want a desert world. I want adequate water and most of the people living in vast underground caverns and along subterranean rivers.

 

[Abernovo]

Hi Joan.
Why aren't they living on the surface? Would it matter if there were seas and oceans above ground?
This is stream of thought posting, so please forgive me if I ramble (which I often do).

A number of problems I can think of.
You're right - if the water had time down to eat through the limestone, it would probably have time to eat out through the limestone as well.
If you have plate tectonics, it will split the land and release water into a depression, causing a sea, and once that happens, it's difficult to put back in the box.
The water flows into where? How do you complete the water cycle?

So, problems are there to be solved.
Could you have only some of the land with cave systems? That might prevent the ground from simply caving in. Hard stone with something like limestone seams for the channels to eat away. There are others who know their geology much better than I do. Too many chambers close together would make the system unstable as well, I imagine.

You'll need a few seas, and possibly some massive lakes with collapsed ground above (similar to some of those in Central America (I think that's where they are), but bigger). That would allow evaporation for the water cycle. I know that means bigger seas, or more of them.

Hope some of that helps.

 

[chrispenycate]

I'd suggest volcanic tubes rather than limestone; limestone id the shells of billions if tiny molluscs, which are only going to develop in shallow seas, But you're going to have more problems running an evaporation cycle that will distil fresh water; underground caves don't get enough solar energy to vaporise the water and make clouds, and ultimately rain. And without rain, all your water is going to be salt (no problem with developing organisms to handle that) and vegetation can't grow; either it has no water, or no light. And without vegetation, no oxygen, low energy lifeforms, I doubt whether life would even attempt multicellular.

So, back to the lava tubes. If we're tectonically active enough, we can use geothermal energy to evaporate the water. Make your world a moon of a gas giant and stress it gravitationally and magnetically. Get that mantle well stirred up, with volcanos spitting megatons of steam (and other, nastier products) into the atmosphere continuously. Evolve trees with great long taproots which penetrate the crust to the points where the subterranean aquifers are close to the surface, and get them to transpire the water up producing, if there is ever a wind-free day in this chaos, localised thunderstorms over the forests. More, more, I'm still not satisfied; do you know how many tons of rain fall every day? Oh, certainly, on Earth most of them fall into oceans and are wasted, but still. Wash the car, organise a cricket match; I need more rain, or we're going to end up with an awful lot of desert.

I'm thinking about it, right?