Posts Tagged ‘energy’

Going underground

Science fiction may often focus on new planets, but we don’t even know much about our own. The Deep Carbon Observatory aims to change one not-so-small piece of our ignorance. The multidisciplinary group of scientists wants to better understand what happens to carbon deep inside the earth, including carbon caught up in living things. That’s right: there is life outside the thin zone that we think of as habitable.

The project is organized into four sections: Deep Carbon Reservoirs and Fluxes, Deep Life, Deep Energy, and Extreme Physics and Chemistry. Even their titles seem science-fictional.

I’m a biologist, so Deep Life is my favorite. The first guiding question for that section: “What’s down there?” How many science fiction tales have “What’s out/down/in/under there” as their guiding question?

Even the chemistry and physics are complicated. We can’t do experiments easily or at all because the temperature and pressure are hard to duplicate: Extreme Physics and Chemistry indeed, at pressures of hundreds of tons per square inch and 2500F.

Reservoirs and Fluxes has to do with movement of carbon into and out of the earth. Volcanoes, anyone? And plate tectonics, with chunks of crust sliding into the mantle and taking carbon with them. The deep carbon cycle operates on a huge scale, and we don’t know much about it.

Deep Energy is just as poorly understood. Our major energy sources are carbon compounds: oil and coal are fossil biological carbon. But it’s also possible that life isn’t needed to produce hydrocarbons, that these compounds are also formed in the deep crust or mantle.

Want to learn more? Living on Earth just interviewed DCO Executive Director Robert Hazen.

Dr. Hazen doesn’t talk about science fiction at all. But what do you think? Doesn’t this just spawn all sorts of science fictional ideas?

The Future of Green Energy?

Switch on treeThe luxuries of our modern life are heavily dependent on having continuing access to a source of electricity. But power generation often requires consumption of limited resources like oil or coal, and generate high levels of pollution. Even “clean” energy sources like solar or hydroelectric power can significantly harm the environment.

Imagine a clean and green source of power that not only doesn’t harm the environment, but helps clean the air. Trees, for example, help reduce atmospheric carbon dioxide levels, and provide shade that makes use of electricity-hogging air conditioners less necessary. And trees and other plants, it turns out, can generate an electrical current that can be tapped.

The xylem tissue in vascular plants like trees transports water, ions and mineral nutrients as sap from the roots to the rest of the plant. There is a difference in voltage between xylem and the soil, which allows the potential for plants to generate an electrical current that could be tapped into.

Recently a team of Japanese scientists demonstrated that a battery could be created from 10 ordinary potted house plants connected in a circuit. They found their “green battery” could generate 3 volts and 3 microAmps of current. So far it has apparently only been used to power a blinking light.

Another research group lead by Brian Otis and Babak Parviz at the University of Washington has shown they can run a circuit entirely powered by Bigleaf maple trees. Their key to success seems to be the use of “nanocircuits”. These custom integrated circuits have lower power requirements than standard chips. Such low power circuits would have broad applications in wireless devices like smartphones and even biosensor contact lenses.

Current applications for tree-powered devices seem limited to monitoring of the environment and wildlife in remote areas where battery-powered devices would be impractical. Trees and other plants simply don’t generate enough power to run our appliances or smartphones.

But I think it’s possible that devices in the future using low-power chips might be able to run on plant power. And perhaps we could engineer trees to produce more tappable electricity. Perhaps we’ll end up living in real-life tree houses.

What do you think the future could bring?

More reading:

Ferris Jabr “The Shocking Truth: Trees are Electric” ScienceLine (2010)

Love CJ, Zhang S, Mershin A (2008) “Source of Sustained Voltage Difference between the Xylem of a Potted Ficus benjamina Tree and Its Soil.” PLoS ONE 3(8): e2963. doi:10.1371/journal.pone.0002963 (free article)

Yamaguchi, T. and Hashimoto, S. (2012), “A green battery by pot-plant power.” IEEJ Trans Elec Electron Eng, 7: 441–442. doi: 10.1002/tee.21754 (subscription required)

Himes C. et al (2010) “Ultralow voltage nanoelectronics powered directly, and solely, from a tree” IEEE Transactions on Nanotechnology 9(1): 2-5 doi:10.1109/TNANO.2009.2032293 (free pdf)

Image: Violation by hapal, on Flickr, licensed under Creative Commons.

Old McDonald Had a Planet

Old McDonald had a planet*,
And on this planet he had a…

Maybe it all starts with a planet: big, small, hot, cold, wet, dry. But a planet needs things living on it, right?

Or maybe it starts with the creatures: plants, animals, something else entirely, and they need a place to live.

Possibly you’re reading some interesting science fiction aliens, and want to know if they make sense.

It’s all about the biology. All three scenarios can be looked at for biological plausibility. We don’t yet# have any non-terrestrial biologies to examine, so I’m extrapolating a bit, but there’s a lot of physical and chemical properties involved that will have to be the same for any physical biological life forms##.

If I’m thinking about whether a fictional ecology can work, I look at three questions.

1. Where does the stuff come from? Can the living creatures get enough basic building blocks to maintain their bodies? Terrestrial life absolutely requires six elements: carbon, hydrogen, nitrogen, oxygen, phosphorus and sulfur (abbreviated CHNOPS), and while it’s possible that one or more of those might be swapped for something else, those six are likely to be important to any other biologies we encounter. They are simply the most effective and appropriate elements for their roles in metabolism and genetics.

If one or more is scarce, the organisms might not be able to get very large or grow very fast, and competition for resources could be extreme. (Biology driving plot, perhaps, something I love to see in my science fiction.)

2. Where does the energy come from? The sun? Chemistry? Heat? How is it processed? Our planet runs mostly on photosynthesis, converting solar energy into usable biochemical forms. Gas giants like Jupiter radiate more heat than they receive from the Sun. This could fuel an ecology that doesn’t rely on solar energy.

Does the amount of energy available match the activity and speed of the species? Photosynthetic organisms are either small, immobile, or both, because that’s what the energy available to them supports. Terrestrial animals almost all rely on plants to concentrate energy into a more efficient form so that they can move quickly. Large fast terrestrial animals all need to breathe oxygen. Anaerobic organisms are very small and slow, and that’s likely to be universally true.

3. Do the evolutionary antecedents make sense? Could this system have developed gradually? (And if not, how was it created? Here’s another good place for story to develop.) Are there obvious relatives, and not organisms that seem entirely unlike everything else on the planet? The movie Avatar was bad at this: every animal had six legs. except the Na’vi. So how’d they lose their other pair of limbs? And why?

I don’t expect every story to meet all three points^. Sometimes that level of detail is irrelevant; sometimes it actively impedes telling the story the author intends. But a little bit of thought about how the whole ecosystem works will help avoid any glaring errors in biology, and choosing to depart from known science is a whole lot different in effect than doing through ignorance.

What do you think? Any fictional biologies that particularly annoy you, or that you think are wonderful?

* EIEIO! I had all sorts of stupid titles for this post, including: “Dammit Jim, I’m a doctor not an ecologist,” and “It’s aliiiiiveee!” Sorry**.

** Not really.

# Yet. I hope I get to see it.

## Leaving out energy-only life, and mechanical life, and some of the wilder Star Trek creatures.

^ I love Sheri Tepper’s Grass, even though it fails at least one of these.