Electric life forms that live on energy
newscientist.com
newscientist.com
This is an oversimplification. Some bacteria have very weird metabolism. (Or, from the other point of view, some bacteria think that we have a very weird metabolism :) ). They oxidize and reduce different kind of compounds to obtain energy. More info: http://en.wikipedia.org/wiki/Microbial_metabolism
The [extremetech] article has very few details and I think that it's misleading. I can't find the original research article.
There are some interesting details in the video. (Is this a video of this experiment?) Apparently these bacteria use O2 (oxigen) and H2S (hydrogen sulfide). The metabolism is probably like: http://en.wikipedia.org/wiki/Microbial_metabolism#Sulfur_oxi...
It should also be noted that any organism that uses oxidative phosphorylation for metabolism (humans included) technically use "pure energy in the form of electron flow" by having carrier molecules like NADH and FADH2 release electrons into the mitochondrial membrane. The electrons then flow through a few proteins, which use the electrons' energy to create a proton gradient in the mitochondrion, which is then used to create ATP (the "currency" of chemical energy in many cells).
> That should not come as a complete surprise, says Kenneth Nealson at the University of Southern California, Los Angeles. We know that life, when you boil it right down, is a flow of electrons: "You eat sugars that have excess electrons, and you breathe in oxygen that willingly takes them." Our cells break down the sugars, and the electrons flow through them in a complex set of chemical reactions until they are passed on to electron-hungry oxygen.
> In the process, cells make ATP, a molecule that acts as an energy storage unit for almost all living things. Moving electrons around is a key part of making ATP. "Life's very clever," says Nealson. "It figures out how to suck electrons out of everything we eat and keep them under control." In most living things, the body packages the electrons up into molecules that can safely carry them through the cells until they are dumped on to oxygen.
> "That's the way we make all our energy and it's the same for every organism on this planet," says Nealson. "Electrons must flow in order for energy to be gained. This is why when someone suffocates another person they are dead within minutes. You have stopped the supply of oxygen, so the electrons can no longer flow."
Talk about a crazy energy source!
> "This is why when someone suffocates another person they are dead within minutes. You have stopped the supply of oxygen, so the electrons can no longer flow." - Kenneth Nealson at the University of Southern California
Chemical oxidation is not, by any sensible analogy, current flow. It is the exchange of electrons, sure, but the tiny amount of charge flowing anywhere, and the huge masking that occurs in aqueous systems, would reliably prevent any normal consequences of current flow (like a B field) from occurring.
Even what happens in neurons isn't really current flow in any real sense, it is the sympathetic diffusion of ions sideways (in and out of the cell all the way along its length, if the medic who explained this to me was talking any sense) which results in charge at one end of the cell "talking to" charge at the other. Obviously if it were actual "flow", i.e. diffusion, of ions your reaction times would be a lot slower.
In my mind, this makes an analogy to electrical systems, for example a simple battery powered circuit more acceptable.
Still agree that connecting it with 'current' is probably not the best approach.
The current in cables work similar way - each electron moves forawrd and back by small distance, never moving far away from the place it started in.
But the information about movement (the elecrtomagnetic field) spreads from one electron to another with the speed of light, so the electrons at the end of cable move as soon as the information gets to them from the begining of the cable.
That's why when you press light switch the light starts almost immediately, despite electrons in cables only moving by millimeters per hour.
AFAICT, shewys don't typically have CO2 fixation capability. It certainly would be possible to engineer the pathway in and I think people are trying.
Note that assembling most simple carbon compounds, e.g. acetate, glycerol, etc. into higher order carbon compounds is not energy-positive (except for some sugars and fats with the concommitant release of CO2).
I'm surprised not to have heard more about this before now, but a search for 'shewanella geobacter' yields a rich trove of primary sources.
Check this out: https://www.youtube.com/watch?v=WhGG__boRxU
Perhaps my favorite TED talk, it was quite mind-blowing to me.
PS: Science fiction seems to love the trope where tiny change destroys civilization but life needs far more than just an energy source.
Don't forget it's been a billion years and plant's still don't use green light. For plankton it was reasonable as green does not penetrate as far but on land it's a huge waste.
"Basically, the idea is to take sediment, stick electrodes inside and then ask 'OK, who likes this?'
...is it just my before-coffee hangovered mind, or they got this completely backwards?! ...would be really sad since NS is one of the few layman friendly decent-quality source of science news :(
1. Harvesting bioelectic generation ability would be neat
2. Possible vector for metabolic disorders?
Cue: Larry Niven's Outsiders, who live on the difference in electric potential between light and shadown.
"In these, they roamed among the stars. They no longer built spaceships, they were spaceships.
But the age of Machine-entities swiftly passed. In their ceaseless experimenting, they had learned to store knowledge in the structure of space itself, and to preserve their thoughts for eternity in frozen lattices of light. They could become creatures of radiation, free at last from the tyranny of matter.
Into pure energy, therefore, they presently tranformed themselves; and on a thousand worlds, the empty shells they had discarded twitched for a while in a mindless dance of death, then crumbled into rust.
Now they were lords of the galaxy, and beyond the reach of time. They could rove at will among the stars, and sink like a subtle mist through the very interstices of space. But despite their godlike powers, they had not wholly forgotten their origin, in the warm slime of a vanished sea."
Yes, the fact that a there are bacteria out there doing this is really cool. However, the ridiculous hype science and tech reporter feel the need to put in their articles is just annoying.
We'll call this science fiction, but - imagine doing your wiring on the fly with self-organizing bacteria, or having to worry about bacteria evolved to leach off your circuit board.
Since we think of metal and electricity as very lifeless, the author is right to point out that this seems alien, even if it's an obvious and less-evolved form of life.
Average Corn yield is ~160 bushels per acer. 60lb per bushel. An acre is 4,046 square meters. A square meter gets 1kw in full sunlight. Call it 8 hours a day of sunlight. Corn takes 63 to 92 days so you can get 2 yeilds per year in some area. Call it 72 for sweet temptation. 72 * 8 * 4,048 / 160 / 60 = ~242 kwh worth of sunlight per pound of corn.
Note: Solar cells are ~22% efficient but they also work all year.
It is far better to think about the simplest forms of energy. And the simplest would be the different force carrying particles:
http://en.wikipedia.org/wiki/Force_carrier
These particles mediate the fundamental particle interactions and therefore are the simplest forms of energy possible.
As for whether kinetic energy is the simplest... it's really more of a multiplier on top of existing force carriers rather than an energy on its own. For example: higher energy photons have higher momentum but it's the photon that's the carrier, it just exists at different levels.
Oh i see, that is what happens. That makes sense now. Didn't know New Scientist has CSI edition too.
I can't be the only one who thought of this when reading the article's title :)