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Strange Bacteria Sustains Itself Without Sunlight
Hahnsoo writes "A colony of bacteria found 2.8 kilometers below the Earth's surface in a South African gold mine is able to sustain itself without energy from the Sun. While sub-surface colonies of microorganisms utilizing sulfur (mostly near deep sea hydrothermal vents) is not new, this particular colony is unusual. The colony does it by relying on radioactive uranium to split water into hydrogen gas. Thus, instead of solar energy and photosynthesis, this species relies on radioactive materials and sulfur/hydrogen to facilitate its energy needs. There is some speculation about life on other planets in the article as well."
Yes, these are natural uranium ores in South Africa.
The radioactive half-life of uranium is in the order of 100 millions of years for the two common isotopes of uranium that the radioactivity of itself is not very significant.
Radioactive materials used for power-production from radioactive decay itself (see radioisotope thermoelectric generator) use radioisotopes with half-lives of tens to hundreds of years.
(a) It's naturally radioactive. Also, from TFA: "Coauthors of the present paper learned of a new water-filled fracture inside a South African gold mine near the Johannesburg metropolitan area and viewed it as an opportunity to study subsurface rock uncontaminated by human activities."
(b) It's not practical to use its radioactivity as a power source, however, because it's only mildly radioactive in the natural state; said another way, it's not appreciably warm, so the amount of heat given off of natural uranium due to its radioactivity is negligible.
(c) Most (nearly all) human-generated nuclear waste has the same answer as (b); of that that is appreciably warm, there's too little of it to be useful as a power source.
(d) You got it.
Note that the bacteria do not use radioactivity directly, but rather use hydrogen from their environment, made from decomposing water exposed to radioactivity, as an energy source. Again from TFA: "This fracture water contained hydrocarbons and hydrogen not likely to have been created through biological processes, but rather from decomposition of water exposed to radiation from uranium-bearing rocks."
radioactive materials absolutely do not rely on sunlight. They rely on big huge stars to make big fat elements, then explode spreading them all over the universe where the coalesce into planets like the Earth.
The hydrogen and sulfur components are likely released as part of volcanic activity. which is not sunlight driven, although it is driven through the energy released due to the effect of solar gravity on the Earth's core.
I'm not really sure what point you're trying to drive here. Likely the bacteria's ancestors required sunlight to survive, if you are so interested in associating sunlight with everything.
“Common sense is not so common.” — Voltaire
Russian satellites often use decay reactors to drive the electronics. You don't get a whole lot of energy out of it, but the reactor can be quite small (small enough to put in a satellite) and lasts for quite some time. (20-100 years)
It is not viable for large scale power, since you would need so much Uranium and other material to get megawatts of power out of it. I think they can make them out of Plutonium too (which is not naturally occurring)
Nuclear "waste" is already converted back into fissile material, if material is radioactively hot it is pretty easy to extract energy from. It's the stuff that is slightly radioactive with a long half life that is not very useful and becomes low grade waste.
Please explain what is "creepy" about fission? Seems like a better deal than burning oil. What is the point of having an electric car if you're just going to charge it by burning coal and oil?
“Common sense is not so common.” — Voltaire
(Slashdotters who already know this can feel free to ignore it. Everyone has to learn science sometime, if you had the good fortune to learn it years ago no reason to jump on someone who hasn't yet.)
Yes, uranium is naturally radioactive. Much of nature is naturally radioactive, including you, incidentally. There is a certain amount of what is called "background radiation" around you twenty-four hours a day, seven days a week, there would still be even if no human had ever drawn a single breath. Uranium just happens to be quite a bit more radioactive than you are, owing to its nuclear structure.
Now, uranium like most metals doesn't come in handily available lumps in the natural world, but is found in ores: the ore is called pitchblend, in the case of uranium. Humans extract pitchblend (at a ratio of a few pounds of pitchblend to a lot of tons of boring old rock), extract the uranium, and then refine/enrich the uranium so that we get the exact isotopes of it we need for our nuclear power/weapons needs. (Isotopes are the same element, except with a different number of neutrons in the nucleus. Different isotopes of elements have vastly different radioactive properties. For example, the most common isotope of hydrogen isn't radioactive at all, and your body contains a heck of a lot of the stuff. The least common isotope of hydrogen, tritium, has two neutrons in it, and is used for making hydrogen bombs.)
So there are essentially three ways an atom can alter the configuration of its nucleus and release energy. Number one, it splits off into two atoms (fission). Number two, it fuses with another atom (fusion). Number three, it spits out something that was in its nucleus (radioactive decay -- there are a couple of types of this, producing radiation of various levels of danger -- alpha decay, for example, can be stopped with a piece of paper, gamma decay on the other hand will penetrate a meter of concrete). You can cause fission by manipulating radioactive decay in the right way, but it will happen really bloody slowly over time regardless -- uranium, for example, has a half life in the millions of years, which means that of a given sample it will take millions of years for one half of it to radiate and transform into whatever the next step is. Now, a bit of pitchblend just sitting on the counter isn't going to be useful for much of anything, although if you handle it for a few months or years you're at an elevated risk of getting cancer (and if you get radium, a radioactive gas, in your lungs, well, its less than good for you). So you can't, say, just chuck it in a specially designed miniature nuclear power plant and have it power your refrigerator. But a comparitively small amount of the concentrated, refined stuff (a few tens or hundreds of kilograms, as I recall), plus a nuclear plant designed to accelerate the fission faster than it occurs in nature, can literally power a city for years.
Nuclear power, even with the downside of producing harmful radiation (which is almost totally controllable, incidentally), is already very useful. Several countries and many, many communities are dependent on it to keep the lights running, the computers playing WoW, and air conditioners conditioning, the welders welding, and all those electricity-using things modern society depends on. If you're an environmentally concerned sort, you might also be happy to know that it generates extraordinarily little pollution compared to the refinement and combustion of fossil fuels.
This lesson in nuclear chemistry has been brought to you by the letter U and the number 235.
Help poke pirates in the eyepatch, arr.
"Hydrogen gas is highly energetic if it reacts with oxygen or other oxidants like sulfate, as the Hindenburg disaster demonstrated."
What's the point of adding these sorts of comments? It's it widely understood that the actual flames captured on the footage was in fact from the covering and paint of the Hindenburg, not the hydrogen which would have very rapidly dissapated in the first place?
Of course they cannot. Bacteria (and life in general) work only in the domain of electromagnetic and gravitational forces. They cannot influence the rate of decay of any nucleus in any way.
Victims of 9/11: <3000. Traffic in the US: >30,000/y
Does that mean, that on Earth the "big elements" are actually from big OLD stars from Long Long ago..almost at the time of big Bang??
Yes. Every element heavier than helium was created primarily either in the core of a star (up to iron), during a nova (almost everything else) or as a decay product of the radioactive decay of a heavier element (which was created during a nova or similar event).
The big bang created hydrogen and a little helium; we have stars to thank for everything else.
It's official. Most of you are morons.
capable of instantly eradicating all life within an 10 km radius,
o wer.shtml/ colmain.html
Do you have a source for that figure?
all of the examples you gave above are cleanable to an extent.
You do realise that coal-fired plants release radioactive waste into the atmosphere during normal operation, right?
Sources:
http://www.bbc.co.uk/climate/adaptation/nuclear_p
http://www.ornl.gov/info/ornlreview/rev26-34/text
http://www.epa.gov/radtown/coal-plant.htm
But feel free to google it for more; they're just the top few results for a search for "coal power station radioactivity".
It's official. Most of you are morons.
I might as well throw down on this a bit...
1: CLEAN TEETH - Buy soft dental picks- easier than flossing and smaller than a toothbrush. They sell them in packs of 50. (This becomes a huge issue in your 40's when the rest of the guys start losing their teeth.)
2: CLEAN BODY (relative to your country's standards). She shouldn't be distracted by the blackheads on your nose.
3: SMILE - and say her name. The most important word in any language is a person's name. It gets their attention in a crowded room almost instantly.
4: Avoid "one itis" / "your my soul mate". I.e. KID them a bit. If no interest- move on to find someone who is.
5: Flirt with every female regardless of age or appearence. Boosting other's egos and giving them a reason to smile is a worthwhile thing for a human to do for others. It helps you because you get over only flirting for sex and "true love."
Also: Ignore every romantic lie you see in movies. If you act the way most romantic movies show you to in real life you are going to creep her out/be "too heavy" or would even be stalking/setting yourself up for an injunction. Despair.com says it best. "Persistance: It's Over Dude. Let Her Go."
The truth is knights in shining armor were pretty vulgar lusty dudes. Women are not attacted to wimpy guys.
She was like chocolate when she drank... semi-sweet at first and then increasingly bitter.