That's the hangup, capturing the methane. Here's some researchers extracting methane from permafrost.
Hmmm, [reads cited site] OK, so they drilled a well to a depth of hundreds of metres to extract hydrates from a zone of unspecified thickness, for an unspecified radius around the well centre. Maybe they used steam heating to destabilise the hydrates, then the methane comes up (while the steam condenses to water). Which is great. Until... Converting hydrate to relatively clean water (or later, water ice) changes it's density from about 0.9 tonnes/m^3 to about 1.0. So for each 10 metre thickness of hydrate converted, you get a 1 metre subsidence of the ground surface, working to collapse your wellbore and and lining pipes (we call it casing). This is a well-understood engineering problem - look up the Ekofisk field, where about a half-dozen oil platforms had to be jacked up by up to 3 metres because of subsidence caused by [reasons entirely unrelated to hydrates] ; it was a major and innovative piece of engineering that the Noggies are rightly proud of. With a little luck, and a skilled and well-equipped drill crew, you might be able to retrieve some of the casing (we call it "pulling casing" ; it's a moderately frequent operation), as long as the wellbore hasn't collapsed too badly. How long your well is going to last depends on the thickness and area of the hydrate layer being extracted - the traditional unit of measure in the oilfield is the acre-foot (area X vertical-thickness-of reservoir) ; how many acres you can drain is determined by the permeability of the reservoir - in this case the soil between the ice crystals in the permafrost. The various bits of permafrost I've squelched through haven't had evidence of good permeability, so that's not a good sign for large productivity per well. The more vertical thickness you extract, the greater the collapse stresses you're going to impose on your wellbore. The limiting case, which you don't want to happen, is if you generate (part of) a circular fracture from your hydrate reservoir to the surface, and your steam (or warm water) and associated methane finds an easier path to a lower pressure environment through the fracture. It's called a blowout - think Red Adair (played by John Wayne in that hilarious film), or more soberingly the Lusi mud volcano in Indonesia. Doubleplusungood. Gut feeling in the drilling professionals - to pursue this strategy, you're going to have to be drilling wells at a spacing comparable to the depth of your hydrate reservoir, and you're going to be lucky to get months of life out of a well. Envisage a fleet of drilling rigs (small ones, it's true) working their way across the permafrost fields. Look at the energy costs this would entail ; and then look at the haul roads, access roads etc that you'll need. It might work ; it might produce more energy than it consumes ; but it'd take a serious amount of project assessment work to determine if it's feasible. Me, I'd be interested to work on such a project, but I'd not invest in it.
I read some tyme ago about a Russian oil company working on a way to capture methane.
Yeah. I bet they'll have had very familiar-sounding conversations, but in Russian. I've worked a fair bit in Russia and I respect their drilling capabilities and experience. Their through-string retrievable bit systems sound fascinating. I'd be really interested to see what they've come up with.
Though I'd love to see that the US has 100s of years of coal, at least the way we're using today. I don't know how long it will last if it's gasified and used for purposes other than power plants.
The state of reserve reporting, internationally and intranationally, makes the state of oil reserve reporting look good. That's before the 25% write-off from Shell's reserve books and such like. Repeating the successful
Some...but... It is well known that many sea mammals (walrus, seals, etc.) scour the sea floor for various critters that live in the muck. Perhaps the geography is different there...I don't know. Since I didn't RTA, I don't know the depth there were talking either.
I don't quite see the relevance, but... At least one species of seal - IIRC, one of the fur seals, routinely hits in excess of a kilometer. Walruses, I don't know. My memory is popping up 60 to 100m, but with a warning bell that it's not a multiple-source datum.
I expect that the temperature at extreme depths is constant.
Certainly at great depths - multiple kilometres - temperatures are nearly uniform, and only very slowly changing. A few centigrade above zero, only. But with respect to submarine permafrost the scenarios I was talking of were in a few tens of metres. Legally and technically the continental shelves extend to 100 or 150m water depth (the technical limits are not wildly at variance with the simplicities assumed by lawyers).
Once you've got more than a few tens of metres of water depth, the insulating effect of sea ice, and the heat-moving capability of the water between the base of the sea ice and the sea bed both act in concert so that it becomes really hard to freeze the sea bed. Engineering can do it - freezing seabed muck to make a stable area for building/ piling/ excavating is in the standard portfolio of engineering techniques. But nature makes neither leaps, nor "coffer dams".
On and off, for several years, sea-level and satellite readings of methane in these areas have been used as indicators of their potential for more-or-less conventional hydrocarbons. Booo - satellite can't be relied on any more for this. I guess that it's back to shooting conventional seismic (which is on schedule anyway), dipping the water for geochemical tracers, looking for natural oil slicks on satelite photos of ice-free water, and all the other conventional techniques. Errr, which were being done any way (or the seismic campaigns were being touted for contractors with suitable seismic boats with suitable gaps in their schedules). Oh well, film at eleven.
> You do know that the depths of the ocean tend to be very cold, right?
Normally..... unless there is volcanic activity in the region like is currently going on around the north pole.
TFA specified that the research cruise was in the Eastern Siberian and Laptev Seas. Check your atlas. The (rather limited) volcanism on the Gaskell (trans-Arctic) mid-ocean ridge is quite a distance away. Plus, it's one of the slowest-spreading ridge in the world, with spreading rate and vigour of volcanicity being strongly correlated.
"...buried under the sea floor before the last ice age, breaking up as higher water temperatures melt the permafrost that had contained it..."
What am I missing?
your scepticism is understandable, but submarine permafrost is well-known. Sea water has ice in it ; this lowers it's freezing point to below zero (centigrade) ; so if you have fresh-water-flooded, fine-grained sea bottom materials, you can freeze the fresh water in the sediment under liquid salty water. (I specify "fine grained" sea bottom materials to slow diffusion of salt into the pore water.)
That's mechanism #1.
Mechanism #2 : Winter comes ; sea freezes at about -3C ; seabed starts to freeze onto the bottom of the sea ice ; winter continues ; ice is -10C; winter continues ; ice is -20C; winter continues ; ice is -30C; winter continues ; seabed ice is now metres thick. Spring comes ; surface sea ice melts in the sun ; top couple of cm of ground ice melts under the sea water, once that gets above 0C ; remaining ice slowly melts. Repeat a hundred times ; you've got a significant build up of ice. Corollary - why is the sea bottom muck fresh-water-wet instead of salt-water-wet? Because when it was deposited, sea level was 50m below present levels, so that what is now seabed was 50m above sea level (and maybe 10s of km from the coast).
This could well be a possible explanation for the 1908 Tunguska blast in Siberia.
The energy yield from the Tunguska event was in the order of 10 megatonnes of TNT (from your cited source ; good enough for an order of magnitude estimate).
One molecule of TNT has 6 carbons plus various other bits that yield energy in detonation (... order of magnitude...) so to get a ball-park figure lets call that 10 megatonnes of TNT 100 megatonnes of methane.
In terms of mass, a really good clathrate at the bottom of the ocean (or plugging an oil well pipeline) can have about 20% by mass of methane in it (NOTE : mass, not volume) so, we need around 500 megatonnes of clathrate.
500 * 10^6 * 10^3 kg = 5 * 10^11 kg of clathrate. Specific gravity of clathrates ~0.9 (wikipedia) So we need 550,000,000 cubic metres of clathrate. As a hemisphere, that's 600-odd metres in radius.
Hmmm, actually, that's not wildly off from the dimensions of the lake near "Tunguska Ground Zero". Which is not what I was intending to demonstrate. Shot myself in the foot there.
But if this was an event related to the formation of that lake... why aren't there more such events all over Russia. What caused this particular bit of Tundra to go boom?
I don't buy it. The mixing needed to get into the explosive limits doesn't work for me ; the height to which the mix must have ascended before the detonation doesn't work ; why detonate when it's got to so-high when it could have detonated as well at ground level, had a limited local effect, and then have a burning pillar of fire for a few hours or days (no evidence of such at "Tunguska Ground Zero") ? But that's my geologist's gut feeling, not a solid refutation. I'd like to see your paper on the subject.
I doubt it. I saw a special on the discovery channel about this stuff once, and they basically said it is so diffuse and spread out on the ocean floor that there is no economic way to recover it.
I've seen and participated in this debate repeatedly on oil rigs, in rooms containing in excess of a hundred man-years experience of geology, marine engineering, pipeline installation, pump engineering and related, relevant engineering disciplines, as well as the management that would have to run such projects efficiently and keep them within budget. (There was also normally food on the table, and coffees afterwards, but no alcohol. Alcohol is banned on professional drilling rigs. Unless you're French.) No-one would say it was impossible ; but the consensus (repeatedly, with different groups of participants) is that it's going to be horrendously expensive to recover, there will be a lot of leakage of methane into the atmosphere, and it's going to require whole new fleets of specialist, ice-hardened, single-purpose designed vessels, as well as the marine crews to keep them on station and on course. Not impossible ; extremely hard ; interesting professional challenges. No hint of people with serious plans to try it. We keep our communal ears to the ground, because we the marine oil-drilling communities, are the people who would be first recruitment pool to be used to do it. Silence on the hiring front. Deduce from that what you will.
A reduction in global carrying capacity, even of just 10 or 20%, is not good news for our species.
For our species, it's not really a problem until we're down to a few hundred thousands of individuals. There'll still be a good sized chunk of genetic biodiversity in a population that size, and given sufficiently improved conditions, a rebound is perfectly reasonable. The other 6,699,600,000 or so of the population aren't particularly important in terms of the species and the gene pool. (Assuming a reasonably random way of selecting who survives and who is culled.)
"gigadeath" is a word that I'm trying to get people to seriously contemplate. It's going to happen, and while it in no way excuses the actions of Uncles Adolf, Joe, Ghengiz and "1918 influenza strain", it does put their rather paltry efforts (not even a half a gigadeath between them) into perspective. My guesstimate for the long-term (megayear) carrying capacity of the planet is closer to a gigaperson than it is to the present population. "gigadeath" then becomes a necessary part of the vocabulary.
AliasMarlowe:The mass extinction at the end of the Permian has been attributed to numerous causes. [SNIP] D.H. Erwin, The Great Paleozoic Crisis: Life and Death in the Permian, Columbia University Press, New York NY, 1993. ISBN:0715301306. Ambitwistor:There is recent evidence that methane clathrate destabilization alone couldn't have caused the PETM,
"PETM" = Palaeocene-Eocene Thermal Maximum That's about 200 million years (plus the rise and fall of the dinosaurs, several large meteorites, and the first radiative differentiation of the eutherian mammals) later than the end-Permian, end-Palaeozoic "Great Dying".
Sorry to be picky, but you do sound like you know more about this sort of thing than 98% of SlashDot contributors, so higher standards are expected.
How much methane would need to be released to create mixtures of between 5 and 15%?
Normal atmospheric concentrations of methane are 1~2ppm v/v. I use this value as a reality check when I'm evaluating the knowledge of gas-analysis contractor staff on oil wells where I'm responsible for QA/QC of (amongst other things) gas analysis data. Loggers, if you get the answer wrong, I'm not going to correct you (until after you've submitted your final reports), but I am going to make note of it and judge your competence accordingly. You are expected to read around your subject, not just to parrot what your training courses tell you.
That's a hell of a lot of methane. Would the air even still be easily breathable at those concentrations?
Hmmm. Interesting question. For the SlashDot audience, 5% is a working approximation to the Lower Explosive Limit of methane in air ; above that figure, the mixture can sustain and amplify a detonation shock wave. (The exact figure varies with pressure, temperature, humidity, and enough other factors to only merit no decimal places.) I can't think of any reason why 5% in air, or even 15% in air would in itself be hazardous to health. At some point, the well-known mild hypnotic (sleep-inducing) effects of alkane gases would come into play, which is one set of hazards ; at a higher concentration you'll eventually start to make the exposed people hypoxic (insufficient oxygen ; I think you'd need to be up in the mid-20s of % methane-in-air for that to become significant) ; my un-checked IANA-medic memory tells me that alkanes cause mild cardiac hypertension before the hypoxia gets significant ; but at 5% and above, methane-in-air, you're one spark away from being several reddish, tattered, smouldering stains on the landscape. Which is not a nice place to be. When I see ambient gas levels hit 5% methane-equivalent, I'm taking action to reduce and control those gas levels because of the explosion risk, which is a very non-trivial hazard to health. From personal experience, I've walked several hundred metres through a gas plume at 5-7% methane in air (we only had one sample point, which peaked at 7% ; I left the analytic equipment running and went up the nearest sand dune, because I knew from past reports that the reservoir in question could put out whole percents of H2S.), one BA set on my back with the mask to hand, and my spare BA set in it's case in my hand. Plus a UV torch to spot the scorpions, it being night-time. No rapidly toxic effects (I ain't dead, yet), and when the "shimmer" of gas coming off the mud died down, I was able to return to my "gas shack" without problems.
Now with all of the methane under the permafrost in Siberia, if an efficient method to capture it can be devised, Russia could become the Saudi Arabia of methane.
which is a truly wonderful plan. Honestly, it is! But could you answer one small question - what's the technology you're going to use for capture of this methane. After all, it's present over very wide areas, which is why the quantities are vast ; but the tonnage under one particular point is actually quite small. If you have more than about 5% of the methane under a target area leaking out of your collection apparatus, then the greenhouse effect impact of the methane leaked is going to be bigger than the impact of the rest of the mthane captured and burned to CO2. To transport the methane captured efficiently to market, you're going to have to compress it considerably. That's got a significant energy cost, so you can take that out of your energy budget. Maybe the clathrate methane ores can themselves be bulk-shipped to closer to market. Ah, but that implies bulk-shipping megatonnes of rather dirty water. Put that on the negative side of the energy-balance equation.
I get quizzed on the potential of exploiting methane clathrates almost every time I go off to do my work - drilling oil wells. The people questioning me, and trying to work out solutions to the problems of exploitation and transport are mainly experienced petroleum engineers, pipeline workers, drilling engineers, mining engineers (making a better living this half-decade in the oil rather than in the minerals ; next half-decade, it'll be back to minerals). While we come up with some interesting and semi-plausible schemes, no-one who actually does this stuff for a living thinks it's going to be anything other than very difficult, and hugely expensive to develop. For a comparison, look at the tar-sands which are just starting to come on-stream and be significant - ideas about methane-clathrate mining are at the stage that tar-sand exploitation was in the early 1970s. It's hardly made it to the level of "back of an envelope".
Methane-clathrates are a potentially significant energy source, but it's not something that's going to be commercial this side of the 2020s, if not the 2030s. Which is OK ; if the banking system hasn't collapsed, that'll be about time for me to retire, and able to experiment with off-the-wall stuff as an option to supplement my income.
Hey, it might even be commercial in time to fill part of the energy gap which will happen after the oil has returned to being a chemical feedstock, and as the coal production is falling through the floor. That'll be good - it'll allow humankind to continue in the delusion that energy is always going to be available for another half-generation or so.
The rest of the world only matter as far as it's providing credit and/ or raw materials to the US. "Human Rights" only apply to the subset of humanity that votes in US elections. No-one else matters.
My spin detector : If (politician's lips are moving, or keyboard is typing) Then (lying, thieving bullshitting spin is being produced) else (politician is a fake)
What is morally ambiguous about shooting people who are threatening to shoot you?
You've substantially distorted the original statement under discussion. The original statement was:
Shooting people who obviously intend harm to you or your property is not a morally ambiguous situation: you shoot to kill.
You either forgot the sarcasm tags, or showed very well what's wrong in the USA.
and you've changed immediately from "harm [you] or your property" to "shoot you". Which may be illustrative of some of the more worrying American traits : the automatic assumption that property is as important as people , and the assumption that all forms of harm involve people with guns.
In most of the world, guns are extremely rare. Until a couple of years ago when airport police started to occasionally carry guns, I'd seen a gun precisely twice in "real life" : once with an RUC police officer behind it and the hole in the front pointing straight at my head, and once with a farmer behind the two barrels and muttering "Gerrorf moi laand". (For Americans : the RUC, Royal Ulster Constabulary, are the only part of the UK police who have ever routinely carried guns.) Most burglaries involve no weaponry more powerful than the screwdriver that is used to jemmy a window ; and the considerable majority of burglaries take place during the day (because the home owners are at work, and the burglars don't want to meet the home owners, and they don't want witnesses). The very small number of burglaries that involve weaponry largely use things like baseball bats (pretty much their only use over here), which obviously occupies one of the burglar's hands, reducing the amount of stuff they can get away with. Ah, problem for the burglar. You can work out the evolutionary consequences for the population of burglars. There's another evolutionary pressure on burglars who contemplate carrying weaponry : the police don't give much of a shit about burglary ; but burglary with a weapon gets lots of police assigned to it and the odds of getting caught are a lot higher. For what payback to the burglar?
Given a choice between getting whacked round the head by a baseball bat and giving up my laptop... here's the laptop. I can always get another laptop, and I've got recent backup and the hard drive is encrypted. So big fucking deal, take the laptop. It's just a lump of bent sand and plastic. The important data - family photos, shit like that - is on a server in an awkward-to-reach place, and last month's backup is in my friend's house. Oh you want the camera too. Sure. Now fuck off, Mr Burglar.
By the way, don't get me wrong ; when I've been facing imminent death (car crashes, underwater, mountaineering), I've fought like the devil to stay alive. But burglary and street robbery are generally not "near death experiences". They're just an infuriating pain in the arse.
Of course, if you think that this factual description is of a ridiculously safe utopia, feel free to try to get a settlement visa. We're also moderately welcoming to asylum seekers and you might be allowed to work for a living after the first half decade.
"it's called castration. I hear it makes you live longer."
Castration makes it impossible to get an erection, but it does not affect sexual interests.
Alan Turing being a classic case in point, and a poster boy for most SlashDot readers. Most people find it unsettling to be reminded that their poster boys were sexual criminals.
for those who've forgotten, Turing was gay (yes - it used to be illegal. Perhaps it should be made compulsory for a few years, to give some straight people a dose of perspective.) ; he was caught by the police doing some act of gross indecency in a public toilet (I haven't seen the detailed testimony, probably there isn't any because he pleaded guilty ; isn't "testimony" an appropriate word in this case [GRIN] ; compare to the case of George Michael) ; he was convicted, and the court required him to be chemically castrated using "massive" doses of female sex hormones (compare to the case of George Michael); this made him start to grow tits, and started to cloud his thinking abilities. So he killed himself. But the castration didn't stop him from being gay.
(By the way, I'm being facetious about making being gay compulsory for a few years. No, I'm just talking about making anal sex the only legitimate form of sexual activity, with all men having to take it as often as they give it and the girls being given free strap-on dildos to use on each other and on the men. Perhaps some sort of modified pedometer would have to be installed on everyone to monitor everyone's give/ take ratio. That's legally possible, and might be enforcible. But would it instantly make everyone in the world gay? Of course not. That's the difference between impulse and action.)
The $18 is a "laughing price" ; they don't want anyone to pay them $18 to read one article. What they (Nature Publishing Group) want you, and lots of others, to do is pay approximately £145 (whatever that is in your currency) for a year-long subscription to the magazine (50 or 51 editions) plus unlimited access to their archives. It is, after all, a magazine, and while it's raw content is given to it by authors, it still has real costs in organising peer review, typesetting (ever tried laying out a page that's going to press? It's demanding work), producing editorial content, plus of course, printing.
You might disagree ; I've voted with my wallet on several occasions and been a subscriber for several years (alternating with Science, BTW). The ink-on-paper copies pile up, hugely. I'm not a subscriber at the moment because I'm working on another project, and I'll look again at the idea in a couple of years.
If you're really interested you should be able to get it free through any library.
You can. Go down the road here to the Central Library (next to the theatre ; opposite the Wallace Monument), pick it off the shelf, and then pay about £0.40 to get the photocopier to work. (Nature is a reference journal - you can't book it out of that library.) Alternatively, you can go down to the University Library and pay your £60 annual fee (discounted to £30 if you're a graduate of one of Aberdeen's University institutions) to read it off the shelf there and to borrow volumes of bound editions of Nature from the stacks. The photocopiers are a bit better and noticeably cheaper.
Contrary to popular opinion, information is not free now, and never has been. Individual commentators on SlashDot may have been insulated from such costs until now, but that doesn't mean that they're not real costs.
at least define which "deg temp" you're referring too.
Different degrees of temporariness ?
Well, there's common or garden temporary - you might need it for a few minutes, hours or days (giving around a x1440 range of coverage).
Then there's the fleeting degree of temporary - like a fleeting thought, oh! she's got a nice pair of tits (being gender neutral here, you might be a hetrosexual male, though it's unlikely on/.). The sort of stuff that would take longer to write down than it would retain it's usefulness. Half-life in SI units of only a few seconds.
Then there's barely apparent degree of temporariness. Normal humans generally don't quite experience this except when trying to read quantum-mechanics papers when it is felt as that feeling that occasionally you actually understand what the fuck they're writing about. This is actually the QM half-life of the Schrodinger's Cat-like co-existence of your states of both understanding the QM paper and not understanding it, before the state collapses. A few humanoids actually do collapse into the "understand QM" state, but for most of us, it's just that "flicker at the corner of the attention" feeling that you might possibly understand this one day. This degree of temporariness is wide ranging, possibly covering from human lifetimes to well under a femtosecond, depending on intelligence, ability to read, whether you can add 2+2 without getting the calculator out.
The final degree of fleetingness - the lifetime of the universe after the LHC achieves beam collision at 115% of initial design criteria. That's when all those people who thought they understood QM start to say "Oh fuck," but don't get very far into it.
Funny thing is that despite both games having convoluted and misdirecting self-help support sources, the problem in both cases was that I had software installed that can mount.isos. Yes, that's right. Other operating systems have native support for this function because it's so damn useful. Game companies on the other hand treated me like a pirate for having such software installed.
So now I'm a pirate, due to the pain that game companies have caused me. Don't get me wrong, I'm not trying to be moral here - after all, I am stealing my entertainment - but the actions of the game companies have turned a paying customer into a pirate. Now there's an own goal for you...
So... what is to stop you from
buying a legal copy of the game, in it's shrink-wrap;
downloading the DRM-free'd pirate version;
installing and using the pirate version
everybody wins
You get the game you want without the hassle of the DRM ; the company gets it's profits and their programmers and artists get to bring husks of bread home to feed the starving children. Oh, I see the problem. It's at step (1), where you buy the game.
(Currently I play "CIV for DOS" and "UFO:Enemy Unknown", both of which I brought legally over a decade ago. Just because they're not new doesn't mean they're not interesting and don't run.)
I doubt 3% increase of air pressure (30cm/10m) will do serious damage to your lungs.
The experiments have been done ; no need for doubt or supposition. Look at either common design of Scuba regulator, or their commercial equivalents ("full face masks") ; where is the pressure regulator? Either between the shoulder blades (and so just a few cm vertical distance from the lungs) ; or at the user's mouth (so getting perhaps 15cm from the top of the diver's lungs) ; or on the diver's cheek (same comment). Very occasionally you'll see people using a twin-hose airset mounted at the waist, so with the regulator up to 40cm deeper than the lungs. This is strongly discouraged because of two hazards - kinking the hoses and air embolism. It's really a "don't do this" situation - only try it if you're definitely going to die otherwise. (I speak as a diver with a non-trivial log book of near-death experiences. Which is why I stopped diving.)
People have an excessive confidence in the abilities of their bodies. Seriously, don't act on your "doubts" and suppositions. Speak to proper dive training organisations. The only substitute for learning from other people's experiments is doing it yourself, and possibly dieing.
When you consider the topography and the age of the site
An important point. Population distribution in Britain is very uneven. Half the population live within approximately 80 miles of Kinder Scout (Derbyshire), but that of course excludes the biggest (and most horrible and self-centred) city ; 95% of the population live in about 50% of the country (which is where the mobile phone masts get put. Go to a less populated area, et voila, there goes your signal, down the tubes.) ; whole tracts of the country have only tiny villages spread thinly around the coasts and along some valleys (who's going to put fibre in to service the couple of thousand inhabitants of Fort Augustus, 30 miles each way from anything resembling a large town?)
Just think of the impact of tearing up 50 yards of a 200 year old cobble stone street. How do you put a monetary value on that?
I'll ask my friend on the local Council's Finance Committee. They have to deal with maintenance of the several miles of cobbled street in town. Where the streets are used for light traffic (cars, delivery vans), the cobbles are re-laid every 30-odd years ; where the traffic is heavier (I'm thinking specifically of the #20 bus route) it's about 15 years. It's just standard maintenance.
Not to mention the 200 year old sewer lines that go with the street.
200 year old sewers? Well, there are a few multi-millennial sewers in Rome, so there could be some multi-century ones. But the big period of sewer building in Britain didn't start until 150 to 170 years ago. Picky, picky.
You do raise a valid point about panspermia theory, oddly enough: escaping life from an extraterrestrial source could actually evolve (or at least perform selection) en route to its final destination.
Evolution requires reproduction. Single organisms don't evolve ; populations evolve. Try this human thought experiment : as of tomorrow morning, all red-haired are going to suffer an evolutionary pressure by being garotted on sight by any other human. This will have a population effect of eliminating the gene(s) for red hair. But for the individual? Their genes don't change, just their vital status. Looking from the other end of the telescope... changes in your genes that have significant effect are called cancer. If you've got a population that's going to evolve, you have to have reproduction. Which means that you either have to have quite a large environment, flying through space. Or you have to have each parent giving rise to just one descendant (otherwise the population starts to increase (1,1,2,3,5,8,13,21... Fibbonacci's rabbits). I one case, you've got a generation ship ; in the other case, you've got minuscule populations.
Panspermia isn't impossible. But it is frightfully difficult. As a geologist, I find it easier to solve the problem of origin of life here on Earth, rather than facing the same problem on some other planet and adding the problems of panspermia.
Slashdot Mirror
Hmmm, [reads cited site] OK, so they drilled a well to a depth of hundreds of metres to extract hydrates from a zone of unspecified thickness, for an unspecified radius around the well centre. ...
Maybe they used steam heating to destabilise the hydrates, then the methane comes up (while the steam condenses to water). Which is great. Until
Converting hydrate to relatively clean water (or later, water ice) changes it's density from about 0.9 tonnes/m^3 to about 1.0. So for each 10 metre thickness of hydrate converted, you get a 1 metre subsidence of the ground surface, working to collapse your wellbore and and lining pipes (we call it casing). This is a well-understood engineering problem - look up the Ekofisk field, where about a half-dozen oil platforms had to be jacked up by up to 3 metres because of subsidence caused by [reasons entirely unrelated to hydrates] ; it was a major and innovative piece of engineering that the Noggies are rightly proud of. With a little luck, and a skilled and well-equipped drill crew, you might be able to retrieve some of the casing (we call it "pulling casing" ; it's a moderately frequent operation), as long as the wellbore hasn't collapsed too badly.
How long your well is going to last depends on the thickness and area of the hydrate layer being extracted - the traditional unit of measure in the oilfield is the acre-foot (area X vertical-thickness-of reservoir) ; how many acres you can drain is determined by the permeability of the reservoir - in this case the soil between the ice crystals in the permafrost. The various bits of permafrost I've squelched through haven't had evidence of good permeability, so that's not a good sign for large productivity per well. The more vertical thickness you extract, the greater the collapse stresses you're going to impose on your wellbore. The limiting case, which you don't want to happen, is if you generate (part of) a circular fracture from your hydrate reservoir to the surface, and your steam (or warm water) and associated methane finds an easier path to a lower pressure environment through the fracture. It's called a blowout - think Red Adair (played by John Wayne in that hilarious film), or more soberingly the Lusi mud volcano in Indonesia. Doubleplusungood.
Gut feeling in the drilling professionals - to pursue this strategy, you're going to have to be drilling wells at a spacing comparable to the depth of your hydrate reservoir, and you're going to be lucky to get months of life out of a well. Envisage a fleet of drilling rigs (small ones, it's true) working their way across the permafrost fields. Look at the energy costs this would entail ; and then look at the haul roads, access roads etc that you'll need.
It might work ; it might produce more energy than it consumes ; but it'd take a serious amount of project assessment work to determine if it's feasible. Me, I'd be interested to work on such a project, but I'd not invest in it.
Yeah. I bet they'll have had very familiar-sounding conversations, but in Russian. I've worked a fair bit in Russia and I respect their drilling capabilities and experience. Their through-string retrievable bit systems sound fascinating. I'd be really interested to see what they've come up with.
The state of reserve reporting, internationally and intranationally, makes the state of oil reserve reporting look good. That's before the 25% write-off from Shell's reserve books and such like. Repeating the successful
I don't quite see the relevance, but ... At least one species of seal - IIRC, one of the fur seals, routinely hits in excess of a kilometer. Walruses, I don't know. My memory is popping up 60 to 100m, but with a warning bell that it's not a multiple-source datum.
Certainly at great depths - multiple kilometres - temperatures are nearly uniform, and only very slowly changing. A few centigrade above zero, only. But with respect to submarine permafrost the scenarios I was talking of were in a few tens of metres. Legally and technically the continental shelves extend to 100 or 150m water depth (the technical limits are not wildly at variance with the simplicities assumed by lawyers).
Once you've got more than a few tens of metres of water depth, the insulating effect of sea ice, and the heat-moving capability of the water between the base of the sea ice and the sea bed both act in concert so that it becomes really hard to freeze the sea bed. Engineering can do it - freezing seabed muck to make a stable area for building/ piling/ excavating is in the standard portfolio of engineering techniques. But nature makes neither leaps, nor "coffer dams".
On and off, for several years, sea-level and satellite readings of methane in these areas have been used as indicators of their potential for more-or-less conventional hydrocarbons. Booo - satellite can't be relied on any more for this. I guess that it's back to shooting conventional seismic (which is on schedule anyway), dipping the water for geochemical tracers, looking for natural oil slicks on satelite photos of ice-free water, and all the other conventional techniques.
Errr, which were being done any way (or the seismic campaigns were being touted for contractors with suitable seismic boats with suitable gaps in their schedules). Oh well, film at eleven.
Stranger In A Strange Land. Audiobook, for a change.
TFA specified that the research cruise was in the Eastern Siberian and Laptev Seas. Check your atlas.
The (rather limited) volcanism on the Gaskell (trans-Arctic) mid-ocean ridge is quite a distance away. Plus, it's one of the slowest-spreading ridge in the world, with spreading rate and vigour of volcanicity being strongly correlated.
your scepticism is understandable, but submarine permafrost is well-known.
Sea water has ice in it ; this lowers it's freezing point to below zero (centigrade) ; so if you have fresh-water-flooded, fine-grained sea bottom materials, you can freeze the fresh water in the sediment under liquid salty water.
(I specify "fine grained" sea bottom materials to slow diffusion of salt into the pore water.)
That's mechanism #1.
Mechanism #2 : Winter comes ; sea freezes at about -3C ; seabed starts to freeze onto the bottom of the sea ice ; winter continues ; ice is -10C; winter continues ; ice is -20C; winter continues ; ice is -30C; winter continues ; seabed ice is now metres thick. Spring comes ; surface sea ice melts in the sun ; top couple of cm of ground ice melts under the sea water, once that gets above 0C ; remaining ice slowly melts.
Repeat a hundred times ; you've got a significant build up of ice.
Corollary - why is the sea bottom muck fresh-water-wet instead of salt-water-wet? Because when it was deposited, sea level was 50m below present levels, so that what is now seabed was 50m above sea level (and maybe 10s of km from the coast).
Scepticism abated? Or, at least, addressed?
The energy yield from the Tunguska event was in the order of 10 megatonnes of TNT (from your cited source ; good enough for an order of magnitude estimate).
One molecule of TNT has 6 carbons plus various other bits that yield energy in detonation (... order of magnitude...) so to get a ball-park figure lets call that 10 megatonnes of TNT 100 megatonnes of methane.
In terms of mass, a really good clathrate at the bottom of the ocean (or plugging an oil well pipeline) can have about 20% by mass of methane in it (NOTE : mass, not volume) so, we need around 500 megatonnes of clathrate.
500 * 10^6 * 10^3 kg = 5 * 10^11 kg of clathrate.
Specific gravity of clathrates ~0.9 (wikipedia)
So we need 550,000,000 cubic metres of clathrate.
As a hemisphere, that's 600-odd metres in radius.
Hmmm, actually, that's not wildly off from the dimensions of the lake near "Tunguska Ground Zero". Which is not what I was intending to demonstrate. Shot myself in the foot there.
But if this was an event related to the formation of that lake ... why aren't there more such events all over Russia. What caused this particular bit of Tundra to go boom?
I don't buy it. The mixing needed to get into the explosive limits doesn't work for me ; the height to which the mix must have ascended before the detonation doesn't work ; why detonate when it's got to so-high when it could have detonated as well at ground level, had a limited local effect, and then have a burning pillar of fire for a few hours or days (no evidence of such at "Tunguska Ground Zero") ? But that's my geologist's gut feeling, not a solid refutation. I'd like to see your paper on the subject.
I've seen and participated in this debate repeatedly on oil rigs, in rooms containing in excess of a hundred man-years experience of geology, marine engineering, pipeline installation, pump engineering and related, relevant engineering disciplines, as well as the management that would have to run such projects efficiently and keep them within budget. (There was also normally food on the table, and coffees afterwards, but no alcohol. Alcohol is banned on professional drilling rigs. Unless you're French.)
No-one would say it was impossible ; but the consensus (repeatedly, with different groups of participants) is that it's going to be horrendously expensive to recover, there will be a lot of leakage of methane into the atmosphere, and it's going to require whole new fleets of specialist, ice-hardened, single-purpose designed vessels, as well as the marine crews to keep them on station and on course.
Not impossible ; extremely hard ; interesting professional challenges. No hint of people with serious plans to try it. We keep our communal ears to the ground, because we the marine oil-drilling communities, are the people who would be first recruitment pool to be used to do it. Silence on the hiring front. Deduce from that what you will.
For our species, it's not really a problem until we're down to a few hundred thousands of individuals. There'll still be a good sized chunk of genetic biodiversity in a population that size, and given sufficiently improved conditions, a rebound is perfectly reasonable. The other 6,699,600,000 or so of the population aren't particularly important in terms of the species and the gene pool. (Assuming a reasonably random way of selecting who survives and who is culled.)
"gigadeath" is a word that I'm trying to get people to seriously contemplate. It's going to happen, and while it in no way excuses the actions of Uncles Adolf, Joe, Ghengiz and "1918 influenza strain", it does put their rather paltry efforts (not even a half a gigadeath between them) into perspective. My guesstimate for the long-term (megayear) carrying capacity of the planet is closer to a gigaperson than it is to the present population. "gigadeath" then becomes a necessary part of the vocabulary.
AliasMarlowe : The mass extinction at the end of the Permian has been attributed to numerous causes. : There is recent evidence that methane clathrate destabilization alone couldn't have caused the PETM,
[SNIP]
D.H. Erwin, The Great Paleozoic Crisis: Life and Death in the Permian, Columbia University Press, New York NY, 1993. ISBN:0715301306.
Ambitwistor
"PETM" = Palaeocene-Eocene Thermal Maximum
That's about 200 million years (plus the rise and fall of the dinosaurs, several large meteorites, and the first radiative differentiation of the eutherian mammals) later than the end-Permian, end-Palaeozoic "Great Dying".
Sorry to be picky, but you do sound like you know more about this sort of thing than 98% of SlashDot contributors, so higher standards are expected.
Normal atmospheric concentrations of methane are 1~2ppm v/v. I use this value as a reality check when I'm evaluating the knowledge of gas-analysis contractor staff on oil wells where I'm responsible for QA/QC of (amongst other things) gas analysis data. Loggers, if you get the answer wrong, I'm not going to correct you (until after you've submitted your final reports), but I am going to make note of it and judge your competence accordingly. You are expected to read around your subject, not just to parrot what your training courses tell you.
Hmmm. Interesting question.
For the SlashDot audience, 5% is a working approximation to the Lower Explosive Limit of methane in air ; above that figure, the mixture can sustain and amplify a detonation shock wave. (The exact figure varies with pressure, temperature, humidity, and enough other factors to only merit no decimal places.)
I can't think of any reason why 5% in air, or even 15% in air would in itself be hazardous to health. At some point, the well-known mild hypnotic (sleep-inducing) effects of alkane gases would come into play, which is one set of hazards ; at a higher concentration you'll eventually start to make the exposed people hypoxic (insufficient oxygen ; I think you'd need to be up in the mid-20s of % methane-in-air for that to become significant) ; my un-checked IANA-medic memory tells me that alkanes cause mild cardiac hypertension before the hypoxia gets significant ; but at 5% and above, methane-in-air, you're one spark away from being several reddish, tattered, smouldering stains on the landscape. Which is not a nice place to be. When I see ambient gas levels hit 5% methane-equivalent, I'm taking action to reduce and control those gas levels because of the explosion risk, which is a very non-trivial hazard to health.
From personal experience, I've walked several hundred metres through a gas plume at 5-7% methane in air (we only had one sample point, which peaked at 7% ; I left the analytic equipment running and went up the nearest sand dune, because I knew from past reports that the reservoir in question could put out whole percents of H2S.), one BA set on my back with the mask to hand, and my spare BA set in it's case in my hand. Plus a UV torch to spot the scorpions, it being night-time. No rapidly toxic effects (I ain't dead, yet), and when the "shimmer" of gas coming off the mud died down, I was able to return to my "gas shack" without problems.
which is a truly wonderful plan. Honestly, it is!
But could you answer one small question - what's the technology you're going to use for capture of this methane. After all, it's present over very wide areas, which is why the quantities are vast ; but the tonnage under one particular point is actually quite small. If you have more than about 5% of the methane under a target area leaking out of your collection apparatus, then the greenhouse effect impact of the methane leaked is going to be bigger than the impact of the rest of the mthane captured and burned to CO2.
To transport the methane captured efficiently to market, you're going to have to compress it considerably. That's got a significant energy cost, so you can take that out of your energy budget.
Maybe the clathrate methane ores can themselves be bulk-shipped to closer to market. Ah, but that implies bulk-shipping megatonnes of rather dirty water. Put that on the negative side of the energy-balance equation.
I get quizzed on the potential of exploiting methane clathrates almost every time I go off to do my work - drilling oil wells. The people questioning me, and trying to work out solutions to the problems of exploitation and transport are mainly experienced petroleum engineers, pipeline workers, drilling engineers, mining engineers (making a better living this half-decade in the oil rather than in the minerals ; next half-decade, it'll be back to minerals). While we come up with some interesting and semi-plausible schemes, no-one who actually does this stuff for a living thinks it's going to be anything other than very difficult, and hugely expensive to develop. For a comparison, look at the tar-sands which are just starting to come on-stream and be significant - ideas about methane-clathrate mining are at the stage that tar-sand exploitation was in the early 1970s. It's hardly made it to the level of "back of an envelope".
Methane-clathrates are a potentially significant energy source, but it's not something that's going to be commercial this side of the 2020s, if not the 2030s. Which is OK ; if the banking system hasn't collapsed, that'll be about time for me to retire, and able to experiment with off-the-wall stuff as an option to supplement my income.
Hey, it might even be commercial in time to fill part of the energy gap which will happen after the oil has returned to being a chemical feedstock, and as the coal production is falling through the floor. That'll be good - it'll allow humankind to continue in the delusion that energy is always going to be available for another half-generation or so.
The rest of the world only matter as far as it's providing credit and/ or raw materials to the US. "Human Rights" only apply to the subset of humanity that votes in US elections. No-one else matters.
My spin detector :
If (politician's lips are moving, or keyboard is typing)
Then (lying, thieving bullshitting spin is being produced)
else (politician is a fake)
4 now.
You've substantially distorted the original statement under discussion. The original statement was :
and you've changed immediately from "harm [you] or your property" to "shoot you". Which may be illustrative of some of the more worrying American traits : the automatic assumption that property is as important as people , and the assumption that all forms of harm involve people with guns.
In most of the world, guns are extremely rare. Until a couple of years ago when airport police started to occasionally carry guns, I'd seen a gun precisely twice in "real life" : once with an RUC police officer behind it and the hole in the front pointing straight at my head, and once with a farmer behind the two barrels and muttering "Gerrorf moi laand". (For Americans : the RUC, Royal Ulster Constabulary, are the only part of the UK police who have ever routinely carried guns.)
Most burglaries involve no weaponry more powerful than the screwdriver that is used to jemmy a window ; and the considerable majority of burglaries take place during the day (because the home owners are at work, and the burglars don't want to meet the home owners, and they don't want witnesses). The very small number of burglaries that involve weaponry largely use things like baseball bats (pretty much their only use over here), which obviously occupies one of the burglar's hands, reducing the amount of stuff they can get away with. Ah, problem for the burglar. You can work out the evolutionary consequences for the population of burglars.
There's another evolutionary pressure on burglars who contemplate carrying weaponry : the police don't give much of a shit about burglary ; but burglary with a weapon gets lots of police assigned to it and the odds of getting caught are a lot higher. For what payback to the burglar?
Given a choice between getting whacked round the head by a baseball bat and giving up my laptop ... here's the laptop. I can always get another laptop, and I've got recent backup and the hard drive is encrypted. So big fucking deal, take the laptop. It's just a lump of bent sand and plastic. The important data - family photos, shit like that - is on a server in an awkward-to-reach place, and last month's backup is in my friend's house. Oh you want the camera too. Sure. Now fuck off, Mr Burglar.
By the way, don't get me wrong ; when I've been facing imminent death (car crashes, underwater, mountaineering), I've fought like the devil to stay alive. But burglary and street robbery are generally not "near death experiences". They're just an infuriating pain in the arse.
Of course, if you think that this factual description is of a ridiculously safe utopia, feel free to try to get a settlement visa. We're also moderately welcoming to asylum seekers and you might be allowed to work for a living after the first half decade.
Alan Turing being a classic case in point, and a poster boy for most SlashDot readers. Most people find it unsettling to be reminded that their poster boys were sexual criminals.
for those who've forgotten, Turing was gay (yes - it used to be illegal. Perhaps it should be made compulsory for a few years, to give some straight people a dose of perspective.) ; he was caught by the police doing some act of gross indecency in a public toilet (I haven't seen the detailed testimony, probably there isn't any because he pleaded guilty ; isn't "testimony" an appropriate word in this case [GRIN] ; compare to the case of George Michael) ; he was convicted, and the court required him to be chemically castrated using "massive" doses of female sex hormones (compare to the case of George Michael); this made him start to grow tits, and started to cloud his thinking abilities. So he killed himself. But the castration didn't stop him from being gay.
(By the way, I'm being facetious about making being gay compulsory for a few years. No, I'm just talking about making anal sex the only legitimate form of sexual activity, with all men having to take it as often as they give it and the girls being given free strap-on dildos to use on each other and on the men. Perhaps some sort of modified pedometer would have to be installed on everyone to monitor everyone's give/ take ratio. That's legally possible, and might be enforcible. But would it instantly make everyone in the world gay? Of course not. That's the difference between impulse and action.)
The $18 is a "laughing price" ; they don't want anyone to pay them $18 to read one article. What they (Nature Publishing Group) want you, and lots of others, to do is pay approximately £145 (whatever that is in your currency) for a year-long subscription to the magazine (50 or 51 editions) plus unlimited access to their archives. It is, after all, a magazine, and while it's raw content is given to it by authors, it still has real costs in organising peer review, typesetting (ever tried laying out a page that's going to press? It's demanding work), producing editorial content, plus of course, printing.
You might disagree ; I've voted with my wallet on several occasions and been a subscriber for several years (alternating with Science, BTW). The ink-on-paper copies pile up, hugely. I'm not a subscriber at the moment because I'm working on another project, and I'll look again at the idea in a couple of years.
You can. Go down the road here to the Central Library (next to the theatre ; opposite the Wallace Monument), pick it off the shelf, and then pay about £0.40 to get the photocopier to work. (Nature is a reference journal - you can't book it out of that library.) Alternatively, you can go down to the University Library and pay your £60 annual fee (discounted to £30 if you're a graduate of one of Aberdeen's University institutions) to read it off the shelf there and to borrow volumes of bound editions of Nature from the stacks. The photocopiers are a bit better and noticeably cheaper.
Contrary to popular opinion, information is not free now, and never has been. Individual commentators on SlashDot may have been insulated from such costs until now, but that doesn't mean that they're not real costs.
Different degrees of temporariness ?
So ... what is to stop you from
You get the game you want without the hassle of the DRM ; the company gets it's profits and their programmers and artists get to bring husks of bread home to feed the starving children.
Oh, I see the problem. It's at step (1), where you buy the game.
(Currently I play "CIV for DOS" and "UFO:Enemy Unknown", both of which I brought legally over a decade ago. Just because they're not new doesn't mean they're not interesting and don't run.)
From Lenovo's website just now.
Of course, it would be nice if they did the laptops without wireless hardware too, but that's just too much to ask.
This isn't the first time that a server has been lost. Or found.
http://groups.google.co.uk/group/alt.folklore.computers/browse_thread/thread/6289e24b593eaf16/17ac734391deebbb?lnk=gst&q=server+behind+drywall#17ac734391deebbb
Don't any of these people remember reading newsgroups 7 years ago? It's not rocket science.
The experiments have been done ; no need for doubt or supposition.
Look at either common design of Scuba regulator, or their commercial equivalents ("full face masks") ; where is the pressure regulator? Either between the shoulder blades (and so just a few cm vertical distance from the lungs) ; or at the user's mouth (so getting perhaps 15cm from the top of the diver's lungs) ; or on the diver's cheek (same comment).
Very occasionally you'll see people using a twin-hose airset mounted at the waist, so with the regulator up to 40cm deeper than the lungs. This is strongly discouraged because of two hazards - kinking the hoses and air embolism. It's really a "don't do this" situation - only try it if you're definitely going to die otherwise. (I speak as a diver with a non-trivial log book of near-death experiences. Which is why I stopped diving.)
People have an excessive confidence in the abilities of their bodies. Seriously, don't act on your "doubts" and suppositions. Speak to proper dive training organisations. The only substitute for learning from other people's experiments is doing it yourself, and possibly dieing.
An important point. Population distribution in Britain is very uneven. Half the population live within approximately 80 miles of Kinder Scout (Derbyshire), but that of course excludes the biggest (and most horrible and self-centred) city ; 95% of the population live in about 50% of the country (which is where the mobile phone masts get put. Go to a less populated area, et voila, there goes your signal, down the tubes.) ; whole tracts of the country have only tiny villages spread thinly around the coasts and along some valleys (who's going to put fibre in to service the couple of thousand inhabitants of Fort Augustus, 30 miles each way from anything resembling a large town?)
I'll ask my friend on the local Council's Finance Committee. They have to deal with maintenance of the several miles of cobbled street in town. Where the streets are used for light traffic (cars, delivery vans), the cobbles are re-laid every 30-odd years ; where the traffic is heavier (I'm thinking specifically of the #20 bus route) it's about 15 years. It's just standard maintenance.
200 year old sewers? Well, there are a few multi-millennial sewers in Rome, so there could be some multi-century ones. But the big period of sewer building in Britain didn't start until 150 to 170 years ago. Picky, picky.
Evolution requires reproduction. Single organisms don't evolve ; populations evolve. Try this human thought experiment : as of tomorrow morning, all red-haired are going to suffer an evolutionary pressure by being garotted on sight by any other human. This will have a population effect of eliminating the gene(s) for red hair. But for the individual? Their genes don't change, just their vital status. ... changes in your genes that have significant effect are called cancer. ... Fibbonacci's rabbits). I one case, you've got a generation ship ; in the other case, you've got minuscule populations.
Looking from the other end of the telescope
If you've got a population that's going to evolve, you have to have reproduction. Which means that you either have to have quite a large environment, flying through space. Or you have to have each parent giving rise to just one descendant (otherwise the population starts to increase (1,1,2,3,5,8,13,21
Panspermia isn't impossible. But it is frightfully difficult. As a geologist, I find it easier to solve the problem of origin of life here on Earth, rather than facing the same problem on some other planet and adding the problems of panspermia.