Wikipedia:Reference desk/Archives/Science/2014 October 27
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October 27
editWhat is the diffrence between Teflon and Plastic"
editI've red in the article "Peripheral venous catheter" the next sentence: Modern catheters consist of synthetic polymers such as teflon (hence the often used term 'Venflon' or 'Cathlon' for these venous catheters). In 1950 they consisted of plastic. Is the teflon isn't kind of plastic? 194.114.146.227 (talk) 02:17, 27 October 2014 (UTC)
- Well, it's kind of a grey area. "Plastics" are generally considered to be organic molecules - teflon is a carbon-fluorine compound...which is not exactly most people's idea of an "organic" molecule. So I suppose you could argue that teflon is not technically a plastic. However, the word "plastic" and the term "organic" are both somewhat poorly defined, so there is ample room for debate. I agree that the article is a bit vague though - it would have been better if they had specified what kind(s) of plastic were in use in the 1950's. Sadly, the article they reference for this claim is on PubMed, and I don't have an account there to see if the original reference was any more specific. SteveBaker (talk) 03:06, 27 October 2014 (UTC)
- Yes, the nomenclature is a bit vague. I've tried a bit, and can't find any digital copy of the 1950 article. Most stuff that old isn't digitized yet (if it ever will be). I found this retrospective [1] from 2008, and this review from 1965 [2]. Both articles just say that the needle was sheathed in "plastic." Apparently the original device was known as the "Massa plastic needle" or "Rochester Plastic needle", that might help someone track down details of the material. SemanticMantis (talk) 14:40, 27 October 2014 (UTC)
- UPDATE:- got it: from this article, 2005 [3]
“ | It began in 1950 with a landmark discovery at the Mayo Clinic by Dr. David Massa, a resident in anaesthesiology. Massa began by shortening a 16-gauge Becton Dickinson (Franklin Lakes, NJ) needle and inserting another steel needle as an inner stylet. It looked much like today’s epidural needle, complete with stylet. Then, over the top of the needle was fitted a polyvinyl chloride (PVC) catheter, which was attached to a metal hub via a crimp band. The tip of the catheter was hardened and shrunk to fit the needle, using ethyl acetate which deplasticized the PVC. This resulted in an ‘over-the-needle’ configuration, which after several further iterations became the famous ‘Rochester plastic needle’ | ” |
- So, the originals were PVC, though I suspect several other materials were tried before Teflon became standard. As thanks for finding the info and reference, I hope OP or someone will update the article :) SemanticMantis (talk) 14:40, 27 October 2014 (UTC)
- I put in the ref and a link to PVC, but the intro could probably use more re-wording if anyone's interested. SemanticMantis (talk) 15:54, 27 October 2014 (UTC)
- So, the originals were PVC, though I suspect several other materials were tried before Teflon became standard. As thanks for finding the info and reference, I hope OP or someone will update the article :) SemanticMantis (talk) 14:40, 27 October 2014 (UTC)
Identification of a naval base structure
editWhat is that tunnel looking thing[4] in the foreground with the American flag? I've seen similar structures in other naval base photos as well. — Preceding unsigned comment added by WinterWall (talk • contribs) 03:57, 27 October 2014 (UTC)
- You mean the white thing? That's the Arizona Memorial. It sits atop the remnants of the ship which the Japanese sunk in 1941. If you mean the rusty cylindrical thing, that's likely part of a smokestack from the ship. Pearl Harbor is rather shallow. The ship's upper structures were removed and the memorial built over top of it. ←Baseball Bugs What's up, Doc? carrots→ 04:07, 27 October 2014 (UTC)
- Yep, see USS Arizona Memorial. Dismas|(talk) 04:10, 27 October 2014 (UTC)
- In that aerial photo, you can see the wreckage of the ship in the shallow, clear water there in Pearl Harbor. ←Baseball Bugs What's up, Doc? carrots→ 05:51, 27 October 2014 (UTC)
- Thank you, guys.WinterWall (talk) 04:42, 27 October 2014 (UTC)
- Yep, see USS Arizona Memorial. Dismas|(talk) 04:10, 27 October 2014 (UTC)
Light blend modes
editFor some reason, I think the sunlight and other light beams use an additive blend mode with the electromagnetic radiation extending it's wavelength nanometres to illuminate light and I don't know where to put the line about the additive blend color on the light, sunlight or something to make it make sense as they have the black parts invisible because of the alpha blending parameter done by electricity being additive and spreads light on the texture shaders to change the brightness and contrast of the objects and the ground to create specularity such as liquid highlights or gloss reflections with the most used reflection method in real life that often uses the camera reflection mapping to convert anything into a reflected image through mirrors. Could somebody give me a clue where to put that line in one of the articles about lights and such illuminating objects with this blending including the X-ray that divides the pixels?--HappyLogolover2011 (talk) 04:12, 27 October 2014 (UTC)
- I don't follow your question, but the answer is probably "no." If your understanding of something starts with "for some reason, I think..." then you should not be inserting that thing into an article. We want Wikipedia to contain reliable, verifiable, sourced information, not speculations and guesses.
- Your question seems to "blend" concepts between the physics of light and computer modeling of illumination. These are two different things, and should not be confused. --Srleffler (talk) 04:40, 27 October 2014 (UTC)
- Don't put it anywhere. If you can point us to some published research on the topic, we might be able to give a more favourable answer. Dbfirs 07:32, 27 October 2014 (UTC)
- You seem to be using the terminology of computer graphics ("alpha channels", "pixels", "shaders" and "blending") and trying to apply it to the real world. That's a really bad idea! The real world doesn't work remotely like computer graphics do. Graphics are a horrible approximation to the thin slice of reality that humans can actually see, and they don't (generally) simulate anything beyond the red, green and blue frequencies that the human eye is sensitive to, and which common display devices can generate. So we can't answer any of this meaningfully - the question is nonsensical. SteveBaker (talk) 13:40, 27 October 2014 (UTC)
which is re-usable for another mission: Rockets, Space-Craft or Space Flight?
editWhich is re-usable for another mission: Rockets, Space-Craft or Space Flight? & also tell if space-craft has solar panels so how they reach earth safely & re-usable for next mission? i am going to create a wikipedia article about re-usable space-crafts, that's why i am creating this section.
Ram nareshji (talk) 10:15, 27 October 2014 (UTC)
- See our article on Reusable launch systems, which already covers this and a fair bit more. As for the solar panels on the Soyuz, they are attached to the service module - the entirety of which is detached before re-entry and left to burn up in the atmosphere. WegianWarrior (talk) 11:47, 27 October 2014 (UTC)
- With Soyuz, not only is the Service Module with the solar panels detached and left to burn up in the atmosphere, but so is the Orbital Module (the round part at the other end). Only the Descent Module, the middle third (29% by length, 43% by mass), is recovered. -- ToE 21:08, 27 October 2014 (UTC)
- The RLV article primarily discusses launch systems and not capsules. My understand is that to date no capsule has ever been reflown.
- SpaceX has flown six Dragon cargo capsules so far. Their service module with the solar panels is lost, as described above, but the capsule itself is recovered and, according to SpaceX's website, is considered reusable. To date, however, none have been reused. Discussion on the boards suggest that this is because the design has been evolving, and that NASA, at least for now, prefers the reliability of new capsules.
- Last month NASA made awards to Boeing and SpaceX for the CCtCap phase of the Commercial Crew Development program. The award is generally described as up to $4.2 billion to Boeing and up to $2.6 billion to SpaceX, but I think that it
is[would be] more informative to break that down.Only half of the total award, up to $2.5 billion to Boeing and up to $0.9 billion to SpaceX, was for the actual development and certification. The other half, up to $1.7 Billion to each company, was for up to six operational flights of that company's spacecraft carrying a crew of four. This price is based on the current $70.7 Million per seat being paid to Russia. (I assume that this is just an initial price that NASA is agreeing to pay in order to spur development, and that prices are expected to fall later.)[This breakdown of prices was suggested here by By Jeff Foust writing for SpaceNews.com, but until NASA releases more details, it is not clear how many, if any, operational flights are covered by the announced award.] Both the Boeing CST-100 and SpaceX's Dragon V2 are described as reusable, but I have not yet heard whether NASA will be accepting rides in used capsules or will be insisting on new. I don't believe that details of the awards (such as a list milestones for the development phase or requirements for the operational flights) have been publicly released yet. -- ToE 13:17, 27 October 2014 (UTC)
- For the solar panels part: On the space shuttle, the solar panels were built inside the two cargo bay doors which were closed and locked for re-entry. For every other spacecraft that's returned to earth safely, there either weren't any large solar panels (Apollo era and earlier) - or they were jettisoned before re-entry.
- One question though: If you know so little about it, why are you even considering writing a Wikipedia article about it?!
- Solar power was not used on the Space Shuttle orbiters. Per Space Shuttle orbiter#Electrical power, "Electrical power for the orbiter's subsystems was provided by a set of three hydrogen-oxygen fuel cells ...". Hydrazine burning auxiliary power units (APU) were used to generate hydraulic power during ascent and during reentry and landing. They would open the cargo bay doors shortly after reaching orbit, not to expose solar panels, but to expose heat rejection units which radiated excess heat from the onboard systems. -- ToE 15:28, 27 October 2014 (UTC)
- Here is a NASA page detailing the Shuttle's Active Thermal Control System. There were two radiator panes on each side of an orbiter's cargo bay, attached to the doors. The aft two panels were fixed to the doors and could radiate only in only one direction, but the forward radiator panels could, if demanded by the thermal loads, deploy away from the doors and radiate on both sides. In File:Sunrise over Spacelab.jpg from STS-90, the deployed forward port radiator panel is clearly visible. -- ToE 15:53, 27 October 2014 (UTC)
- X-37B, USAF's mini-shuttle, is a long duration spacecraft which does use solar panels. I don't now how accurate this artist's conception is, but if that is representative of their solar array, they would have to refurl it to stow it in the payload bay. I hope they have a means of jettisoning the array in case the furling mechanism jams. -- ToE 17:04, 27 October 2014 (UTC)
Lymphogranulomatosis
editI encountered this word in a WWII-era memoir. Here in the English Wikipedia it doesn't redirect to anything, while a search here brings up various associations with Hodgkin's lymphoma. Are they exactly synonymous? What would be a suitable redirect for lymphogranulomatosis? -- Deborahjay (talk) 12:40, 27 October 2014 (UTC)
- Merriam Webster defines this term as: "the development of benign or malignant nodular swellings of lymph nodes in various parts of the body; also : a condition characterized by these" - so I'd guess that any such swelling would be described this way - and I presume that Hodgkin's is just one reason that this could happen. So I think a redirect would be a very bad idea. We wouldn't want everyone with swollen lymph nodes to automatically assume that they had Hodgkin's disease. It probably needs an article of it's own...with cross-links between it and Hodgkin's lymphoma. SteveBaker (talk) 13:45, 27 October 2014 (UTC)
- I just checked some other dictionaries and one said "an infectious granuloma of the lymphatic system. The term is used to identify several inflammatory, granulomatous or sarcomatous disorders, such as Hodgkin's disease, lymphadenoma, lymphadenoma venereum, and sarcoidosis." - so it would DEFINITELY be incorrect to redirect Lymphogranulomatosis to Hodgkin's lymphoma. SteveBaker (talk) 13:48, 27 October 2014 (UTC)
- Agreed. Note Lymphogranuloma venereum, which is among the most common conditions with which this term is associated. -- Scray (talk) 00:37, 28 October 2014 (UTC)
- I just checked some other dictionaries and one said "an infectious granuloma of the lymphatic system. The term is used to identify several inflammatory, granulomatous or sarcomatous disorders, such as Hodgkin's disease, lymphadenoma, lymphadenoma venereum, and sarcoidosis." - so it would DEFINITELY be incorrect to redirect Lymphogranulomatosis to Hodgkin's lymphoma. SteveBaker (talk) 13:48, 27 October 2014 (UTC)
- We could create a list article, giving SteveBaker's definition of Lymphogranulomatosis, and a list of the conditions that cause it. CS Miller (talk) 10:03, 28 October 2014 (UTC)
- In Russian Lymphogranulomatosis (w:ru:Лимфогранулематоз) = Hodgkin's lymphoma. In German they are also synonymous. Ruslik_Zero 20:38, 28 October 2014 (UTC)
- Yeah - but this is the English language Wikipedia - and we can't really base article naming and redirection on the meanings of words in other languages. SteveBaker (talk) 13:57, 29 October 2014 (UTC)
- Where User:Ruslik0's point is relevant is at the stage of interwiki linking, especially now that this is handled via Wikidata. A lack of 1:1 correspondence across languages for a Latin medical term indicates the need for caution in attributing nomenclature. -- Deborahjay (talk) 20:15, 29 October 2014 (UTC)
- Yeah - but this is the English language Wikipedia - and we can't really base article naming and redirection on the meanings of words in other languages. SteveBaker (talk) 13:57, 29 October 2014 (UTC)
- In Russian Lymphogranulomatosis (w:ru:Лимфогранулематоз) = Hodgkin's lymphoma. In German they are also synonymous. Ruslik_Zero 20:38, 28 October 2014 (UTC)
Why do people do so little to fight volcanoes?
editMy understanding is that people in Iceland have frequently fought lava flows, directing them away from inhabited areas. So why do people in Hawaii seem to leave it up to the lava flow to decide which way to go, even where there is no clear indication of which way it will choose? [5] Even beyond this, why don't people drill into volcanoes and try to make artificial vents for lava to be channeled away to uninhabited areas, or even take on magma reservoirs proactively and cool them with lots of water, making use of turbines and condensers to cool and recycle it while not coincidentally making a fortune in geothermal power? I feel like there's this huge assumption of helplessness in the face of a phenomenon that really isn't even very powerful by comparison to the thermal mass humans move in ordinary waterworks. Wnt (talk) 22:04, 27 October 2014 (UTC)
- This USGS page describes the Icelandic attempts to cool and divert lava flows, but also mentions attempts in other places, including Hawaii. This page describes some of the issues with doing things the Icelandic way in Hawaii, specifically the availability of seawater, as very large volumes are required. Mikenorton (talk) 22:20, 27 October 2014 (UTC)
- That's a good question. In the header, I mean. The followup is definitely good, too, but the question alone really made me think. Thanks! All I can offer in return is "Because they're too hot." Sorry. InedibleHulk (talk) 23:01, 27 October 2014 (UTC)
- Which volcanoes? There may be things that can be done in some cases to ameliorate the effects of some volcanoes. But the word "volcano" encompasses a wide range of very disparate geological phenomena, and the fact that something could maybe be done for some kinds of volcanoes doesn't mean that anything could be done for others. The Hawaiian type of volcanoes are a peculiar type which isn't necessarily like any other type. Shield volcano covers some of the information on the Hawaiian type: You'll note that the text says "Most of what is currently known about shield volcanic eruptive character has been gleaned from studies done on the volcanoes of Hawaiʻi island, by far the most intensively studied of all shields due to their scientific accessibility;[16] the island lends its name to the slow-moving, effusive eruptions typical of shield volcanism, known as Hawaiian eruptions." You'd have to believe that if Kīlauea is the possibly most studied volcano on earth, someone would have come up with some way to stop ameliorate its effects. It isn't as simple as you seem to make it out to be, as though thousands of vulcanologists had been studying Kīlauea for decades, and to a person they said "You know, we could totally fix this thing, but man, fuck all those Hawaiians" That isn't how it works. The scale and scope of the situation likely makes it beyond the means to fix. --Jayron32 23:22, 27 October 2014 (UTC)
- I was wondering about this myself, watching what's going on in Hawaii. I know the Icelanders were successful at least once using water to freeze a dike to divert the flow away from a town. I'd look into the money and political aspect of it, both, would it threaten other towns if diverted, and is there environmental opposition to "interfering" with nature, or worse, with Pele. ABC tonight showed the authorities were quite happy to build new roads at an emergency pace and build protective barriers to protect electric poles. This shoes that the "all is lost" attitude is not being applied equally. It does not seem irrelevant that the activist native community is a large part of the constituency of the ruling party in the state. μηδείς (talk) 01:34, 28 October 2014 (UTC)
- Again, in this case we're comparing mountains to molehills, almost literally. The Icelandic situation you are talking about is likely the volcano Eldfell on the island Heimaey. Eldfell was a smallish cinder cone which erupted over a few months and put out a TINY fraction of the Lava that Kīlauea puts out. Eldfell is 200 meters tall, and the size of the footprint of that lava flow is probably 1.5 square kilometers. Kīlauea has been erupting more-or-less nonstop for 30 years, it's 1200+ meters tall, and part of a single volcano (including the neighboring calderas of Mauna Loa and Mauna Kea) which is many orders of magnitude larger than the Heimaey. Look, Heimaey is about as big as Manhattan south of Central Park. The Big Island of Hawaii (which is basically all the single volcano) is a tad smaller than the state of Connecticut. The ability to save the fishing village on Heimaey in no way relates to the ability to do the same on the Big Island of Hawaii; the scale difference is like swatting a fly versus swatting an eagle. --Jayron32 12:15, 28 October 2014 (UTC)
- We're only talking about this flow Jayron, not plugging the volcano. The facts it is a bigger volcano and has been erupting for 30 years are hardly relevant - it's an engineering project, and whether it might be successful or not (I made no guarantee, that's "above my paygrade"), it's not being tried for one reason - political opposition. μηδείς (talk) 17:19, 28 October 2014 (UTC)
- Mikenorton's answer is really helpful; those links might be enough to seed an article on diversion of lava flows. The sources explain that pumping seawater to divert lava is easiest very near the ocean (i.e. to save a harbor) rather than far away, and of course Hawaii has more internal development by far than Iceland. That said, I still can't believe that the sort of people who you see in TV shows about gold digging in Alaska couldn't manage to use half a dozen earth movers to make a trench sufficient to accommodate something like this, backed up by a strong dike with the overflow, at a rate fully equal to the 10-15 yards per hour that the lava flows. Based on the scale of the trees in the foreground, it's just not all that wide and not all that deep either. (Obviously, I'd expect them to work in a number of separate zones for maximum efficiency, and plan completion well before the magma enters!) Wnt (talk) 12:07, 28 October 2014 (UTC)
- Again, in this case we're comparing mountains to molehills, almost literally. The Icelandic situation you are talking about is likely the volcano Eldfell on the island Heimaey. Eldfell was a smallish cinder cone which erupted over a few months and put out a TINY fraction of the Lava that Kīlauea puts out. Eldfell is 200 meters tall, and the size of the footprint of that lava flow is probably 1.5 square kilometers. Kīlauea has been erupting more-or-less nonstop for 30 years, it's 1200+ meters tall, and part of a single volcano (including the neighboring calderas of Mauna Loa and Mauna Kea) which is many orders of magnitude larger than the Heimaey. Look, Heimaey is about as big as Manhattan south of Central Park. The Big Island of Hawaii (which is basically all the single volcano) is a tad smaller than the state of Connecticut. The ability to save the fishing village on Heimaey in no way relates to the ability to do the same on the Big Island of Hawaii; the scale difference is like swatting a fly versus swatting an eagle. --Jayron32 12:15, 28 October 2014 (UTC)
- I was wondering about this myself, watching what's going on in Hawaii. I know the Icelanders were successful at least once using water to freeze a dike to divert the flow away from a town. I'd look into the money and political aspect of it, both, would it threaten other towns if diverted, and is there environmental opposition to "interfering" with nature, or worse, with Pele. ABC tonight showed the authorities were quite happy to build new roads at an emergency pace and build protective barriers to protect electric poles. This shoes that the "all is lost" attitude is not being applied equally. It does not seem irrelevant that the activist native community is a large part of the constituency of the ruling party in the state. μηδείς (talk) 01:34, 28 October 2014 (UTC)
- It depends on the volcano. I recall when Mt. St. Helens erupted, and the standard way to "fight" it was to flee - preferably westward, i.e. upwind. ←Baseball Bugs What's up, Doc? carrots→ 12:39, 28 October 2014 (UTC)
- As I noted above, apples and oranges here. St. Helens is a Stratovolcano which is a VERY different sort of geologic phenomenon than a Shield volcano. The former explodes. The latter oozes. --Jayron32 12:43, 28 October 2014 (UTC)
- Even so, I don't know why people didn't try to figure out a way to drill into the flank of the stratovolcano ... from a safe bunker, that is ... and release the pent-up gas in some more controlled way. Wnt (talk) 13:02, 28 October 2014 (UTC)
- Ever stick a needle in an over-inflated balloon? Same deal. --Jayron32 13:20, 28 October 2014 (UTC)
- Ever stick a needle through the neck of a balloon? You can indeed deflate it slowly and safely. The key would be (obviously) not to create a path out that could plausibly expand to accommodate a full eruption, even assuming other measures you make to limit the outward flow fail. Wnt (talk) 13:24, 28 October 2014 (UTC)
- You know what, you go ahead and do all that. The belief that an untrained layperson, who has a sudden "idea", would be better at solving a problem which thousands of experts, who actually understand the principles involved, spend their whole lives studying, is baffling. I'll trust those who actually study volcanoes, thanks, rather than someone who just has an "idea" but lacks the self awareness to understand their own lack of knowledge and ability in this area. I don't know much about volcanoes, but I do know that there are many people who do, and I trust them because they know more than me about this. --Jayron32 13:52, 28 October 2014 (UTC)
- Objective here is to understand why. It is possible that there are good, scientific reasons not to do this. For instance, maybe the magma contains supersaturated gas and tampering with it in any way causes "bumping", though I would find it hard to believe. It is also possible that there are political reasons (public fear) or budget reasons but no scientific reason to discard the possibility of experimenting with such ideas. You have not answered which. Wnt (talk) 14:10, 28 October 2014 (UTC)
- You know what, you go ahead and do all that. The belief that an untrained layperson, who has a sudden "idea", would be better at solving a problem which thousands of experts, who actually understand the principles involved, spend their whole lives studying, is baffling. I'll trust those who actually study volcanoes, thanks, rather than someone who just has an "idea" but lacks the self awareness to understand their own lack of knowledge and ability in this area. I don't know much about volcanoes, but I do know that there are many people who do, and I trust them because they know more than me about this. --Jayron32 13:52, 28 October 2014 (UTC)
- Ever stick a needle through the neck of a balloon? You can indeed deflate it slowly and safely. The key would be (obviously) not to create a path out that could plausibly expand to accommodate a full eruption, even assuming other measures you make to limit the outward flow fail. Wnt (talk) 13:24, 28 October 2014 (UTC)
- Ever stick a needle in an over-inflated balloon? Same deal. --Jayron32 13:20, 28 October 2014 (UTC)
- Even so, I don't know why people didn't try to figure out a way to drill into the flank of the stratovolcano ... from a safe bunker, that is ... and release the pent-up gas in some more controlled way. Wnt (talk) 13:02, 28 October 2014 (UTC)
- As I noted above, apples and oranges here. St. Helens is a Stratovolcano which is a VERY different sort of geologic phenomenon than a Shield volcano. The former explodes. The latter oozes. --Jayron32 12:43, 28 October 2014 (UTC)
People have been thinking of ideas to stop or divert lava flows for well over a century. This BBC piece provides a quick overview of the methods that have been tried and the very limited success they have had. Here you can find the topic discussed in context of the current eruption in Hawaii. And if you search Google Scholar, you'll find thousands of scientific papers on the subject. And as to whether the fundamental difficulty is due to science, engineering, or economics, the answer is yes. Abecedare (talk) 14:57, 28 October 2014 (UTC)
- @Wnt:, the fundamental difference between a volcano like Kīlauea and Mt. St. Helens, is that the magma that forms Mt. St. Helens starts to crystallize and solidify at temperatures and pressures that are still well below the surface. You can imagine that the magma turns to something like glue. Rather than calmly flowing out of the volcano, it seals all of the holes and becomes plugged. Drilling another hole into a volcano like Mt. St. Helens wouldn't make any difference as the magma would rapidly seal it. Even though it is plugged the magma continues to push from behind causing the whole mountain to be raised up. For a mountain like that, the explosion generally comes when persistent increase in elevation leads to a major landslide. The landslide reduces pressure of the magma, causing gas to come out of solution. The expanding gas pushes away the overlying rock, further reducing the pressure and leading to more gas releases, and in almost no time at all half the mountain has been blown away. The glue-like nature of the magma generally prevents small releases of the pressure, so that only big eruptions (those capable of ripping large vents through the overlying rock) end up happening. You might be able to pre-detonate a volcano like Mt. St. Helens by triggering landslides or otherwise blowing large holes in the mountain, but you would have a hard time knowing whether the eruption that you caused was "better" than what would have happened anyway. Drilling small holes generally isn't going to do anything though. Dragons flight (talk) 17:41, 28 October 2014 (UTC)
- @Dragons flight:I've seen things about the expanding gas many times... the problem is, I can't make sense out of them. Removing rock reduces pressure causing gas to come out of solution and... increasing pressure beyond what it was??? Why does a reduction in pressure cause an increase in pressure? Unless there's truly supersaturated gas needing only nucleation, how can that happen?
- 1 Substances become orders of magnitude bigger when gaseous. 2 Even the thinnest, hottest lava is still denser, and much more viscous and harder to swim in than water (though the density probably urges it downhill faster than an organic fluid that viscous), exploding volcano magma is I guess acting like the Boston Marathon bomber's black powder container. Even deep sea nuclear bombs don't have enough power to break containment. 3 Just because bubbles form, doesn't mean they can escape. The viscousness of some magma is silly. 4 A kilo of undissolved magma gas is roughly an order of magnitude bigger than a kilo of room temperature gas. A liter of magma gas bubbles has an order of magnitude more pressure than a liter of air. Sagittarian Milky Way (talk) 23:21, 28 October 2014 (UTC)
- Suppose you lined your borehole with excellent insulators, with heating elements embedded to further ensure a fixed temperature is maintained where the magma is fluid. Then could the magma be steadily withdrawn and processed? Wnt (talk) 18:46, 28 October 2014 (UTC)
- @Dragons flight:I've seen things about the expanding gas many times... the problem is, I can't make sense out of them. Removing rock reduces pressure causing gas to come out of solution and... increasing pressure beyond what it was??? Why does a reduction in pressure cause an increase in pressure? Unless there's truly supersaturated gas needing only nucleation, how can that happen?
- Gas dissolved in solution is generally stable (unless supersaturated). Large pockets of gas are generally not stable. You remove the overlying pressure, this causes gas to come out of solution and bubbles to form. The bubbles are then buoyant so rock collapses around them allowing the gas to squirt towards the surface. If the gas pocket is large enough, the effort of it flowing towards the surface has enough force to carry away more of the mountain with it. Which in turn removes more pressure and releases more gas. If you have ever held a beach ball or other inflatable object underwater and then released it, then that might convey a bit of the tendency for buoyant gases to push their way out. The pocket of gas doesn't directly create a higher pressure on the mountain, rather the point is that the pocket of gas is both buoyant and mobile which allows it to erupt outward.
- If you made your borehole hot enough, and could keep it hot, then presumably you could draw out magma. Not sure how practical it would be though. At the temperatures high enough to get the magma to flow easily, there would be a tendency to start melting the mountain around the bore hole as well, and having some very large thermally insulated borehole seems pretty fantastical. Dragons flight (talk) 23:50, 28 October 2014 (UTC)
- I was thinking of Space Shuttle tile, recalling a famous image of someone holding one in his hand as it glowed cherry red. What's interesting is you're saying that if some magma is withdrawn to maintain constant pressure, the volcano stays stable. But if too much is withdrawn and pressure drops, gas pockets would form and then start working their way out due to intense local pressure from buoyancy. That's a nicely clear explanation (hope I have it right...). Makes me think though that if you could actually detect the gas pocket itself in a volcano near eruption, and directly remove the gas from it... you'd not have to keep the gas hot of course, and the bad effect of reducing the pressure would be directly offset. Unless there's more than one gas pocket. ;) Still, if the gas is the specific thing that takes apart the mountain, I'd think you could relieve it directly. Wnt (talk) 00:05, 29 October 2014 (UTC)
- Wnt, Jayron is right with a stratovolcano-you might set one off early to get a huge pyroclastic explosion now, rather than a huger one later. Building dikes to dam lava flows from shield volcanos is an entirely different manner, and it is theoretically possible and has been done, but there is loud political opposition to this by the activist environmentalist and native Hawaiian constituencies of the Democratic party, which runs Hawaii, see the link I gave under Pele above in bold to see what happens when you try even to discuss diverting the flow. The answer to your question is politics. μηδείς (talk) 00:23, 29 October 2014 (UTC)
- There's also the problem of liability. A volcano which naturally erupts is an enormously expensive act of nature. A volcano which erupts after I've been mucking about with it is potentially an enormously expensive lawsuit in the making. Anyone hurt or financially damaged by the eruption could easily make the case that I caused the problem and bring all kinds of problems back onto me. Matt Deres (talk) 16:37, 29 October 2014 (UTC)
- Sovereign immunity protects the state and its officials unless there's actual criminal negligence. The answer to Wnt's question is politics. It might be the case that a diversion plan wouldn't work, or would cost significantly more than relocating the residents--but this hasn't been demonstrated. See the linked article as to why they aren't even discussing any concrete plans. μηδείς (talk) 16:52, 29 October 2014 (UTC)
- There's also the problem of liability. A volcano which naturally erupts is an enormously expensive act of nature. A volcano which erupts after I've been mucking about with it is potentially an enormously expensive lawsuit in the making. Anyone hurt or financially damaged by the eruption could easily make the case that I caused the problem and bring all kinds of problems back onto me. Matt Deres (talk) 16:37, 29 October 2014 (UTC)
- Wnt, Jayron is right with a stratovolcano-you might set one off early to get a huge pyroclastic explosion now, rather than a huger one later. Building dikes to dam lava flows from shield volcanos is an entirely different manner, and it is theoretically possible and has been done, but there is loud political opposition to this by the activist environmentalist and native Hawaiian constituencies of the Democratic party, which runs Hawaii, see the link I gave under Pele above in bold to see what happens when you try even to discuss diverting the flow. The answer to your question is politics. μηδείς (talk) 00:23, 29 October 2014 (UTC)
- This year in Hawaii they've been experimenting with alternative means of mitigation, including some kind of a multi-layered insulating pen and wrap for existing wooden power and telephone polls, and to get authentic data they can't do any lava flow diversion. That's okay with everyone because very little non-state property is threatened at present, and those who have been threatened have already been paid off for the experiments to proceed. 71.215.67.106 (talk) 23:16, 29 October 2014 (UTC)
- Nothing to offer, just wanted to say this is an interesting discussion to read. Good work! InedibleHulk (talk) 01:40, 30 October 2014 (UTC)
Medeis has spoken, and decided their opinion is fact. Pay attention people, and stop discussing this. --Onorem (talk) 01:47, 30 October 2014 (UTC)
highest price of oil per barrel
editwhat is the highest price of oil per 'barrel' (unit volume) if we take 'oil' to mean the verified oevre in oil of one painter. For example, all of the verified Van Gogh oil prints that are on the market, could be divided by their volume and multiplied by the volume of a barrel of oil, to give the price per barrel of 'van gogh' oil. By this metric which verified painter would have highest price per barrel, and who would it be? 212.96.61.236 (talk) 23:33, 27 October 2014 (UTC)
- this is probably unquantifiable or at least you'll never get a definitive response because many works by the most prominent oily artists go unsold and estimates for those paintings cannot be reliably made...i think that da vinci might be up there though, since he had like 15 paintings with oil or something and they're all widely known and sell for bout a hundred million quid ? also minimalist painters who use oil might be up there too ~Helicopter Llama~ 00:25, 28 October 2014 (UTC)
- Infinite, for any painting that doesn't use oil. The question doesn't make sense because a painting consists of much more than just oil--there's also paper, wood, pigments, dirt, hairs from the paintbrush, etc. The thing that has value is the creativity and authorship behind the painting, not the painting's physical components. --50.46.159.94 (talk) 07:43, 28 October 2014 (UTC)
- Undefined, if there is no oil. Also, the first painting which is very perfect squares of various colors on a background is worth 8 figures and is analyzed like the Bible or the Mona Lisa. An unestablished artist with proof of making one the next day (filmed a rare tropical aurora behind it), and proof of ignorance of the precedent (160 mph hurricane outside his cave, auroral storm prevented all chance of radio contact), rescued from a desert isle a year later with it will never sell for much. If he had done Jackson Pollack, though.. then jackpot! (If "splatter painting" was not after "perfect squares of various colors" then replace it with a gimmick that is - I'm not sure of the chronology) Sagittarian Milky Way (talk) 00:35, 29 October 2014 (UTC)