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October 26

Ebola virus hardiness

How long does the Ebola virus remain infectious outside a living host (bat, human, dog, swine, or other carriers)? Ebola virus disease says that it is highly infectious on the skin of a dead victim, but for how long? The article just says it is infectious on surfaces for "a few hours." How about on things contaminated by fluids from the victim (blood, feces, vomit) on sheets, toilets, clothing, doorhandles? They went through a great effort to remove everything from the apartment of the Dallas victim's family, but if the stuff becomes noninfectious after "a few hours,"why couldn't they have just locked the door for a day or two, rather than destroying all personal belongings, carpets, etc? When sources say the virus is not infectious after so many hours, does that assume it is exposed to fresh and sunshine, while in moist dampness it could persist indefinitely? I know that some bacterial pathogens sporify such as anthrax, and can remain infectious indefinitely. What about viruses? If the infectious potential only persists for "hours" (2, 20, 200?) then why the ritual of cleaning bowling alleys, taking airplanes out of service, and sending in hazmat cleaners to apartments? Is it a legitimate health precaution or "public health theatre"? Edison (talk)

How much do we know for sure about ebola? The story seems to change daily. It reminds me of the early years of the AIDS panic. ←Baseball Bugs What's up, Doc? carrots→ 14:41, 26 October 2014 (UTC)[reply]
Yes, health officials have an annoying habit of saying "it can't b spread by X", when they really should say "we haven't yet observed it being spread by X". Now, with a disease that's been around and unchanged for thousands of years, those two are pretty much the same. But in a relatively new and rare disease/strain, you can't just assume that a means of transmission is impossible because you haven't observed it yet. StuRat (talk) 16:06, 26 October 2014 (UTC)[reply]
Your first point is completely untrue. I can virtually guarantee you that no scientist/health official has explicitly said "it can't b [sic] spread by X", and will have said "we haven't yet observed it being spread by X". It's the obnoxious media "simplifying" the accurate wording scientists use for consumption by the ignorant soundbite-expecting public. As a scientist who has had their research misrepresented in the media, I feel this is an important point to make. Fgf10 (talk) 19:05, 26 October 2014 (UTC)[reply]
Have to agree with StuRat on this. Saw it myself on TV. An expert said something along the lines that if a victim is not showing signs and symptoms then s/he is not contagious and they can safely carry on with their normal work. There is something called 'theoretical' risk. Here, in the UK, one can only exhume 'known' smallpox victims if one has had a Small Pox vaccination. Likewise, if an archaeologist is exploring a plague pit, then it is understood that there is a 'theoretical' risk of contracting Yersinia pestis. (doctors have a saying: If you hear hoofs... think horses not zebras( the common not the exotic) Meaning: A doctor would not normally consider a patient with a cough as having Yersinia pestis. But if his patient says Oh and by the way, I am an archaeologist and currently working in an old plague pit, the doctor can then switch mode and consider the possibility of plague. This is because medial science does not know exactly how long the causative agents of these two diseases remain viable. The experts on TV where pontificating about thing that they have no scientific evidence for. Yet, perhaps, the allure of appearing on TV, overcame their conservatism and good judgment.--Aspro (talk) 22:50, 26 October 2014 (UTC)[reply]
I haven't heard the statement about Ebola that "It can't be spread by X". I did hear the statement about HIV that "It can't be spread by X", in particular to "It can't be spread by insects", when the Belle Glade cluster of HIV infections still isn't explained unless it was a rare case of the virus being spread by mosquitos. Statements that "it can't be spread by X" are more appropriate to varicella or to Y. pestis, with centuries of data, than to Ebola, and by now HIV is somewhere in between. (I think that it can reasonably be said that Ebola can't be spread by mosquitos, because if it could, most of the population in Liberia, Sierra Leone, and Guinea would be infected, but no one said that it could be spread by mosquitos. That isn't an argument against effective mosquito control, because malaria is still a serious problem in those countries.) Robert McClenon (talk) 15:59, 27 October 2014 (UTC)[reply]
I had read that the virus can survive for a couple of hours on a hard, dry surface - up to 24 hours on moist/soft surfaces and an unknown, but definitely much larger, amount of time in human corpses. A lot of the caution involved here is because there are unknowns. This virus is just not that well understood - and there is always the possibility of mutant strains that can break the rules. When you're dealing with something with the ability to become an unstoppable global pandemic with a potential for deaths in the billions, an excess of caution is definitely required.
Viruses are tremendously variable in their capabilities. The HIV virus is incredibly fragile and can hardly exist outside of the human body at all. The classic Tobacco mosaic virus can live for up to nine years on a dessicated plant leaf - and can form essentially inorganic crystals that can survive for decades in a wide range of conditions - it's capable of infecting 120 different plant species in nine distinct families. I'm sure there are examples all along that spectrum.
SteveBaker (talk) 14:56, 26 October 2014 (UTC)[reply]


This virus was first written up years ago. It clearly is of interest in the public health world, and could potentially cost many lives and many billions of dollars economic disruption. It is surprising if no controlled studies were done to furnish reliable answers to obvious questions such as I posed about how authorities can do the minimum disruption to ensure some contaminated apartment, bathroom, school, cruise ship or shopping mall will not be a source of future cases. Overreaction ("public health theatre") to reassure the public seems to be the rule so far in the U.S if the statements about a few hours or 24 hours for the infection potential of fluid deposits is correct. If some animal species is infected in a similar manner to humans (lab rats, or rabbits ideally, or even swine perhaps?) it would seem straightforward to do parametric testing and determine what measures are really necessary when an infected person has deposited his bodily fluids on something. If semen remains infective for weeks after the accepted 21 days, then what about blood? Ebola survivors are welcomed a a curative to transfuse new victims. This seems to be an anomaly. Edison (talk) 18:21, 26 October 2014 (UTC)[reply]
The main reason is that "this virus" hasn't been seen before. Every strain of Ebola is potentially a whole new surprise - see Ebola Reston for how surprising they can be. Though the reaction to that potential surprise should not have been first to broadly assure people that casual contact won't spread the virus, then to discount abundant fatalities in Liberian health workers as the result of poverty and ignorance, and only to start freaking out and taking protective measures after a couple of Americans die.
As far as viral stability in general, I think the viral envelope is a consideration. Viruses like HIV and Ebola that have envelopes are actually made up, in part, of a mix of phospholipids from the host's plasma membrane. This means that lipid peroxidation would seem inevitably to be a limitation. (Caveat: there's no literal guarantee that the virus couldn't totally shield itself from oxygen, or work even after the envelope is severely oxidized... I do doubt it though) Without taking time to really dive into the topic I'm only finding possibly-irrelevant references for this though like PMID 18598719, PMID 8686266. Wnt (talk) 13:20, 28 October 2014 (UTC)[reply]
Think Wnt is on the right track. 99.9% of the time, clinicians can be assured that each viral infection will follow the same course as the last, but occasionally an un-caricaturist epidemic brakes out, which suggests that a virus strain has mutated. In the fullness of time, maybe will we have a full RNA analysis, so know if this was the case. The point is: when such an un-caricaturist out outbreaks like this occurs, received medical dogma (like we heard at the start of the outbreak) should be replaced with Err , this is unusual. Let's look at this without letting medical dogma cloud our vision. Trouble is, that it appears to me that the individuals that move up from practising healthcare to administrators, loose touch with the reality of diseases. For someone of my age it was only a few decades ago that HIV/AID's was considered to be akin to GPI. Thought to be a psychiatric disorder attributed to the 'immorality of homosexuals'. Then heterosexuals started getting diagnoses with it. By then it had become wide spread and prepubescent children were contracting it from blood transfusions. When the Apollo 11 crew came back, were they not held in quarantine on the precautionary principle? There is only so much money in the pot for healthcare, so shouldn't that money be wisely directed to issues that may pose the greatest threat -by the experts that know , rather than left in the hands of administrators that use political one-upmanship to elevate their status (and financial remunerations)? This is the 21st Century, so let,s have protocols put in place to nip these emerging plagues in the bud. It will be less expensive in the long run.--Aspro (talk) 23:08, 28 October 2014 (UTC)[reply]
A thought has just come to me. Air travel is a lot safer to day than in the past. Much of this is because airline pilots have to undergo 'Recertification' [1]. This ensures that they haven't developed any bad habits, haven't forgotten the basic etc. Ie, still competed to be responsible for several hundred passengers (souls; men, women, children, grandparents etc.). Some of the healthcare representatives that I have seen of late on TV are responsible for the well-being of a hell of a lot more people, (millions). Should they not undergo recertification as well? Human kind has (slowly) progressed, by getting rid of the smooth talking pontificators who play politics for all their worth and replacing them with competent specialists. History has show that this is more economic in the long run.--Aspro (talk) 23:40, 28 October 2014 (UTC)[reply]
To identify oneself as an Infectious Diseases physician in the United States, one has to maintain certification - now a continual process of learning modules, practice improvement modules, and in-person examinations. Many adult Infectious Diseases clinicians also maintain certification in Internal Medicine, which requires continual recertification as well. Of course, some are just "pundits", and anyone with an ego (e.g. George Will on the subject of Ebola virus becoming airborne) can do that. -- Scray (talk) 14:51, 29 October 2014 (UTC)[reply]

Difference between diffusion of vapors and diffusion of gases

In today's present, it is been obvious that the separate sections of practical physics of thermodynamics thermostatics already had not been scientific perspectives. However, there is been a fundamental difference between the physical phenomena diffusion of vapors and diffusion of gases, so that, is been any significant technical differences between the steam turbine and gas turbine?--Alex Sazonov (talk) 17:03, 26 October 2014 (UTC)[reply]

There is no difference between a vapour and a gas, those terms are synonyms. However, technically speaking, steam is not a vapour, but an aerosol. That being said, at the macroscopic scale, steam is equivalent to a vapour, albeit constituted of very large "molecules" (droplets). Since the droplets that from the steam are significantly larger than individual molecules in gas, kinetic friction plays a much more important role when discussing wear and tear on a turbine. The design and operation of the steam turbine would need to compensate for the difference. If steam is heated to above 100°C, it becomes an actual vapour - water vapour. I suspect that most "steam" turbines are actually water vapour turbines. Plasmic Physics (talk) 22:20, 26 October 2014 (UTC)[reply]
  • More precisely, the word "steam" is used in two different ways. Either it means water vapor or it refers to the aerosol mist formed by water vapor condensing in air. In the context of steam locomotives, steam turbines, and so on, it means water vapor. See here or here, for example.--174.88.134.249 (talk) 04:56, 27 October 2014 (UTC)[reply]
The term "steam quality" refers to any of a variety of engineering approximations about the percentage of steam that is gaseous water, compared to the percentage that is suspended droplets of water. Nimur (talk) 22:47, 26 October 2014 (UTC)[reply]
Did the vapour and gases been homogeneous substance and uniformity of aggregate physical states of matter, that could be considered as the same physical phenomenon?--Alex Sazonov (talk) 04:13, 27 October 2014 (UTC)[reply]
Did the dynamical kinetics of vapour and gases been the homogeneous dynamical kinetics?--Alex Sazonov (talk) 11:51, 27 October 2014 (UTC)[reply]
Combining advanced terminology with your level of English is probably not the best choice in this instance. I for one, am completely confused by what you are trying to ask. Try asking with simpler words, then we can try to interpret what you mean to ask. Plasmic Physics (talk) 20:35, 27 October 2014 (UTC)[reply]
... and please don't make your words harder to understand by adding been to every sentence? The present tense (third person) of the English verb "to be" is just "is". Dbfirs 00:01, 28 October 2014 (UTC)[reply]
Now, now, we're not here to fix others' grammar to the nth degree. I'm simply trying to help him, help others to interpret for themselves what he is trying to communicate. Plasmic Physics (talk) 03:21, 28 October 2014 (UTC)[reply]
Despite the fact that the physics of thermodynamics and thermostatics studied so, that they had no scientific perspectives. I'm interested in acceptable and unacceptable methods of studying thermodynamics and thermostatics of homogeneous physical environments and their aggregate physical condition.--Alex Sazonov (talk) 09:31, 28 October 2014 (UTC)[reply]
OK, you're asking about scientific methodology? I don't know if there is particular which is more applicable to the field of thermodynamics than any other field of science, but try scientific method. Plasmic Physics (talk) 05:28, 29 October 2014 (UTC)[reply]
What is a concrete scientific method of studies did concludes about the homogeneous of the physical environment of gases and vapour?--Alex Sazonov (talk) 07:29, 29 October 2014 (UTC)[reply]
What is "Homogeneous of the physical environment"? Dynamic equilibrium? Plasmic Physics (talk) 08:34, 29 October 2014 (UTC)[reply]
In what why the diffusion of gases always had become to an explosion of gases and diffusion of vapour always had become to condensation of vapour?--Alex Sazonov (talk) 09:40, 29 October 2014 (UTC)[reply]
My apologies, but I'm abandoning this thread. It is simply too difficult to interpret. Plasmic Physics (talk) 10:09, 29 October 2014 (UTC)[reply]
I’m explain this by the physical fact, that the gases and vapour are always had during none homogeneous thermodynamic and thermostatic processes, that is at the basis of the dynamics of vapour and dynamics of gases as well as their statics are always been a different physical phenomena.--Alex Sazonov (talk) 10:31, 29 October 2014 (UTC)[reply]
Phenomena of physics of gases are always been different from the phenomena of physics of vapour.--Alex Sazonov (talk) 14:02, 29 October 2014 (UTC)[reply]
I interpret one question to be whether a turbine optimally designed for a vapor (a gas at less than the critical temperature) would also be optimally designed for use with a supercritical fluid. My suspicion is that supercritical fluids are less compressible and this should affect the design, but I know nothing about turbines! Wnt (talk) 13:36, 28 October 2014 (UTC)[reply]

October 27

What is the diffrence between Teflon and Plastic"

I'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)[reply]

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)[reply]
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 [2] from 2008, and this review from 1965 [3]. 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)[reply]
UPDATE:- got it: from this article, 2005 [4]
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)[reply]
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)[reply]

Identification of a naval base structure

What is that tunnel looking thing[5] 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)[reply]

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)[reply]
Yep, see USS Arizona Memorial. Dismas|(talk) 04:10, 27 October 2014 (UTC)[reply]
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)[reply]
Thank you, guys.WinterWall (talk) 04:42, 27 October 2014 (UTC)[reply]
Resolved

Light blend modes

For 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)[reply]

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)[reply]
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)[reply]
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)[reply]

which is re-usable for another mission: Rockets, Space-Craft or Space Flight?

Which 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.

Soyuz Spacecraft has two solar panels.
Soyuz Spacecraft has two solar panels, so while returning earth, how solar panels will get closed

Ram nareshji (talk) 10:15, 27 October 2014 (UTC)[reply]

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)[reply]
Only the middle third, the Descent Module, safely returns to Earth.
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)[reply]
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 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.) 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)[reply]
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?!
SteveBaker (talk) 13:35, 27 October 2014 (UTC)[reply]
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)[reply]
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)[reply]
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)[reply]

Lymphogranulomatosis

I 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)[reply]

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)[reply]
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)[reply]
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)[reply]
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)[reply]
In Russian Lymphogranulomatosis (w:ru:Лимфогранулематоз) = Hodgkin's lymphoma. In German they are also synonymous. Ruslik_Zero 20:38, 28 October 2014 (UTC)[reply]
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)[reply]
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)[reply]

Why do people do so little to fight volcanoes?

My 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? [6] 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)[reply]

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)[reply]
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, October 27, 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)[reply]
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)[reply]
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)[reply]
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)[reply]
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)[reply]
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)[reply]
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)[reply]
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)[reply]
Ever stick a needle in an over-inflated balloon? Same deal. --Jayron32 13:20, 28 October 2014 (UTC)[reply]
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)[reply]
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)[reply]
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)[reply]

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)[reply]

@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)[reply]
@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)[reply]
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)[reply]
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)[reply]
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)[reply]
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)[reply]
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)[reply]
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)[reply]
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)[reply]
Nothing to offer, just wanted to say this is an interesting discussion to read. Good work! InedibleHulk (talk) 01:40, October 30, 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)[reply]

highest price of oil per barrel

what 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)[reply]

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)[reply]
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)[reply]
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)[reply]

October 28

Space blanket - contra indication

I've red in the article "space blanket" in French that the contra indication of "space blanket" is a storm. I don't understand why is that. Before, I thought that the place to use it, it's only in storms and things like this. I'm wonder. 149.78.224.210 (talk) 00:33, 28 October 2014 (UTC)[reply]

If I'm reading your question correctly, you're wondering why a space blanket shouldn't be used during a storm. If that's so, it's due to the blanket being coated with a thin film of metal. As metals conduct electricity, it would be a likely place for lightning to strike. Dismas|(talk) 01:40, 28 October 2014 (UTC)[reply]
Not the way lightning works. It just traversed miles of air and a tiny bit of mylar isn't going to change it. Pointy or height is what causes high electric fields, not metal. --DHeyward (talk) 04:14, 28 October 2014 (UTC)[reply]
Several feet (a couple of meters) of conductive material may not make a difference to where the lightning bolt touches the ground, but it'll make a difference to where the electricity conducts to when it does. Not likely to be a big deal—unless those few feet are the difference between being seriously shocked and not. --174.88.134.249 (talk) 05:28, 28 October 2014 (UTC)[reply]
Is there a reliable source for that contra-indication? I would have expected the blanket to act like a Faraday cage.--Shantavira|feed me 10:42, 28 October 2014 (UTC)[reply]
I would expect nothing of the sort. Lightning would simply rip through the mylar. Justin15w (talk) 14:37, 28 October 2014 (UTC)[reply]
Plus that 5 to 6 feet tall column of extremely conductive mostly-salty-water might just take the strike first! SteveBaker (talk) 13:54, 29 October 2014 (UTC)[reply]
The reason has to be some other thing. The foil in a space blanket reflects heat from your body back at you, so you lose less heat than you otherwise would...it also traps warm air close to your body to reduce 'wind chill'.
The French article says absolutely nothing beyond that you shouldn't use it in a storm - and it has no references for that claim (which is usually a red flag!) - I couldn't find any such contra-indications in any of the places I searched for "How To" type stuff on storms or space blankets.
At this point, I'd ignore what the French article says - and perhaps re-ask this question on the talk page of the French article...or use the "View history" tab to figure out who added that statement to the article and ask them directly where they got that information from. SteveBaker (talk) 13:54, 29 October 2014 (UTC)[reply]

What is this a state?

In my country, in the USSR-Russia had always assumed that a state is the only the legitimacy of public statutus, so that a private deal which had not disobeying by the public rules is not been a private deal.

Did a state above all things is the legitimacy of private statutus or a state above all things is the legitimacy of public statutus?--Alex Sazonov (talk) 12:17, 28 October 2014 (UTC)[reply]

1) This is the science desk. You may want to ask this at The Humanities Desk instead. 2) You seem to be asking about issues related to Power of a sovereign State to regulate Contracts between legal persons who are "private" (not arms of the state), be they persons or corporations. Is that correct? Your English is hard to follow. --Jayron32 12:32, 28 October 2014 (UTC)[reply]
You understood me correctly, becouse all notariate (all notaries) in the USSR had always been a public (state)!--Alex Sazonov (talk) 13:31, 28 October 2014 (UTC)[reply]
In the USSR, a private deal which not had a public (state) approval, that is a private deal which is not been a notarial deal always was formed black market (shadow economy).--Alex Sazonov (talk) 15:00, 28 October 2014 (UTC)[reply]
Wikipedia has articles on black market, shadow economy, and handshake deal which may lead you places you are interested in learning about. --Jayron32 16:46, 28 October 2014 (UTC)[reply]
(Did) the cost of a private deal had be determine a nature of its statutus?--Alex Sazonov (talk) 17:35, 28 October 2014 (UTC)[reply]
This question does mean, (Did) the cost of a private deal had be determine a nature of statutus of this private deal?--Alex Sazonov (talk) 08:26, 29 October 2014 (UTC)[reply]


We can assume that in the legal right of Ancient Rome, all private deals between patricians and plebeians and foreigners were never been equal in their legal right and legal economic status, so all private deals between the patricians could be the legal nature of the impossibility of their challengeability. That is why in the USSR all notarially statutus had always been a public (state)!--Alex Sazonov (talk) 05:03, 29 October 2014 (UTC)[reply]

The main question of state doctrine of right of the USSR, Did a statutus of public (state) right been a statutus of international right?--Alex Sazonov (talk) 11:44, 29 October 2014 (UTC)[reply]

state of matter

The following discussion is closed. Please do not modify it. Subsequent comments should be made on the appropriate discussion page. No further edits should be made to this discussion.

Matters exist in solid, liquid or gas state. What is the state of electrons, protons or neutrons? --Diwas Sawid (talk) 16:18, 28 October 2014 (UTC)[reply]

This question was asked in two locations. It arguably belongs here, but there are already answers at WP:RDM, so let's continue it there --Jayron32 16:45, 28 October 2014 (UTC)[reply]
The discussion above is closed. Please do not modify it. Subsequent comments should be made on the appropriate discussion page. No further edits should be made to this discussion.

This question was suggested to be asked here.Is it true that configuration of atoms ( made by elecctron ,proton etc ) determines state?? If so, In what form electron proton lies???Diwas Sawid (talk) 01:35, 29 October 2014 (UTC)[reply]

I think that in nature always be only electrons which in different substances always had a different names!--Alex Sazonov (talk) 06:11, 29 October 2014 (UTC)[reply]

Converting 5V USB to 12V?

I'm often annoyed at portable rechargeable consumer electronics (like portable speakers) requiring an AC adaptor to recharge. USB charging seems far more convenient as I'm always going to have a USB recharger nearby for my smartphone (at home, my car, the office). The main response I've gotten back is USB is limited to 5V, while their AC adaptor outputs 12V or 18V or what have you. So what does that mean? If it charged via USB, it would just be very slow? Or does the voltage difference just make it impossible? --76.168.132.112 (talk) 20:24, 28 October 2014 (UTC)[reply]

The issue is not just voltage - it's power. USB provides very little power, and can only provide it at a fixed DC voltage. The power limitation is why the USB port can not be used as a universal charger; the voltage is an engineering detail that could be worked around with existing technology.
Electric power is very simply computed: it is voltage times current. The voltage (by itself) is not necessarily the limiting factor.
USB provides 5 volts, and very limited current: usually, 500 milliamps. This means that USB can not (usually) provide more than 2.5 watts of power.
The amount of power is going to dictate how fast your battery charges; how bright your screen gets; how large an electric motor you can drive.
But there are other details. Power must be provided at a voltage that the device can handle. If the voltage is too low, the device won't even work - whether it's a charger on an appliance. If the voltage is too high, the device may be damaged.
Wasteful energy losses - like heat - are primarily determined by current - so lowering the current usually lowers losses. Consider a power supply that provides 10 watts at 18 volts. (P = V*I), so the device draws a little more than half an ampere. The same amount of power could be delivered by low current at very high voltage - say, a million volts driving ten microamps - but at some point, the voltage levels become unsafe for use around humans. High voltages can cause electrocution; very high voltage electricity can leap across air gaps, zap through wire insulation, and so on. At the opposite extreme, the same amount of power could be delivered by very low voltage and very high current - say, a million amps, driven by 10 microvolts - but resistive heating means that the wires would waste so much energy (as heat) that their insulation catches fire! This is to say nothing of the impracticality of building such a power-supply.
Engineers make trade-offs to make sure that the right amount of power gets to the device, at the correct voltage and current - balancing safety against usability and convenience. A few standards have formed; consumer-devices that are mass-produced are designed to operate within these standards. Engineering practicality means that it is easier, safer, and more efficient to provide higher power using higher voltage than USB can provide. But the power still has to come from somewhere - even if the voltage is converted! Until the device itself needs less power than the USB port can provide, trying to charge it at 5 volts isn't an option. Even if you boosted to 12 volts, you wouldn't get energy for free!
Nimur (talk) 21:03, 28 October 2014 (UTC)[reply]
To recharge a battery, you need a little more voltage than the battery itself provides...how much more depends on the battery technology. So you can certainly recharge a typical 1.5 volt AA or AAA cell - or even two or three of them in series - using USB. The current (amperage) limitations of USB will limit the speed that it recharges.
So if you need 12 volts to recharge something, then USB (by itself) won't cut it. There are ways to add some circuitry to increase the voltage from 5v to 12v - but the amount of power available (volts times amps) stays the same, or a little worse. So going up from 5v to 12v would decrease the amps to less than half...possibly much less than half depending on the efficiency of the voltage conversion circuitry. Generally, it's just easier to get a separate charger. SteveBaker (talk) 13:39, 29 October 2014 (UTC)[reply]

mixing medicine liquid with another liquid

what is the reason of the mixing a liquid medicine in another liquid (like saline), while we can inject only the medicine liquid? 149.78.224.210 (talk) 23:57, 28 October 2014 (UTC)[reply]

Because medicines are carefully calibrated at certain concentrations. Pharmacodynamics is a tricky thing, and changes to how drugs are formulated and delivered can have large effects on things like their effectiveness and their toxicity. For that reason, procedures and formulas are created, which should always be followed, because the people who created the protocols know what they are doing, and you probably don't. --Jayron32 11:12, 29 October 2014 (UTC)[reply]

What is the difference between syrup and elixir?

149.78.224.210 (talk) 23:58, 28 October 2014 (UTC)[reply]

Read the articles you already linked, and decide for yourself. --Jayron32 11:13, 29 October 2014 (UTC)[reply]

October 29

Ocean Water density and temperature

Water, as I understand it, is one of those weird molecules where the angle between the two hydrogen atoms increases when it freezes. This makes the solid form of water less dense than the liquid form (whence, icebergs float as their volume displaces warmer liquid water more than its own weight - ice is less dense than liquid water). It's also my understanding that the maximum density of water is achieved at about 3°C. The deep oceans are at this nearly constant temperature because anything warmer is less dense and rises and anything colder is less dense and rises so the deep oceans are at maximum density and virtually a constant temperature (and also the reason why at such depths it's a liquid). So does that mean if the ocean cools, there could also be sea level rise especially if a large majority of the ocean were at maximum density when cooling started? Could the volume of water increase by 1/3 if the temperature went from 3°C to 0.01°C? --DHeyward (talk) 01:38, 29 October 2014 (UTC)[reply]

Fresh water reaches its maximum density around 4°C. But the temperature at maximum density decreases about linearly with increasing salinity. At a salt content of around 25 per mil (2.5%) the temperature of maximum density intercepts the freezing temperature. So, for salinities above 25 per mil water always becomes more dense as temperature decreases. The graph near the bottom of this page shows the relationship.
The mean ocean salinity is about 35 per mil, so sea level always increases with increasing mean ocean temperature. There are a few patches of ocean where salinity is less than 25 per mil (notably the Baltic Sea) but these are only small fractions of the global ocean. Short Brigade Harvester Boris (talk) 03:59, 29 October 2014 (UTC)[reply]

What is a good way to identify tablets?

what is a good way to identify tablets (pills) where I see a lot of kinds of them? Is there any way to identify them according something unique or it can be some tablets are identical and no eazy way to identify them 149.78.224.210 (talk) 01:54, 29 October 2014 (UTC)[reply]

Given the obvious hazards of getting it wrong, the only advice we can give you is that you shouldn't search for advice on such matters from random strangers on the internet. If you are in any doubt as to the identity of a medical substance, don't take it... AndyTheGrump (talk) 01:58, 29 October 2014 (UTC)[reply]

I don't take any tablet, but it interests me theoretically. In addition, I'm an EMT so it interests me from this view.149.78.224.210 (talk) 02:02, 29 October 2014 (UTC)[reply]

I actually had an answer for you until you said you were an EMT. If so, you would already know where to find that information. The police do too. Prescription OD's are common for EMT's and they are trained on how to identify tablets so they know how to respond. --DHeyward (talk) 02:08, 29 October 2014 (UTC)[reply]
Yup - if the OP actually is an EMT, there is no way we should be giving advice on such matters - per policy, we don't answer requests for medical advice, and helping out EMTs with things they clearly ought to know already would seem even less advisable. AndyTheGrump (talk) 02:14, 29 October 2014 (UTC)[reply]

Do you think I'm lying? I'm EMT-B (read here). Why do you think EMTs know to identify tablets? EMTs know CPR mostly and some first aid but no more. 149.78.224.210 (talk) 02:18, 29 October 2014 (UTC)[reply]

In which case you already have access to people who can answer your question. Ask them. AndyTheGrump (talk) 02:22, 29 October 2014 (UTC)[reply]
The U.S. National Institutes of Health has a site where you can input the physical characteristics of pills and it will tell you what they may be.    → Michael J Ⓣ Ⓒ Ⓜ 03:42, 29 October 2014 (UTC)[reply]

Thank you Micahel. I wish everyone would study from you how to help. 149.78.224.210 (talk) 03:55, 29 October 2014 (UTC)[reply]

I don't see what the problem is. Google the specifics of the pill and you should be able to come to a consensus quickly. Justin15w (talk) 03:54, 29 October 2014 (UTC)[reply]
If you websearch "pill identification" you'll find a variety of tools, but that is indeed a good one. I don't think it is a bad thing for people who get prescriptions filled to routinely look up the pills they get in order to verify there are no mistakes made. I mean, every once in a while you read about some little kid having her prescription bottle filled with methadone or something by accident, and turning up dead, and it just breaks your heart. Wnt (talk) 03:57, 29 October 2014 (UTC)[reply]
I've started seeing prescription bottle labels including a physical description of the drug ("This is a red solution that may be cloudy", "This is a white, round-shaped tablet impronted with [number] on the front", etc.). DMacks (talk) 17:19, 29 October 2014 (UTC)[reply]

We have a book at home (a few years old now) which is a home guide to medicines and drugs, published by the British Medical Association. It has a drug identification section with pictures and descriptions of all the tablets and capsules commonly prescribed in the UK. However, the latest version doesn't seem to have the drug identification section - probably because there are now the online tools that do the job better. To answer the other part of your question, from what I've seen in that book It would appear (although I can't say for certain) that all prescription tablets and capsules are produced in a unique form so they are identifiable by a combination of shape, colour, scoring and often a number stamped on them. Richerman (talk) 00:18, 30 October 2014 (UTC)[reply]

OP: Note that the standards determining pill shape, size, color and marking differ from country to country. So if you are really based in Israel as your IP indicates you will need to refer to the applicable national standards, and using the NIH or FDA website could be dangerously misguided! Abecedare (talk) 00:29, 30 October 2014 (UTC)[reply]

facebook

I've taken the liberty of moving this to the computing Refdesk. Wnt (talk) 03:20, 29 October 2014 (UTC)[reply]

(Unfortunately, the question was asked FIRST on the computing desk and didn't get any responses, so the OP evidently posted it here in the hope of getting an answer. Punting it back to WP:RD/C isn't likely to help much.) SteveBaker (talk) 15:31, 29 October 2014 (UTC)[reply]

Right prefrontal cortex function

What do Brodmann areas 8-9 and 46 do on the right hemisphere? What might low grey matter volumes in these regions indicate? — Preceding unsigned comment added by 68.39.237.199 (talk) 15:34, 29 October 2014 (UTC)[reply]

We have articles on all of these:
I would not want to speculate on what low grey matter volumes might indicate. - EronTalk 20:28, 29 October 2014 (UTC)[reply]

The main property of the electrons

Did the electrons had an electromagnetic perdurability (constancy), that is the electrons are in different physical environments remain its electromagnetic constant?--Alex Sazonov (talk) 16:56, 29 October 2014 (UTC)[reply]

Electrons always appear to have the same electric charge from a distance. This amount is called the elementary charge. Even when travelling at close to the speed of light, or deep in a gravitational well the charge will appear to be the same. Though I will say that the Fine-structure constant which depends on this charge, is claimed by some to vary at different places in the universe. I think this is incorrect, and that is remains constant in our Universe.

Given a battery and a device, how can you calculate how long the battery will last?

If a battery has 50000mAh, and the device needs 5V and 500 milliAmps, will the battery last 100 hours? What if the device required a different amount of Volts, how would it be different? What's the formula for this? — Preceding unsigned comment added by Senteni (talk • contribs) 18:17, 29 October 2014 (UTC)[reply]

For your first question, it depends on the battery's voltage. Actual energy capacity would be more accurately expressed in watt hours rather than ampere-hours. However, batteries are more or less fixed voltage sources, and so manufacturers g ahead and do the amps = watts / volts conversion, presenting capacity in amp hours with voltage as a fixed given.
So, if you use 50k mAh batteries in a device that draws 500 mA, you would indeed expect 100 hours of battery life. I skip voltage because, presumably, the device is intended for a particular battery configuration at a particular voltage and the batteries in use match that. Note that this holds even in multi-battery configurations: if you have a 6V device that uses 4 AA batteries and draws 100 mA, and you use AA batteries with 1000 mAh capacity, you'll get 10 hours of use. Each battery is only rated for 1000 mAh at 1.5 volts, but when placed in series, you've got either 4000 mAh at 1.5 V or 1000 mAh at 6 V (or whatever other conversion factor you like, per W = V * A). — Lomn 19:22, 29 October 2014 (UTC)[reply]
That's correct. Theoretically, the battery in question should last 100 hours. However, there are no firm standards for rating battery capacity. Some manufacturers rate useful life only (down to some minimum voltage), while others will rate capacity for a complete discharge to 0V. Your device might need a minimum voltage to function, which would also affect the amount of useful energy you can draw from the battery. If this is for a practical application, you might want to consider doing some tests and derating your battery based on the results. Mihaister (talk) 22:53, 29 October 2014 (UTC)[reply]

Does driving behind semi trucks increase gas mileage?

Title

Yes, but it's also extremely dangerous. Please see Drafting_(aerodynamics)#Tailgating_and_hypermiling.--Shantavira|feed me 20:02, 29 October 2014 (UTC)[reply]
There was a compelling demonstration of this done by Mythbusters - the amount of fuel savings is impressive at higher speeds - but the dangers are rather extreme. What may be surprising is that tailgating not only saves the tailgater gas - it also saves it on the truck. SteveBaker (talk) 01:56, 30 October 2014 (UTC)[reply]

Macadam

Combined with below question so we don't get overlapping unnecessary redundancies. μηδείς (talk) 00:26, 30 October 2014 (UTC)[reply]

Road sub base & Macadam base

In highway design, how do engineers decide whether unbound or bound materials should be used for sub base? Is it to do with durability and load? Is macadam generally used in the base course of highways?Clover345 (talk) 23:36, 29 October 2014 (UTC)[reply]

October 30

Cygnus CRS Orb-3

Why did the rocket explode? --EditorMakingEdits (talk) 02:48, 30 October 2014 (UTC)[reply]

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