Jump to content

Wikipedia:Reference desk/Archives/Science/2011 July 17

From Wikipedia, the free encyclopedia
Science desk
< July 16 << Jun | July | Aug >> July 18 >
Welcome to the Wikipedia Science Reference Desk Archives
The page you are currently viewing is an archive page. While you can leave answers for any questions shown below, please ask new questions on one of the current reference desk pages.


July 17

[edit]

Peripheral Lung

[edit]

I'm from a non-scientific background, but as part of my research I'm reading an article that discusses the effect of various asbestos fibres on the lungs. A sentence reads 'The rod-like amphiboles appear to penetrate the peripheral lung more readily than chrysotile fibers'. What is the 'peripheral lung'? Does it simply refer to the edges of the lung? Or is it a term of art? Cheers Joaq99 (talk) 10:56, 17 July 2011 (UTC)[reply]

Yes, it's just the outside of the lung as opposed to the central part. It's the part that is adjacent to the pleural cavity, and it's probably, in context, a somewhat unnecessary adjective. - Nunh-huh 12:44, 17 July 2011 (UTC)[reply]

Thanks Joaq99 (talk) 22:31, 18 July 2011 (UTC)[reply]

Diamond test

[edit]

How can I tell if my diamond is real, at home ? It does appear to scratch glass, but just barely. Would any fake diamonds scratch glass ? Is there any other home test ? (I do realize that a professional appraisal will be needed, but want some indication, before that.) 68.79.93.3 (talk) 00:17, 17 July 2011 (UTC)[reply]

Wikihow has a whole list of tests: #3 (reflection), #10 (fog test) and maybe #9 (heat probe) seem to be the simplest to try. Clarityfiend (talk) 01:15, 17 July 2011 (UTC)[reply]
Thanks, that looks useful. Unfortunately, many of those tests are subjective, and only mean the stone "probably is" or "probably isn't" a diamond. I was hoping for an absolute, objective test. 68.79.93.3 (talk) 03:01, 17 July 2011 (UTC)[reply]
You will have to ask an expert. It is pretty tough to differentiate a synthetic diamond from a real one. — Preceding unsigned comment added by 88.8.79.148 (talk) 13:51, 17 July 2011 (UTC)[reply]
That's because synthetic diamonds are real diamonds. Dauto (talk) 15:12, 17 July 2011 (UTC)[reply]
Yes, the question does not make clear what the OP means by "real." Do you mean "a stone cut from a natural monolithic carbon crystal that was mined in the ground"? Or, do you mean "a very high-quality carbon crystal with few chemical impurities, negligible optical aberrations, and no visible inclusions or discoloration"? Nimur (talk) 16:34, 17 July 2011 (UTC)[reply]
I have the impression that real means "not costume jewelry". It is starting to look like the OP found a box of shiny stuff under the bed and really has no idea what it is. Looie496 (talk) 17:41, 17 July 2011 (UTC)[reply]
In that case, I'd think one of the easiest ways would be to find the density by carefully weighing the unknown things and then finding the volume by measuring the displacement in a graduated cylinder or something like it and comparing that to the density of diamond, which is about 3.5–3.53 g/cm3. This would be better at ruling things out, since other things could also have a density within this range, but a density far outside this range would do well to rule out diamond. Peter Michner (talk) 20:24, 17 July 2011 (UTC)[reply]

Get a real diamond if the suspect diamond scratches (rather than just crushes) it, then the suspect is a real diamond. μηδείς (talk) 23:31, 17 July 2011 (UTC)[reply]

Err, what if the suspect crushes the real diamond? Cuddlyable3 (talk) 14:52, 18 July 2011 (UTC)[reply]
Is that a riddle?μηδείς (talk) 21:19, 18 July 2011 (UTC)[reply]
Wouldn't you check the refraction angle first? That should be much easier then density if the stone is in some kind of setting. Googlemeister (talk) 13:21, 18 July 2011 (UTC)[reply]
Specifically, how do I tell a diamond from a YAG crystal ? 68.79.93.3 (talk) 04:34, 22 July 2011 (UTC)[reply]

SEEKING JOB INDIA

[edit]

HOW CAN I GET JOB IN MECH ENGG FEILD IF I HAVE SUBJECT BACK.BUT COMPLETED MY DIPLOMA IN MECH ENGG — Preceding unsigned comment added by 223.176.146.116 (talk) 07:52, 17 July 2011 (UTC)[reply]

Firstly, turn off caps lock. Typing in capitals makes it sound like you're shouting. Secondly, can you rephrase your question so it's more clear? It doesn't make much sense at the moment. Bear in mind that, on the whole, we know very little about the Indian education system and job market. Your best choice would be to contact your educational establishment's career service or write to an engineering company and ask. Brammers (talk/c) 08:45, 17 July 2011 (UTC)[reply]
Seriously, the ability to write a sentence in grammatical English people can understand, and to explain clearly what you want - these should help you no matter what the situation may be in your field. Wnt (talk) 15:26, 17 July 2011 (UTC)[reply]
If you are looking for a list of open mechanical engineering positions in India, try something like http://www.engineerjobs.com/jobs/mechanical-engineering/india/ If you think language issues might be preventing your employment, you might try http://englishcentral.com or the like. 99.24.223.58 (talk) 18:24, 17 July 2011 (UTC)[reply]

Yellowing of beige office equipment over time

[edit]

It seems that the beige hard plastic often used in office equipment in the recent past turns yellow over time. What is the cause of the yellowing? Is it exposure to light? UV? Heat? Something in the air? — Preceding unsigned comment added by 98.114.146.248 (talk) 09:51, 17 July 2011 (UTC)[reply]

In years gone by this phenomenon was due to cigarette smoke! After the smoking ban in offices in the UK, I haven't noticed it as much. --TammyMoet (talk) 10:20, 17 July 2011 (UTC)[reply]
According to this patent, brominated flame retardants are to blame. Brammers (talk/c) 10:40, 17 July 2011 (UTC)[reply]

How is a rocket supported at the launch pad before ignition?

[edit]

Before ignition, how is a rocket supported (mechanically) on the launch pad? Is it supported at its bottom? Or is that on its side? — Preceding unsigned comment added by 98.114.146.248 (talk) 09:57, 17 July 2011 (UTC)[reply]

A launch pad usually includes a vertical service structure or launch tower, which is connected to the rocket at various points and provides access for pre-lauch checks, fuelling and crew transfer - see File:Saturn V and service structures.jpg for an example. I am not sure how much mechanical support it actually provides. Gandalf61 (talk) 10:17, 17 July 2011 (UTC)[reply]
The tower prevents the rocket being tipped sideways by the wind, but it doesn't support the weight of the rocket (which gets very heavy once it's been fuelled). Instead there are pylons built around the flame pit which mate with hardpoints on the undersurface of the rocket, between the rocket motors. These support the weight of the fully fuelled launcher. In the case of the Saturn V (and I think in many others) the pylons were integrated with the hold-down arms (in the photo on that page the vehicle rests on the light-coloured block at the top of the arm pylon). A photo of the Saturn V pit with the hold-down arms in place, but without the vehicle, is here, and one with the vehicle resting on the pylons (and with a temporary maintenance deck covering the pit) is here. The other function of the hold-downs, incidentally, is as their name implies - they hold the vehicle down for the second or two between when its engines start and when they're confirmed to be at full power. If the vehicle was unrestrained then it might flip over during that phase, when the motors have spooled up at different rates and so provide asymmetric thrust. The launch control systems keep the hold-down arms in place, holding the rocket back against its own massive thrust, until they've confirmed that all the motors are fully at power and the flight dynamics system is able to stabilise the rocket by gimballing the motors. A longer discussion of the Saturn V ground systems is here. -- Finlay McWalterTalk 11:06, 17 July 2011 (UTC)[reply]
On the pad, the weight of the Space Shuttle's SRBs (indeed the whole vehicle) is carried by the SRB hold-down posts, although in this case the holding-down is ceased when an explosive severs the bolt, rather than a complicated arm swinging out of the way. A video showing the SRB post is here; the technician explains that for the Shuttle system the SRB posts hold the weight not just of the SRBs but of the external tank and the orbiter (so they don't have hold-downs or pylons of their own). Note that, because the SRBs are solid, the sequence is different from the Saturn V sequence I discussed above. In this case the orbiter's main engines fire and the vehicle is held down until they're confirmed to be at full power; then (nearly simultaneously) the SRB hold-down posts are exploded and the SRBs are lit (with the vehicle unrestrained). This is because a liquid-fuelled engine can be shut off if something goes wrong, but once an SRB is ignited it burns to term (and there's no dynamic control over its level of thrust), so there's no ground abort mode left once they're lit. -- Finlay McWalterTalk 11:20, 17 July 2011 (UTC)[reply]
Things are very different for a Soyuz launcher, however. There's no pylons, no separate hold-down arms or bolts, and really no tower. Instead a Soyuz pad has four huge arms which fold out from the corners of the pad (lots of photos here). Images of a Soyuz held by its arms are here and here. These arms hold the weight of the laden Soyuz rocket as it's fuelled and prepared. Before launch a further service arm is withdrawn, leaving the rocket hanging over the pit ready to go. When the motors are fired these arms act as the hold-downs; once everything is stable and at power, the arms retract (rather vigorously) and the launcher is unrestrained and takes off. -- Finlay McWalterTalk 11:32, 17 July 2011 (UTC)[reply]
A video of Soyuz TMA-9 launching is here. There are actually two service arms (the first is retracted about 1 minute into the video, the second only a few seconds before the engines are lit). Note that the vehicle spends nearly 10 seconds held down while the first stage engines spin up. -- Finlay McWalterTalk 11:40, 17 July 2011 (UTC)[reply]
Without a hold-down system, a sudden gust of wind could topple a rocket, since it is extremely tall, typically, compared to the width of the base. There is little inherent stability, with the center of mass so high up. I suppose the launch is delayed and the crew does not enter the capsule if weather trends make such gusts likely, and they could certainly monitor the surrounding air mass with weather balloons and aircraft. Edison (talk) 12:44, 17 July 2011 (UTC)[reply]
Is there an obvious reason why all rockets may not be launched from a below-ground Missile launch facility ? The underground silo protects against wind and can provide side support over the whole length of the rocket, and possibly increase thrust at launch by constricting the exhaust outlet. Cuddlyable3 (talk) 14:45, 17 July 2011 (UTC)[reply]
Wind isn't a big issue, as it's easily solved by systems you need anyway (the hold-down system and the service tower). Even silo launches don't try to constrict the launch exhaust (ref, see also Flight magazine 25th May 1961). A silo configuration forces you to vertically integrate the vehicle (with cranes): the Russians seem to generally prefer horizontal integration of Soyuz - they assemble it horizontally on a big arm, and then swing the whole thing to vertical at the pad (although the Ariannespace Soyuz facility will use vertical integration for the Fregat and payload (ref, with extra-naff music). And a silo forces you to integrate at the launch site, so you tie up the launch site preventing it being used for another launch in the mean time - both the NASA vertical-integration on a movable platform and the Russian horizontal integration on a TEL-like boom allow the vehicle to be constructed elsewhere, while the pad is being used by someone else. A silo, especially for a large rocket, is tremendously expensive to build and a pain to run. The only plus I can see for a civilian launch from a silo is that you get to control the weather, but every time a Shuttle can't launch because it's a bit cold (for, you know, Florida), you can almost hear sniggering from Plesetsk (which, for example, is scheduled to launch three rockets, including a Soyuz/Fregat, in December, when winter temperatures get down to -30°C). -- Finlay McWalterTalk 15:53, 17 July 2011 (UTC)[reply]
Furthermore, silos are expensive; all joking aside, the space industry does not spend money unnecessarily. A silo launching facility is a lot of very complicated construction and design effort, and really only amounts to a "peripheral" engineering objective to the space-craft. Four seconds into the mission, the entire launchpad facility serves no purpose.
I also have a vague recollection that some element of SALT II or a more recent proliferation treaty that regulated underground launch facilities; so, civilian rocket launch facilities may have to make special accommodations to comply with necessary international treaties. Underground silos, civilian or otherwise, might constitute a "hardened facility." Here's some specific language from START I: "...Such a space launch facility is still subject to the provisions of subparagraph 4(b) of Article IV of the Treaty, which limit the aggregate number of silo launchers"; and a silo is defined as a "structure located in the ground." So, treaty compliance may be a (non-obvious) reason to put the civilian rocket launchers above ground. Nimur (talk) 16:48, 17 July 2011 (UTC)[reply]
That said, there are civilian launches from silos. The Dnepr-1 is launched from silos at Baikonur (a map on this page suggests there are at least four) and from Dombarovsky. That's because Dnepr is based on the military silo-based R-36 missile, and it was easy for them to keep launching from a silo. (Although Tsyklon, another R-36 based launcher, is launched from a pad, e.g. at Plesetsk 32). -- Finlay McWalterTalk 17:16, 17 July 2011 (UTC)[reply]
I'm not a lawyer, but I read the above as "subject to the treaty provisions...," not as "forbidden." Undoubtedly, the conversion of an ICBM into a civilian space vehicle drew the attention of the treaty verification folks. In fact, this BBC News article from 1999 suggests that the conversion may have been part of the treaty compliance to eliminate SS-18 missiles. Nimur (talk) 17:59, 17 July 2011 (UTC)[reply]
Yes, I imagine that's correct (I didn't mean to imply the contrary). In fact I'm slightly confused about the Kazakh deployments of the SS-18: R-36 (missile)#Deployment lists its only operational deployments in the KSSR as at somewhere in the Semipalatinsk oblast (the NE) and the Turgay oblast (which Britannica suggests is in the NW). Neither is at all near Baikonur/Tyuratam. So either the silos at Baikonur were purely for the test program (and very possibly didn't count towards the treaty either) or they've actually been built or adapted from other uses to support Dnepr launches. Anyway, we're diverging a bit from the OP's original question about weight-bearing on the pad. I confess I can't find concrete (sic) evidence about how R-36/Dnepr launched, but videos of Tsyklon launching from Plesetsk suggest it has a pylon style support, and ditto for Zenit. -- Finlay McWalterTalk 18:19, 17 July 2011 (UTC)[reply]
I thought rockets were supported by their fuel, in the same way that air supports a party balloon. 2.97.209.26 (talk) 22:12, 17 July 2011 (UTC)[reply]
Think instead of an Airship. Neither they nor balloons go far in space where there is no Buoyancy. Cuddlyable3 (talk) 22:29, 17 July 2011 (UTC)[reply]
Clearly you do not understand what I meant. 92.28.249.93 (talk) 20:57, 18 July 2011 (UTC)[reply]
While hydrogen is indeed very buoyant in air, liquid hydrogen which forms part of the fuel for most liquid-fuel rockets is about 60 times denser than air. This may be the source of your misconception, though even if it were gaseous hydrogen it would not come close to lifting the 2,000,000-kilogram (4,400,000 lb) space shuttle.-RunningOnBrains(talk) 13:25, 18 July 2011 (UTC)[reply]
How can I say "what a stupid answer" while still being polite? 92.28.249.93 (talk) 20:57, 18 July 2011 (UTC)[reply]
Rocket fuel might be a structural support in the fuel tank if the walls of the tank are thin enough that the fuel tank needs internal pressure to keep from collapsing. That might be another possibility. Googlemeister (talk) 15:12, 18 July 2011 (UTC)[reply]
That's not the case (at least not with any real launch system). Firstly the launcher has to be moved around when it's empty (fuelled liquid rockets are much too dangerous to be driven and hoisted around), and the empty first stage of a rocket on the pad has to sustain the weight of the rest of the rocket above it. Secondly a launcher stage, just prior to burnout, is mostly empty but still has to sustain the load imposed by the thrust of its own engines without failing. Even solid rockets, which are stable enough to be moved around when fuelled, are robust when spent - the shuttle's SRBs survive impact with the ocean at 50 mph. -- Finlay McWalterTalk 15:56, 18 July 2011 (UTC)[reply]
They could pressurize the tank with nitrogen before fueling, and at the altitude where the tank is mostly empty has a low outer air pressure. Not saying that is what they do, just something they could do. Googlemeister (talk) 15:59, 20 July 2011 (UTC)[reply]
Well, I'm really surprised that anyone could possibly have imagined that I was suggesting that a rocket would float into the air because its filled with liquid hydrogen or whatever. I meant that the pressurised fuel tank would play a part in the structural support of the rocket. Have you never seen a bouncy castle? Even when its empty of fuel, its still deliberately pressurised with inert gas such as nitrogen. I recall reading that this was done to save weight. I'm not sure if every rocket was designed like this, but I recall that at least one of them was. 92.28.249.93 (talk) 20:57, 18 July 2011 (UTC)[reply]
I remember hearing that the pressurized fuel tank was used as part of the structure as well. This page on the Russian SS-8 ICBM mentions that they had pressurized fuel tanks, but I can't find a source that says they used the pressure in the tanks as structural support. The SS-9 appears to have used combustion products to pressurize the fuel tanks during flight source, which may mean that it used pressure to support the structure. Tobyc75 (talk) 02:23, 19 July 2011 (UTC)[reply]
The V-2 had compressed nitrogen tanks in it, although they could have been just to help push the fuel out. 2.101.5.83 (talk) 11:26, 19 July 2011 (UTC)[reply]
See SM-65 Atlas#Design regarding the use of balloon tanks "made of very thin stainless steel... with minimal or no rigid support structures. Pressure in the tanks provides the structural rigidity required for flight. An Atlas rocket would collapse under its own weight if not kept pressurized, and had to have 5 psi nitrogen in the tank even when not fuelled". Ref: SM-65 Atlas - United States Nuclear Forces - 220.101 talk\Contribs 09:43, 20 July 2011 (UTC)[reply]

water temperature -> air temperature equivalent conversion rate

[edit]

I've been doing some SCUBA diving lately, just went out today and the water temperature was about 10 degrees. I know that water conducts heat away from the body a lot more efficiently than air so I was wondering if there is some equation or conversion chart to work out what air temperature this would feel like. (e.g when you read a weather report and it says "Temperature: 10 Feels like: 8" because of wind chill or other factors, what does water "feel like"?). Benjamint 11:38, 17 July 2011 (UTC)[reply]

I went through a few months of NAUI training courses and never recalled any such "conversion" or even a rule of thumb. What I do recall is the "what thickness wet-suit to use" chart. You can find such charts everywhere, here's a wetsuit vendor chart with temperature-guide.
Another detail I recall that was strongly emphasized is the "expected time until hypothermia" chart: the number of minutes a clothed swimmer or diver can expect to remain conscious at various water temperatures. I think this was reproduced in the NAUI textbook; you can also find it online by searching for "cold water survival." Navy Preventative Medicine manual has such a chart, and FM-55-501 also publishes a survival-time chart. As a diver, because you are fully submerged, your survival time is much lower than a surface swimmer; but you compensate some by wearing a wetsuit (or a dry suit). The most unintuitive thing is that hypothermia will set in even if the water is as warm as, say, 75° F (23° C) - it just takes about 3 to 6 hours; and the diver will lose consciousness and suffer health effects just as if the water were slightly above freezing. Nimur (talk) 17:11, 17 July 2011 (UTC)[reply]
We could probably make some sort of "air equivalent hypothermia temperature", but honestly it wouldn't have much bearing on reality. In 50 °F (10 °C) water, you'd probably lose consciousness about as fast as being naked in 0 °F (−18 °C) air. But again this ignores the important details that Nimur brings up; that your survival time is greatly dependent upon many factors. An equivalent temperature scale wouldn't have much use, IMHO. -RunningOnBrains(talk) 22:11, 17 July 2011 (UTC)[reply]

why does suntan lotion (all brands) have a characteristic smell?

[edit]

is it because there is a single anti-UV chemical, and it has that smell, or what? The same is not true for any other "category" of lotion... 188.222.102.201 (talk) 12:01, 17 July 2011 (UTC)[reply]

Cocoa butter? --Jayron32 12:43, 17 July 2011 (UTC)[reply]
I don't think they all smell the same. Most of them smell of coconut oil to me, but some (Ambre Solaire) smell of bergamot oil. --TammyMoet (talk) 17:51, 17 July 2011 (UTC)[reply]
The sunscreen article mentions that the active ingredients in sunscreen tends to be "aromatic molecules conjugated with carbonyl groups". Probably molecules of that form all interact in a similar way with the receptors in your nose. Rckrone (talk) 06:07, 18 July 2011 (UTC)[reply]

Female Common Snapping Turtle

[edit]

How old must a female common snapping turtle be before she can lay eggs74.14.157.157 (talk) 13:52, 17 July 2011 (UTC)[reply]

I don't know but I know a man who might. It's a website dedicated to turtles, I'm sure they can help you. Richard Avery (talk) 14:11, 17 July 2011 (UTC)[reply]
4 to 6 years.[1] 99.24.223.58 (talk) 18:47, 17 July 2011 (UTC)[reply]

Citation of self-published blogs?

[edit]

If I were to blog on new scientific proofs or concepts I've been working on, I have self-published these and, to the best of my understanding, I have automatic copyright protection to them. I also know that most journals do not accept material that's been already published or under copyright, so blogging would normally cut-off that avenue. I am not sure if journals make exceptions to this, so how often do scientists find themselves blogging ideas without the benefit of peer-review and their blogs being cited accordingly? I will add that I have a rather large financial incentive to retain copyrights and a public interest in making my ideas public ASAP. --Modocc (talk) 15:53, 17 July 2011 (UTC)[reply]

There is negligible monetary value in the copyright of an academic paper; if there is value it is in patentable ideas, and it's a central part of patenting that the ideas are kept secret until the patent is submitted. So I don't understand what you mean when you say you have a financial incentive in the copyright. In general, many universities and research labs attempt to "measure" the success of a scientist with schemes that weigh the publication of papers in respectable journals, and the citation of papers in other papers published in such journals. From a scientific and public-interest perspective scientists might very well want to rush their findings out as quickly as possible (via things like blogs and arXiv); if doing so was to the detriment of the chances of being published in a journal, researchers who did so would be cutting their own throats. -- Finlay McWalterTalk 16:44, 17 July 2011 (UTC)[reply]
Much of what you said is true to an extent, however the success of any writing is based on merit and any interest in it. In addition, it would be incumbent on researchers to cite previously published material no matter where it is published. Also, a popular or well-cited blog might bring the researcher a financial reward (and the exact amount is not always that important anyway, which is why I suppose arXiv exists). In my case, I making claims that could upturn some very entrenched and widely accepted dogma. I'm interested in knowing whether or not there are many examples of blogs being cited. --Modocc (talk) 17:08, 17 July 2011 (UTC)[reply]
Of course there are examples. There are hundreds of thousands of volumes of research journals. Academic journals range from reprints of informal mailing-lists and conferences, to prestigious magazines read by millions of academics worldwide. What matters is, do such examples of citations of self-published works exist in your preferred journal? If you are aiming for a highly prestigious journal, the answer is "almost certainly not." Nimur (talk) 17:15, 17 July 2011 (UTC)[reply]
Thanks. I am not aiming to be cited by any particular journal. I just want to get some of my ideas out there into the public arena as soon as I can manage it. --Modocc (talk) 17:31, 17 July 2011 (UTC)[reply]
Blogging is relatively new, but for decades scientists have been writing books chapters that often are not peer-reviewed and raise all the same issues. The basic principle is not to say something in an unreviewed forum if you intend to say exactly the same thing later in a reviewed forum. It is certainly possible to cite book chapters in a scientific paper, and it ought also to be possible to cite blogs, as long as they have some assurance of permanence.
Let me also point out one other important fact: the vast majority of peer-reviewed scientific publications are about presenting evidence, not just presenting ideas. To jaundiced scientists like me, ideas are a dime a dozen -- it is evidence to support them that really matters, and the forum in which an idea was presented is of little importance. So what it comes down to is this: it is fine to discuss your ideas in a blog, but don't use a blog to present your experimental data. Looie496 (talk) 17:36, 17 July 2011 (UTC)[reply]
I once wrote to a physicist if he would be interested in reviewing one of my ideas, and he wrote back only if it made a prediction. Perhaps he has missed out on making an important observation or prediction; the waste basket perhaps. In any case, I know that with our large populace engaged, ideas abound, which is why both merit and interest (which correlates strongly with shared knowledge and intelligence) matters. and empirical evidence can often increase both. Providing a new model to fit existing evidence is also important and I will be doing that. --Modocc (talk) 18:14, 17 July 2011 (UTC)[reply]
Any scientific theory that isn't predictive is completely worthless as a scientific theory. In fact, if it's not predictive it's probably more of a "Theory" than a "Scientific theory".
But, don't be confused about the kind of prediction the scientist wants. It's not some prognostication about the future. In science a prediction is "If we ran the experiment X, we would get result Y if my theory is correct, and result Z if my theory is wrong."
The first step to having people not roll their eyes at your scientific theory is to provide a way to test if it's right or wrong. Ideally a test that could be done now with current technology, but that's not strictly required. APL (talk) 22:00, 17 July 2011 (UTC)[reply]
Confirming predictions does not necessarily validate a model and if all things are equal in terms of entailment, the model that is significantly simpler is often preferred per Occams razor. --Modocc (talk) 00:57, 18 July 2011 (UTC)[reply]
But failing predictions invalidates a model. That's the point. Also "simpler" in Occam's sense does not mean "less math" or "simpler math", it means "fewer assumptions". --Stephan Schulz (talk) 01:14, 18 July 2011 (UTC)[reply]
That's true about models that fail predictions, and some current models might have flunked those tests, although models get tweaked. If neither model fails though, the models may still have the same number of assumptions, but nevertheless differ in complexity. --Modocc (talk) 02:16, 18 July 2011 (UTC)[reply]
Occam's razor doesn't prioritize for "least complexity", just for "least assumptions". Two models with the same number of un-evidenced assumptions are equal in the eyes of Occam's razor. (This is a common misunderstanding of the principle.)APL (talk) 22:55, 18 July 2011 (UTC)[reply]
My model does entail fewer un-evidenced assumptions. Thanks for clarifying that for me. --Modocc (talk) 03:22, 19 July 2011 (UTC)[reply]
I'm guessing you would get more constructive feedback (even if some of the feedback isn't constructive) from submitting to ArXiv than trying to go directly from blogging to submission to peer reviewed journals. Also, I suspect journal editors will appreciate, provide better feedback for, and respond more favorably to unsolicited amateur submissions with preprints on ArXiv. As others have pointed out, the financial interest in copyrights is often dwarfed by the financial interest in patent rights. 99.24.223.58 (talk) 18:53, 17 July 2011 (UTC)[reply]
I see your point clearly, but if my work sits on arXiv, that may reduce their incentive to reprint it and at this point, I'm not planning on a reprint (and if my current work has merit I will likely get to reprint or publish a derivative work anyway). The ArXiv option is tempting, because I certainly hope to get some constructive feedback, but I'd like to do that by soliciting it from different people, especially from those that are likely to be more receptive to the somewhat difficult mental gymnastics of shifting from the current paradigm. I also want to update my material on a real-time basis as I am getting that feedback, so perhaps I'll worry about a more permanent and formal publication later... I think. --Modocc (talk) 19:24, 17 July 2011 (UTC)[reply]
Try searching for the peer reviewed literature reviews in your field, and see if any of them have email addresses for corresponding authors who might be able to recommend better fora for your work. 99.24.223.58 (talk) 22:04, 17 July 2011 (UTC)[reply]
Wow. a new model to fit existing evidence, making claims that could upturn some very entrenched and widely accepted dogma requiring mental gymnastics of shifting from the current paradigm. Claims like that are heard quite often. This article is required reading. Cuddlyable3 (talk) 22:13, 17 July 2011 (UTC)[reply]
Indeed, the reason for the discussion of predictive ability above, which the questioner said was agreeable, is so that theories can be compared to empirical evidence. 99.24.223.58 (talk) 22:49, 17 July 2011 (UTC)[reply]
This handy tool may be very useful for deciding if the material is likely to be worth publishing at all. Also see This wonderful paper. --Jayron32 23:09, 17 July 2011 (UTC)[reply]
True and my apologies for being so nebulous on that because I am doing my best to avoid wp:NOR and because there are appropriate forums where I can discuss some of my research after I blog it (should I decide that this strategy is best). As to the merits of my work, I do want to be engaged in public discussions in order to get appropriate and transparent feedback until either I abandon my work or I have a version of it polished enough to be published in a peer-review journal (if only for citation purposes, because I do hope to maintain my blog). I will likely also have important questions to ask here to help me expand on my understanding of the current literature. --Modocc (talk) 00:38, 18 July 2011 (UTC)[reply]
You're confused on the copyright issue. Everything you write is technically copyrighted by you. Journals have no trouble accepting such things for copyright reasons as long as you are willing to sign over (varying degrees of) your copyright claims to them. The latter policy can vary by journal and by author (I know of some authors who insist on retaining their copyrights when they publish — the journals let them because they are big wigs and the journals get a lot out of publishing their articles).The bigger issue will be that it is has been already published which reduces the likelihood that anyone will go racing to your journal article for the latest information. --Mr.98 (talk) 01:01, 18 July 2011 (UTC)[reply]
Incidentally, I saw a talk recently by a well-established economist who could get zero interest in publishing his articles from traditional journals, peer review, etc. Finally he put the data up on arXiv and it was a huge hit — he's gotten huge amounts of attention now not only from academics, but from the world at large. (He's the guy who found that you could predict stock market activity from monitoring twitter feeds.) All of which is to say that if you find yourself unable to get traction in traditional circles, arXiv can be a great idea. I'm not sure why you're so worried about keeping your copyright. Remember that copyright only protects expression of an idea, not the idea itself. (If it's a process or an idea that will make you money, you need to patent it.) You need not be too concerned with the copyright on your article unless you intend to republish exactly the same article again and again. I've happily signed away my copyrights on my published articles and yet continue to talk about the topics in them all I want. You don't forfeit that, you just give the journal exclusive access to that particular expression of the ideas. --Mr.98 (talk) 01:10, 18 July 2011 (UTC)[reply]
Your right, and I had forgotten that. Perhaps journals don't like it either if you send a copy to more than one of them at the same time or do they? My persistent confusion and concern is because I once got back what appear to be form letters from several journals (I'm pretty sure that is who I sent the stuff to... it was over twenty years ago and my memory is fuzzy) saying they didn't accept copyrighted work. Those letters were not explanatory and didn't make a whole lot of sense to me at the time. Or was it just a naive mistake for me to put a copyright notice on the paper. I am still confused and am wondering what on earth happened. I am also not so much worried about copyright as I am about rejection. I'd rather have feedback from a large number of critics than trying to get past any confusion that might persist with one or two unimpressed reviewers. I've come across quite a few intelligent people that nevertheless had difficulty shaking off their misconceptions. --Modocc (talk) 01:48, 18 July 2011 (UTC)[reply]
(1) Every journal I have ever seen forbids submitting a manuscript that is currently under consideration elsewhere. (2) Legally, anything you write is automatically copyrighted, without requiring any specific action on your part. (Unless you are an employee of the US government writing as part of your official duties.) (3) Almost every journal, when it accepts a manuscript, requires the authors to sign a form that transfers copyright to the journal. (4) Putting a copyright notice on a submitted manuscript basically sends a message that the author is paranoid, since it serves no genuine function. Looie496 (talk) 02:39, 18 July 2011 (UTC)[reply]
OK, I was very naive, but to say I signaled paranoia is a bit much. I should have made myself aware of their submission policies, which I didn't, and I thought I had a better chance of finding someone who liked the paper. --Modocc (talk) 03:12, 18 July 2011 (UTC)[reply]
I didn't mean to say that you were paranoid, only that what you did would have been perceived by the editors as paranoid. Looie496 (talk) 04:22, 18 July 2011 (UTC)[reply]
Another potential problem may be the journal may believe someone other then the author is claiming copyright or there is something else odd with the history of the paper which they would likely not be interested in exploring. Nil Einne (talk) 08:45, 18 July 2011 (UTC)[reply]

chemistry

[edit]

is a saturated solution a true solution? — Preceding unsigned comment added by 14.98.121.141 (talk) 16:08, 17 July 2011 (UTC)[reply]

Yes, until it precipitates, which can happen, for example, sometimes because of mechanical shock, impurities, or radiation, as well as because of the usual factors of time, temperature, pressure and evaporation. 99.24.223.58 (talk) 18:56, 17 July 2011 (UTC)[reply]

pancreatic vs bile duct cancer

[edit]

Do we call it 'pancreatic cancer' if cancer cells originate in bile duct and grow to pancreas as the stage naming, treatment and severity differs? Also, how do we find the source of origin of cancer cells? — Preceding unsigned comment added by 122.174.40.59 (talk) 20:36, 17 July 2011 (UTC)[reply]

Maybe. Cell tissue type can be determined by staining, microscopic analysis, observation of in vitro cultures, some antibody tests, genetic sequencing and maybe karotyping, among other methods if I remember correctly. 99.24.223.58 (talk) 21:59, 17 July 2011 (UTC)[reply]
Cancers are classified by the type of cell the develop from, not where they are found per se. Terms like throat cancer are colloquial, not technical terms. See Bile duct cancer. μηδείς (talk) 23:51, 17 July 2011 (UTC)[reply]
Right. Histopathology has more information about the biopsy process. 99.24.223.58 (talk) 02:10, 18 July 2011 (UTC)[reply]

Polyploid cherries

[edit]

After a little researching cherries without stones (to no avail), an advantage of polyploid fruits is that they are seedless/have smaller seeds, why hasn't anyone tried to engineer polyploid cherries? 86.147.205.85 (talk) 22:38, 17 July 2011 (UTC)[reply]

Looking at Polyploid#Examples_of_polyploid_crops, none of the examples are Stone fruits. Perhaps the Prunus genus does not display polyploidy readily. --Jayron32 22:44, 17 July 2011 (UTC)[reply]
Maybe they have a bitter aftertaste, like early attempts at seedless grapes. Please see seedless fruit. 99.24.223.58 (talk) 22:53, 17 July 2011 (UTC)[reply]
The way different fruits develop embryologically has to be the determining factor. Most seedless fruits have a large multiseeded structure (banana, watermelon) whose development is independent of that of any one seed. The main difficulty in developing seedless grapes was the fact that the flesh of the fruit tended not to develop without the stimulus of the seed. Given that drupes like cherries are fruits surrounding a single seed, it may simply be that in drupes, no seed means no fruit. A google search for seedless drupe gets a whole of one hits: http://www.new.dli.ernet.in/rawdataupload/upload/insa/INSA_1/20005b7f_393.pdf. A search for unfertilized drupe gets none. μηδείς (talk) 23:44, 17 July 2011 (UTC)[reply]
Polyploid cherries exist and are even cultivated, as described in PMID 15354194 -- mainly sour cherries, if I understood correctly. Looie496 (talk) 00:26, 18 July 2011 (UTC)[reply]
Potential seedlessness is not the only advantage for polyploid organisms. Polyploidy is naturally rampant in seed plants, and often leads to a larger plant and fruit. Induced polyploidy can restore fertility to hybrids with odd numbers of chromosomes made even. μηδείς (talk) 00:45, 18 July 2011 (UTC)[reply]
I'm not exactly sure why you want to get rid of cherry pits. They're really not that bad — they're located in a predictable spot (unlike, say, orange), there's only one of them per fruit (unlike watermelon, which to my mind have probably the most annoying seeds), and they come out fairly clean (unlike some peaches, for example). The only really bad thing I can think of about them is if one of them makes its way into preserves, and you crunch down on it unexpectedly as it's hidden in a sandwich, but that's a matter of quality control. --Trovatore (talk) 05:49, 18 July 2011 (UTC)[reply]
Pipless cherries would be more convinient when making pies and the like. Googlemeister (talk) 14:35, 18 July 2011 (UTC)[reply]
I'd be content to have cherries whose pips were solidly rooted to the stem they come with, so that you could pull them out with it. Wnt (talk) 01:36, 19 July 2011 (UTC)[reply]
Exactly. μηδείς (talk) 01:45, 19 July 2011 (UTC)[reply]
That might be difficult. The ability for a sweet stone fruit to be easily eaten is obviously essential and necessary for its reproduction, so there might be redundant genes and genetic-chemical mechanisms which weaken the connection between the cherry and its stem. However, I am fascinated by this idea and I believe it is easily within reach of anyone who has a few spare decades to grow a series of cherry trees. 99.2.148.119 (talk) 03:15, 20 July 2011 (UTC)[reply]