Wikipedia:Reference desk/Archives/Science/2009 August 3

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August 3

acid strength versus pH versus acid ability (for strong acids)

Something that I don't quite get is the different behaviours of strong acids, since they all undergo complete dissociation. I have a salad of various conceptions. Why isn't there a lower bound on pH and pKa after complete dissociation?

I understand in some reactions, the acids form reactive intermediates after being protonated, and it is them and not the protons that carry out the reaction, especially in electrophilic substitution. I am not referring to this.

But take say, magic acid, and say I diluted magic acid to a pH of 1, and diluted a solution of hydrochloric acid to a pH of 1, and then added a hydrocarbon (or some other tough-to-protonate substance) -- would the magic acid behave similarly to the hydrochloric acid?

I do imagine that eventually among the strong acids the limiting factor becomes not the H+ concentration but the conjugate base which will "take away" the proton on substances that do not like to be protonated, even if the H+ concentration is very high -- because then the conjugate base concentration is very high too, and the conjugate base becomes a better proton acceptor than whatever is being protonated. Am I heading in the right direction here? John Riemann Soong (talk) 00:55, 3 August 2009 (UTC)

Actually, the better way to think of it is that strong acids are those whose pKa is higher than that of hydronium (H₃O⁺). That means that, in all of the strong acid, hydronium has a higher "proton affinity" than does the acid, so the acid fully deprotonates. If you change the solvent to something that isn't water, for example pure acetic acid, then your list of "strong" acids would change to those that have a lower pKa than that of the "acetium" ion, and likewise for any given solvent. --Jayron32 03:52, 3 August 2009 (UTC)

When you say "But take say, magic acid, and say I diluted.." do you mean in water, or in a totally inert solvent - the two situations are different - in water, as mentioned above the acid species is H3O+ .. so both act the same (since water is easily protonated by strong acids)

In an inert (non basic solvent) the pKa matters - so the magic acid and hydrochloric acid will have different aciditys - because H-Cl and H-magic still exist (they will have dissociated in water)

pH is the -log of the H+ concentration - so the more acid you add the lower the pH goes - there is a lower bound - determined by how concentrated an acid can be (I think about 20Molar is about the maximum)

Simialiar pKa is the -log of the dissociation constant - the more readily a compound dissociates the lower it goes - the dissociation constant is a ratio, and so can go from 0 to infinity (ie unbounded) In reality total dissociation is impossible, but the dissociation constant can get very very big.

"Complete dissociation" is an approximation - in practice it's 99.999% or more dissociation - so it can be treated as being total when measuring H+ concentrations.

You should at least read the first paragraph of pH and pKa linked above, or another source - to make sure you understand what pH and pKa are, and how they are measured (ie a logarthyms), and how they are different.

"I do imagine that eventually among the strong acids.." - no. You are describing deprotonation, ie the action of a base, not an acid. In general a strong acid makes a very stable base - eg HCl makes H+ and Cl-, Cl- is the base - it is not a good base - it is a very weak base, and is stable. The factor when comparing very strong acids (in pure form) is the stability of the conjugate base, and its lack of ability to accept a proton. Thus weaker conjugate bases are better.83.100.250.79 (talk) 11:24, 3 August 2009 (UTC)

I meant obviously the conjugate base ... I mean, sure Cl- is a weak base, but then protonated alkanes are very strong acids. John Riemann Soong (talk) 11:57, 3 August 2009 (UTC)

If you're trying to protonate say an alkane, or benzene with different very strong acids both the pKa of the acid, and the pKa of the acid form of the alkane contribute to the extent of protonation.

eg if

Alkane + H+  >>> [AlkaneH]+  (equilibrium constant = A) .. how hard it is to protonate the alkane

and

Acid >>> conjugatebase- + H+  (equilibrium constant = B)  .. how strong the acid is

Then for the reaction

Alkane + Acid >>> [AlkaneH]+ + conjugatebase-

The overall equilibrium constant is AB (multiply) - so the acid strength is still a factor. If you're not familar with why it's A times B - the articles Chemical equilibrium might help - or ask.83.100.250.79 (talk) 13:10, 3 August 2009 (UTC)

Did you mean acids that are very strong because of the stability of the conjugate base - there are examples of this - a mixture of HF and PF₅ is a very strong acid - not because HF is strong but because the anion PF₆^- is very very stable. ? Conversely there are very strong acids which the main reason for their strength can be considered to be in greater part the instability of the cation eg CH5+

Though to be absolutely correct it's the difference in stability of the acid and conjugate base that governs the acidity.83.100.250.79 (talk) 13:56, 3 August 2009 (UTC)

Mmm, but pH (external H+ concentration) also dependent on acid strength ... if I diluted magic acid to a pH of 1, would it still be able to protonate alkanes, but just more slowly in diluted form? That is, if I didn't know the Ka of the strong acids, or what the acids were, in my solution nor their concentration, but I could measure the pH, would it all that would matter for most protonation reactions? (Again just looking purely at the protonation aspect: I'm ignoring reactions where the derivative products of the acids end up playing a role, e.g. with nitryl ions, sulfonation, etc.) John Riemann Soong (talk) 14:04, 4 August 2009 (UTC)

As per the answer by "Jayron" above - it depends on what you dilute it with - with water, or any weaker acid then the answer is no (the dilutant acts as a buffer)

If you are trying to protonate hexene, and the dilutant is hexane, then yes it will still work. (at 1Molar) (at very low concentrations the low concetration of acid will start to have a significant effect on the extent of protonation).

The limiting factor is the strongest base in the solution. eg if the solvent is Ether then the protonating strength of the solution is limited (approximately but effectively) to the protonating strength of the Et-OH⁺-Et cation.

To avoid confusion (in the answers) you need to say what the solvent will be when diluting. It's difficult to find a truly inert solvent for magic acid. (and some potential inert solvents may not work well because they are not polar enough to dissolve certain acids)83.100.250.79 (talk) 20:27, 4 August 2009 (UTC)

OH that makes sense now! In magic acid, dissociation doesn't really occur until the proton-SF6 complex meets with another molecule, and if I add magic acid to water or a solvent that can act like a base, I'll lose a lot of the protonation capability as heat because the formation of H3O+ will be strongly exothermic and H3O+ will turn out to be a much weaker acid than magic acid, no matter its concentration. It's all about the solvent. Thanks guys. John Riemann Soong (talk) 23:04, 4 August 2009 (UTC)

Digestion

How long after eating does it take before you can no longer vomit it. Bugboy52.4 | =-= 02:33, 3 August 2009 (UTC)

I'm pretty sure that once the food has passed out of the stomach into the intestines (i.e. past the pyloric valve) that it is pretty much only going out the back door... --Jayron32 04:29, 3 August 2009 (UTC)

According to our article on Vomiting, the retroperistalsis starts at about the middle of the small intestine. Pyloric valve is relaxed, so it does not prevent the small intestine content from joining the vomitus. I did not know that, I am not a doctor (not an MD, that is; my PhD does not help here, it's in physics :) ; but I really hope our article is right. --Dr Dima (talk) 06:08, 3 August 2009 (UTC)

I have heard elsewhere that the intestine contents do not back up into the human stomach. ReverenceReference to a reliable source is called for. By the way, a physicist should start his answer to such a question be saying "http://www.physics.csbsju.edu/stats/WAPP2_cow.html] Assume a spherical stomach..."

faecal vomiting (or stercoraceous vomiting) occurs in some circumstances (not normal ones: it generally involves some form of bowel obstruction or other problem). If you want to reference to a source (especially those deserving reverence) then here's BMJ 1910, Lancet, 1859, Palliative Care manual 1998, Nursing textbook 1988 and so on and so forth. Gwinva (talk) 00:32, 4 August 2009 (UTC)

Crash location on the Moon of Ranger 4 (April 26, 1962)

The article Ranger 4 gives three different sets of lunar coordinates for the crash site: “15°31'S 130°42'W” (infobox); “15.5°S 229.3°E” (paragraph 4, lifted from this page); and “15°30'S 130°42'W” (paragraph 5). The longitude of all three is equivalent, but the latitude in the infobox differs by one minute from the other two. The article List of artificial objects on the Moon gives a different location for the crash of Ranger 4: “12.9°S 129.1°W”. Since this location was on the far side of the moon, how did NASA even know where it was in 1962? Were they just estimating based on its trajectory at the time it was last sighted? See this source from NASA which gives a different longitude (229.5°E rather than 229.3°E), attributed to a statement by William Pickering. I would speculate that lunar orbiting missions in later years were able to pinpoint the location better, but if you read Wikipedia you only see different coordinates given with no indication of their source. Also there are three different formats for lunar coordinates used in the same article, which is unprofessional. —Mathew5000 (talk) 03:33, 3 August 2009 (UTC)

I don't know how NASA knew the location. Suggest you take this to Talk:Ranger 4. Cuddlyable3 (talk) 09:54, 3 August 2009 (UTC)

Well “15.5°S 229.3°E” is a rather unconventional way to express a longitude. One would normally either give a number in the range 0..180 followed by E or W (east or west) - or give a number in the range 0..360 without either an E or a W. So 229.3E is really (360-229.3)=130.7W - but that's in degrees. So 15.5°S 229.3°E is the same thing as 15°30'S 130°42'W so the error between the three sets of numbers in our main article is actually just one arc-minute in latitude. Since that's in the least significant digit, we're probably looking at different roundoff errors between numbers obtained from different sources...so the Ranger 4 article is actually pretty reasonably self-consistent (although one could wish they'd used the same representation in all three places in order to avoid confusion). However, 12.9S 129.1W is nowhere near there. It is of serious concern that these articles are not indicating their sources - because checking sources is the way we are supposed to be able to correct (or at least explain) these kinds of discrepancies. That's a serious matter that you should certainly take up with the authors of the article on the talk: page. SteveBaker (talk) 12:54, 3 August 2009 (UTC)

I elected to use NASA's coordinates from NSSDC ID: 1962-012A. They may have been guessing, but it's the most authoritative figure we've got. They most likely plotted the range and angle from the telemetry, and used ballistic curve fitting to arrive at the most likely impact point. The Lunar Reconnaissance Orbiter program is prioritizing imaging of landing and impact points for all human artifacts. As of June 22, 2012, Ranger 4 isn't yet on the list of imaged spacecraft. Cmholm (talk) 09:50, 20 June 2012 (UTC)

Vegetable

Are there any vegetables that are used in desserts? Jc iindyysgvxc (talk) 06:19, 3 August 2009 (UTC)

Of course! Carrots are great for a cake or a tzimmes. Other veggies can do great in desserts just as well. Here is an article in Gourmet on vegetable desserts. If you google for vegetable desserts, you'll find many others, too. Bon appetit! --Dr Dima (talk) 06:37, 3 August 2009 (UTC)

Mmmm, rhubarb pie. Deor (talk) 11:10, 3 August 2009 (UTC)

Pumpkin pie is also a classic. Livewireo (talk) 17:28, 3 August 2009 (UTC)

I'm assuming that by "vegetables" Jc iindyysgvx means "not fruit", which disqualifies pumpkins. -- Finlay McWalter • Talk 00:44, 4 August 2009 (UTC)

Some people (evil, evil people) seem to use liquorice in desserts. Sweet potato pie is made from sweet potato. -- Finlay McWalter • Talk 00:53, 4 August 2009 (UTC)

And ginger is a root too. -- Finlay McWalter • Talk 00:54, 4 August 2009 (UTC)

There seem to be a number of yam (vegetable) dessert recipes online, another tuber. -- Finlay McWalter • Talk 01:05, 4 August 2009 (UTC)

Mmm... sweet potato pie. – ClockworkSoul 03:00, 4 August 2009 (UTC)

And mint. -- Finlay McWalter • Talk 01:07, 4 August 2009 (UTC)

Cinnamon (bark), sugar (made either from tubers or stems), maple sugar (from sap), and the various syrups, treacles, and toffees that are made from sugar. -- Finlay McWalter • Talk 01:18, 4 August 2009 (UTC)

Arrowroot, and its flour. -- Finlay McWalter • Talk 01:24, 4 August 2009 (UTC)

Nonstandard, but this is pretty cool. Oh, and how can we possibly forget: chocolate, vanilla, and coffee.

Most of these responses seem to be assuming that vegetable just means plant. That's true at a very basic level, but I doubt it's what the OP was interested in, which (I surmise) referred to vegetables in the sense of "you should eat five (or whatever it is) servings of vegetables per day". The only answers that are responsive to that question are the ones about carrots and yams (sweet potatoes). oh, and I missed the pumpkins --Trovatore (talk) 03:24, 4 August 2009 (UTC)

Oh, and in this sense, pumpkins are definitely a "vegetable" and not a "fruit". Botanically, a fruit is anything that has seeds (more or less; I'm not a botanist), but culinarily, a fruit mostly has to be sweet (though it might also be sour enough that the dominant impression is sour rather than sweet). --Trovatore (talk) 03:55, 4 August 2009 (UTC)

Potato pancakes make the list, so do amaranth cookies. For a light summer desert try butterhead lettuce with a dressing made from sour cream, lemon juice and sugar. (Serve cool but not chilled.) Sweet corn counts which adds a whole list of things from cornflake crubles to pies to corn muffins etc. If you have friends in South Africa they could send you some gooseberry jam and you could try one of the countless cookie and cake recipes with jam filling. Arrowroot is listed in Root vegetable but seems to be missing from List of culinary vegetables. One can make all sorts of desserts from that. 71.236.26.74 (talk) 06:28, 4 August 2009 (UTC)

Corn is not a vegetable in the "eat five veggies a day" sense. It's a starch. Sweet potatoes are also a starch, of course, but they get counted because of their carotenoid content. --Trovatore (talk) 06:38, 4 August 2009 (UTC)

Scars

Can scars really "burst open"? I can't see any mention of this in our article, and the first page of Google results looks more like cases of unhealed wounds reopening. AlmostReadytoFly (talk) 08:48, 3 August 2009 (UTC)

Well, I think so. For example if you have previously had a Caesarian section and are considering a natural childbirth they do a procedure called "trial of scar" which I imagine might be an assessment of exactly the risk of a scar bursting open. --BozMo talk 12:08, 3 August 2009 (UTC)

Trial of scar isn't really a diagnostic test. It just means going ahead with a vaginal delivery, but keeping an eye out for signs of the old scar rupturing, and doing a Caesarean if any occur. --Sean 14:36, 3 August 2009 (UTC)

Bleeding inside a space suit seems to have saved an astronaut's life. "..a suit was punctured in space. That incident was apparently caused by using the glove as a hammer to drive a balky pin. A 1/8" steel bar migrated out of the palm restraint and punctured the glove. In that one case, the steel bar and the astronaut's blood sealed the puncture;.." Cuddlyable3 (talk) 09:50, 3 August 2009 (UTC)

Was this meant to go up here? --Sean 14:36, 3 August 2009 (UTC)

The incident is already mentioned there. Cuddlyable3 (talk) 19:04, 3 August 2009 (UTC)

I would think that a tapered rubber plug going from say 1/16 inch to 1/2 inch would be useful. Push it into the hole until the leak is minimized. A 6 mm hole in a glove was said above to give the astronaut 1/2 hole to get back inside a pressurized place. Even direct pressure from a finger should slow the leak. A plastic bag with a sticky seal tied tightly around the glove should also be a life saving measure. A wire could clamp it around the metal glove fitting, or the metal attachment of a boot, for that matter. Edison (talk) 18:51, 3 August 2009 (UTC)

Diamorphine pills

Do UK physicians prescribe diamorphine in pill form? I remember a chap at school who had what he purported were diamorphine pills, but now I imagine all diamorphine is delivered by needle. 82.111.24.28 (talk) 13:43, 3 August 2009 (UTC) EDIT: I should add, I have no medical need for this information, am not asking for advice etc etc

Diamorphine/Heroin can be delivered orally. It is used as an analgesic for cancer patients in the UK. Fribbler (talk) 17:35, 3 August 2009 (UTC)

Diamorphine is available orally. It is rarely used in the oral form. It has about twice the potency of morphine. However it is a pro-drug. Diamorphine's main benefit over morphine is its greater solubility in water, hence it is useful in minimizing the volume in a syringe driver. Axl ¤ [Talk] 15:48, 4 August 2009 (UTC)

Afterimage

Since the human eyes is very sensitive, then what about if I'm in the blue light all the time, how come I still notice blue. When I'm in a green light all the time, the green light is still visible to me. What will happen if I'm in a room full of green light, would I still notice the green light. Would this be possible for a white object to look orangeish yellow, while pink object looking black? This never seems to happen in my lifetime. Since cherry color is at the front end of spectrum, violet is at the back end of spectrum, the fronter the spectrum, the color is easier to wash away?--69.229.108.245 (talk) 17:43, 3 August 2009 (UTC)

Your brain compensates, so if you look at something that you know should be white your brain will compensate for any colour in the ambient light so that it looks the "correct" colour. If you don't know what colour something is supposed to be you can easily get it wrong - try working out the colours of cars under sodium street lights. I don't think it makes any difference what end of the spectrum a colour is, the brain doesn't work in terms of wavelength, it works in terms of how much each of the three types of colour sensing cells in the retina (cone cells) is stimulated. --Tango (talk) 18:09, 3 August 2009 (UTC)

If your eyes are exposed to one color of light, afterwards things of that color will look very desaturated, and things of the complememtary color will have enhanced saturation. You say you "notice blue," but isn't it desaturated or less vivid compared to when you have not been exposed to light of the same color? Edison (talk) 18:46, 3 August 2009 (UTC)

Personal observation - back in the days when I used to spend long periods working at a monochrome computer monitor that displayed green letters on black, when looking out of the window for up to an hour or so afterwards I would see, for example, white cars as being pale magenta. Such chromatic adaptation effects (see under Color vision) can involve both a degree of photoreceptor fatigue (see under Complementary colour) and unconscious mental adjustment (see under Color constancy).

This is why, for example, one has to use different kinds of film for indoor and outdoor photography - pictures taken with outdoor film indoors under incandescent (tungsten) lights look astonishingly orange, even though to our acclimatised eyes such lighting seems quite "normal." Conversely, try out the effects of a "daylight bulb" (available from most arts/crafts supply stores) indoors at night. 87.81.230.195 (talk) 21:16, 3 August 2009 (UTC)

This effect is very noticeable if you ski with goggles. Ski goggles are typically tinted orange or yellow, and after taking them off the snow appears blue or purple. Rckrone (talk) 04:19, 4 August 2009 (UTC)

Rorschach Ink Blot Test

Why do psychologists always use the same set of pictures? Why don't they generate a random picture?Quest09 (talk) 18:06, 3 August 2009 (UTC)

Because they know what various responses to the standard inkblots mean. They wouldn't know how to interpret responses to random ink plots. One of the things they look at is whether you come up with original responses or the same kind of responses as other people come up with, that certainly couldn't be done with random inkblots generated for each person. --Tango (talk) 18:16, 3 August 2009 (UTC)

(ec)Because there are set interpretations for subject responses. If there weren't, all the test would show was whether the subject had the same set of mental disorders as their psychiatrist. (insert usual caveats about Rorchach being untrustworthy and thus showing nothing of the sort). -- Finlay McWalter • Talk 18:18, 3 August 2009 (UTC)

(oh, would that I could find an image of the Rorschach blot from Wilt (film) online). -- Finlay McWalter • Talk 18:21, 3 August 2009 (UTC)

Doesn;t using the same ten pictures for 70 years make the test very coachable? Edison (talk) 18:44, 3 August 2009 (UTC)

Well, yeah, but in most situations the patient doesn’t have some motive for fooling the psychologist. That would be about as useful as surreptitiously taking insulin before a glucose tolerance test, in order to trick the doctor into thinking you don’t have diabetes. Red Act (talk) 18:59, 3 August 2009 (UTC)

Well, it's a little more complicated than that. They are now quite easy to stumble upon online (and on Wikipedia) and a lot of psychologists are starting to wonder if the test is going to lose its use altogether for that reason. There was an article on this recently in the New York Times: A Rorschach Cheat Sheet on Wikipedia?. As for the motive to fool a psychologist, I think to assume total rationality in the realm of psychological or even medical practice on behalf of the patient is probably not totally correct. We all get a bit hung up about being diagnosed, I imagine. --98.217.14.211 (talk) 22:45, 3 August 2009 (UTC)

There has been a major change in the nature of this issue because the standard set of blots recently came out of copyright protection. That's why they recently ended up here on Wikipedia causing such an upset with the Physchologists. Check out this long argument about the ethics of Wikipedia doing that: Talk:Rorschach_test/images. SteveBaker (talk) 23:56, 3 August 2009 (UTC)

Scientific American mentions this subject here. Bus stop (talk) 00:04, 4 August 2009 (UTC)

A psychologist who was trained on projective tests in the 1940's tole me that he could achieve the same results by having the examinee give his reactions to random cartoons, magazine illustrations or cereal box illustrations. This seems way to the mumbo~jumbo edge of science. Edison (talk) 01:32, 4 August 2009 (UTC)

Remember it's not just whether they can interpret them, but in many case whether they have the science (or whatever Edison wants to call it) to back it up. I'm pretty sure that the Rorschach blot tests have been extremely widely studied and there is an extensive amount of peer reviewed studies analysing the reliability of the interpretations. This is obviously not the case for random blots. Beyond the ethical reasons, I believe the Rorschach blots have (partially) formed the basis for a number of psychologists analyses of patients in court. Likely also in other legal settings, e.g. deciding whether to commit someone, ready they can safely be released etc. If you go to court, and say I gave these random blots and these are the results and this is what I think they mean and someone asks you why and you say, well it's what I think, your evidence is not going to have much weight. If you point to the countless studies to support you, your evidence will carry far more weight. Similarly, an opposing lawyer (or whatever), can get their expert to testify if they feel your conclusions aren't supported by the science. Nil Einne (talk) 13:10, 4 August 2009 (UTC)

Except that according to this Scientific American article from 2005: [1] the test is used in many situations, many of them in court evaluations, for which it has no proven effectiveness. 75.41.110.200 (talk) 13:46, 4 August 2009 (UTC)

Does use in court prove that a technique is scientifically valid? Several "expert testimony" types have been recently discredited for producing convictions of people later cleared by more exact DNA analysis. Those included matching of bites and hair, and footprints. A psychological test should be valid and reliable, and should have recent norms applicable to all the groups it is used on. The Rorshach has many failings documented in peer reviewed journals, as summarized in [2], which said the analysis criticized it for having norms based on small sample sizes, with norm groups that are not representative of the population, and which tend to classify normal people as having pathology. The studies also say that reliability is lacking: two different interpreters may score a session differently. The article says on the good side that the test may be useful for "schizophrenia, bipolar disorder, and borderline personality disorder," but doubts its validity for some other disorders. Edison (talk) 14:15, 4 August 2009 (UTC)

It would seem to me that this is more a failing of the legal system then anything else. If these tests have no proven reliability in a given situation or have even been proven unreliable, then that should have been challenged and disallowed in court. A key point here I think is returning to what I said, that this reliability and unreliability is well documented and I presume, known, therefore it should in theory be easy to challenge in court. This compares to some random test where there is little documentation and few scientific studies, which would be even more inappropriate to use in court. Nil Einne (talk) 10:21, 9 August 2009 (UTC)

History of science: from pseudoscience to empirical science

Historically, chemistry started as alchemy and astronomy as astrology. Is there hope for any kind of pseudoscience? —Preceding unsigned comment added by Quest09 (talk • contribs) 18:07, 3 August 2009 (UTC)

Not really. It's not that various types of science come from things that would now be called pseudoscience, it is that the entire concept of science came from the entire concept that is now called psuedoscience. Some pseudoscientific things could turn out to be right, but it would just be a coincidence. --Tango (talk) 18:12, 3 August 2009 (UTC)

It seems quite possible that future historians of science might look back on the beginnings of what by then is an established branch of science, and see that in the past it was considered pseudoscience. Things which might be called obvious hoaxes if presented now might really be just engineering challenges. But from this point, it it appears to run afoul of presently accepted scientific laws, and if it cannot be replicated in the labs of a skeptic, if it is not a robust phenomenon, then it is presently properly called pseudoscience. There might really be ways to "reading minds." Some glimmerings of that have been achieved with cortical evoked potentials recorded by scalp electrodes (the P300 potential), and by functional MRI. Cold fusion might be found practical. Messages or visits from extraterrestrials might occur. Levitation (they can do it magnetically with frogs in a lab) and "invisibility cloaking" (early steps toward it have been written up) might be practical on the human scale in the distant future. Edison (talk) 18:43, 3 August 2009 (UTC)

The difference between science and pseudo-science is one of method, not one of results. --Stephan Schulz (talk) 19:50, 3 August 2009 (UTC)

I don't think that affects the point that things like alchemy were a precursor (whether scientific or not) of more useful studies. Who knows, "cold fusion" research might eventually inspire something useful even though it almost certainly won't be limitless clean energy. Dragons flight (talk) 20:15, 3 August 2009 (UTC)

There is scientific research into cold fusion. It's fringe science for the most part, but it is science. It is certainly possible that something will come of it and it could well mean (near) limitless clean easily accessible energy. --Tango (talk) 20:33, 3 August 2009 (UTC)

An historian of science would tell you that historically speaking, what is "science" and "not science" has changed rather dramatically, and our modern definitions of "science" that people cling to (e.g. methodological rules, etc.) are often quite, quite recent. ("Falsifiability" didn't come into vogue as a demarcation criterion until the 1950s.) And most philosophers and historians are not at all content with the idea that such criteria can be applied historically or presently. (See demarcation problem.)

So yes, sure, things that are now considered "pseudoscience" could, depending on the circumstances, become the germ of something that is considered to be "real" science.

On the other hand, there is no reason to assume ahead of time that they will, and the fact of a few examples of things that did become important (alchemy, for example) does not actually prove anything about the likelihood of current pseudosciences becoming accepted as sciences. It is no more encouraging than the fact that some scientists were initially ridiculed but were later revered—the fact of it does not help you distinguish between the ones who were rightly ridiculed and those who are not (and a great deal of the scientists ridiculed deserved to be). One of my favorite Carl Sagan quotes: "But the fact that some geniuses were laughed at does not imply that all who are laughed at are geniuses. They laughed at Columbus, they laughed at Fulton, they laughed at the Wright Brothers. But they also laughed at Bozo the Clown." --98.217.14.211 (talk) 22:36, 3 August 2009 (UTC)

I'm going to agree that alchemy and astrology are not true precursors. The true ancestor of all modern science is the ascendance of secular knowledge and its codification. A process that started with the renaissance and just meandered its way across Europe. This codification dealt with almost all aspects of life but was arguably most transformative in how it dealt with natural phenomenon. This codification has been extended to all measurable phenomenon with remarkable results. Gentleman scholars such as Boyle had a need to create chemistry as we know it not to progress alchemy but to have a more complete secular explanation of the world. They were scientists first and chemists second, chemistry was just another part to understand. Chemistry in particular only developed after the scientific method (or process) had been successfully applied to number of other fields such as astronomy, physics, biology, and anatomy. I think chemistry is the youngest of the hard sciences (or "hard" natural philosophies). This isn't to say that early natural philosophers didn't use some of the "raw data" and "hints" they collected from alchemists or astronomers but they contextualized the data very differently. They had completely different motivations and interpretations. The early scientists really had to start data collection from scratch since maintaining a good reliable community record (a defining aspect of science) was part of the new codification system. Alchemy didn't evolved into chemistry, the practice of science spread to the transformation of matter and became known as chemistry.--OMCV (talk) 01:49, 4 August 2009 (UTC)

I just want to note that no professional historian of science today would agree with you. All have long since accepted that the line between "real" chemistry and alchemy is not only blurry, but impossible to distinguish. There is no methodological, epistemological, or quantitative criterion that you can use that successfully puts the "alchemists" on one side and the "chemists" on the other. Trying to say, "oh, well science developed, and got applied to alchemy" is even more incorrect from a historical standpoint. (There is no point in trying to go into strict historical details here, but if you want recommended reading on the topic, I'd be happy to send it along.)

Once question one might ask oneself is, what are the stakes in trying to draw that line, anyway? Is it because we want to say that bad science is always bad science and will always be? (Which is sort of obviously absurd, and certainly not epistemologically justified.) Or is it because we want to avoid having to give any credence to bad or pseudoscience today? (We don't really have to, even if the historical argument is as such, as I've emphasized.) --98.217.14.211 (talk) 01:58, 4 August 2009 (UTC)

That sounds rather post-modern to claim that things are too blurry to distinguish. From what I can understand a value for secular knowledge did emerge at some point and after a time dominated many cultures understanding of natural phenomenon. It was a cultural phenomenon that I would describe in evolutionary language whether or not that language is in vogue for historians. No doubt the edges blur just as the edges of "species" blur. I think alchemy would have gone on forever without any significant "progress" without the very significant introduction of a "methodology". In my view cross pollination form the other hard sciences. Like I said, Boyle and the The Sceptical Chymist seems to be a reasonable, if imperfect, place to draw the line for chemistry. But I am interested in the mainstream historic perspective, is it more consistent to follow disciplines according to its subject matter than it is to follow underlying practices and philosophies?--OMCV (talk) 02:19, 4 August 2009 (UTC)

Historians would say: you can't follow disciplines according to subject matter when the question of disciplinary lines themselves is a point of contention. (This whole debate is a subset of boundary work, in the parlance of sociologists of science.) You follow practices, philosophies, etc., but that's where things get the most mixed up, where you see that the "chemists" and the "alchemists" believe almost exactly the same things, do almost exactly the same experiments, and by modern standards, neither has the slightest claim to being more "accurate" or "progressive" than the other. Science textbooks (for obvious pedagogical reasons) emphasize the "modern" aspects of the chemists and emphasize the "pre-modern" aspects of the alchemists, but if you look at the whole of their practices you find that methodologically, philosophically, and certainly in terms of practice there is tremendous overlap. Historians have long since concluded (which you may take as you will) that trying to sort these out into even rough categories doesn't illuminate what people were doing at the time, and rather butchers any real account of how these people worked or what they cared about. The "popular" history of science is one that ignores (or marginalizes) the crazy moments and emphasizes the clever moments (Kepler is a perfect example of this). It makes for a good read, and encourages the modern scientist to feel superior in their position, but it doesn't actually represent the history of things accurately. --98.217.14.211 (talk) 15:29, 4 August 2009 (UTC)

You claim that the methods and goals of alchemist are indistinguishable yet I see big differences. Alchemists are known for their search for the transmutation, philosopher's stone, and a variety of other very ambitions methods to control the world. In contrast "chemists" choose much smaller problems their modest ambitions are rather boring compared to those of alchemists. Work like Jan Baptist van Helmont on conservation of mass and Boyle's work linking pressure and volume. This was a radical shift in the sort of questions asked concerning the transformation of matter. Some might argue that these models of the world had been proposed earlier (since they were). But that brings us to the second point these questions where now supported with empirical evidence instead of well written although idle speculation. Their was also the transition from secret experiments to public experiments. While "methodologically, philosophically, and certainly in terms of practice there is tremendous overlap" between the modern and pre-modern it doesn't make them indistinguishable. The use of this understanding and distinguishing modern form pre-modern is to teach people how to think like modern scientists, a student of science shouldn't try to create a philosopher's stone equivalent instead the student should look for fundamental questions, albeit a boring questions to the untrained, that can be answered with available resources. For most people subjects like photodiode, nuclear magnetic resonance, even high temperature superconductivity are extremely boring subjects until they are converted into a useful technology. Having the public understand that the technology pipeline begins with basic research where scientists tackle what appears to be boring and useless questions is very important for the health (ie funding) of the pipeline. As it is most people don't want to see money spent on research unless it is directly related to a tangible product that improves their lives (philosopher's stone). I agree that the cleaver stories are aggravating but most of my grips revolve around popular histories focus on theoreticians and devaluement of experimentalists and less prominent researchers. For every noble laureate their is a massive amount of grunt work that goes largely unacknowledged.--OMCV (talk) 22:39, 5 August 2009 (UTC)

Chemistry is a tough example; but in astronomy or physics, there are a few critical moments - like the publication of Principia or the church trial of Galileo - where one can definitely draw down the line and say, "in one corner, Modern Scientific Method, and in the other corner, outdated knowledge devoid of empirical basis". Specific instances and specific dates are more difficult in chemistry, but the adoption of atomic theory in the 18th century is a pretty crucial turning point. Nimur (talk) 02:23, 4 August 2009 (UTC)

Well, I don't want to spend all my time nit-picking here, but in one corner you've put a grand old alchemist (Newton) who was roundly criticized by scientists and philosophers in his day of violating basic, obvious tenants of science (e.g. postulating an occult force—Gravity), in the other you've rather dramatically simplified something that is considered by most scholars to be a specific political transaction rather than a broad philosophical transaction. Let me just say: the version of this you get from science textbooks and pop science is not, in fact, what historians believe at all, and they do not take this position just because they are namby-pamby postmodernists (many are not at all), but because careful study of it along historical lines (not presuming to find the conclusion that you expect) simply doesn't warrant it. --98.217.14.211 (talk) 15:29, 4 August 2009 (UTC)

I think the importance of drawing lines is so that as scientists we can successfully transmit our culture and its values. Values which including honesty and forthrightness. "Falsifiability" isn't the best example to give about the malleability of scientific philosophy over time since the ideas contained in the concept already existed in science in a variety of forms. Popper just codified the "concept" under a word, as Popper's fame diminishes so will the importance of the term "falsifiable". Nimur I think you are right that chemistry is hard but I think thats part of what makes its history interesting.--OMCV (talk) 02:36, 4 August 2009 (UTC)

Occam's Razor is a much more time-honored principle than falsifiability - it fills the same mental niche of allowing us not to have to concern ourselves with things that are just too crazy. The razor accords more flexibility in interpretation than falsifiability does - but on the downside, it's not as rigorous. The bottom line is the same though: There are a literal infinity of unproven and/or unprovable hypotheses (Russell's teapot, etc) - if we had to seriously consider them, our minds would be crippled by it.

Does this apple fall from the tree because the earth imposes a gravitational force on it - or is there an invisible purple unicorn from the planet Zaa'arg pulling it off the branch? Do I reject the latter argument because of the impossibility of proving that invisible purple unicorns exist (unfalsifyability) - or do I reject them because they introduce concepts like invisibility and the existance of unicorns which are unnecessary to our explanation? It doesn't really matter. The only way to proceed without being blindsided by that impossible number of useless ideas is to rigorously prune them.

Falsifiability and Occam's razor are vital and powerful tools for reasoning about the universe - almost as essential as the scientific method itself.

Pseudoscientific concepts always fail the razor - and often fail falsifiability too. We can falsify things like telepathy if the practitioner will submit to careful pre-agreed scientific study methods - and abide by the conclusions. However, it doesn't work like that. The tiny proportion of pseudo-science practitioners who actually agree to submit to these tests (eg James Randi Educational Foundation's million dollar prize) inevitably, fail to win. Mostly they just make up some lame excuse like "Well, my powers don't work when scientists study them." - which moves them firmly into the "unfalsifiable" category. Those who refuse to undergo these tests (despite the offer of a million dollars!) are already in the "unfalsifiable" category. But we could have avoided doing the experiment or offering the money at all just by invoking the razor...if telepathy worked, there would have to be a whole order of communications media that no experiment has yet revealed - the tissues of the brain would have to function in ways entirely differently than cellular biology would have us believe - we'd have to wonder why evolution has not given all of us use of this faculty. Since there is not a single experiment that points towards such things being true - the hypothesis that the practitioner is a lying, cheating bastard is far less complicated conclusion than it is to assunme that almost all of physics and biology is incorrect. Occam's razor really helps out under those circumstances - even though we know that it's not always right. SteveBaker (talk) 04:04, 4 August 2009 (UTC)

Lovely that you use the gravitational force as your pro-razor argument; you do realize that this was exactly the criticism that was made against Newton (postulation of new, invisible, "occult" forces) by his fellow philosopher-scientists in saying that what he was doing was not actually science? I bring this up only because what seems "most likely" (when one is not making a deliberate false dilemma, as in your unicorns) his historically contingent. When you've been taught that there are "forces" and one of them is named "gravity" and it is as obvious as night and day then you say, "oh, yes, that seems most plausible." When you've been taught something else, you tend to see things otherwise. Gravity is a wonderful example, in that the only way any of the larger gravitational schemes seem "most likely" is if you have built up a tremendous educational edifice beforehand. Saying that "no, it's not a force, it's a warping of space-time" certainly isn't compelling until you've already bought in to quite a few other concepts first. (And when you get into certain realms of science—e.g. quantum mechanics—Occam's Razor becomes something all the more queerer indeed. It is hard for me to see how it applies at all to my favorite experiment.) --98.217.14.211 (talk) 15:29, 4 August 2009 (UTC)

(Outdent) - Occam's Razor is not meant to suggest that the universe actually is simple - only that our scientific explanation of it should be as simple as possible. Both examples you cite - the introduction of a previously unknown force, and the treatment of a photon as a particle and a wave - are examples of how complicated the universe actually is. Scientific methodology demands that the introduction of these concepts be skeptically challenged (and as you say, they were). But in the face of overwhelming experimental evidence, and overwhelming observational data, there's no denying that some invisible force of gravity is exerting an effect - so Newton's peers had to accept a new addition to their conceptual world view. Regarding your assertions about historiography, I've got to respectfully disagree. As I mentioned earlier, I really think that an in-depth review of the writings of Newton or Galileo demonstrates that these guys were way ahead of their time, in terms of constructing logical ideas and testing them observationally. Short of a few "refresher" courses on modern differential equations and some computer science, Newton or Galileo would fit right in with a modern science team - because alchemist or not, these guys understood how to put aside their expectations and accept the data. But not only this - they proceeded to synthesize a new idea to explain the observations, still seeking as simple a method as possible. Galileo did not say that "The earth rotates the sun, therefore alien UFOs built the pyramids"; nor did Newton suggest an "invisible hand of God" pushing planets around.

I took a few history courses on the development of the scientific method, and I was stunned to see historians telling me how science works (when - sorry for my pejorative stereotypes here, but personal experience! - these guys hadn't even passed through the freshman courses in biology, physics, or chemistry. And yet, they professed to "understand" the scientific method "better" than us real scientists, because they'd analyzed it "in the writing of the era" and all this other "humanities" nonsense. At the end of it, though, they're obfuscating some key points. The famous dead white guys like Newton and Galileo earned their position in history because they were so pivotal in the development of the scientific method - which, and let me state this very plainly for the Humanities and Philosophy enthusiasts in the room - is not a fuzzy, vague concept that has evolved over the centuries. The scientific method is very simple. It can be phrased in a thousand different ways, but it is very simple:

• Step 1: Think about something. ("Hypothesis")
• Step 2. Find a way to test what you thought, by building an experiment or observing nature. ("Test")
• Step 3: If you were right, great! If you were wrong, think again. ("Confirm or refute hypothesis")

Different philosophers of science emphasize different parts of this method - Popper's "falsifiability" has to do with the way that "step 1" needs to be phrased in order to make "step 2" feasible. All the rigorous reviews of experimental data collection that make up the bulk of 21st century science fall into the category of improving "step 2." And finally, this is the part that never seems to get across to people who don't actually study science - "Step 3" took a really long time for humans to get to. When Aristotle hypothesized that inertia did not exist (i.e. that the proverbial horse-cart will stop as soon as you disconnect the horse), he never bothered to test it - he never bothered to follow through on his implications and watch the real world. But then, 1500 years of looking at real world kinematics never inspired anyone to say, "wow, that is patently incorrect, and totally out of sync with what I see every single day." Newton's contributions to the mathematical description of physics were monumental - but equally important is that he challenged a millenia-old, incorrect theory. As 98. brought up, this was really part of an entire era of re-thinking old, broken ideas. But closing the feedback loop that is the Scientific Method - being willing to admit when an idea needs some re-work - is a huge leap forward in human comprehension of our universe. Once we got this stupidly simple three-step process down, it was trivially easy to start applying it to build up a body of scientific knowledge. (Philosophers and historians can debate about the fuzzy and vague borders of this body of knowledge, but they should lay off the "vagueness" of the scientific method). But this is why the period of time from ~ 1650 to ~ 1850 saw the explosion of accurate knowledge about physics, chemistry, biology, and engineering - because as soon as you are willing to check your work, it becomes possible to do things correctly. The more subtle parts, like advanced thermodynamics, subatomic physics, etc., took a long time to get right, because they're extraordinarily complicated compared to Newtonian physics - but we got those down pretty well, and we're now working on the even more subtle parts of science. Nimur (talk) 13:12, 5 August 2009 (UTC)

What is meant by 'any kind of pseudoscience'? Sometimes it is hard to distinguish between a science and pseudoscience. A good example for this thread would be neurolinguistic programming. I believe this started out as just some claims by the two guys who founded it, but now there is lots of research into the area. See: List of studies on Neuro-linguistic programming and NLP and science. Some of those studies show efficacy, but at what point do you classify NLP as science or pseudoscience? --Mark PEA (talk) 12:10, 4 August 2009 (UTC)

NLP doesn't fail either Falsifiability or Occam's Razor - so we can't simply hand-wave it away as pseudo-science. That doesn't mean that NLP is true - it just means that we can't dismiss it out of hand on those grounds. That suggests that we should probably do some serious experiments to test whether it's true or not. If it does turn out to work, we don't have to invent any new fundamental laws - all we're saying is that the brain is more complicated than we thought - which should come as no surprise to anyone who has considered such equally unlikely-sounding things as the placebo effect. However, if we do all of those investigations - and it turns out that NLP doesn't work - then if people continue to pursue it then we should probably label them as advocates of pseudo-science. SteveBaker (talk) 15:21, 5 August 2009 (UTC)

car brakes question

If someone was to wear their brake pads all the way down to metal, would it be possible to melt the remaining portion of the brakes, or will the friction of using the brakes not get hot enough for that? This is a hypothetical question, I advise that those who have worn brake pads and or damaged rotors get them replaced. Googlemeister (talk) 20:51, 3 August 2009 (UTC)

If you're braking metal to metal you can get some quite nasty consequences. Metal conducts heat very nicely so heat gets transferred from the discs to the brake calipers - that will wreck them in short order. You can also boil the brake fluid and wreck your entire brake hydraulic system. Exxolon (talk) 21:35, 3 August 2009 (UTC)

Yeah - the brakes can only get so hot before the brake fluid boils. Since the gasses that result are easily compressible, you lose all braking force and the brakes will release...in short...no brakes! Assuming you don't crash as a result, there would then be plenty of opportunity for the brakes to cool off - but they'll never recover full pressure after that...and there is a good chance you'd blow a brake hose or something along the way. You'd also gouge the disks (or drums) and disk brakes would probably warp too. SteveBaker (talk) 23:07, 3 August 2009 (UTC)

A bit of OR here: you don't need to wear the pads down to nothing, either. If the disks have been machined smooth once too often, they can heat up enough to boil the fluid, under sustained braking (eg down a steep hill, the last place you want to find yourself with no brakes).- KoolerStill (talk) 20:03, 5 August 2009 (UTC)