Wikipedia:Reference desk/Archives/Science/2013 November 25

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.

November 25

Identifying dinosaur species from tiny bone fragment

This query was prompted by seeing dinosaur-bone beads and jewelry at an art fair: given one of those items (which are tiny, spherical beads or cabochons and presumably retain no trace of their original shape), would it be possible to determine in a non-destructive manner what species (or even higher taxon) it came from? 69.111.191.53 (talk) 02:10, 25 November 2013 (UTC)

I am reminded of the Astragalus of Necrolemur, a paper I read several years ago. Its author made his entire career by identifying extinct primates almost exclusively from tiny ear-bone and wrist fragments. The scientific skeptic in me knows that there is at least a little hand-waving in the process; but the paper has many elements of rigorous palaeontological investigation. And its author has a certain literary flourish: announcing to a world who had been desperately holding its breath, "the previously unknown astragalus of the Eocene omomyid Necrolemur has been discovered." Finally! Nimur (talk) 15:35, 25 November 2013 (UTC)

Interesting... I don't blame him for sounding excited, though, because anything called the Astragalus of Necrolemur is clearly a magical McGuffin. (PS: I'm the OP, my IP just seems to have changed overnight.) 69.111.73.99 (talk) 16:58, 25 November 2013 (UTC)

It might be possible to say something on the basis of a bone-bead, because there are differences in bone density and perhaps one or two other aspects of structure that might survive in a fossil. But if the shape has been lost, it wouldn't be possible to identify the species or anything close to it. Looie496 (talk) 16:16, 25 November 2013 (UTC)

...all of which leads me to wonder whether the vendor of these items is really selling dinosaur bones in the first place. Since birds are now considered to be therapod dinosaurs, you might be getting an old chicken bone! SteveBaker (talk) 18:43, 25 November 2013 (UTC)

Except I don't think even the oldest of chicken bones would be fossilized. Unless there's a way to turn fresh bone into stone in a matter of days-- perhaps a Young Earth Creationist might know? 69.111.73.99 (talk) 21:27, 25 November 2013 (UTC)

Fossil says that fossils can be as recent as 10,000 years old - which (I presume) would mean that bird fossils might be much easier to obtain than a 66 million year old dinosaur. SteveBaker (talk) 23:42, 25 November 2013 (UTC)

Fair point, but according to Chicken#Origins domestic chickens probably don't go back quite that far (though presumably some related birds do). Also this page says that the avian fossil record is poor because birds have hollow bones. So I doubt that bird fossils would be more common than non-avian dinosaur ones (nor would their bone structure be as conducive to carving into beads, if they're hollow and more fragile). 69.111.73.99 (talk) 03:08, 26 November 2013 (UTC)

I would say it's not necessarily impossible. If William R. Maples can identify specific people by the tiny fragments of charred bone left after cremation, then it's probably not impossible to identify a dinosaur genus from pretty much anything. The difference of course is in the depth of knowledge; landmarks for human bone identification have been studied for a long time and the rich variety of human skeletons is well recorded; many dinosaur genera are completely unknown or only known from incomplete portions. But if it's a well studied dinosaur, it might be possible. Matt Deres (talk) 01:14, 28 November 2013 (UTC)

Electrochemistry question

Is the dropping mercury cathode still used for voltammetric analysis? I'm currently working on a design project for a multipurpose potentiostat which can make several different analyses using interchangeable electrodes and multimode software, but we can't agree on whether to include a polarography mode -- I'm in favor of at least making provision for it, while two of my teammates argue that it's not needed at all. Thanks in advance! 24.23.196.85 (talk) 03:20, 25 November 2013 (UTC)

Yes, there are several journal articles from the last decade discussing current DME applications, and potential applications (no pun intended). From what I can find, DMEs seems to be uncommon in polarography. Nonetheless, it seems appropriate to make provision for it as you suggest. Plasmic Physics (talk) 10:39, 25 November 2013 (UTC)

Electrolysis

Why is it so that electrowinned copper occasionally exhibits a latency when redissolving in concentrated hydrochloric acid? The electrolyte consists of mixed sulfates. Plasmic Physics (talk) 10:50, 25 November 2013 (UTC)

Lack of dissolved oxygen or oxides? Copper shouldn't dissolve in hydrochloric acid, should it? Maybe the answer by pisgahchemist here can shed some light... Ssscienccce (talk) 16:18, 25 November 2013 (UTC)

Copper will not dissolve in hydrochloric acid, but it will in nitric acid, due to the ability of nitric acid to oxidize the copper. It's the nitrate ion, not the acid part, that does the dissolving. See [1]. You get blue copper nitrate solution and brown nitrogen dioxide gas. But the chloride ion is a pretty crappy oxidizing agent, so HCl shouldn't do squat. --Jayron32 20:21, 25 November 2013 (UTC)

Does that mean I broke my copper, seeing as how it does dissolve? Plasmic Physics (talk) 21:26, 25 November 2013 (UTC)

Are you sure it was copper, and not already oxidized copper, like red Copper(I) oxide? Because dropping copper into concentrated HCl should do absolutely nothing interesting, per the Standard electrode potential (data page), which clearly shows that the E^o of Cu + 2H⁺ --> Cu²⁺ + H₂ to be -.340 V. Either you're providing some excess energy somewhere, or its simply not going to do anything. I can leave a penny in HCl overnight, and get a penny back the next day. It'll be a bit cleaner, but otherwise unchanged. --Jayron32 00:45, 26 November 2013 (UTC)

I'm positive it was copper. It does not seem likely that cuprous oxide would be deposited at the anode. Plasmic Physics (talk) 02:20, 26 November 2013 (UTC)

From this topic on Gold refining forum: "As I understand it, it seems that, once the HCl + oxygen dissolves a little copper, it becomes self-perpetuating, from the action of the copper chloride that is produced." Some tests another poster did seem to agree with that hypothesis.

There's a paper with the title "Dissolution of copper in hydrochloric acid solutions with dissolved molecular oxygen", available for $41.95. The abstract mentions this was in the presence of cupric chloride, and "the dissolution rate of copper exhibited first order kinetics with respect to CuCl2 concentrations above 0.01 mol dm⁻³" Ssscienccce (talk) 05:48, 26 November 2013 (UTC)

OK, so now that we've established that copper is attacked by oxygenated hydrochloric acid, let us get back to the original question - why does the reaction intermittently show a latency? Plasmic Physics (talk) 08:23, 26 November 2013 (UTC)

Oxygenated hydrochloric acid is likely forming chloroxy anions (hypochlorite, hypochlorite, chlorate, perchlorate, etc.) For example, ClO2(g) +  H+ +  e− <-> HClO2(aq) has a standard potential of +1.9 V, which is more than enough to oxidize copper. You would need enough dissolved oxygen to generate enough ClO2 in situe to actually do the reaction, but I suppose that it's possible. --Jayron32 18:40, 26 November 2013 (UTC)

Spectroscopic film ?

I saw on a science show where they held up a "special film" to a neon light, and the film then showed a series of lines, the spectrum of neon. Presumably this works because each line on the film is opaque to all but one narrow frequency of light. What is the name of this special film, where can I get some, and how much does it cost ? StuRat (talk) 14:08, 25 November 2013 (UTC)

Maybe it was a diffraction grating? DMacks (talk) 14:15, 25 November 2013 (UTC)

While I obviously can't definitively say that what StuRat saw was a diffraction grating, that demonstration certainly works with a diffraction grating. Assuming you are based in the US there are several formats of diffraction grating available from Edmund Scientific, such as these, which cost $7.95 for 15, or in fashionable cardboard glasses format for a dollar fifty. Equisetum (talk | contributions) 14:53, 25 November 2013 (UTC)

Some of those say they are "single-axis" and others say "double axis". I'm guessing that single axis is the one I saw ? With double axis, would I see two spectrographs overlapping, at right angles ? If so, what's the use in that ?StuRat (talk) 21:42, 25 November 2013 (UTC)

With christmas time coming up you can probably find those glasses locally for a couple of bucks, if you don't mind the spectrum ending up displayed as images of snowflakes or "happy holidays" instead of nice clear bars. :-) They also show up around the 4th of July for watching fireworks. Katie R (talk) 17:36, 25 November 2013 (UTC)

Sounds annoying, but I will look for them. I wonder how to determine which local stores would have them. StuRat (talk) 21:44, 25 November 2013 (UTC)

My mother-in-law in the Detroit area works at English Gardens, a garden center chain, and usually brings home a few pairs every year. If you happen to be near one it would be worth checking out. They work best with point sources - I think the idea is to use them to look at Christmas lights . Now that I think about it, they're probably a lot more interesting with LED lights than incadescent. I've pointed a laser through them, and it ends up projecting the image very clearly onto the wall. Katie R (talk) 12:52, 26 November 2013 (UTC)

Social inhibition of urination

Why do some people find themselves unable to urinate when standing next to someone else at a urinal? Does this phenomenon have a name? How prevalent is it? 129.215.47.59 (talk) 17:26, 25 November 2013 (UTC)

In laymen's terms, it is called piss shy; that link is a redirect to the real article Paruresis --Jayron32 17:44, 25 November 2013 (UTC)

It has also slightly more tastefully been called Shy bladder. Mingmingla (talk) 17:46, 25 November 2013 (UTC)

You've tasted what? --Jayron32 17:50, 25 November 2013 (UTC)

Drinking urine is blue. Well, the link is, whether or not methylene blue is used. DMacks (talk) 18:09, 25 November 2013 (UTC)

I notice that the article states "The codes and procedures for drug testing in sports are set by the World Anti-Doping Agency (WADA). Enquiries to WADA reveal that their doping codes do not cater for the condition at all, and they say they have never had any reports of problems with it." Yet a report on a WADA website mentions "Elite athletes have to undergo doping-controls. In over 50% of cases delays occur because the athlete experiences a sudden inability to urinate. 46% of these delays exceed one hour." Ssscienccce (talk) 21:50, 25 November 2013 (UTC)

Sounds like they need some cross-transfer of ideas. Those of us who are male, and old enough to have potential prostate problems, sometimes have doctors order a urine external flow test. For this you are requested by a (usually) pretty nurse to urinate while she uses a simple gadget to measure the flow rate in ml per second. When she is ready, she tells you to "let it go!" and then maybe says "is that the best you can do?". Nurses usually tell you to imagine having a shower while peeing - it works nearly every time apparently. 121.221.118.84 (talk) 02:40, 26 November 2013 (UTC)

It has also been called Bashful bladder syndrome. Richerman (talk) 18:13, 25 November 2013 (UTC)

I suspect that bashing someone with a full bladder in said area could be a way of overcoming the problem... DMacks (talk) 18:25, 25 November 2013 (UTC)

Nope. The feeling to go completely leaves. A similar condition is an overwhelming need to go when arriving home regardless of feeling before. Brain is a weird mind farking thing. --DHeyward (talk) 08:38, 26 November 2013 (UTC)

Funnily enough, the thing that's telling you that info about your brain is ... your brain. It seems to have a low opinion of itself. Maybe time for a brain transplant, and this time try to get one with a little bit more self-esteem.  :) -- Jack of Oz ^{[pleasantries]} 09:14, 26 November 2013 (UTC)

I suffer from it, I call it stage fright. I grew up in a European country where urinals were not common, never got used to urinating with other people beside me. Vespine (talk) 03:45, 27 November 2013 (UTC)

Platinum Daniell cell

If I were to make a Daniell cell with a platinum cathode instead of copper and platinum chloride instead of copper sulphate, would I need platinum(II) chloride or platinum(IV) chloride? I am asking this question on behalf of user:DPL bot who keeps bugging me for an answer, but I don't know. SpinningSpark 18:55, 25 November 2013 (UTC)

PtCl₂ would work (it's soluble in HCl, so that's not a problem):

Zn²⁺+2e^- <->Zn(s) -0.76V

Pt²⁺+2e^- <->Pt(s) +1.188V

together give Zn+Pt²⁺ --> Zn²⁺+Pt(s) +1.948V

So you can use it, whether you need to, I dunno.. Ssscienccce (talk) 13:01, 28 November 2013 (UTC)

Liquids at zero pressure

Are there any substances that exist as a liquid at zero pressure? — Preceding unsigned comment added by 74.15.137.253 (talk) 19:56, 25 November 2013 (UTC)

Zero pressure (like absolute zero) is an idealized state that does not really exist, except as an asymptote you can approach, but never realize. A perfect vacuum cannot be realized. As soon as you put a liquid into a vacuum, it will start to evaporate instantly, and then you don't have a vacuum anymore. --Jayron32 20:18, 25 November 2013 (UTC)

True. Is there a substance that doesn't sublimate at zero pressure? 74.15.137.253 (talk) 21:09, 25 November 2013 (UTC)

That would imply a vapor pressure of zero at a temperature above 0° K, not sure if that is possible, wouldn't quantum effects, uncertainty principle statistical randomness prevent that? Ssscienccce (talk) 22:06, 25 November 2013 (UTC)

There is no such thing as zero pressure, and by extension, there is no such thing as a substances that exist as a liquid at zero pressure. Plasmic Physics (talk) 07:02, 26 November 2013 (UTC)

The fact that asteroids exist implies that those solids do not sublimate much at temperatures and pressures near 0, as found in deep space. StuRat (talk) 07:03, 26 November 2013 (UTC)

Sublimation of solids at near absolute vacuum become a significant factor when discussion the heat death scenario of the end of the universe. Plasmic Physics (talk) 07:54, 26 November 2013 (UTC)

What would happen if you started heating the asteroid, but kept it in a zero pressure environment? Would it ever melt? Is there any substance in deep space that wouldn't melt if you heated it? 74.15.137.253 (talk) 02:20, 27 November 2013 (UTC)

Depending on the asteroid's constitution, it may melt or sublimate when heated in the low pressure environment of space. Diamonds are found in space, they sublime instead of melting. Plasmic Physics (talk) 05:11, 27 November 2013 (UTC)

Woops, I meant to ask if there was any substance that *would* melt in deep space. 74.15.137.253 (talk) 20:38, 27 November 2013 (UTC)

One substance that may not melt is Buckminsterfullerene, it can sublime, but has no known liquid state, even under pressure a triple point or critical point has not been observed. (Hope this is right!) Graeme Bartlett (talk) 09:47, 27 November 2013 (UTC)

Could you please clarify this comment? Why doesn't zero pressure exist(at least as an idealization)? 74.15.137.253 (talk) 02:18, 27 November 2013 (UTC)

Quantum fluctuations cause there to always be a non-zero pressure. Essentially the same reason, why zero Kelvin is unattainable. Plasmic Physics (talk) 05:11, 27 November 2013 (UTC)

The pressure of a gas is dependent on the speed of the molecules (the temperature), their atomic mass, and the number per unit volume. Even if there is 1 hydrogen molecule per km³ at 2.7 Kelvin (the cosmic background temperature), there will be some pressure. According to the ideal gas law, this would be a pressure of 2.7 * 10^-32 Pa. Very close to a vacuum, but not quite. CS Miller (talk) 19:54, 27 November 2013 (UTC)

All liquids have a finite (>0) vapor pressure. This is the result of molecules or atoms of the liquid evaporating into the surrounding environment. The higher the vapor pressure, the faster the liquid evaporates. Some of the atoms or molecules in the surrounding environment will condense back onto the liquid. While a true zero pressure environment does not exist, the environment can be maintained at a much lower pressure than the vapor pressure, which can approximate zero pressure. If the partial pressure of the substance in the surrounding near-vacuum is lower than the vapor pressure, the liquid will evaporate faster than it is replaced by re-condensation. Some liquids, like gallium at just above its melting point, have a very low vapor pressure, so they evaporate very slowly. Such liquids can exist for a long time at a very low pressure. So the answer to the original question is basically yes, but the liquid will eventually evaporate completely if the partial pressure is kept below the vapor pressure.--Wikimedes (talk) 08:06, 28 November 2013 (UTC)

Entirely sterile rooms

Which facilities commonly have absolutely sterile (including air) rooms and do such compartments have some specific name? I assume that operation rooms and many scientific facilities don't have sterile air as well. Perhaps in such highly bioclean rooms food wouldn't mold and corpses wouldn't corrupt? 93.174.25.12 (talk) 22:56, 25 November 2013 (UTC)

I've heard of the 'clean room'. Plasmic Physics (talk) 23:05, 25 November 2013 (UTC)

That's a cleanroom. Note that they are not sterile, but have a "controlled level of contamination." SemanticMantis (talk) 23:24, 25 November 2013 (UTC)

Note: Rare New Microbe Found in Two Distant Clean Rooms; November 06, 2013, Jet Propulsion Laboratory ~E:71.20.250.51 (talk) 23:35, 25 November 2013 (UTC)

Manufacture of sterile active pharmaceutical ingredients is generally conducted within clean rooms; these can't be sterilised later, unlike sterile medical supplies like syringes, bandages, pads, swabsticks which are usually sterilised after production and packaging by applying ethylene oxide in a vacuum chamber. (thats's why the packaging is made of porous paper); others are the preparation of vaccines and parenteral products (food that is administered by infusion), an example of hands-on training of aseptic processing can be seen here. Air in operating rooms is filtered 20-25 times per hour to achieve low numbers of airborne pathogens (source), absolute sterility isn't really necessary for patients with a working immune system. Complete aseptic environment is most important when working with products that are a good growth medium for bacteria or molds, that have to be stored for a period of time and that would be damaged or destroyed when sterilized after production. Regarding specific names: "aseptic (filling, finishing, processing) core" is widely used, in job ads for example. Ssscienccce (talk) 01:38, 26 November 2013 (UTC)

Bear in mind that any food or corpse introduced into such an environment would bring their sources of corruption with them. I doubt rate of decay would be much different, unless they were irradiated or otherwise sterilized first. Rojomoke (talk) 05:32, 26 November 2013 (UTC)

Engineering definition

I recently heard a definition of engineering I've never heard before, coming from a former engineering director. He said that engineering is not the application of science to design, build and maintain new products, structures and services but the application of science to make money. Is this definition correct? Can't this definition be used for any discipline under a for profit company, which is most disciplines? — Preceding unsigned comment added by Clover345 (talk • contribs) 23:54, 25 November 2013 (UTC)

That sounds more like cynicism or sarcasm than a "definition". ~E:71.20.250.51 (talk) 00:02, 26 November 2013 (UTC)

A common engineering maxim is "engineers make for a penny what any fool can make for a pound". Cynisism it may be, but there is some truth in it. To me, engineering is about making things in a professional environment and very little about applying scientific principles. As a practising engineer 99% of what we did (I am retired now) was based on experience rather than hard science worked out from first principles. SpinningSpark 00:13, 26 November 2013 (UTC)

Do you think it's only a handful of detailed design teams which are concerned with hard science? Clover345 (talk) 00:13, 27 November 2013 (UTC)

There's lots of them but usually with a directed outcome. A lot of research grants are really hard science engineering. Room temperature super-conductors for example is an engineering problem. Super-string theory is not. --DHeyward (talk) 00:23, 27 November 2013 (UTC)

There is more than one way to say what is realy the same thing. Previous posters have nailed it. Another way is what I was taught in company induction training in my first job after campleting engineering at university: Engineering is about the Three M's - Where is the (specialised) Machinery comming from? Where is the (skilled) Manpower comming from? Where is the Money coming from (loans? other financing?) ? These three questions are what senior engineers, engineering managers, and the heads engineering companies are fundamentally concerned about. 121.221.118.84 (talk) 00:42, 26 November 2013 (UTC)

I think it defines the person who said it more than it defines engineering. He never heard of nonprofit organizations, open-source, volunteers, hobbies? Working on an irrigation project in the third world, building a three stage amateur rocket, designing nuclear weapons, it's all engineering... Ssscienccce (talk) 02:05, 26 November 2013 (UTC)

Here's one of a series of strips of Dilbert talking about engineering.[2] ←Baseball Bugs ^{What's up, Doc?} carrots→ 02:40, 26 November 2013 (UTC)

Engineering is about producing products quickly, cheaply and with high quality. But you can only pick two of those. It runs the gambit of the three combinations of two choices. --DHeyward (talk) 00:18, 27 November 2013 (UTC)

That is a specilised branch of engineering called production engineering. A much greater range of employment for engineers has nothing to do with producing products. Consider the consulting engineer who is called in to check the structural analysis of a proposed bridge, or work out the safety of an existing bridge that has been hit by a ship. Or an engineer ensuring safety and relaibility on an electric power transmission line. And it is absolutely not true that an engineer has to pick 2 out of quick, cheap, and quality. Many cases are a balance of all three, and the sign of a good engineer is to achieve all three in good measure. Quality is fitness for purpose. Consider resistors used in electronics. These are turned out by the millions at a fraction of a cent each. Each one conforms to a specification, which has allowable variation in dimensions and electrical properties. There is absolutely no point in making them to a tighter spec, or gold plating the leads. The appliance, radio, microwave oven or whatever will not work ANY better. Resistors fail in service very very rarely. Hence they are totally fit for purpose and the quality is very very high. 121.221.4.89 (talk) 04:54, 27 November 2013 (UTC)

You're missing the point. Maybe it's easier to understand it as one constraint is fixed and the other two are variable. You can always find an engineer/firm willing to do it quicker, cheaper or higher quality (consulting, production, design, etc) and an engineers "product" is not the finished good like a resistor, it's the design. Those are three fundamental tradeoffs. It's a truism and maxim, not something that is applied to any one particular product that may be in various stages of maturity. For example, take the engineering firms that put out oil well fires. There are lots. The most famous are usually quick with excellent results but they ain't cheap. If you find a firm that's just as quick and cheaper, guess why they are cheaper? They aren't "worse" and still fill their niche and do their job. Same with your bridge consultant. Same with transmission line design. Your "sign of a good engineer" is nonsense. None of those constraints are a measure of goodness of the engineer. Iterative designs are subject to those constraints as well which is your resistor example and production engineering. The manufacturer can make the resistor from a higher quality design at the cost of time and expense. --DHeyward (talk) 11:06, 27 November 2013 (UTC)

Well, DHeywood, you've not only missed the point yourself, you have no idea what you are talking about. An engineer's role does not end in a design, it begins with a design.

A design is what designers (so called creative people) do, not what an engineer does. Consider buildings and bridges: an architect (what designers are called in the construction industry) does the design, put simply, what it will look like. Design is related to art, and is taught in completely different university courses to engineering. An engineer takes the design and performs engineering analysis to determine a sound structure, dimensioning of power, water, and aircon to conform to the architect's vision. Consider a TV set. TV manufacturers employ designers who work out what a new model will look like, shape, colours, finish, location of controls, to comply with fashion or trends. Designers would not know a wire from their waist. Similarly, engineers usually know little or nothing about how to do design. The engineer by rational analysis and calculation works out the electronic circuit and selects parts and dimensional detail to conform to the designer's design. Interestingly, good consumer electronics designers get paid more than engineers - TV sets and toasters are bought by poeple emotionally tied to appearance, and matching what they might want is not easy and needs talent.

I have over 45 years experience as an engineer. I can thus certainly do engineering, but I can't do design -in part because I am not fashion conscious. Part of my career was responsibility for electric power stations. My role/responsibility did not end with a design (The owners/clients generally got their own in-house team or contractor to do the design - in this case essentially the tender specification against which my company and others submitted tender responses). My responsibility was to work out the engineering details, project manage (ie arrange and coordinate manpower, machines, and cash flow) them to completion and handover of completed power stations to the owners. Finished goods as it were. But it did not/does not end there. There is an ongoing responsibility to look after waranty claims if any, and monitor operations so that over time the owner achieves reliable and profitable operation, and engineer and arrange corrective action if appropriate.

You've missed the point entirely on resistors. They are built to a specification. As long as they conform to the spec, that's all that is required. Building to a higher "quality" is pointless. That applies to all manner of engineering parts and products.

121.221.4.89 (talk) 15:38, 27 November 2013 (UTC)

I'm sorry that was your experience. Microprocessor "architects" are engineers. They are "creative" and "engineers." Programmers are software engineers. They are creative as well. Your observation on a "spec" for resistors misses the spec which is cost, time-to-build/time-to-market, and tolerance. When prototyping, cost is secondary usually but they need it quick and working. The first F-35 is REALLY expensive. It was designed by engineers, not architects or fashion people. The final F-35 is not nearly as expensive and they amortize the cost engineers do various aspects and functions throughout the lifecycle. But Phantom Works are all engineers and perhaps applied scientists. The Boeing assembly line has engineers as well working a whole different set of criteria of meeting cost and time-to-build constraints. They'll figure out the optimum number of welders and jigs and what not to meet schedule and cost. Electrical generators that you spec'd for the power plant was designed by an engineer. Perhaps as an upgrade or revision or as a completely new from scratch design. But designed nonetheless. Engineers hold probably the vast majority of patents inventions they assign to their employer. A number of companies and industries have "technology readiness levels" that are basically all engineering work started with applied scientific principles to mass production. Still all engineering. --00:38, 28 November 2013 (UTC)

A lot of truth in the above anonymous statement. But it doesn't refute that DHeywood was wrong to say that engineers produce designs and that their role ends with a design - it confirms the opposite. I'm not at all sorry about my career. It proved to be continually interesting and rewarding personally. It's quite a buzz to take a friend or cousin to a power station and be able to say "That is there because of my efforts. Several hundred worked (architects, subordinate engineers, technicians, tradesmen, labourers) on it for a year under my overall direction." The job pays well too! Those generators I spec'd may have been designed. They WERE engineered by a generator engineer. All this reminds me of what a colleague who is an electronics engineer tends to say when at social gathering some electronics hobbyist or radio ham says "Oh, you design things?" My colleague will typically reply with "No, I don't do dresses and hats." I have a rather better respect for designers and architects however. But never confuse engineering with designing. They are quite different roles requiring quite different qualifications and aptitudes. 1.122.117.242 (talk) 01:26, 28 November 2013 (UTC)