text:
Talk:Four-stroke engine

Vandalism
This article was vandalized over several edits on 11 October 2007. My first attempt at undoing the vandalism left some junk still in the article and it took me a few tries to recover all the deleted content, sorry about the flood of edits. The result, or at least the intent, was for the current (163698357) revision to be identical to the one six revisions back (163691542). What I really needed was to view the differences to an old revision as part of the preview, but oh well. -- TSylvester 00:52, 11 October 2007 (UTC)

Concerns about the animation
The animation appears backwards, is much too fast, does not label the air and fuel intakes, and it is not even clear when the fuel is ignited, nor where the exhaust goes.68.5.64.178 07:42, 4 November 2006 (UTC)

Serious concerns about terminology
I have looked through the engine section on Wikipedia and I have some serious concerns about the terminology, which I feel is misleading or inaccurate. I should mention that I have no problems with the content of the articles. I have a degree in mechanical engineering and a strong background with engines, which alone should not give me unquestioned authority here. But rather, I'm hoping that my opinion and research will at least be considered and discussed. I have outlined below my list of problems with the terminology here:

 * A four-stroke engine is NOT the same as an Otto cycle engine. There are four-stroke cycles that are NOT Otto cycles, mainly the Diesel cycle. This is, in my opinion, the most serious error.
 * I submit that an Otto cycle engine does not necessarily need to be four-stroke. The generally accepted definition of the Otto cycle (which is an idealized cycle) is based on the thermodynamic cycle - isentropic compression, constant-volume heating, isentropic expansion, constant-volume heat rejection. This cycle is concerned only with the compression and power strokes. Whether or not there are intake and exhaust strokes is irrelevant. (Of course, adding boost or backpressure changes the cycle but these are not ideal for a naturally aspirated engine.) The very first paragraph in Internal Combustion Engine Fundamentals by Dr. John B. Heywood (which is considered to be one of the premier authorities on engines) reads, "The internal combustion engines which are the subject of this book are spark-ignition engines (sometimes called Otto engines, or gasoline or petrol engines, though other fuels can be used) and compression-ignition or diesel engines." This quote is being posted under fair use policy. Dr. Heywood (and I) equate the Otto cycle to an ignition by spark, and NOT to a particular number of strokes. Additionally, he equates the Diesel cycle to compression ignition. Throughout the rest of his book, he uses the terms "spark-ignition" and "compression-ignition" almost exclusively to differentiate between engine types. It is my opinion that this terminology is the most accurate and most descriptive way to categorize engines, and I suggest that it be used throughout all Wikipedia engine articles.

Any responses to my request?

Why the hell is the Otto Cycle redirected to a four-stroke engine section? The Otto cyle is an ideal cyle for a petrol engine. The Diesel cycle is also four-stroke, but it is different to the Otto Cycle. 61.69.176.55 (talk) 00:35, 30 December 2008 (UTC)

 * I also think that the ideal Otto cyle should be explained separately. As a Physics teacher I am more interested in the ideal model than in the real four-stroke engine. I think that the material contained in the MIT Open course should be an adequate starting point.--Gonfer (talk) 17:31, 15 May 2009 (UTC)

Signed User:Fyre4ce

i believe one stroke is one up or down movement of the piston .if something is wrong change or mark it,everyone does and even delete stuff they have no clue about .usually it will come close in the end. also language is not always exact.keep is simple most people just  want essential information in a first reference and no course in  thermo. good luck.Wdl1961 (talk) 01:47, 30 December 2008 (UTC)Wdl1961 (talk) 02:06, 30 December 2008 (UTC)

It is nice to have an automotive engineer here. I, for one, do not have the depth of knowledge about engines that I do about some other articles to which I have contributed. If I am at fault about four stroke and Otto, compression ignition seems a refinement rather than a departure from the principle that shocked apart Otto's early engine. Wikipedia needs to be consistent with modern technical terms, without loosing the readers in them. To the extent that it does not interfere with looking deeper into the technical literature, it seems that how real engines work is more appropriate here than idealized thermodynamic definitions. This is pointed out by the apparent failure of Carnot to lead the way to compression. (Being a physicist who has worked with engineers, I can imagine his frustration.) David R. Ingham 07:07, 17 January 2006 (UTC)

hi Fyre4ce, You are right, I am also a mechanical engineer and my search to otto engine brought me here. I place a PV and TS diagram of OTTO Cycle but some one remove it. I think these people does not understand the diffrence between otto cycle and four stroke cycle.I strongly belive that there should be two pages one for four stroke engines and one for otto cycle. NOT ALL ENGINES RUNNING ON FOUR STROKE CYCLE RUN ON OTTO CYCLE.

User:124.125.21.126, 28 July 2006

David,

Thanks for the reply. I'm very new to Wikipedia and, if nothing else, it's nice to know that someone out there is listening. :-) I think it's entirely possible to use a standard in terminology that will be both informative and not stand in the way of more in-depth research. I also think it's important to make reference to the idealized thermodynamic cycles, because I think understanding how a real engine relates to its idealized cycle is an important part of understanding how the engine works (and this was how it was taught at the university where I studied - ideal model first, how the real world situation differs next). What do you think should be my next step? Before I would consider making sweeping changes to the naming and organization of the information in the engine section, I would want to go through all the main articles carefully and lay out a new standardized and corrected scheme. This will take some time. I would like to get approval from other editors but I also don't want to find myself patiently waiting for months for a "sure, that sounds good" that may or may not ever come, and that may or may not be from someone with a background in the subject. Since you seem to have experience writing on Wikipedia on technical topics, I am hoping you can give me some advice.

Thanks, Fyre4ce 23:12 Jan 17, 2006 EST

 * You're not likely to find any definitive editor of this article to approve your endeavor. Even if one or two people tell you it's okay, that's not how it should work.  The process is a bit different.  Just make the changes, and as frustrating as it may be, others will come along and change whatever they think is not right.  Like they say, be brave about editing... --flyhighplato 05:07, 18 January 2006 (UTC)

"....Scalpel!" (It will actually take me a while before I'm really ready to start cutting and pasting.) Fyre4ce

 * The term 'four-stroke' is widely used as a synonym to the Otto cycle, but I agree with you when you say this is incorrect terminology. I urge you to start editing. This article as well as the Diesel-related articles all require some major reconstruction, as much of the terminology is incorrect and the loose connections between an idealized cycle and a real world engine application needs to be set straight. - Victor van Poppelen (talk • contribs)

The Otto cycle and four-stroke cycle are different things. I came to this article hoping to explain to a friend the difference between the diesel and otto cycles, and instead found a rough description of the four-stroke cycle that conflates the diesel and otto cycles as if they are the same thing. I agree with a move to reconstruct - this article would make a good base for the definition of four-stroke and the otto cycle could be described properly.

I would have to think there should be a differentiation between 4 stroke and 4 cycle. There are six distinct cycles in a four stroke gasoline spark ignition engine: 1. Intake, 2. Compression 3. Combustion 4. Blowdown 5. Exhaust 6. Overlap

The 'blowdown' period when the piston is on the power stroke and the exhaust valve opens until it reaches BDC. Once the exhaust valve is open, power is no longer being produced in the cylinder and the expanding hot exhaust gasses are already moving out the exhaust system. This is key to efficiently evacuating exhaust gases, as using the piston to push out the full volume of exhaust gas from the cylinder would result in severe losses to power.

The overlap period is also a key cycle in the four stroke gasoline spark igniton engine. It is the period near TDC exhaust when both the intake and exhaust valve are open at the same time. During this cycle the exhaust gases are exiting the cylinder, and as the intake valve opens the velocity of the exhaust gases exiting the cylinder cause fresh air to purge the cylinder of any remaining burning gases for a brief instant before the exhaust valve closes. —Preceding unsigned comment added by 216.139.21.100 (talk) 06:14, 28 March 2008 (UTC)

You forgot the Moistening Cycle and the Dry-out Cycle, so there are really eight cycles. —Preceding unsigned comment added by 71.234.211.101 (talk) 22:01, 5 April 2009 (UTC)

It appears that the incorrect use of terminology has caused the foundational problem here. The basic issue is with the use of the word "stroke" when one means "cycle". The stroke is the distance the piston travels in one direction or the other. The term cycle has to do with the total process of number of full transits of the piston, up or down. Therefore the actual name is four-cycle ICE, as opposed to two- or six-cycle engines. - KitchM (talk) 22:34, 28 May 2011 (UTC)

The use of the terms "two cycle", "four cycle", or "n-cycle" are wrong. "Stroke" and "cycle" not synonymous and calling something "four cycle" is akin to referring to a computer "cracker" or telephone "phreaker" as a "hacker". It is a suborning of the terminology and should be discouraged even if it is commonly understood vernacular. 71.96.8.17 (talk) 04:13, 14 October 2013 (UTC)

mnemonic paragraph
I'm removing the following paragraph since it looks unencyclopedic to me. I can't see any way to fix it and, honestly, no reason for such a mnemonic in an encyclopedia (it's not a high school clue sheet) --- cbraga 20:40, Jun 9, 2004 (UTC)

 * One way to remember the four strokes and their functions is the series "suck, squeeze, pop, phooey", or alternatively "suck, squeeze, bang, blow". The four "strokes" are also present at each stage of a jet engine, where they are performed simultaneously rather than as a sequence.

And yet it is notable as a mnemonic (used for instance to answer a four year-old's question, "how do cars work"). But if it has no place in wiki, so be it. Agingjb (talk) 12:44, 17 September 2015 (UTC)

Desmodromic valve timing
I'm thinking of doing the same to the Desmodromic valve timing section. Does anyone have and idea about how to fix it?

Acegikmo1 01:13, 11 Jul 2004 (UTC)

 * I've rewritten it - see what you think. Incidentally I thought that the mnemonic above was actually quite worth keeping - it's a common phrase and including it to my mind doesn't subtract from the "encyclopedicness" of the article, whatever that means. Graham 03:28, 11 Jul 2004 (UTC)

 * If you'd like to reinstate it, I wouldn't object.

 * Acegikmo1 03:35, 11 Jul 2004 (UTC)

Hello, I'm french, and read this article. I'm sorry to say that i disagree with the interest of the desmodromic valve train. The only advantage of this device is to avoid the problem of inertia at high speeds. The advantages you explain is the one of VVT (variable valve timing) or VTEC from Honda. (I'm motorist, see the Page of Rémy in the french wikipedia)

 * Hello. Are there factual inaccuracies in the desmodromic section? The article currently states that the advantage of desmodromic valves is that they perform better at high speeds, which you seem to agree with. I don't know anything about it, though, so if you see inaccuracies, please feel free to fix them or point them out. -- Wapcaplet 15:48, 24 Oct 2004 (UTC)

For reference : http://scarbsf1.com/valves.html Ericd 21:50, 16 May 2005 (UTC)

Desmodromic valves have the advantage that the force varies according to the speed (the valve acceleration) instead of depending only on the lift and the spring stiffness. At least in principle, this means low wear and friction at low speed combined with no valve float at high speed. It may only save reciprocating mass if materials like carbon fiber, that can't make good springs are used. Otherwise, like with Panhard's torsion bar valve springs, the lever will weight as much as the spring would have. Another option is sleeve valves (as Panhard used earlier) that rotate instead of reciprocating, but coil valve springs work better than anyone would have expected. David R. Ingham 17:02, 6 January 2006 (UTC) For reference : link title End problem off valves

For this article animations  Andrew Feliks 30 March 2009 —Preceding unsigned comment added by 77.114.30.205 (talk) 14:25, 30 March 2009 (UTC)

Animation
The 4-stroke animations are broken. They don't run in Windows Media Player 9 or Winamp, as far as I can determine. They should be fixed or removed. Quicksilver 19:15, 15 Jun 2005 (UTC)

Has this animation been nominated as a featured animation or picture or whatever? It is very nice. David R. Ingham 06:02, 6 January 2006 (UTC)

Animation Direction
Cool animation!! I would like to point out that 99.99% of all IC engines rotate clockwise when looking at them from the front. The "funny" rotation immediatly seemed un-natural to me. However, this view could be looking at the engine from the flywheel end, or the 2nd engine in a contra rotating marine application.

The monikers: suck, squeeze, bang, blow were taught in the U.S. military. 69.213.205.190 18:03, 5 October 2005 (UTC)

That number seems too large. In two piston-engine airplanes, unless costs of stocking pars are cut, one goes clockwise and the other counterclockwise. In one engine airplanes, German-Swiss and Anglo-American engines turn, or turned, in opposite directions, as seen in photos showing the propellers. Reed valve two strokes can run either way. The Messerschmitt KR200 and Spatz Kabinenroller used this instead of a reverse gear. Small model airplane engines can be used as pushers or with left or right propellers, by starting them in the opposite direction.

Anyway, I don't see anything showing wether the annimation is from the front or the back (or the engine is transverse mounted). David R. Ingham 05:56, 6 January 2006 (UTC)

This looks correct as viewed from the flywheel (rear) end, assuming a left hand drive USA vehicle, with: 1. an inline engine, transversely mounted with the transaxle toward the driver's side. 2. the driver's side bank of a V engine mounted classically. 3. the forward bank of a V engine mounted transversley with the transaxle on the driver's side. The spark plug is centered in the combustion chamber, and there appear to be separate intake and exhaust camshafts, so I would assume this matches #1 above. (very common DOHC arrangement) BobJones 23:48, 20 June 2006 (UTC)

Output Limit paragraph
The last paragraph in this article specifically states that it applies to four-strokes. Piston speed, however, is the limiting factor on all reciprocating engines, not only four-strokes. Shouldn't someone move this section to reciprocating engine page? - victorvp (talk)

History
According to

 * Hardenberg, Horst O., The Middle Ages of the Internal combustion Engine, Society of Automotive Engineers (SAE), 1999

the 1862 Otto (O#O) engine did not have exactly the modern four stroke cycle and did not work for long.

Also it says he knew nothing about Carnot and discovered the advantages of compression by turning the flywheel backward by hand! David R. Ingham 06:13, 6 January 2006 (UTC)

The statement that he invented the four stroke cycle was not exactly what the German courts found. His patent was not held to cover internal compression or even the four stroke cycle. See internal combustion engine. David R. Ingham 06:02, 10 January 2006 (UTC)

terminology and focus problems
I agree with Fyre4ce about the problems with this article. The "four-stroke cycle" describes a particular operating concept for an internal combustion reciprocating piston engine; it is not a synonym for the Otto cycle (despite the fact that Otto's first engine was indeed a four-stroke).

The Otto cycle is an idealized thermodynamic model of the processes taking place in a gasoline, spark-ignited engine; the title "four-stroke cycle" should be restricted to a page describing the details of operation of a real four-stroke piston engine (e.g. valve timing, output limits, volumetric efficiency, etc.), and a page describing the Otto cycle should be far more focused on the ideal thermodynamic cycle (isentropic compression/expansion, constant volume heat addition, constant volume heat rejection, and the analyses that fall out of that simple model). See the page on Carnot Cycle to get an idea of what I'm talking about. It's fine to enumerate the differences between reality and theory, but in writing about a theoretical construct, the focus ought to be on the details of that construct.

I'd be happy to help rewrite an article, but I don't know anything (yet) about the shorthand used in producing things like integrals and section headings. IOW, I'm not ready yet. I will need to study the "how to edit a page" guide first.

Joe Frickin Friday 18:14, 27 January 2006 (UTC)

Four-stroke engines utilze Carnot cycle? Moreover, somebody subtitled an Otto cycle graph as Carnot cycle. 89.75.129.67 (talk) 17:57, 26 September 2011 (UTC)

"Output limit" paragraph
There is a lot of confusion here, and this does not seem the best place to discuss these things. Rod/stroke ratio seems independent of which cycle is used. Without supercharging, the output limit depends most on the air intake. I suggest starting over. David R. Ingham 07:04, 7 March 2006 (UTC)

I agree with that. There are other limiting factors which predominate depending on context. Piston speed limitations are real enough but it never stopped shortening the stroke and spinning it like a turbine anyway. Overall air flow is a more important limiting factor. The rod/stroke ratio thing is a somewhat overblown pet theory of Smokey Yunik but it shouldn’t be presented as the ultimate power secret. The section should be tweaked.--=Motorhead 00:52, 10 March 2006 (UTC)

Couldn't agree more with both the above postings - air flow/breathing capability is the most important factor. Practical mechanical limitations are of course still relevant. I also think the undersquare versus oversquare implications should be clarified (oversquare lends itself better to high RPM because of piston speed and acceleration, and because greater area for valves allows breathing to be maintained at high speeds; there is a popular misconception that undersquare engines produce more torque for the same swept volume due to longer moment arm of the crank throw - forgetting that the smaller piston has less total force acting on it from the combustion gases, I believe the advantage of undersquare engines is that less exposed surface area of the combustion chamber means less heat energy is lost so more can be converted into useful work). I vote for starting over - a total rewrite rather than trying to patch-up the existing section on Output limit. —Preceding unsigned comment added by Mimiselfani (talk • contribs) 01:34, 7 June 2008 (UTC)

see edit Rod/Stroke ratio Wdl1961 (talk) 23:40, 4 January 2009 (UTC)

motor fetishism
The reverted edit [] reminds me of Coleman's abnormal psychology textbook (I think that may be Coleman, James C. (1964). Abnormal Psychology and Modern Life (3rd ed.). Illinois: Scott, Foresman and Company.  Or the first edition, 1950.)  His example was a boy who was sexually aroused only by exaust pipes. This edit is similar. David R. Ingham 04:41, 8 March 2006 (UTC)

Efficiency
Some typical and maximum efficiency levels would be useful. Tobyw 12:29, 8 March 2006 (UTC)

valve clearance adjustment
Some formatting needs to be fixed in this section, there's a random "Headline Text" thing and some writing that goes on forever off to the right (at least in Safari) Thetrump 23:06, 6 April 2006 (UTC)

I don't feel like this section belongs here at all. Maybe there could be a separate article on maintenance procedures for 4-stroke engines. If it is decided that this article should include maintenance procedures, they should go in their own section, and would presumably contain more than just a single procedure. Furthermore, the valve clearance adjustments outlined here are specific to engines with solid valve lifters, which very few, if any, modern massed-produced 4-stroke engines utilize.

Removed illustrations
I'm certainly biased (since I made them) but I'm somewhat dismayed to see the individual illustrations of each stage in the cycle replaced by a single animated .gif (this edit). While the new animation is very nice (and more realistic-looking than my pics), I don't think it's an adequate substitute. This is especially true for those (like me) who find continuously animated graphics annoying, and have their browsers configured to play them once only. Why not include both still and animated versions? It's not like this article suffers from an overabundance of images :-) -- Wapcaplet 13:39, 28 July 2006 (UTC)

Compression stroke and Exhaust stroke
I have a request: Someone knowledgeable about engines please write the above two articles. The animated image Image:4-Stroke-Engine.gif is scheduled to be Picture of the day on November 4, 2006 and will appear on the Main Page. However, it is against policy to have red links on the Main Page, so you have until then to get these articles written, or at least stubbed. Thanks.  howch e  ng   {chat} 17:01, 4 October 2006 (UTC)

shifted from article
shifted this content added by an anon IP

their are major differences in a two stroke and a four stroke two stroke means that the (for example) dirt bike motor receives power on every turn of the crank shaft creating shorter faster bursts of power. the four stroke receives power on every other turn of the crankshaft creating bigger longer bursts of power. The two stroke has something called a power band which is when the bike hits a certan RPM and explodes with power where a four stroke has all of its power when you need it no wait for a power band.

add it in if it seems to be useful, I couldn't figure where to put it. thanks xC | ☎  08:02, 6 July 2007 (UTC)

Four stroke = Otto
This is big mistake, can not beleive someone can put these two things as one. It looks that diesel engine can not be four stroke.--Billy the lid (talk) 10:05, 16 May 2008 (UTC)

effect of usage 4 stroke
dun know?? anybody knows?? —Preceding unsigned comment added by 60.50.78.58 (talk) 07:48, 13 July 2008 (UTC)
 * car go. NJGW (talk) 17:11, 13 July 2008 (UTC)

Bad Article
Why does the animation not even follow the otto cycle? In fact, why is the Otto cycle (an oscure engineering/thermodynamic representation), a dominating feature of this article? It doesn't represent a single real engine, and is not the only thermodynamic model out there for a four stroke. And no-one except mechanical engineers would be interested, and no-one except mechanical engineers would be enraged by the inaccuracy of it all! Why not just tone down the Otto business and tone up the 4-stroke practical info, applications and what-not? 86.44.202.31 (talk) 22:52, 16 September 2008 (UTC)
 * Why isn't there more information on the otto cycle that redirects to this page? The four stroke cycle redirects here too. The diesel cycle and diesel engine have separate pages. Shouldn't the four stroke engine and four stroke cycle have separate pages also? It is clear these are two separate subjects addressed to those who would expect to find different information in each. 84.44... is one person to indirectly suggest this, I second it. —Preceding unsigned comment added by 64.56.17.154 (talk) 02:44, 18 October 2008 (UTC)

I'm not an expert, but I'm editing this article anyway :-)
Not only is this a bad article, but this talk page is full of almost two years worth of whining and complaining by people who aren't doing much of anything to fix the situation. What an awful Talk page this article has. Yeesh.

I am not an expert, but I am wading in anyway attempting to fix the major formatting and layout problems here, and trying to improve it with more general information and cross-article links. (You can blame me for the Otto engine video. I recorded and uploaded it.)

Wikipedia is a collaborative project built by non-experts, and so if people think it's a bad article, you can't do much worse to it by trying to fix it, can you? So please, FIX IT rather than complain about it.

(Please refer to the Wikipedia editing policy page Be bold for more confidence in your editing skills.)

DMahalko (talk) 01:07, 23 October 2008 (UTC)

"Relational Vibration"--need new term?
I've added relational vibration, as it is referred to in my text book, as the effect the speed of pistons can have on the rest of the vehicle. This is referred to in my book as "Relational Vibration", but I've noticed that the copyright is from the mid 90's...does anyone know if there is a new term to refer to this? —Preceding unsigned comment added by Williamsburgland (talk • contribs) 23:48, 28 November 2008 (UTC)
 * This is a pure invention on your part, so cite your references. Andy Dingley (talk) 00:08, 29 November 2008 (UTC)
 * I think it's completly unprofessional of you to keep accusing me of simply inventing this...citation added —Preceding unsigned comment added by Williamsburgland (talk • contribs) 02:50, 29 November 2008 (UTC)

 * I've reverted this again, as the ref you added doesn't appear to include it:
 * Finally, increased piston speed can impact something known as relational vibration, or a vibration felt throughout the vehicle as said vehicles forward speed approaches the speed of the pistons. The higher the piston speed, the greater the effects of relational vibration.
 * http://books.google.com/books?id=mX1-OJBQ6ngC&pg=PA378&lpg=PA378&dq=piston+speed+fuel+efficiency&source=web&ots=ijrmSC2ryX&sig=akBenKYwvHm3soTVE8bblV_UCPU#PPP1,M1
 * Could you please point to where (page number?) this ref supports your claim? Andy Dingley (talk) 22:07, 30 November 2008 (UTC)
 * Apologies on the late reply...it appears as though the PDF I cited did not include the entire document...I stand by my material but cannot provide a link, so per Wiki guidelines I agree that the term should be removed. —Preceding unsigned comment added by Williamsburgland (talk • contribs) 18:19, 12 December 2008 (UTC)
 * Can you please cite a page, so that I can check the book. I can't see it, nor can I see it in any of my fairly extensive library of similar books. Andy Dingley (talk) 22:09, 12 December 2008 (UTC)

there is coverage of relational vibration between engine and supporting structure  on pg 292 http://books.google.com/books?id=mX1-OJBQ6ngC&pg=PA378&lpg=PA378&dq=piston+speed+fuel+efficiency&source=web&ots=ijrmSC2ryX&sig=akBenKYwvHm3soTVE8bblV_UCPU#PPP1,M1

Wdl1961 (talk) 22:17, 25 January 2009 (UTC)

I've worked in the field of automotive noise and vibration for 30 years and have never heard this term. It also does NOT appear in the textbook Wdl cites, according to google search. p292 certainly does not discuss it, or indeed anything associating piston speed and vehicle speed (an absurd concept BTW). Greglocock (talk) 12:10, 27 January 2009 (UTC)

 * I've worked in high-precision optics, and I'm somewhat familiar with it! The concept is real enough, but it isn't going to happen in a car engine (for engineering-viable values of piston speed and road speed). It has been a problem in the past with some steam paddleships. As to the book, then it's not in my paper copy anywhere I can find it, nor in the index, nor on my p292. Andy Dingley (talk) 13:44, 27 January 2009 (UTC)

there is coverage of relational vibration between engine and supporting structure  on pg 292 http://books.google.com/books?id=mX1-OJBQ6ngC&pg=PA378&lpg=PA378&dq=piston+speed+fuel+efficiency&source=web&ots=ijrmSC2ryX&sig=akBenKYwvHm3soTVE8bblV_UCPU#PPP1,M1

just delete "relational" and read the rest of pages 291-292 -293 dealing with general vibration

Wdl1961 (talk) 16:21, 27 January 2009 (UTC)

 * There is coverage of Bigfoot in that ref if I delete the word "vibration" and insert the word "sasquatch"! You can't treat a reference in that way.
 * "Relational vibration" has a definition. By the nature of that definition, it's not going to affect cars and car engines. Vibration from the engine certainly does, but it's of other forms and not describable under that definition. The effects of coupling through the engine mounts (and expecially notions of "tuning" resonant frequencies around such mounts) will have vastly more influence on vibration into a car chassis than the road speed at which it's travelling. Andy Dingley (talk) 17:32, 27 January 2009 (UTC)

try tuned, coupled ,transmitted , oscillation, noise , critical frequency,vibration,resonance,coupling,

every piece of machinery or computer i worked on/with had one or more of these and did not care about the label.

yuor computer has a relational frequency with the transmitter,eardrums?

also try classification,groups,classes,relations,concepts

Wdl1961 (talk) 21:40, 27 January 2009 (UTC)

 * Nobody is denying that engines vibrate and cause the surrounding structure to vibrate. We're just saying that the phrase 'relational vibration' has no particular meaning or usage in this field. I suppose this means I have to check ALL the references you've given now to see if they really support the statements made, since you don't seem to understand why this is an issue. Thanks a bunch. Greglocock (talk) 22:30, 27 January 2009 (UTC)

all of the above is simply energy transfer of some freqency /frequencies of some magnitude from point a to point b (sometimes? both ways) each discipline thinks theirs is unique ,nothing unique about it

Wdl1961 (talk) 01:28, 28 January 2009 (UTC)

 * I don't know what you are trying to prove. Can you find JUST ONE SOLID reference to the phrase "relational vibration"? If not then we aren't having a discussion, you seem to be trying to justify providing a misleading reference. To help you out, I have 3 Noise and Vibration reference books by my desk, here at home, I also have 3 engine textbooks. Now, guess how many of those have the phrase in the index? None. It doesn't appear in the McGraw Hill dictionary of Physics and maths either. So it is either a very specialised term, or a neologism, or a mistranslation. I favour the latter, relative vibration would be my guess, but of course that has nothing to do with matching piston speeds and vehicle speeds, which is still an absurd concept.Greglocock (talk) 01:51, 28 January 2009 (UTC)

Q.E.D.

Wdl1961 (talk) 02:10, 28 January 2009 (UTC)

google Results 1 - 10 of about 91,600 for relational vibration. (0.06 seconds)

Sound Accord - - The Sound Self Part Two When we are fluent in the language of

relational vibration

, we inhabit the territory of the heart with confidence, grace, and ease. ... www.sound-accord.com/-_the_sound_self_part_two - 16k - Cached - Similar pages Wdl1961 (talk) 03:06, 6 February 2009 (UTC)

I have to say you are wrong that this relational vibration term exists. You performed a bad google search. Try searching google with relational vibration in quotes. The number of results drops suddenly to about 120. Then add the word engine to clarify its relation to this topic. It drops to 30, almost all of which, surprisingly, in one way or another reference this talk page. So yes my friend, you are in fact the only person on the entire internet using relational vibration in conjunction with engines. This case seems settled. 128.6.83.117 (talk) 01:54, 7 May 2009 (UTC)

the phenomena excists. all of above about  the label .so use the label and ref you like and change it.

then the problem is solved.

Wdl1961 (talk) 14:27, 6 July 2009 (UTC)

 * What on earth are you on about? Nobody has provided a single decent ref to the idea in relation to engines. Greglocock (talk) 10:20, 7 July 2009 (UTC)

 * every mechanical engineer knows what it is or he will find out the hard way

//tacoma narrows bridge\\

maybe we need a new wiki article

Wdl1961 (talk) 14:07, 7 July 2009 (UTC)
 * In relation to the Tacoma Narrows Bridge, you're probably referring to resonance (which it seem, ironically, wasn't actually the cause of the Tacoma Narrows Bridge collapse despite what many believe). Resonance does most certainly occur in engined, but has never been described using the term "relational frequency" anywhere ever.
 * To be honest, I must say "relational frequency" sounds like a term that describes the phenomenon of resonance quite well (a phenomenon caused by two the relationship between frequencies), but Wikipedia is not the place for coining new phrases. ɹəə pıɔnı  15:47, 7 July 2009 (UTC)

 * I'm not sure why we need a new phrase anyway. The OP was originally suggesting it was to due to the matching of piston speed and vehicle speed, which is laughable. OT Yes, it's funny the way that everybody who sees the Tacoma film in high school is taught that it was a resonance. Greglocock (talk) 23:19, 7 July 2009 (UTC)

 * what is the term and refs we should use ??
 * i (mistakelingly) thought that was the original issue

Wdl1961 (talk) 00:03, 8 July 2009 (UTC)

there is a vibration article and Torsional vibration article in wiki

Wdl1961 (talk) 01:51, 13 August 2009 (UTC)

edit Rod/Stroke ratio
for a basic article this section is very long with mostly insignificant info.

belongs in racing article maybe

Wdl1961 (talk) 03:20, 4 January 2009 (UTC)

--

Rod/Stroke ratio
see the 28 January 2009 article revision Wdl1961 (talk) 22:03, 28 January 2009 (UTC)

Highlighted Issues on page
I replaced the cleanup box on the page with one highlighting the articles' issues more precisely. I think DMahalko is absolutely right in his comment here. There's no use complaining and then not doing anything about the article, and it's fairly ridiculous that it has gone over 2 years without improvement. Anyway, I'm not an experienced Wikipedia editor, but this is a subject I know at least a little bit about so I'll attempt tackling it when I have the time, maybe late next week. In the mean time, if anyone else has an interest in helping out, or has suggestions, do comment. ɹəə pıɔnı  20:38, 25 February 2009 (UTC)

to shift to racing article
I suggest shifting to racing article Ierrotpre (talk) 10:21, 22 March 2009 (UTC)

CHP engines
The source [1] given in the very last paragraph for Efficiency and CHP engines is very confusing and not very informative.

A few links i found that explained it much better are

http://www.toolbase.org/Technology-Inventory/Electrical-Electronics/combined-heat-power

http://www.northeastchp.org/nac/CHP/basics.htm

I'm not confident in my editing abilities to make this change myself —Preceding unsigned comment added by 75.180.8.80 (talk) 02:45, 23 March 2009 (UTC)

Scavenging pump/blower?
The introductory section ends with "The largest and intermediate size diesel engines are usually two-cycle engines, requiring scavenging air pumps or blowers." Can someone please explain what a scavenging air pump or scavenging blower is please? This piqued my interest because I read the following on the British Rail Class 55 article: "The Class 55's engines were not turbocharged, although they did have scavenging blowers." It would be interesting to learn how a scavenging blower relates to a turbocharger. Thanks!--Rfsmit (talk) 21:17, 3 August 2009 (UTC)
 * Okay, a visit to the Two-stroke engine article cleared that up. The mention of "scavenging" should be removed from this article, given that it only applies to two-stroke motors.--Rfsmit (talk) 21:23, 3 August 2009 (UTC)
 * No, it's worthwhile noting that because a two stroke isn't a four stroke, they require this extra equipment. There's little between them in terms of thermodynamic cycle, it's just that the four stroke does 4 things in one place over time, the two stroke splits the same things into more than one place, so can use the cylinder for a power stroke in every revolution rather than every second revolution. Nor are all scavenge blowers Roots type. Some are mechanically driven centrifugal blowers, these days most are probably turbochargers. Andy Dingley (talk) 00:32, 4 August 2009 (UTC)

 * if turbocharger it needs power at startup.  Wdl1961 (talk) 03:53, 4 August 2009 (UTC)

 * It doesn't need power at startup, it just doesn't spin and so the scavenging is ineffective until the engine starts to turn over under its own power and the turbo can start to spin up. Yes, this does tend to make startup exhaust a bit claggy, until it settles down. Andy Dingley (talk) 10:16, 4 August 2009 (UTC)

have not seen a big diesel without a positive displacement pump but never say never. i would try to get a ref in it and i am curious. you could put all of this in the article Wdl1961 (talk) 13:39, 4 August 2009 (UTC)

 * If you haven't seen one personally, then I'm sure they don't exist. Make sure you speedy delete the Deltic articles then. Andy Dingley (talk) 14:21, 4 August 2009 (UTC)
 * i hate to admit there are things existing i have never seen and certainly being build  right now. just fix the article wih the best info, good luck.Wdl1961 (talk) 14:49, 4 August 2009 (UTC)
 * Why do you think the article is broken and what needs to be fixed? Andy Dingley (talk) 16:33, 4 August 2009 (UTC)
 * both the four and two stroke articles should come to essential points sooner and clearer.the details should come later.Wdl1961 (talk) 18:26, 4 August 2009 (UTC)

removes moisture from the engine oil by drawing crankcase
""Efficiency is also intentionally reduced to improve engine reliability and service life, such as with positive crankcase ventilation, which removes moisture from the engine oil by drawing crankcase vapors into the engine intake.""

it would be nice to get a ref with a percentage loss.

Wdl1961 (talk) 04:06, 11 August 2009 (UTC)

 * I agree. You asked for the ref, so you have the motivation. Get to it. ;) -- DMahalko (talk) 05:39, 11 August 2009 (UTC)
 * i think it is less than +/- 0.1 % Wdl1961 (talk) 12:12, 11 August 2009 (UTC)

False Reference
The reference at the beginning to Otto have any relationship to Beau De Rochas is FALSE. Otto's work was based on Etienne Lenoir's 1860 Atmospheric Engine. I am removing that reference. I am inserting the factual reference. Krontach (talk) 05:39, 22 May 2011 (UTC)

Four-stroke engines with high power-weight ratio
Can perhaps the differences between the four stroke motors be explained in particular in regards to power-weight ratio. For example, the Radial engine and Napier Deltic have very high power-weight ratio's 91.182.145.107 (talk) 14:17, 6 November 2011 (UTC)

Confusion
The Section numbered 3.1.1 and headed 'Otto Engines' confuses fractional distillation, a purely physical process that separates different molecules without altering them, and cracking, a chemical process that breaks molecules into smaller ones. This is definitely an error. The section also implies that low flash point is always directly connected to low octane number, which I suspect is also an error. 86.152.112.92 (talk) 23:52, 21 October 2012 (UTC)

You are absolutely correct; the process described, and the illustration, are of fractional distillation, using a fractionation tower. I believe it may also confuse "low weight", with "low molecular weight"; it appears to suggest that "low weight" compounds rise higher because they weigh less. In fact, low molecular weight compounds boil at lower temperatures, and travel further up the column, the temperature of which decreases along its length, before condensing and being drawn off as a characterised fraction such as kerosene. It would not matter if the tower were horizontal, as long as it has a temperature gradient, fractionation would work the same. I suppose the real issue is that a discussion of four-stoke engines should not include an explanation of anything that does not make an engine a four stroke engine; plenty of four-stroke engines run on ethanol, biogas, biodiesel and even used cooking oil. The refining of crude mineral oil is irrelevant. 58.175.42.9 (talk) 12:29, 4 April 2013 (UTC)

Lead section too big
I think the lead section of this article is too big. The part about the description of the stroke could easily be made into a separate section; so could some of the history, it's duplicated bellow anyway.

Aisteco (talk) 18:15, 9 August 2013 (UTC)

GIF
The gif at the top of the page is missing some illustrations. The spark plug fires twice in a 4 stroke engine. Once during power stroke, again during the exhaust stroke. The image only shows the spark igniting during the power stroke. Maybe a side note? 199.19.248.20 (talk) 01:23, 12 April 2016 (UTC)

 * Nope, a 4 stroke engine only requires a single firing of the spark plug at the start of the power stroke. However, many 4 stroke engines add an extra firing during the exhaust stroke to clean-up any unburnt fuel. This helps emissions but is not a strict requirement of the 4 stroke engine. Practically all engines with a distributor (ie typically older than 1990) use single firing.  Stepho  talk 01:46, 12 April 2016 (UTC)

 * Can we include your reply as a side note to the exhaust phase? 199.19.248.20 (talk) 02:16, 12 April 2016 (UTC)

 * Sure. Go for it. Although maybe wait a little (a day?) for others to make suggestions.  Stepho  talk 03:11, 12 April 2016 (UTC)

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Wikipedia
I hope,This page is very helpful...plz supporting. Shriya chaturvedi (talk) 12:09, 1 March 2021 (UTC)

Humphrey Pumps
Is it worth including a mention the Humphrey pump? They were in most cases four stroke ICEs, although they were distinct in that they had no pistons, force for imparted directly from the gas to the water, or vice versa. In terms of thermodynamics, they were most similar to Atkinson engines, utilising a variable stroke length. — Preceding unsigned comment added by 81.104.42.30 (talk • contribs)

 * Certainly. That was a type of ICE I had never seen before and I found it interesting.
 * Don't forgot to sign your talk page comments with 4 tildes ( ~ ) .  Stepho  talk 22:03, 2 May 2021 (UTC)

Reverting twice now
, did you read the source at all?

"'Most modern internal combustion-powered vehicles are 4-strokes, powered by either gasoline or diesel fuel.'"

You are being unreasonably obtuse here. Qualified and reinserted. Dennis Brown - 2¢ 21:32, 19 November 2021 (UTC)

 * Damn. I found the sentence just before it but somehow missed that one. Although I think the source itself isn't clear about what it counts. Do motorised vehicles include container ships (massive 2 stroke diesels), jet planes (Brayton cycle), motorbikes (2/4 stroke), golf carts (electric), personal old-age scooters (electric)? They also don't say if they are couning only in America, only in western countries or also include India and Africa (where 2 strokes are popular). I think they are trying to say that most road vehicles (ie passenger cars, road going trucks, motorbikes) in the US are 4 stroke. But they only say it as a side comment and don't go into specifics. Not a good reference for the point it is being used to support.  Stepho  talk 22:38, 19 November 2021 (UTC)
 * Are you saying you believe it is incorrect and most cars/trucks/motorcycles/vehicles are 2 stroke? The definition of a vehicle "a thing used for transporting people or goods, especially on land, such as a car, truck, or cart" by itself clarifies that we are talking about land vehicles, not ships.  It isn't at all common to call a ship a "vehicle".  If you want to improve the source and/or wording, that's fine.  Most people's interactions from day to day (all over the globe) when it comes to motorized transport (buses, taxis, cars, trucks, motorcycles, trains) are what we are talking about.  The majority of interactions with these motors, by far, is going to be four stroke, this includes diesel trains . This is worth mentioning in the lede, as it tells the reader that the topic of the article is what is most common in their own day to day dealings.  Dennis Brown - 2¢ 13:10, 20 November 2021 (UTC)
 * Heh? Are you claiming that a ship cannot be a motorised vehicle? Of course a ship can be a motorised vehicle. A typical oil tanker or modern passenger liner is a ship and is motorised. The claim in both the article and the refence was to motorised vehicles - no qualification was given to limit it to land vehicles. The article made the claim about 4-stroke being the most common and then gave a list of some example applications but this sample list is separate from the claim and not supported by any reference.
 * Do I believe the statement? Undecided - far too little information is given. I believe it is true in the context of road going vehicles in western countries. But the reference didn't say that. If you look at the context of road going vehicles in India then 2-stroke motorbikes become a large force that needs to be quantified. Africa is an unknown figure in this equation that might swing either way. China used to have lots of 2-stroke motorbikes back in the 1990s (personal experience) but they have pretty much outlawed them now. Not sure about Russia.
 * The reference made an off-the-cuff, throw-away comment about them being the most common. It provide no reasoning or support about how they came to that conclusion, nor even qualification about which domain it was applicable too. Given that it is informal webpage talking to potential US students, I can only assume that the context of the reference is road-going, US vehicle. The article then takes that as a bold claim that all internal combustion vehicles (which includes vehicles in India, ships, jet planes, golf carts, etc) have 4-stroke engine as the most common variation. A bold claim from a weak source.  Stepho  talk 23:17, 20 November 2021 (UTC)
 * This is why I said you are being obtuse. Dennis Brown - 2¢ 01:13, 21 November 2021 (UTC)
 * Then you will need to educate me. By the way, under WP:BRD we should technically revert the claim.  Stepho  talk 03:19, 21 November 2021 (UTC)
 * Technically, two people want it included and one doesn't, so there is more to it. I noticed your addition to the source, which is perfectly fine.  I'm working on other sources, but real life gets in the way.  Whatever the outcome, it makes perfect sense to state and demonstrate how common the engine is, particularly since virtually every automobile on the planet uses the technology, just for starters.  Dennis Brown - 2¢ 12:07, 23 November 2021 (UTC)
 * Technically, it is not a vote, so 2-1 doesn't decide it. Agreed that it is mostly likely true for the restricted case of automobiles in western countries - just not sure about the general case of all types of vehicles in all countries. But I don't mind waiting a while. Cheers.  Stepho  talk 20:21, 23 November 2021 (UTC)
 * Again, this is the obtuse I spoke of. I know it's not a vote.  I'm not new.  It means you are the only one that didn't want it, so there is a rough consensus to include if possible as two did want it.  Consensus is how things are decided around here.  I think your "restricted case of automobiles in western countries" is overstating the case, however, as autos in almost all countries are 4 stroke, particularly in the era of Paris Accord and the Kyoto Protocol.  The same is true for motorized equipment used for construction, etc.  In parts of the US, 2 stroke are flatly illegal.  Even in India and China, virtually all autos are 4 stroke, and that counts for a sizable chunk of the global population alone.  I'm not quite as US centric in my estimation as you keep trying to tell me I am. Dennis Brown - 2¢ 20:45, 24 November 2021 (UTC)
 * I'm not being stubborn for the joy of it - my nature tends to not rock the boat. But you keep restricting this discussion to just cars. The claim is that 4 stroke engines are the most common for all motorised vehicles. A golf cart is a motorised vehicle, a ship is a motorised vehicle, a jet plane is a motorised vehicle, a 2-stroke motorbike is a motorised vehicle, an electric car is a motorised vehicle, etc. The claim and the support simply don't line up.
 * I know you've been here a long time and you're one of the editors I trust to normally do the right thing. That's why I'm a bit confused about why you're using such a weak reference to support such a bold claim. I also know how consensus works. It's about discussing reasons. I've given my 2 reasons (counting all regions, counting all types of motorised vehicles). But you've barely touched on the region issue and haven't address the type issue at all.  Stepho  talk 21:39, 24 November 2021 (UTC)
 * You need to go back and read the discussion more closely. I haven't restricted it to anything.  Autos are simply ubiquitous; they serve as one obvious example.  And if you go look up "vehicle", you will find that ships can be included, but are generally not.  The word vehicle generally refers to land only.  Not my opinion, but the dictionary definition.  As for electric cars, they would be neither 4 nor 2 stroke, so irrelevant for the statement, however, it would be noting elsewhere how they are displacing 4 stroke motors.  Another comparison that adds perspective.  I haven't touched on the region issue because that isn't the focus.  Establishing the relative numbers, globally, was the goal.  Further in the article, absolutely plenty of room to touch on which countries buck the trend, or where the numbers/ratios are different.  Feel free to actually add content.  Sources are quite difficult, I've discovered, as I've poured through dozens to get actual numbers with no success.  If I found 4 was less common, I would obviously change the content to reflect that, but I haven't found anything better than is currently used.  As it is the Thanksgiving holiday through Sunday, I expect to be rather busy with family, but don't mistake that for me forgetting.  They are just more important that a citation. Dennis Brown - 2¢ 23:25, 24 November 2021 (UTC)
 * Respectfully, I disagree with almost all your points in your last comment but I don't mind waiting. Enjoy the holidays.  Stepho  talk 10:12, 25 November 2021 (UTC)

Wiki Education assignment: 4A Wikipedia Assignment
— Assignment last updated by Marciadc (talk) 18:02, 24 April 2024 (UTC)

title: Talk:Four-stroke engine


text:
Lumina

Lumina may refer to:

Literature

 * Lumina, a literary journal published by Sarah Lawrence College
 * World of Lumina or Lumina, a graphic novel by Emanuele Tenderini and Linda Cavallini

Music

 * "Lumina", a song by Joan Osborne from Relish (album)

Video games

 * Lumina, an Elemental Spirit in the role-playing game Secret of Mana
 * "Lumina, the Sword of Luminescence", an elemental sword wielded by the titular protagonist, Brave Fencer Musashi

Automobiles

 * Chevrolet Lumina, a 1989–2001 American mid-size car
 * Chevrolet Lumina APV, a 1990–1996 American minivan
 * Holden Commodore, a 1978–2020 Australian mid-size car, sold in various markets as the Chevrolet Lumina from 1998 to 2011

Businesses and organizations

 * Lumina Foundation for Education, an American grant-making foundation
 * Lumina Media, a former American publisher

Places

 * Lumina, Constanța, Romania, a commune
 * LUMINA, a residential development in San Francisco

Other uses

 * Lumina (desktop environment), for TrueOS and other Unix and Unix-like systems
 * Lumina (typeface), a foundry type made by Ludwig & Mayer
 * Lumina, the plural form for Lumen (anatomy), the innermost layer of a hollow organ such as the stomach or an artery

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/

title: Lumina


text:
University of Colorado Colorado Springs

The University of Colorado Colorado Springs (UCCS) is a public research university in Colorado Springs, Colorado. It is one of four campuses that make up the University of Colorado system. As of Fall 2023, UCCS had over 11,431 students, including 9,540 undergraduates and 1,891 graduate students. It is classified among "R2: Doctoral Universities – High research activity".

History
The campus history begins with the creation of Cragmor Sanatorium, which is now Main Hall. In 1902, William Jackson Palmer donated funds to build a sanatorium (a place for treatment, rehabilitation, and therapy for the chronically ill). The Cragmor Sanatorium opened in 1905 and was nicknamed the "Sun Palace" due to its sun-loving architecture. In the following decades, it developed a following among the cultural elite, and many of its patients were wealthy. However, they were hit hard by the Great Depression in the 1930s and Cragmor suffered from financial distress into the 1940s. It was briefly reinvigorated in the 1950s when a contract with the Bureau of Indian Affairs established Cragmor as a treatment center for Navajos with tuberculosis. About ten years later, the Navajo patients were transferred elsewhere.

As early as 1945, the University of Colorado offered classes in the Colorado Springs area at various locations, mostly Colorado College. By the 1960s, however, a permanent campus was desired.

On February 16, 1961, the Committee for the Expansion of the University of Colorado was formed. The co-chairmen were Joseph Petta and Ronald B Macintyre. Members included Angelo Christopher, Clint Cole, Albert Hesse, Don King, Don Kopis, Rosemary Macintyre, Dorothy Petta, Harrington Richardson, Joseph Reich, Robin Tibbets, Mike Valliant, Phyllis Warner, and John Whigham. (These Co-founders are all honored on a plaque in the lobby of the current campus site.) On March 4, 1961, they submitted a resolution to expand the extension of The University of Colorado to Colorado Springs. Legislators were favorable. After several more years of local and state meetings in June 1964, the next phase of UCCS's development came about when Dr. George Dwire, the executive director of the Cragmor Sanatorium, began formal actions necessary to transfer the assets of the Cragmoor Corporation to the University of Colorado. The solution came when George T. Dwire sold the Cragmor Sanatorium property for $1 to the state, which became the property of the University of Colorado in 1964.

In 1965, UCCS moved to its current location on Austin Bluffs Parkway in the Cragmor neighborhood of Northern Colorado Springs. The campus is located at one of the highest parts of the city.

Because of its ties to Hewlett-Packard, initial university programs focused on engineering and business, and classes were held in the Cragmor Sanatorium building, what is now Main Hall, and Cragmor Hall, a modern expansion of Main Hall. The first building built exclusively for UCCS, Dwire Hall, was not complete until 1972.

A 1997 community referendum merged Beth-El College of Nursing with UCCS. In recent years, programs such as the Network Information and Space Security Center were added to connect the university with the military to improve national security. Other programs, including the CU Institute for Bioenergetics and the Institute for Science and Space Studies, cast an eye toward the future.

In 2001, UCCS purchased an 87000 sqft building at the corner of Union and Austin Bluffs to house the Beth-El College of Nursing.

College of Letters, Art & Sciences
The College of Letters, Arts & Sciences is the UCCS college of liberal arts and sciences. The College of LAS gives access to accelerated bachelor's degrees, and three Ph.D. degrees through the seventeen departments at UCCS.

Helen and Arthur E. Johnson Beth-El College of Nursing and Health Sciences
The Helen and Arthur E. Johnson Beth-El College of Nursing and Health Sciences is the UCCS nursing school. It has two departments: Health Sciences and Nursing. The college is accredited with the Colorado State Board of Nursing and the Commission on Collegiate Nursing Education. Both departments are primarily located in University Hall, roughly half a mile east from the main campus at the intersection of Austin Bluffs Parkway and Union Boulevard. intersection.

College of Business and Administration
The College of Business and Administration is the UCCS business school and is located in Dwire Hall. The college was established in 1965. It is accredited by the Association to Advance Collegiate Schools of Business.

College of Education
The College of Education is the UCCS school of education. The College of Education was previously located in Columbine Hall on the UCCS campus; it has since relocated to University Hall down at the intersection of Austin Bluffs Parkway and Union Boulevard. It is accredited by the Council for the Accreditation of Educator Preparation (CAPE), the Colorado Department of Education (CDE), the Colorado Commission on Higher Education (CCHE) and the Council for Accreditation of Counseling and Related Educational Programs (CACREP). It is primarily a Colorado state educator licensure program.

College of Public Service
The College of Public Service offers degrees in criminal justice, public administration and social work. UCCS CPS is located in the Academic Office Building on the UCCS Campus. UCCS College of Public Service offers the only Master of Public Administration NASPAA (Network of Schools of Public Policy, Affairs, and Administration) accredited program in the Pikes Peak Region.

College of Engineering and Applied Science
The College of Engineering and Applied Science is the UCCS engineering college. In the U.S. News & World Report "America’s Best Colleges," the 2008 college rankings edition, "the magazine’s editors ranked the UCCS undergraduate engineering program ninth in the nation among public engineering schools offering bachelor’s or master’s degrees."

UCCS College of Engineering and Applied Science consists of three departments: the Department of Computer Science (computer science); the Department of Electrical and Computer Engineering (electrical engineering, computer engineering), and the Department of Mechanical and Aerospace Engineering (mechanical engineering, aerospace engineering). The college is accredited by the Accreditation Board for Engineering and Technology (ABET). In conjunction with the College of Business it offers the unique Bachelor of Innovation which won the 2008 ASEE new program innovation award.

Thanks to the college's proximity to U.S. government and military installations and the technology private sector, the college has partnerships with several institutions, including defense contractors and semiconductor manufacturers (Intel, Boeing, Agilent, Northrop Grumman, Lockheed Martin), United States Department of Energy National Laboratories (Los Alamos and Sandia), and the military (United States Northern Command, Air Force Space Command, and the United States Air Force Academy).

The college makes use of two buildings on campus:
 * The Engineering Building houses the Department of Computer Science, Department of Electrical and Computer Engineering, dean's office, Advanced Development and UNIX Laboratory, Specialized Software Development Laboratory, Software Development Laboratory, Communications and Signal Processing Laboratory, Control Systems Laboratory, Electronics Laboratory, Electromagnetics Laboratory, Microelectronics Research Laboratories (MRL), and VLSI Circuit Design Laboratory.
 * In 2009 a $56.1-million Science and Engineering Building was completed at the center of campus to add needed laboratory and lecture space for the Department of Mechanical and Aerospace Engineering as well as the Physics, Chemistry, and Biology departments. It holds an expanded computer, wind tunnel, fluids, instrumentation, and other mechanical engineering laboratories with an enlarged machine shop and research space, design studios with payload and project areas. The building was later named Osborne Center for Science and Engineering after its most significant donors, Ed and Mary Osborne.

El Pomar Institute for Innovation and Commercialization
University of Colorado's El Pomar Institute for Innovation and Commercialization (EPIIC) is located on the campus of the University of Colorado at Colorado Springs (UCCS).

National Institute for Science, Space and Security Centers
The National Institute for Science, Space and Security Centers (NISSSC) is a multi-disciplinary institute. The NISSSC includes the Center for Homeland Security (CHS); the Center for Space Studies (CSS); the Center for Science, Technology, Engineering & Mathematics Education (CSTEME); and the Trauma, Health & Hazards Center (THHC).

Center for Space Studies
The Center for Space Studies (CSS) is an educational and research & development organization formed under affiliation with UCCS and the NISSSC. Founded in 2004, the center's mission is to promote research, education and outreach in the domain of space technology. The CSS is led by Dr. Scott Trimboli, associate dean of the College of Engineering and Applied Science at UCCS. CSS is located in Colorado Springs, Colorado.

Research
The Center for Space Studies projects include:
 * Satellite Thermal Modeling for FalconSAT (Dr. Andrew Ketsdever)
 * Tethered Satellite Orbit Determination (Dr. Steven Tragesser)
 * Emergency Response Operations System Integration (Dr. Roger Sambrook)
 * Terahertz Technology for Multiphase Flow Applications (Dr. Andrew Ketsdever & Dr. Hoyoung Song)
 * Small Satellite Simulator Development (Dr. Scott Trimboli)

Buildings

 * Ent Center (2018) - Home to the Visual and Performing Arts classes. Also hosts some events for the students, and also is sometimes used by the Colorado Springs Philharmonic orchestra.
 * Main Hall (1914) – Administration building containing the Bursar's office, admissions, student success center, etc.
 * Cragmor Hall (1959) – Administration building containing orientation rooms, student recruitment, counseling, and financial aid.
 * Dwire Hall (1972) – Renovated from 2006 to 2007, it serves as the building for classes in business, economics, languages and cultures, and film studies.
 * The El Pomar Center (1975) – Home to the Kraemer Family Library and technical support. Renovated at the beginning of the millennium to expand the library and add the University Center.
 * Engineering and Applied Sciences (1985) – Serves as the building for engineering, math, and science classes.
 * Anschutz Engineering Center (2024) - New annex to the current Engineering and Applied Sciences building.
 * Campus Services (1996)
 * Columbine Hall (1997) – The new home for most LAS classes, also containing writing center, communications lab, and a lecture hall.
 * Summit Village (1997) – This is the first of UCCS's student housing, now catering to freshmen only. Divided into Vail, Steamboat, Telluride, Aspen, Keystone, Monarch, and Breckenridge (laundry, computer facilities, and seminar rooms). Summit houses altogether about 800 freshmen.
 * University Center (2001) – Addition to El Pomar, this is the center of campus life where activities and seminars are held. The information desk, bookstore, newsroom, and campus recreation offices are housed in the lower level. A basketball court and gym will soon to be expanded to include larger facilities for games and a multi-use area to help ease the strain on the facility until permanent facilities near 4-Diamonds are constructed sometime during the mid-twenty-teens.
 * University Hall (2001) – Building purchased for Beth-El Nursing and other programs.
 * Services/Campus Police/Health Clinic/Parking Garage (2004)
 * Alpine Village (2004) – The second village in student housing, Alpine is divided into Shavano, Antero, and Crestone Houses, and caters now to all non-freshmen choosing to live on-campus. Students who live here must access campus via a trail or shuttle.
 * Campus Recreation Center (2007) – Recently completed, this recreation building for students, replacing the current facilities at the University Center, features a swimming pool, a climbing wall, and a full basketball court, along with the full complement of equipment.
 * Osborne Center for Science and Engineering (2009) – Formerly the "Science and Engineering Building", renamed in May 2011, this building was designed by AR7 Architects (now NAC Architecture) and provides a twofold expansion of science and engineering classrooms and facilities, and connects via a bridge to the Engineering and Applied Sciences building.
 * Centennial Hall (2010) – The building was completely gutted and rebuilt inside with the exception of new classrooms added in 2006. Formerly called the Science Building, it was built in 1981 and used for science and anthropology classes along with the student art gallery.
 * UCCS Events Center (2010) – Money originally allocated to construct a temporary new home for Mountain Lion athletics was instead added to a larger budget to significantly expand the current athletics gym and create a new Events Center, which will, in addition to providing a larger gym for volleyball and basketball, will serve as a venue for conferences and large lectures when completed. Now the Events Center is called the Gallogly Events Center.
 * Summit Village Expansion (2013) – Two additional residence halls adjacent to Aspen House.
 * Alpine Parking Garage & Recreational Field (2014)
 * Academic Office Building (2014) – Academic office building at the former site of Building 20 on Regent Circle.
 * Village at Alpine Valley(2016)- Added three residence halls and a new dining hall.

Master plan and future growth
In 2000, the CU Board of Regents designated UCCS as the CU growth campus. In 2003, the Colorado Legislature approved revisions in the university's statutory role and mission to remove geographic and program restrictions. In 2005, the Regents approved a seven-year plan that calls for the university to add to its base of 7,650 students (Fall 2004), 347 FTE faculty and 254 FTE staff.

The 2006–2012 plan called for growth to 9,100 students with corresponding increases in faculty, staff, programs and campus infrastructure.

In addition to the completion of the recreation center, Dwire Hall renovation, and the third wing of the new science/engineering building, the seven-year plan also calls for the renovation and transition of the old Heller Center on the other side of the bluff that campus sits in front of into a sort of "arts retreat". This project is expected to cost around $4.4 million. Also, by 2014, two new buildings are in the works for Summit, and by that year the Alpine Village should be built out with three additional buildings across from the current ones.

With construction on the new Austin Bluffs/Union interchange, the construction of a new frontage road from campus to University Hall began as well, enabling a closed circuit connecting Cragmor Campus with University Hall, making access to Austin Bluffs unnecessary.

From 2014 a new indoor athletics complex will be constructed along Nevada in the existing 4-Diamonds area. North Nevada is the second phase of campus in the long-term, and extreme long-term build-out calls for dozens of new buildings, academic halls, and another resident village to be built along Nevada.

Slated for completion by the end of 2019, a new road will connect the main campus with the Ent Center for the Arts. This road will bypass Stanton Road running through the Eagle Rock neighborhood.

Athletics
UCCS competes in NCAA Division II in the Rocky Mountain Athletic Conference (RMAC), fielding teams in men's basketball, women's basketball, women's volleyball, men's cross country, women's cross country, men's indoor track and field, women's indoor track and field, men's outdoor track and field, women's outdoor track and field, men's golf, men's soccer, women's soccer, women's softball and women's lacrosse.

The school mascot is the mountain lion, Clyde, with official colors of gold and black, the same school colors of CU-Boulder (black, gold and silver).

Honor societies
In addition to its honors programs, UCCS has chapters of the following honor societies on campus:

 * Alpha Kappa Delta (sociology)
 * Alpha Lambda Delta (freshman)
 * Alpha Phi Sigma (criminal justice)
 * Beta Gamma Sigma (business)
 * Chi Sigma Iota (counseling)
 * Delta Phi Alpha (German)
 * Eta Kappa Nu (electrical engineering)
 * Omicron Delta Epsilon (economics)
 * Phi Alpha Theta (History)
 * Pi Alpha Alpha (public affairs)
 * Pi Delta Phi (French)
 * Psi Chi (psychology)
 * Sigma Delta Pi (Hispanic)
 * Sigma Tau Delta (English)
 * Sigma Theta Tau (nursing)

Professional fraternities: Phi Alpha Delta (pre-law) and Delta Sigma Pi (business)

School publications

 * The official campus newspaper is The Scribe, since 1966.
 * The university is home to Writers' Forum, a national literary journal founded in 1974.
 * URJ-UCCS: Undergraduate Research Journal at UCCS
 * riverrun is the student literary and arts journal published annually. They take poetry, fiction, nonfiction, and visual art submissions. riverrun must never be capitalized because it is a reference to the first word of the book Finnegans Wake, which starts in the middle of a sentence. The beginning of the sentence is at the end of the book.

Notable students, alumni, and staff

 * Max Aaron - 2013 U.S. national champion figure skater
 * Steve Bach (B.S. in business) - former Colorado Springs Mayor, first "Strong Mayor"
 * Jason Brown - 2015 U.S. national champion figure skater and Olympic bronze medalist
 * Teresa A. H. Djuric (M.A. in Curriculum and Instruction, 1994) - U.S. Air Force Brigadier General
 * John Herrington (B.A. in mathematics, 1983) - first Native American to go to space, aboard Space Shuttle Endeavour in 2002
 * Yusef Komunyakaa (B.A. 1975) - first African-American to win Pulitzer Prize for poetry
 * Mary Lou Makepeace (M.P.A. 1979) - first female mayor of Colorado Springs, serving from 1997 to 2003
 * Charlee Minkin (born 1981), Olympic judoka
 * John Morse (B.S. in business, M.P.A. 1996) - former president of the Colorado Senate
 * Mirai Nagasu - 2008 U.S. national champion figure skater and 2010 Olympian
 * Apolo Ohno - speed skater, most decorated American Winter Olympic athlete of all time
 * Raquel Pennington - professional mixed martial arts fighter, competing in the UFC's bantamweight division
 * Jugal Kalita - Computer Science Professor, Language Information and Computation (LINC) Lab
 * Garrett Swasey - UCCS police officer who died in the line of duty at age 44 during the Colorado Springs Planned Parenthood shooting
 * Derrick White - basketball player

International exchange

 * Dual degree – 🇹🇼 Ching Yun University, Taiwan (3–2 programs)

title: University of Colorado Colorado Springs


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User:Pjamescowie

Articles
All English Wikipedia main, main talk, and template namespace articles or edits produced by Pjamescowie are dual licensed as described below. Any other namespace (such as Wikipedia:) is excluded. This license is retroactive, however, I reserve the right to cease using the dual license at any time by removing this notice from my page. The most recent notice shall have priority. I encourage you to dual-license your contributions as well.

Images
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title: User:Pjamescowie


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Krýsuvík

Krýsuvík (also Krísuvík, both pronounced in Icelandic) is an area in Southwest Iceland at about 35 km from Reykjavík.

Geography and access
It is situated on the Reykjanes peninsula between Þorlákshöfn and Grindavík and accessed by Routes 42 and 427.

Name
The name Krýsuvík means "bay of Krýsa," a folk tale figure from the area. Krýsa was an old woman who, together with her cousin Herdís,  could use witchcraft. They had a discussion about the borders of their respective lands; one wanted to cast a spell so that all the fish in a nearby lake would be hairy, the other intended to bring up a storm and let all fishermen die. The dispute ended with the death of both of them. The folk tale says that they were buried side by side, and the place of the graves is still known to locals.

The Ögmundarhraun lava flows which were emitted by the nearby Krýsuvík volcanic system in the 12th century, destroyed the Krýsuvík farm, which was located at the coast, and filled up the bay.

History
There were farms in the vicinity from the Middle Ages till 1945. After the eruption known as the Krýsuvík fires in the middle of the 12th century, probably in 1151-1188, the main farm was transferred to a place under the mountain Bæjarfell. The name Krýsuvík was still used for the farm, though the buildings were at a distance of some kilometers from the sea. The farm had a reputation for being very rich till the end of the 19th century. Being near the sea, the farm had additional income from fishing and hunting. Commerce was also done, because the farm was a junction of old trails from the north to the south coast. Also the sulfur of the nearby geothermal areas was mined and exported. However, Krýsuvík was too far away from upcoming industry and commerce and therefore abandoned in the middle of the 20th century.

Árni Gíslason, one of the richest people in Iceland in the 19th century, lived in Krýsuvík. In 1949, a new farm (Fjósið) was constructed near the maar Grænavatn, but for many reasons, never used much as such.

As all the estate farms in Iceland, Krýsuvík had its own small proprietary church, in this case from the 13th century until 2010. The last building was a 19th century timber church built in 1857. The church was then changed into an apartment building for some time after 1927. In 1964, the mayor of Hafnarfjörður had the church renovated and used for weddings and placed under the protection of the National Museum as part of the National Museum’s Buildings Collection. It burned down in January 2010. An association was formed to build a replica, which was done by students and teachers at the technical school in Hafnarfjörður. The replica was driven to the site by truck and unloaded in 2020.

Sites

Under the mountain Bæjarfell is a boarding school for young people who have problems with drug abuse.

In the vicinity are some maars and the high temperature geothermal area of Seltún, all part of the Krýsuvík volcanic system. The largest lake in the area, Kleifarvatn, began to diminish after an earthquake in 2000; 20% of its surface disappeared by 2005, but it had filled up again by 2019. Many interesting tuff rock formations are to be found at its western coast near Route 42 on the slopes of Sveifluháls.

The Ögmundarhraun lava field south of Krýsuvík includes some kīpukas, vegetation islands in the lava field, which can be reached by hiking trails. One of them, the Húshólmi, contains some ruins of the medieval farm of Krýsuvík. Scientists identified some stone fences within the same kipuka as being older as the official time of settlement (874). They used tephrochronology and saw that the famous bimodal settlement tephra (landnámslagið) derived from a combined eruption series within the Bárðarbunga-Veiðivötn and Torfajökull systems in the years 871-874, was covering these structures.

A jeep track runs down to the sea from Krýsuvík and Route 427. It ends at the high cliffs of Krýsuvíkurbjarg or Krýsuvíkurberg  which are renowned as bird cliffs with thousands of Icelandic sea birds like arctic terns, puffins, fulmars and more. About 63,000 pairs of birds were counted there shortly before 2014. But the cliffs, which can be reached on foot, are also a window in the geologic past. The lava flows covering the area came mostly from the crater up on Geitahlíð tuya, not from the Krýsuvík, but from the neighbouring Brennisteinsfjöll volcanic system. The area is protected as part of Reykjanesfólkvangur.

Krýsuvík is a popular hiking area, and tourism infrastructure such as wooden pathways has been developed.

The music video for the song "Never Forget" by Greta Salóme and Jónsi was filmed in this area.

title: Krýsuvík


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Thirty-Six Stratagems

The Thirty-Six Stratagems is a Chinese essay used to illustrate a series of stratagems used in politics, war, and civil interaction.

Its focus on the use of cunning and deception both on the battlefield and in court have drawn comparisons to Sun Tzu's The Art of War. Zhang Yingyu's The Book of Swindles, a late-Ming-dynasty work that focuses on the realms of commerce and civil society, shares some thematic similarities.

Unless otherwise specified, Chinese texts in this article are written in "Traditional Chinese, pinyin" format.

Origin
The name of the collection comes from the Book of Qi seventh biographical volume, Biography of Wang Jingze (王敬則傳). Wáng was a general who had served Southern Qi since the first Emperor Gao of the dynasty. When Emperor Ming came to power and executed many members of the court and royal family for fear that they would threaten his reign, Wang believed that he would be targeted next and rebelled. As Wang received news that Xiao Baojuan, son and crown prince of Emperor Ming, had escaped in haste after learning of the rebellion, he commented that "of the thirty-six stratagems of Lord Tán, retreat was his best, you father and son should run for sure." "Lord Tán" refers to general Tan Daoji of the Liu Song dynasty, who was forced to retreat after his failed attack on Northern Wei, and Wang mentioned his name in contempt as an example of cowardice.

The number thirty-six was used by Wang as a figure of speech in this context, and is meant to denote "numerous stratagems" instead of any specific number. Wang's choice of this term came from the I Ching, where six is the number of yin that shared many characteristics with the dark schemes involved in military strategy. As thirty-six is the square of six, it therefore acted as a metaphor for "numerous strategies". Since Wang did not refer to any thirty-six specific stratagems, the thirty-six proverbs and their connection to military strategies and tactics are likely to have been created after the fact, with only the collection's name being attributed to Wang.

The prevailing view is that contents of the Thirty-Six Stratagems originated in both written and oral history. Some stratagems reference occurrences in the time of Sun Bin, approximately 150 years after Sun Tzu's death. The original hand-copied paperback was believed to have been discovered in China's Shaanxi province, of an unknown date and author, and put into print by a local publisher in 1941. The Thirty-Six Stratagems came to the public's attention after a review of it was published in the Chinese Communist Party's Guangming Daily newspaper on September 16, 1961. It was subsequently reprinted and distributed with growing popularity.

The Thirty-Six Stratagems are divided into a preface, six chapters containing six stratagems each, and an incomplete afterword that was missing text. The first three chapters generally describe tactics for use in advantageous situations, while the last three chapters contain stratagems that are more suitable for disadvantageous situations. The original text of the Thirty-Six Stratagems has a laconic style that is common to Classical Chinese. Each proverb is accompanied by a short comment, no longer than a sentence or two, that explains how said proverb is applicable to military tactics. These 36 Chinese proverbs are related to 36 battle scenarios in Chinese history and folklore, predominantly of the Warring States period and the Three Kingdoms period.

Content
The Thirty-Six Stratagems consists of six chapters, with each chapter consisting of six stratagems.

Deceive the heavens to cross the sea (瞞天過海, Mán tiān guò hǎi)

 * Mask one's real goals from those in authority who lack vision by not alerting them to one's movements or any part of one's plan.

Besiege Wèi to rescue Zhào (圍魏救趙, Wéi Wèi jiù Zhào)

 * When the enemy is too strong to be attacked directly, attack something they cherish. The idea is to avoid a head-on battle with a strong enemy, and instead strike at their weakness elsewhere. This will force the strong enemy to retreat in order to support their weakness. Battling against a tired and dispirited enemy will give a much higher chance of success.

Kill with a borrowed knife (借刀殺人, Jiè dāo shā rén)

 * Attack using the strength of another when in a situation where using one's own strength is not favourable. For example, trick an ally into attacking them or use the enemy's own strength against them. The idea is to cause damage to the enemy via a third party.

Wait at leisure while the enemy labors (以逸待勞, Yǐ yì dài láo)

 * It is advantageous to choose the time and place for battle while the enemy does not. Encourage the enemy to expend their energy in futile quests while one conserves their strength. When the enemy is exhausted and confused, attack with energy and purpose.

Loot a burning house (趁火打劫, Chèn huǒ dǎ jié)

 * When a country is beset by internal problems, such as disease, famine, corruption, and crime, it is poorly-equipped to deal with an outside threat. Keep gathering internal information about an enemy. If the enemy is in its weakest state, attack them without mercy and annihilate them to prevent future troubles.

Make a sound in the east, then strike in the west (聲東擊西, Shēng dōng jī xī)

 * In any battle the element of surprise can provide an overwhelming advantage. Even when face-to-face with an enemy, surprise can still be employed by attacking where they least expect it. Create an expectation in the enemy's mind through the use of a feint. Manipulate the enemy to focus their resources somewhere before attacking elsewhere that is poorly defended. Tactically, this is known as an "open feint".

Create something from nothing (无中生有, Wú zhōng shēng yǒu)

 * A plain lie. Make somebody believe there was something when there is in fact nothing or vice versa.

Openly repair the gallery roads, but sneak through the passage of Chencang (明修棧道，暗渡陳倉, Míng xiū zhàn dào, àn dù Chéncāng)

 * Deceive the enemy with an obvious approach that will take a very long time, while ambushing them with another approach. It is an extension of the "Make a sound in the east, then strike in the west" tactic, but instead of merely spreading misinformation to draw the enemy's attention, physical decoys are used to further misdirect the enemy. The decoys must be easily seen by the enemy to draw their attention while acting as if they are meant to do what they are falsely doing to avoid suspicion.
 * Today, "sneaking through the passage of Chencang" also has the meaning of having an affair or doing something that is illegal.

Watch the fires burning across the river (隔岸觀火, Gé àn guān huǒ)

 * Delay entering the field of battle until all other parties become exhausted by fighting amongst each other. Go in at full strength and finish them off.

Hide a knife behind a smile (笑裏藏刀, Xiào lǐ cáng dāo)

 * Charm and ingratiate oneself with the enemy. When their trust is gained, move against them in secret.

Sacrifice the plum tree to preserve the peach tree (李代桃僵, Lǐ dài táo jiāng)

 * There are circumstances where short-term objectives must be sacrificed in order to gain the long-term goal. This is the scapegoat strategy where someone suffers the consequences so that the rest do not.

Take the opportunity to pilfer a goat (順手牽羊, Shùn shǒu qiān yáng)

 * While carrying out one's plans, be flexible enough to take advantage of any opportunity that presents itself, however small, and avail oneself of any profit, however slight.

Stomp the grass to scare the snake (打草驚蛇, Dǎ cǎo jīng shé)

 * Do something unaimed, but spectacular ("hitting the grass") to provoke a response from the enemy ("startle the snake") to have them give away their plans or position. Do something unusual, strange, and unexpected to arouse the enemy's suspicion and disrupt their thinking. It is more widely used as a warning: "[Do not] startle the snake by hitting the grass". An imprudent act will give one's position or intentions away to the enemy.

Borrow a corpse to resurrect the soul (借屍還魂, Jiè shī huán hún)

 * Take an institution, a technology, a method, or even an ideology that has been forgotten or discarded and appropriate it for one's own purposes.

Lure the tiger down the mountain (调虎離山, Diào hǔ lí shān)

 * Never directly attack an opponent whose advantage is derived from their position. Instead, lure them away from their position to separate them from their source of strength.

In order to capture, one must let loose (欲擒故縱, Yù qín gù zòng)

 * Cornered prey will often mount a final desperate attack. To prevent this, let the enemy believe they still have a chance for freedom. Their will to fight is hampered by their desire to escape. The enemy's morale will be depleted and they will surrender without a fight when the illusion of escape is revealed.

Tossing out a brick to lure a jade gem (拋磚引玉, Pāo zhuān yǐn yù)

 * Bait someone by making them believe they gain something or to just make them react to it; "toss out a brick" to obtain something valuable from them in return ("get a jade gem").

Defeat the enemy by capturing their chief (擒賊擒王, Qín zéi qín wáng)

 * If the enemy's army is strong but is allied to the commander only by money, superstition, or threats, target the leader. If the commander falls, the rest of the army will disperse or join one's side. If they are allied to the leader through loyalty, beware, as the army can continue to fight on after their death out of vengeance.

Remove the firewood from under the pot (釜底抽薪, Fǔ dǐ chōu xīn)

 * Take out the leading argument or asset of someone; "steal someone's thunder". This is the essence of the indirect approach: instead of attacking enemy's fighting forces, direct attacks against their ability to wage war. Literally, take the fuel out of the fire.

Disturb the water and catch a fish (渾水摸魚／混水摸魚, Hùn shuǐ mō yú)

 * Create confusion and exploit it to further one's own goals.

Slough off the cicada's golden shell (金蟬脱殼, Jīn chán tuō qiào)

 * Mask oneself. Either leave one's distinctive traits behind and become inconspicuous or masquerade as something or someone else. This strategy is mainly used to escape from a stronger enemy.

Shut the door to catch the thief (關門捉賊, Guān mén zhuō zéi)

 * To capture one's enemy, or more generally in fighting wars, to deliver the final blow to the enemy, plan prudently for success; do not rush into action. Before "moving in for the kill", first cut off the enemy's escape routes and any routes from external aid.

Befriend a distant state and strike a neighbouring one (遠交近攻, Yuǎn jiāo jìn gōng)

 * Invading nations close to oneself carries a higher chance of success. The battlefields are close to one's domain and as such is easier for one's troops to receive supplies and defend the conquered land. Make allies with nations far away from oneself, as it is unwise to invade them.

Obtain safe passage to conquer the State of Guo (假途伐虢, Jiǎ tú fá Guó)

 * Borrow the resources of an ally to attack a common enemy. Once the enemy is defeated, use those resources to turn on the ally that lent them in the first place.

Replace the beams with rotten timbers (偷梁換柱, Tōu liáng huàn zhù)

 * Disrupt the enemy's formations, interfere with their methods of operations, and change the rules that they are used to following. In this way the supporting pillar, the common link that makes a group of men an effective fighting force, is removed.

Point at the mulberry tree while cursing the locust tree (指桑罵槐, Zhǐ sāng mà huái)

 * To discipline, control, or warn others whose status or position excludes them from direct confrontation; use analogy and innuendo. Without directly naming names, those accused cannot retaliate without revealing their complicity.

Feign madness but keep your balance (假痴不癲, Jiǎ chī bù diān)

 * Pretend to be incompetent to create confusion about one's intentions and motivations. Lure the opponent into underestimating one's ability until they drop their guard.

Remove the ladder when the enemy has ascended to the roof (上屋抽梯, Shàng wū chōu tī)

 * With baits and deceptions, lure the enemy into treacherous terrain and cut off their lines of communication and escape routes. To save themselves, they must fight both one's own forces and the elements of nature.

Decorate the tree with false blossoms (樹上開花, Shù shàng kāi huā)

 * Tying silk blossoms on a dead tree gives the illusion that the tree is healthy. Using artifice and disguise, make something worthless appear valuable and vice versa.

Make the host and the guest exchange roles (反客為主, Fǎn kè wéi zhǔ)

 * Usurp leadership in a situation where one is normally subordinate. Infiltrate one's target. Initially, pretend to be a guest to be accepted, but develop from inside and become the owner later.

The beauty trap (Honeypot) (美人計, Měi rén jì)

 * Send the enemy beautiful women to cause discord within his camp. This strategy can work on three levels. First, the ruler becomes so enamoured with the beauty that he neglects his duties and allows his vigilance to wane. Second, the group of men will begin to have issues if the desired women court another man, thus creating conflict and aggressive behavior. Third, other females at court, motivated by jealousy and envy, begin to plot subversions that further exacerbate the situation.

The empty fort strategy (空城計, Kōng chéng jì)

 * When the enemy has stronger forces and one expects to be overrun at any moment, act calmly and taunt the enemy, so that the enemy thinks they are walking into an ambush. This stratagem is only successful if in most cases one has a powerful hidden force and the stratagem is seldom used.

Let the enemy's own spy sow discord in the enemy camp (反間計, Fǎn jiàn jì)

 * Undermine the enemy's ability to fight by secretly causing discord between them and their friends, allies, advisors, family, commanders, soldiers, and population. While they are preoccupied with settling internal disputes, their ability to attack or defend is compromised.

Inflict injury on oneself to win the enemy's trust (苦肉計, Kǔ ròu jì)

 * Pretending to be injured has two advantages: first, the enemy is lulled into lowering their guard since they no longer consider one to be an immediate threat. Second, ingratiating oneself with the enemy by pretending the injury was caused by a mutual enemy conserves one's strength while one's enemies fight each other.

Chain stratagems (連環計, Lián huán jì)

 * In important matters, one should use several stratagems applied simultaneously after another as in a chain of stratagems. Keep different plans operating in an overall scheme; if any one strategy fails, apply the next strategy.

If all else fails, retreat (走為上策, Zǒu wéi shàng cè)

 * If it becomes obvious that one's current course of action will lead to defeat, retreat and regroup. When one's side is losing, three choices remain: surrender, compromise, or escape. Surrender is complete defeat, compromise is half defeat, but escape is not defeat. As long as one is not defeated, there is still a chance. This is the most famous of the stratagems and is immortalized in the form of a Chinese idiom: "Of the Thirty-Six Stratagems, fleeing is best" (三十六計，走為上計, Sānshíliù jì, zǒu wéi shàng jì).

title: Thirty-Six Stratagems