Wikipedia talk:Mediation Cabal/Cases/2010-11-21/Kendrick mass

Hello! I will now invite the three parties to write brief statements on this matter. I understand that this has gone on for quite a bit of time and you may have written many statements in the past --- however, I want what you write to focus on areas of possible agreement. Please remember to use civility and open-mindedness as we can use that as a better way to start this process.

After I read through your statements and the past history of the case, I will try to begin discussion of possible consensus points before we get to the bigger questions. Cheers, Lord Roem (talk) 18:23, 31 December 2010 (UTC)[reply]

Summary of the dispute[edit]

The issue can be reduced to the issue of appropriate sourcing and giving due weight to the sources. I think that we all agree that

(1) Wikipedia guidelines apply, especially WP:SOURCE and WP:OR.

(2) There are multiple secondary sources ([1]) that define Kendrick mass as "Kendrick mass = IUPAC mass x (14/14.01565)" (essentially a graph scaling procedure) and report Kendrick mass in units of daltons (Da).

(3) There is a primary source ([2]) that reports Kendrick mass in Kendrick units and uses the symbol Ke, suggesting a kendrick unit.

(4) There are general guidelines for metrology (ISO 31, IUPAC Green Book, etc.) that should be followed where possible.

The dispute can be reduced to the relative weight given to 1–4 above. I would argue that 1 > 2 > 3 > 4 by WP:PSTS and that WP:WEIGHT would suggest that (2) be given more coverage than (3) in the article, but that (3) should be mentioned (see the discussion here for example [3]). I think that Kehrli is arguing that conflicts between (2) and (4) should be resolved in favor of (4) and that only (3) should appear in the article. I disagree because (a) I don't think that there is a conflict and (b) even if there is a conflict, the concept of "verifiability, not truth" tells us to keep (2) even if it isn't "nice" from a metrology standpoint. I think that Nick Y. might not agree with me on (a) but would agree on (b) and on the need to include the concepts of (2) with proper weight with respect to (3). --Kkmurray (talk) 00:00, 3 January 2011 (UTC)[reply]

I agree with Kkmurray near perfectly. He points out that I might not agree with his point (a). I actually agree, but with limited conviction and concern. There *may* be some minor conflict but for the most part there is not. I simply find point (a) moot and distracting from editorial decision making since Kkmurray's point (b) is clear as day and closes the case completely and would take precedence over the debate in point (a) anyways. Debating point (a) validates Kehrli's position that we should choose truth, elegance and internal consistency over verifiability. We should not even be discussing which notation and units are better in this context. If the prevailing notation in the field is in my opinion horribly flawed, I will nonetheless use it in the context on Wikipedia. I might go write an article *somewhere else* about how and why everyone should change there practices and notations, but not here. I happen to be doing exactly that about another subject to be published in the primary literature. Some day the prevailing notation, units and practices may change at which point we will change Wikipedia to reflect the prevailing usage. The big picture issue here is "verifiability vs. truth". There are many inconsistencies in the scientific literature that Kehrli sees. He/she then formulates a "better" way and implements it directly in Wikipedia in hopes of swaying the community to essentially adopt a new approach. He/she has become aware of the lines of support, such as citing literature, needed to support his/her argument and make the conflict more subtle. However, one source that supports his/her opinion does not win over 20 sources. I would prefer that Kherli was to realize the purpose of wikipedia and contribute constructively within that context rather than find ever more effective ways to push his/her POV.--Nick Y. (talk) 17:58, 6 January 2011 (UTC)[reply]

I will wait for Kehrli's statement before proceeding. But I would like to thank both parties so far for explaining the controversy succintly. Lord Roem (talk) 01:56, 7 January 2011 (UTC)[reply]

Kehrli's summary of the dispute[edit]

1) On one side we have an International vocabulary of metrology (VIM) which is a consensus of the IUPAP (representing all physicists), the IUPAC (representing chemists), the ISO (representing the trade an commerce) and the International Organization of Legal Metrology OIML representing the law. In other words: VIM establishes a terminology that is the consensus of science, commerce and trade, and law.

2) On the other side we have a small group of scientists that continue using an old and outdated jargon in a small field of science (roughly 100 publications by roughly 50 scientists). Living in an ivory tower, they do not care and probably not even know about VIM.

3) The jargon they use is by no means consistent. Different groups use different jargon. People in the same group use different jargon. Even worse: within a single paper they use terminology that is contradictive.

4) Among the 100 or so publications there is also one ([4]) that mostly keeps the to VIM terminology. This publication is also the most current publication.

5) The other 100 or so publications by no means use a "common jargon". It is more like every publication uses its own jargon.

6) Legal entities (like companies, governments, courts) are mostly required by law to use VIM terminology. University researchers are not.

7) All relevant rules in the Wikipedia manual of style favor the use of VIM terminology.

Based on these facts, I proposed a set of questions on which we hopefully can find a consensus:

Are there verifiable rules about terminology in quantitative science, trade and commerce?

Agree, it is called the VIM (International vocabulary of metrology). It is the common ground of IUPAP, IUPAC and ISO. Kehrli (talk)

Do some scientists verifiably keep to the VIM terminology in the subject matter?

Agree, in this paper they largely do: [5] Kehrli (talk)

Do most scientists in this matter verifiably not keep to the VIM terminology and use their own jargon instead?

Agree. In many papers they do not.Kehrli (talk)

Is the jargon at least used in a consistent manner?

Disagree. Many jargon users (also Marshall) do not even use it consistently within the same publication. Kehrli (talk)

Should Wikipedia use one of these jargon terminologies just because it is verifiably in use?

Disagree. The fact that some people do something in a verifiable way is not a sufficient reason to use it in Wikipedia. More formally: WP:VERIFY is a necessary but not a sufficient requirement. This logical fallacy is described in the necessary and sufficient condition article. Kehrli (talk)

I hope by answering these questions frankly we will find common ground. Kehrli (talk) 11:03, 9 January 2011 (UTC)[reply]

Thank you for your statement and to everyone for commenting in an amicable way so far. I believe the dispute is laid out but I have one question before we proceed further. Kehrli, the VIM terminology would support what definition? A kendrick unit or the dalton?? Which one is it on the side of? -- Lord Roem (talk) 00:34, 10 January 2011 (UTC) Let me rephrase. What things do you specifically want in the article based on the VIM sources? -- Lord Roem (talk) 00:46, 10 January 2011 (UTC)[reply]

I just finished reading through the talk page of the article and I believe I understand the sides much better now. I appreciate that all parties have set forth paths to reach compromise, and I encourage everyone to engage in discussion on each of these proposed 'list of questions'. At the same time, I will begin a path as well. In this way, everyone will get an oppurtunity to discuss every element of the dispute, starting with the foundational questions first. If anyone has any concerns, questions, etc., with this mediation process, I ask that you state it here. We need to engage each other in open communication, and that means keeping the debate here so we can centralize the discussion.

Lastly, I ask that we keep a 'hands-off' approach to the disputed articles for the time being, whatever current state they may be in, to prevent any flare-ups. I feel everyone wants to reach an agreement and so this process very possibly can be successful. Cheers, Lord Roem (talk) 02:26, 10 January 2011 (UTC)[reply]

Lord Roem, my main concern is that this will become extremely technical. I would have appreciated a mediator with excellent knowledge in metrology, because in the end this is all about metrology, not chemistry. What is your field of expertise? You should at least read the VIM in order to get a concept of the terminology rules we are talking about. You can download the VIM from here: [6].

Kermit and Nick will try to frame this as a conflict between VIM plus a single paper vs. all other papers. This is not true, since what they consider a single jargon in all other papers is in fact a mess of many different jargons which are incompatible among each other. Your knowledge in metrology will have to become good enough to see through this. Kehrli (talk) 11:32, 10 January 2011 (UTC)[reply]

(outdent) - So far the discussion has remained relatively easy to get through, and for that I do applaud all parties. For the sake of disclosure, yes, I do not have expierence in the field of metrology; nonetheless, I see that both 'sides' see the question as 'what source should be used' and the appropriate WP:WEIGHT thereof. I am personally creating articles in the field of law. I wish to read through one more talk page before I go to the next step. -- Lord Roem (talk) 15:46, 10 January 2011 (UTC)[reply]

Kerli's questions restate my points 4, 3, 2, 2, and 1 in that order so I think that the dispute can be reduced to assigning their relative precedence. It appears that Kehrli agrees with Point 2 that all secondary and most primary sources define "Kendrick mass = IUPAC mass x (14/14.01565)" and use Da units, but that his interpretation of VIM and other general metrology guidelines that don't mention or define Kendrick mass (Point 4) lead him to believe that these sources should not be used in the Kendrick mass article. This appears to be giving one source (Junnien 2010 - Kehrli's Question 2 and my Point 3) undue weight, counter to WP:WEIGHT. Using Wikipedia to "correct" the work published in primary and secondary sources in chemistry so that it is consistent with an editors interpretation of the general guidelines in metrology is not consistent with the WP:OR concept of no original research. --Kkmurray (talk) 14:56, 10 January 2011 (UTC)[reply]

I agree with your point (1) and of course the VIM is a much better source than some papers which are about chemistry, not terminology. Kehrli (talk)

The equation "Kendrick mass = IUPAC mass x (14/14.01565)" is a good example of faulty terminology: what is IUPAC mass? Where is it defined? Where is the source? What is the meaning of Kendrick mass? According to usual terminology it must be the mass of Mr Kendrick, which is obviously not the meaning here. It is nowhere defined in a clean and adequate way except in the most recent paper that you decline. Your point (2) is written in such a jargon that nobody outside chemistry can even understand it. I certainly do not agree with it because I can not even understand it. Nor can you. You never told us the interpretation of this equation. I wrote several 100 words about it, you didn't write a single word. Not even an example. Of course VIM does not define Kendrick mass because it is a concept that does not make sense. Nor does VIM define IUPAC mass, even though IUPAC has co-authored VIM. Why do you think this is? Because IUPAC mass is a meaningless term. A wrong concept that would only confuse Wikipedia readers. When using my terminology, Wikipedia readers can look up the terms they don't understand. They can look it up in Wikipedia, in VIM, in the IUPAP red book, in the IUPAP green book. They will find hundreds of sources. In contrast, your sources are not even accessible to the readers of Wikipedia unless they are willing to pay 20 buck. And if they would pay, they would not even find these terms defined. No sources at all.Kehrli (talk) —Preceding undated comment added 21:50, 10 January 2011 (UTC).[reply]

It is clear that the authors mean that the units used in the measurement, typically Da, remain the same after the multiplication. Kim et al. 2003 [7] is especially clear about this. --Kkmurray (talk) 03:31, 11 January 2011 (UTC)[reply]

Guidelines for this process[edit]

1. Remember to act in good faith with all mediation participants. This process is meant to encourage discussion, and compromise, not a method to battle with others.

2. Be open with your views and don't be shy - we need a basis to trust everyone.

3. Recognize the purpose of mediation - to prevent escalation.

4. I ask that you 'watch' this page so that you are alert of all new discussions, replies, etc. — Preceding unsigned comment added by Lord Roem (talk • contribs) 22:11, 10 January 2011 (UTC)[reply]

Keeping these things in mind, let us begin the process.

I have tried to craft questions from the point of view of both sides, to try to energize discussion about everyone's 'central argument'. I encourage everyone to discuss both below. Once we conclude here, we will have a better foundation for reviewing issues of weight. -- Lord Roem (talk)

I. Does the 'VIM' establish a "Kendrick unit" as opposed to a Da?[edit]

The reason I start here is because there seems to be a dispute as to whether one of the sources even states a "Kendrick unit" exists. Before we can proceed to determining the weight of sources, we need to determine what the sources say. This question is leaned for discussion from the pov of those saying there is no kendrick unit even established in the VIM. This should give a chance for detailed discussion of the source itself. Lord Roem (talk) 21:59, 10 January 2011 (UTC)[reply]

The VIM source ([8]) does not mention Kendrick mass, Kendrick unit, or Dalton unit. It “covers the basic principles governing quantities and units” but does not go beyond the basics. --Kkmurray (talk) 04:06, 11 January 2011 (UTC)[reply]

No "Kendrick ____" related sources exist outside of a very small body of mass spectrometry literature.--Nick Y. (talk) 18:45, 11 January 2011 (UTC)[reply]

The VIM states the fundamental rules for quantities and units. It is not the place to define the units itself. Therefore the kendrick mass unit is not defined in VIM. Nor is the dalton mass unit, nor is the pound, nor is the ton, nor is the atomic mass unit. No mass units are defined in VIM. Only the kg is mentioned as an example. The VIM is like a constitution: it sets the fundamental rules. You will not find a definition of the road signs in the constitution. It is only important that any road sign does not violate the constitution. Unfortunately, the terminology pushed by Kermit and Nick violate the VIM. This violation is why the VIM is important in this matter. Kehrli (talk) 21:52, 11 January 2011 (UTC)[reply]

Kehrli, as it seems that the VIM does not define a kendrick 'unit' - what source do you have that defines it? I am trying to look into the sources to determine what they actually say before trying to WP:WEIGH them. - Lord Roem (talk) 21:59, 11 January 2011 (UTC)[reply]

There are many sources. Google for the search term "Kendrick mass units". There will be about 10 papers where people use units of mass that they call Kendrick. Then, also look at the references here:Kendrick_unit#Definition. Kehrli (talk) 22:18, 12 January 2011 (UTC)[reply]

II. Is there anything wrong with the VIM source?[edit]

This question is from the "pov" of Kehrli who argues for the VIM source. Is there anything that would state that usage of the VIM is, on its face, bad? In other words, without getting into interpretations of the source itself or its given weight, is the VIM source a 'reasonable' source to use? Lord Roem (talk) 21:59, 10 January 2011 (UTC)[reply]

VIM is a reasonable source within its scope of basic principles of quantities and units. Since it does not mention or define Kendrick mass or a Kendrick unit, it cannot be used to support the existence of a Kendrick unit per WP:SYN, but it is a reasonable source for basic metrology definitions. --Kkmurray (talk) 04:25, 11 January 2011 (UTC)[reply]

VIM is an excellent source for how units *should* be defined and if a new unit is to be created this would be the primary guidance. If we were to be discussing how to create and define the Kendrick unit properly in the capacity of scientists generating a useful new unit this would be the best place to look. The problem with VIM in this case and with Kehrli's wikipedia editing in general is that defining new units properly is not what wikipedia is about, nor is it our job as wikipedia editors to weigh in on issues that are currently in debate within the scientific community such as the birth of a new unit. (We might REPORT on the debate however, just not engage in it). This whole issue is extremely nascent and probably will never gain much traction anyways. If a new unit were to ultimately be widely accepted it will be decades from now and in my opinion never. There is by far more debate right here on these issues than in the whole world. Kehrli has probably put more thought into the proper definition of a Kendrick Unit than anyone. His/her position is well thought out, consistent with VIM and elegant but not reflective of prevailing usage or the actual state of defining a new unit in the scientific literature. --Nick Y. (talk) 19:27, 11 January 2011 (UTC)[reply]

I agree with Kermit's statement. The VIM is the "common metrologic enumerator" of science, commerce, trade, and law. It is therefore a prime source for terminology in Wikipedia, which is not exclusively targeted at chemists. Articles in Wikipedia should not contradict VIM terminology. It is evident that the VIM does not define the Kendrick mass unit, in the same way as the constitution does not define the road signs.

I strongly disagree with Nick's statement: he gives the impression that the Kendrick mass unit was first introduced and defined by me in Wikipedia. This is completely wrong. The Kendrick mass unit was mentioned in several papers many years ago. Just to give an example, Marshall and co-authors wrote in 2001:

All of the Kendrick mass values may then be scanned to find each series of ions differing by (say) 14.000 ± 0.001 Kendrick mass units. (Can. J. Chem. 79: 546–551 (2001))

The Kendrick mass unit was first introduced by Kendrick himself in 1963. He defined it quite properly. Since he was a modest man, he did not call it Kendrick mass unit. This was only done later by other researchers like Marshall above, in order to give him credit. Kendrick did not name the unit, instead he referred to the CH₂ mass scale. Let me also say that Kendrick's 1963 definitions agree much better with VIM than the text proposed by Kermit. This is quite remarkable because the VIM did not even exist at that time. In other words, if Kermit would stick to the terminology of Kendrick, we would have much fewer problems here.Kehrli (talk) 22:35, 11 January 2011 (UTC)[reply]

Would you be able to post a link to the Marshall paper and any other articles using this terminology? -- Lord Roem (talk) 22:38, 11 January 2011 (UTC)[reply]

Marshall source[edit]

So the applicable section of the Marshall source says:

Mass spectral data were converted to the Kendrick mass scale to facilitate separation and identification of pseudohomologous series (i.e., a series of compounds differing in mass by 14.01565 Da (CH2) from one member to the next). In the Kendrick mass scale (18), each mass value is multiplied by (14.00000/14.01565), so that the Kendrick mass of CH2 becomes 14.00000. With this convention, members of a homologous series differing by multiples of CH2 each have identical mass defect. All of the Kendrick mass values may then be scanned to find each series of ions differing by (say) 14.000 ± 0.001 Kendrick mass units. The type for each such series is then determined from the z-value (CnH2n + z) to locate porphyrins containing V=O, Ni, and Na (see below).

My question then to Nick and Kkmurray would be: firstly, do you believe this source can be used to say the existance of a 'kendrick unit' or do you believe that to be extrapolation and b) do you have problems with the Marshall source?

If we can explore these things now that the source has been identified we can move in the right direction. -- Lord Roem (talk) 23:15, 11 January 2011 (UTC)[reply]

Kehrli is misreading Marshall here. Marshall is explicit in using Kendrick mass as a shorthand for the measured mass (typically in units of Da) multiplied by the ratio of the nominal mass of the repeat unit divided by the exact mass of the repeat unit. In other words the "Kendrick mass = IUPAC mass x (14/14.01565)" for CH₂ repeat units that one finds from Marshall and others throughout the literature. One may count in units (plural) of Kendrick mass but the unit (singular) typically associated with Kendrick mass is Da as Marshall's definition indicates. Marshall does not define a new unit of mass and this is reflected in his work and in the secondary sources. An open access paper by Marshall is here: [9]. --Kkmurray (talk) 03:03, 12 January 2011 (UTC)[reply]

Kermit is misreading Marshall here. Marshall writes:

... differing by (say) 14.000 ± 0.001 Kendrick mass units.

If Marshall would think that the the unit (singular) typically associated with Kendrick mass is Da then he would have written:

... differing by (say) 14.000 ± 0.001 Dalton mass units.

or

... differing by (say) 14.000 ± 0.001 Dalton units.

or

... differing by (say) 14.000 ± 0.001 Da.

or

... differing by (say) 14.000 ± 0.001 daltons.

I do not know and do not want to speculate what Marshall actually wanted to say, but from what he wrote we must conclude that he believes there is a Kendrick mass unit that is different than the Dalton mass unit. There is no hint whatsoever that backs the interpretation of Kermit. Kermit's claim is equivalent to the following analogy: imagine somebody writes: my mass is 100 lbs and then Kermit says: this person actually wanted to say that her weight is 100 kg even though everyone sees that it is a slim person that cannot possibly be 100 kg. In fact, we all know that the mass of ¹²CH₂ is not 14.000 ± 0.001 Da. Kehrli (talk) 20:41, 12 January 2011 (UTC)[reply]

The word "unit" can mean one of a collection of identical things or it can mean a standard of measure. From the context and the equation, it is clear that Marshall means the former. The secondary sources citing Marshall's primary source interpret Marshall's meaning this way as well. Per WP:PSTS we should not try to guess what Marshall means if this has already been interpreted by secondary sources (see [10]). --Kkmurray (talk) 23:19, 12 January 2011 (UTC)[reply]

The Dalton mass unit is also one of a collection of identical things. Hence I do not disagree with your interpretation. But I say the Kendrick mass unit is also a unit of mass. That is so obvious that we should not even talk about it. We have:

the atomic mass unit amu

the unified atomic mass unit u

the Dalton mass unit Da

the kg mass unit kg

and the Kendrick mass unit Ke

There is no reason whatsoever why the latest should be treated differently than all the others.

Kendrick source[edit]

Kendrick, in his paper where he introduced what we now call the Kendrick method, made quite clear that he considers this a new unit of mass. He wrote:

THE CH2 MASS SCALE: Masses on the O¹⁶ scale (atomic mass units) and C¹² scale (U) can be converted to the CH₂ scale by dividing by 1.0014361 and 1.0011178, respectively.

Kendrick makes hereby clear that he sees his new mass scale as a addition to the existing mass scales. Especially he makes clear that it is not in dalton or u. Kendrick's terminology is mostly in line with VIM. There are some errors:

1) it should be ¹⁶O instead of O¹⁶.

2) he should have given his new unit a name

3) He did not explicitly say what to divide. He should have written: ... by dividing the numerical factor by 1.0014361 and 1.0011178, respectively.

These are all minor errors. There is really now reason to misinterpret Kendrick's writing in such a gross way as it was done by following authors. Especially it is worth to mention that:

1) Kendrick DID NOT scale an existing unit, which extremely contradicts VIM

2) Kendrick DID NOT introduce a Kendrick mass (or an equivalent terminology) which contradicts VIM

3) Kendrick DID NOT use the term IUPAC mass to indicate a mass in units of Da or u

4) Kendrick DID NOT scale a mass, thereby changing the mass of the CH₂ molecule.

All the really grave errors were introduced later, by other scientists. They thereby referred to Kendrick, which obviously is wrong. It is a sad fact that many chemists just do not pay attention when it come to terminology. We all know that. It is obvious that Kendrick's article backs my view much better than Kermit's and Nick's view.Kehrli (talk) 11:01, 13 January 2011 (UTC)[reply]

Junninen source[edit]

When we complete discussion of the Marshall source above, we should move to the Junninen source. We need to address in this section a) whether the source creates a definition of a "kendrick unit" and b) whether the source is, on its face, reasonable to be used in Wikipedia. -- Lord Roem (talk) 23:19, 11 January 2011 (UTC)[reply]

Junninen writes:

It simplifies the interpretation of a complex organic mass spectrum by expressing the mass of hydrocarbon molecules in Kendrick units (where m(¹²CH₂) = 14 Ke) instead of Dalton (where m(¹²C) = 12 Da) (Kendrick, 1963). In Kendrick units all the members of the homologous series have the same Kendrick mass defect ...

This is a clean definition, completely analogous to the IUPAC definition of the Da, in a good journal. And it is in line with VIM, the constitution. It is also very recent. It is the best source ever.Kehrli (talk) 23:35, 11 January 2011 (UTC)[reply]

The source appears to define a Kendrick unit, if somewhat obliquely. It is inconsistent with the balance of the literature in the field. But, as a peer reviewed publication in a respected journal (link here: [11]) it is a reasonable source to be considered per WP:WEIGHT. --Kkmurray (talk) 03:38, 12 January 2011 (UTC)[reply]

Here is the definition of the unified atomic mass unit in the IUPAC green book:

u = m_a(¹²C)/12 (Capter 3.7 )

Here is the definition of the Kendrick mass unit in the Junninen paper:

m(¹²CH₂) = 14 Ke

Simple math brings this equation into the following form:

Ke = m(¹²CH₂)/14

This is exactly equivalent to the official IUPAC definition of the unified atomic mass unit u.

Now I would like to see the source from Kermit that shows that the Ke definition is somewhat obliquely.

Conclusion: this definition is very consistent with the most important publication about terminology in the field. Kermit's claim is not based on sources and is quite strange. Kehrli (talk) 20:15, 12 January 2011 (UTC)[reply]

Let's not use the language 'outrageous' here.

Kkmurray, would you be please post either here or on my talk page the sources you use to indicate your stated unit measurement? As it appears there is a source that can be led to say there is a Kendrick unit, let us now look to the other side before applying a 'weighing' factor for the article. Lord Roem (talk) 20:22, 12 January 2011 (UTC)[reply]

I think we all agree that you can find sources that state IUPAC mass of CH2 = 14.0157 Da and Kendrick mass of CH2 = 14.0000 Da even though this terminology is, strictly speaking, illegal. (It is illegal to mess around with units, after all. I wonder what Kermit would say if he found out that at his gas station, the owner would have rescaled the gallon to a smaller volume. Fact is: the official definitions of units may not be manipulated. This is why we have NIST and its standards.) We do not even have to look for a source here. As I wrote above: almost every possible and impossible chemistry jargon is found in the literature. This is why I think we can safely pick the one jargon that also happens to be in line with VIM, the IUPAC green book, the IUPAP red book and the ISO 8000 standards. We can still mention other terminology. And that is what I did in the article Kendrick (unit). Kehrli (talk) 21:56, 12 January 2011 (UTC)[reply]

...and now we make it to the crux of the dispute. Shall we ignore the vast majority of sources because we judge them "Illegal" (or false sources) in favor of one or two sources that are more closely in line with VIM (truth)? And by ignore in mean give zero weight, as if nobody has ever used Da. Or should we reflect the verifiable and noteworthy, properly weighted to reflect actual practice (i.e. reality). The reality on this particular issue is that: most do not define it as unit in and of itself, there are a very few instances of people defining it as such but they exist, there are some cases where it is poorly defined and open to interpretation. The notability of this entire issue is low. The notability of the sources that define the unit as a unit in and of itself are low (save the original Kendrick paper, which is not entirely clear either and definitely does not define a "Kendrick Unit" per se). Junninen is a valid source. It is a well written paper, clear and more closely in line with some of the principles of VIM (which is good). Is it the only source or primary source we should be looking at? No.--Nick Y. (talk) 17:26, 13 January 2011 (UTC)[reply]

Nick tells the story as if there was one source (Junninen) against all other sources. That is far from the truth. Fact is: there are hardly two papers that use the same terminology. Many papers have overlap in the terminology, but it is fair to say that whatever terminology we use, it will always contradict the majority of the papers somewhere. This is no surprise because most papers contradict themselves. Even Junninen has some self-contradictory terminology. There are about 10 papers that use Kendrick mass units. There are about 5 papers that use (illegal) Dalton scaling. In addition there are 1000 or more sources about terminology that prohibit Dalton scaling and allow Kendrick mass units. As I wrote above, the original Kendrick publication includes no Dalton scaling. By every metric you use, Dalton scaling is on the loosing side. Thinking outside the box (this is outside the chemistry world), scaling of units is not acceptable. If Wikipedia were targeted at chemists, we could discuss whether to include Dalton scaling or not. Since Wikipedia is targeted at he general public, there simply is no question: Dalton scaling is not acceptable. It is illegal jargon of a few ignorant chemists. Kehrli (talk) 21:05, 13 January 2011 (UTC)[reply]

The point of the exercise below (of posting sources on each side) is so we can evaluate whether they are a) good sources in their own right and b) whether they actually say what the editor is claiming they say. We need to bring the dispute down to the case-by-case level. I can understand your concerns but we we need to look at every source cited below for the opposite side of the equation (no pun intended) as the foundation for how we actually weigh the articles. For me to present compromise ideas, I need to know what sources listed by Kkmurray below, if any, you have problems with. This will give Kkmurray and Nick a chance to directly answer your concerns instead of going in circles, which everyone is doing at the moment. So...I ask all parties to bring their discussion to the "Pro-Da" definition sources (for lack of a better word) as listed by Kkmurray below. Once I see how everyone feels about using these sources, it will be much easier to forge a proposal that all parties would be satisfied with. Cheers, Lord Roem (talk) 21:29, 13 January 2011 (UTC)[reply]

Reom, unfortunately I do not have access to most of these journals. I cannot possibly give a balanced comment based on the short citations. However, what I can say clearly is that according to what Kermit calls the original definition(The Kendrick mass is obtained by multiplying the observed mass by the ratio of the nominal mass of CH₂ divided by the exact mass of CH₂), the formula must read:

Kendrick mass = IUPAC mass * (14 Da / 14.01565 Da)

This means all papers that write:

Kendrick mass = IUPAC mass * (14/14.01565)

are using self-contradicting terminology, because they use a mixture of dimensionless masses and dimensioned masses. We can rule them out as reliable sources.

More importantly: none of these papers are about terminology. They are all about chemistry. Our discussion, however, is not about chemistry, where we all agree. It is about terminology. So we need to consider literature on terminology. We need to look into the VIM, the IUPAP red book, the IUPAC green book, the ISO 80000 standards and all the books about metrology.

I would like to give an analogy: Assume cooks would be as negligent as chemists and most of them would misspell potato. Imagine we would have a discussion on how to spell potato in Wikipedia. All English dictionaries, of which there would be 20, would insist on potato. However, a large number of cooks would bring out their recipes and cook books (of which there would be 2000) and would argue that there is a majority of 900 cook books that spell potatoe. 300 would favor potado, and 800 would go for potato. Which spelling should go into Wikipedia?

I also have to say that Kermit played his cards well. Suddenly he argues a different line: the Kendrick mass unit is no longer defined by the definition Ke = m(CH2)/14. He now uses nominal mass in his argument. In his article Kendrick mass he did not do this yet. A smart move. This obfuscates that a new unit is introduced. Unfortunately it also obfuscates the fundamental principle of the Kendrick analysis. Also, the basic problem remains: it is not legal to manipulate units. If some scientists do it in their ivory towers, that's bad enough. It really should be avoided to have this nonsense in Wikipedia. We need the Kendrick mass scale as it was introduced by Kendrick, and which implies Kendrick mass units. Kehrli (talk) 23:15, 13 January 2011 (UTC)[reply]

I have a few questions then for all editors, primarilly to Nick and Kkmurray -- What is your take on Kehrli's statement that the other sources violate VIM and other rules? And to Kehrli, do you have a source that actually says that the usage of this scaling is 'illegal'? In other words, how can we prevent the reader from thinking its improper extrapolation? -- Lord Roem (talk) 00:19, 14 January 2011 (UTC)[reply]

I've looked at the VIM document and I don't see how the Kendrick mass procedure described in the sources is a violation of it. In a Kendrick mass analysis, a set of physical quantities (mass) is multiplied by a number. The number is obtained by dividing the nominal mass of F by the exact mass of F. The unit part of the physical quantity is not being manipulated, the numerical part is. If Kehrli could provide the specific section number and concept that the sources violate, that would help my understanding of this. I also don't understand how Kendrick's use of the word "scale" can be used to infer that a new unit was defined. A section number and concept would be helpful here as well. When Kendrick used the word scale, he may not have meant "quantity-value scale" in a rigorous sense, he may have meant "a calibrated line" as on a plot or a graph. --Kkmurray (talk) 03:35, 14 January 2011 (UTC)[reply]

We do not have any sources that say that any of these definitions violate VIM. The violation of VIM by these sources is currently unverifiable. What my take or Kehrli or kkmurray's take is irrelevant. We might be able to reason out a yes or no but that would be a novel conclusion unsupported by any source. Nevertheless I will discuss briefly. I am personally uncertain which view of the Kendrick procedure is less in line with VIM, creating a new unit unnecessarily for what amounts to an ad hoc procedure or scaling to adjust the mass defect slightly for convenience and clarity. I work with several ad hoc scaled unit systems, some of which are very flawed but simplify discussion greatly. Some of these even contain approximations, that is two values are set to be equal that are not. I seriously doubt we could fit some of these into VIM and maintain usability since they are fundamentally wrong. VIM is for defining a new unit. If a new unit is not being defined then VIM does not apply. We as scientist are free to have informal but useful discussions/tools using approximations that violate ALL the rules as long as it is somehow informative. My primary take on this claim, however, is that it may be an appropriate minor footnote if verifiable. It should not drive content. Content should be driven by practice and the actual state of usage in the literature within the discipline and area being edited. Kehrli above makes the point that there are actually many different definitions that are somewhat contradictory. Why not report "there are many different definitions in the literature that are somewhat contradictory. The most common procedure is... ".--Nick Y. (talk) 16:41, 14 January 2011 (UTC)[reply]

I agree with Nick that VIM and other documents are not sources for the Kendrick mass article directly, but instead they should inform WP:UNITS which in turn can guide the content of the article. Further, VIM is more akin to the Federalist Papers than the constitution; it is a BIPM "Guidance Document" not a set of inviolable rules. However, I think that we need to identify the specific points of VIM and other documents that are at least purported to apply if we are to avoid synthesis (per WP:SYN) of VIM with Junien and any other "contrary" Kendrick mass definitions. Further, VIM seems to form the basis of Kehrli's objections to the "Original" and "General" definitions so these arguments must be made clear. That said, I have continued to look at the cited metrology sources and have not found anything that would indicate that the Kendrick mass procedure is in any way incorrect. The IUPAC Green Book cited above is available on-line here: [12] so we can all consult it. As with the VIM, it would be helpful if Kehrli would point out the specific page number and section where the appropriate guidelines are listed. Finally, I disagree with the statement that there are "many different definitions that are somewhat contradictory". The definitions are clear although the concept may be confusing much as the concept of constant dollars in economics can be confusing even when clearly formulated. But overall, Nick Y. is correct: this is about sources, weight, and no original research. --Kkmurray (talk) 19:19, 14 January 2011 (UTC)[reply]

Quick note: I was not actually stating the "many different definitions that are somewhat contradictory" as my position or text that I would want to include in the article but rather a *reasonable* position that one might take; this is as opposed to rejecting the whole body of literature because there are some contradictions internally or with VIM. I actually don't see that many contradictions and when there is some poor choice of language the point remains clear and consistent with other source to me. --Nick Y. (talk) 21:22, 14 January 2011 (UTC)[reply]

I want to wait for Kehrli to explain where and why he finds the Da sources to be "illegal" under VIM. After that, and discussion there, I will offer proposed compromises for discussion. -- Lord Roem (talk) 17:11, 15 January 2011 (UTC)[reply]

I looked at an additional metrology source, the IUPAP red book (available here [13]), and did not find anything that would suggest that the Kendrick mass definitions violate VIM. After reading these documents and re-reading Kehrli's statements at Talk:Kendrick_mass (especially [14]), I think that I can more clearly identify Kehrli's misconception and point out how the metrology argument for a Kendrick unit is flawed. As Kehrli points out, a physical quantity is a property that can be measured and expressed as a number and a unit, for example an ion with a mass of 100 Da: the number is 100 and the unit is Da. The misconception comes from the assumption that, in the scientific literature, Kendrick mass is intended to represent a physical quantity and is something that can be measured. It does not; it is obtained from a physical quantity, but is not meant to represent anything in the real world. For the 100 Da ion above, Kendrick mass = 100 Da x (14/14.01565) = 99.888 Da. The 99.888 Da does not imply that the ion is suddenly 0.1% lighter or that the Da unit is 0.1% larger, in violation of physical reality or VIM respectively. A new Kendrick unit is not needed to "fix" the quantity calculus. The so-called "Kendrick mass" is an abstract quantity that is obtained from a physical quantity and it would be a confusing and trivial exercise if not for the utility of Kendrick mass defect plots in helping identify similar compounds from mass spectra. --Kkmurray (talk) 16:52, 17 January 2011 (UTC)[reply]

I will organize and primary and secondary sources on Kendrick mass and post below. --Kkmurray (talk) 23:35, 12 January 2011 (UTC)[reply]

Da sources[edit]

Please list here sources indicating the usage of Da instead of Ke.

Based on the discussion here, I will try to craft compromise proposals for discussion later this week. -- Lord Roem (talk) 22:36, 12 January 2011 (UTC)[reply]

Definitions of Kendrick mass, called the "Original Definition" and "General Definition" are given below with a corollary on units that follows from the definitions. The sources are listed in chronological order, indicated as primary or secondary, and with notes indicating which of the definitions and/or corollary the source supports. This is not an exhaustive list of sources but includes key primary source, a majority of the secondary sources, and many recent sources. Per WP:WFTE, I have included two sources that appear to run counter to the definitions and corollary below. To the best of my knowledge these are the only "contrary" sources in the peer reviewed Kendrick mass literature.

Definition of Kendrick mass:

(1) Original Definition (CH₂ functional group) : The Kendrick mass is obtained by multiplying the observed mass by the ratio of the nominal mass of CH₂ divided by the exact mass of CH₂:

Kendrick mass = IUPAC mass x (14/14.01565)

(2) General Definition: The Kendrick mass for any functional group F is obtained by multiplying the observed mass by the ratio of the nominal mass of F to the exact mass of F

Kendrick mass = observed mass x (nominal mass F)/(exact mass F)

(3) Corollary: if (as is typically the case) the IUPAC mass/observed mass is reported in units of Da, Kendrick mass is reported in units of Da.

Sources

Kendrick, Edward (1963). "A Mass Scale Based on CH₂ = 14.0000 for High Resolution Mass Spectrometry of Organic Compounds". Analytical Chemistry. 35 (13): 2146–2154. doi:10.1021/ac60206a048.

"Masses on the O^I6 scale (atomic mass units) and C¹² scale (U) can be converted to the CH₂ scale by dividing by 1.0014361 and 1.0011178, respectively"

Primary Source - Kendrick's original article. Observed masses are multiplied by a number thus the unit associated with the observed mass is retained. No "new" unit is mentioned or defined.

Qian, Kuangnan; Rodgers, Ryan P.; Hendrickson, Christopher L.; Emmett, Mark R.; Marshall, Alan G. (2001). "Reading Chemical Fine Print: Resolution and Identification of 3000 Nitrogen-Containing Aromatic Compounds from a Single Electrospray Ionization Fourier Transform Ion Cyclotron Resonance Mass Spectrum of Heavy Petroleum Crude Oil". Energy & Fuels. 15 (2): 492–498. doi:10.1021/ef000255y.

"Kendrick mass = IUPAC mass × (14/14.01565)"

Primary Source - Original definition, first use

Hughey, Christine A.; Hendrickson, Christopher L.; Rodgers, Ryan P.; Marshall, Alan G.; Qian, Kuangnan (2001). "Kendrick Mass Defect Spectrum: A Compact Visual Analysis for Ultrahigh-Resolution Broadband Mass Spectra". Analytical Chemistry. 73 (19): 4676–4681. doi:10.1021/ac010560w. PMID 11605846.

"Kendrick mass = IUPAC mass × (14/14.01565)"

Primary Source - Original definition

Kujawinski, Elizabeth B.; Hatcher, Patrick G.; Freitas, Michael A. (2002). "High-Resolution Fourier Transform Ion Cyclotron Resonance Mass Spectrometry of Humic and Fulvic Acids: Improvements and Comparisons". Analytical Chemistry. 74 (2): 413–419. doi:10.1021/ac0108313. PMID 11811416.

"Kendrick mass = (observed mass) (nominal mass of CH₂)/exact mass of CH₂"

Primary Source - Original definition with terms stated explicitly

Hughey, Christine A.; Rodgers, Ryan P.; Marshall, Alan G. (2002). "Resolution of 11 000 Compositionally Distinct Components in a Single Electrospray Ionization Fourier Transform Ion Cyclotron Resonance Mass Spectrum of Crude Oil". Analytical Chemistry. 74 (16): 4145–4149. doi:10.1021/ac020146b. PMID 12199586.

"For example, elemental compositions assigned to peaks at 406 Da suffice to identify members of the same homologous series at masses differing by integer multiples of 14.000 00 Da in Kendrick mass (e.g., 322, 504, 588, and 644 Da), because those compounds differ only in their number of CH₂ groups."

Primary Source - Kendrick mass reported in Da units.

Kim, Sunghwan; Kramer, Robert W.; Hatcher, Patrick G. (2003). "Graphical Method for Analysis of Ultrahigh-Resolution Broadband Mass Spectra of Natural Organic Matter, the Van Krevelen Diagram". Analytical Chemistry. 75 (20): 5336–5344. doi:10.1021/ac034415p. PMID 14710810.

"The Kendrick mass defect of points along a trend line represents a characteristic difference in the elemental formula (e.g., CH₂, COO, H₂, H₂O, etc.). If we label these trendline variations as F, then the following equations can be used to define the Kendrick mass defect for any F trendline.

Kendrick mass (F) = observed mass × [(nominal mass of F)/(exact mass of F)]"

Primary source - Original source for General Definition of Kendrick mass expression. Note that the General Definition is not compatible with a Kendrick (unit), which is only applicable to F=CH₂.

Davies, Geoffrey F.; International Congress of Ophthalmology Glaucoma Society; Ghabbour, Elham A. (2003). Humic Substances: Nature's Most Versatile Materials. Washington, DC: Taylor & Francis. ISBN 1-59169-015-3.{{cite book}}: CS1 maint: multiple names: authors list (link)

"KM=IUPAC Measured Mass x (14/14.01565)"

Secondary Source (Book) - Original Definition and abbreviation KM.

Marshall, Alan G.; Rodgers, Ryan P. (2004). "Petroleomics: The Next Grand Challenge for Chemical Analysis". Accounts of Chemical Research. 37 (1): 53–59. doi:10.1021/ar020177t. PMID 14730994.

"Kendrick mass = IUPAC mass × (14/14.01565)"

"First, compounds of the same class and type but different number of CH₂ units are separated by 14 Da in nominal Kendrick mass, but zero difference in Kendrick mass defect, and thus fall on a single horizontal line."

Secondary Source (Review) - Original definition and Kendrick mass reported with Da units.

Wu, Zhigang; Rodgers, Ryan P.; Marshall, Alan G. (2004). "Two- and Three-Dimensional van Krevelen Diagrams: A Graphical Analysis Complementary to the Kendrick Mass Plot for Sorting Elemental Compositions of Complex Organic Mixtures Based on Ultrahigh-Resolution Broadband Fourier Transform Ion Cyclotron Resonance Mass Measurements". Analytical Chemistry. 76 (9): 2511–2516. doi:10.1021/ac0355449. PMID 15117191.

"Kendrick mass = IUPAC mass × (14.00000/14.01565)"

Primary Source - Original definition

Zhang, Li-Kang; Rempel, Don; Pramanik, Birendra N.; Gross, Michael L. (2005). "Accurate mass measurements by Fourier transform mass spectrometry". Mass Spectrometry Reviews. 24 (2): 286–309. Bibcode:2005MSRv...24..286Z. doi:10.1002/mas.20013.

"Kendrick mass = IUPAC mass × (14.00000/14.01565)"

Secondary Source (Review) - Original definition

Meija, Juris (2006). "Mathematical tools in analytical mass spectrometry". Analytical and Bioanalytical Chemistry. 385 (3): 486–499. doi:10.1007/s00216-006-0298-4. PMID 16514517. S2CID 44611533.

""In 1963, Edward Kendrick proposed a mass scale that is based on the mass of CH₂ (14 u by definition) as an alternative to the IUPAC mass scale, which is based on the mass of ¹²C (12 u by definition) [Kendrick 1963]. Such a scale effectively converts the mass of CH₂ from 14.01565 u (in IUPAC ¹²C scale) to 14 u (by definition). "

Secondary Source (Review) - Note that unified atomic mass unit (symbol: u) and Dalton (symbol: Da) are equivalent. This article is explicit in indicating that the unit associated with Kendrik mass is u or equivalently Da.

Mopper, Kenneth; Stubbins, Aron; Ritchie, Jason D.; Bialk, Heidi M.; Hatcher, Patrick G. (2007). "Advanced Instrumental Approaches for Characterization of Marine Dissolved Organic Matter: Extraction Techniques, Mass Spectrometry, and Nuclear Magnetic Resonance Spectroscopy". Chemical Reviews. 107 (2): 419–442. doi:10.1021/cr050359b. PMID 17300139.

"In brief, the measured mass is converted to a “Kendrick mass”, where the mass of -CH₂ is defined as 14.000 Da, instead of the IUPAC mass, 14.01565 Da"

Secondary Source (Review) - This article is explicit in indicating that the unit associated with Kendrik mass is Da. It also defines the term "IUPAC mass": the observed mass in Da.

Panda, Saroj K.; Andersson, Jan T.; Schrader, Wolfgang (2007). "Mass-spectrometric analysis of complex volatile and nonvolatile crude oil components: a challenge". Analytical and Bioanalytical Chemistry. 389 (5): 1329–1339. doi:10.1007/s00216-007-1583-6. PMID 17885749. S2CID 44948146.

"IUPAC mass measured by MS is multiplied by a factor of 0.99888 (14.00000/14.01565, i.e., the ratio of nominal mass and accurate mass of CH₂)."

Secondary Source (Review) - Original definition in words; note that some authors use accurate mass and exact mass interchangeably.

Marshall, A. G.; Rodgers, R. P. (2008). "Mass Spectrometry Special Feature: Petroleomics: Chemistry of the underworld". Proceedings of the National Academy of Sciences. 105 (47): 18090–18095. Bibcode:2008PNAS..10518090M. doi:10.1073/pnas.0805069105. PMC 2587575. PMID 18836082.

"Kendrick mass = SI mass x (14.00000/14.0565)."

Secondary Source (Feature) - Original definition; note that SI mass is used in place of IUPAC mass; however it is clear from the above that the unit associated with Kendrick mass is identical to that associated with SI mass, IUPAC mass, or observed mass.

Headley, John V.; Peru, Kerry M.; Barrow, Mark P. (2009). "Mass spectrometric characterization of naphthenic acids in environmental samples: A review". Mass Spectrometry Reviews. 28 (1): 121–134. Bibcode:2009MSRv...28..121H. doi:10.1002/mas.20185. PMID 18677766.

"The International Union of Pure and Applied Chemistry (IUPAC) mass scale defines ¹²C as having a mass of exactly 12 Da. The Kendrick mass scale essentially uses a mass scale where CH₂ has a mass of 14.00000 Da, instead of an IUPAC value of 14.01565 Da. To convert an IUPAC mass to the Kendrick mass scale, the following equation is used:

Kendrick mass = IUPAC mass x CH₂ value on Kendrick scale / CH₂ value on ¹²C scale

Kendrick mass = IUPAC mass x 14:00000/14.01565"

Secondary Source (Review) - Original definition; explicitly states that Kendrick mass has unit Da.

Reemtsma, Thorsten (2009). "Determination of molecular formulas of natural organic matter molecules by (ultra-) high-resolution mass spectrometryStatus and needs". Journal of Chromatography A. 1216 (18): 3687–4301. doi:10.1016/j.chroma.2009.02.033. PMID 19264312.

"For the case of molecular formula determination the now-called Kendrick mass (KM) of a mass spectrometric signal is calculated from the detected mass according to Eq. (1):

KM=mass_detect (14.00000/14.01565)"

"If the Kendrick mass defects of molecules are plotted against their integer mass it rapidly becomes obvious that series of alkyl homologs arrange along horizontal lines with a nominal mass spacing of 14 Da"

Secondary Source (Review) - Original definition; symbol for Kendrick mass is KM. Unit associated with Kendrick mass explicitly indicated as Da.

Laskin, Julia; Laskin, Alexander; Roach, Patrick J.; Slysz, Gordon W.; Anderson, Gordon A.; Nizkorodov, Sergey A.; Bones, David L.; Nguyen, Lucas Q. (2010). "High-Resolution Desorption Electrospray Ionization Mass Spectrometry for Chemical Characterization of Organic Aerosols". Analytical Chemistry. 82 (5): 2048–2058. doi:10.1021/ac902801f. PMID 20146449.

"For the O-Kendrick diagram, the Kendrick mass (KM_O) is calculated by renormalizing the International Union of Pure and Applied Chemistry (IUPAC) mass scale to the exact mass of oxygen using eq 1:

KM_O=observed mass x (nominal mass of O/exact mass of O)"

Primary Source - General definition, oxygen atom

Ohta, Daisaku; Kanaya, Shigehiko; Suzuki, Hideyuki (2010). "Application of Fourier-transform ion cyclotron resonance mass spectrometry to metabolic profiling and metabolite identification". Current Opinion in Biotechnology. 21 (1): 35–44. doi:10.1016/j.copbio.2010.01.012. PMID 20171870.

"Kendrick mass = IUPAC mass x 14/14.01565

Secondary Source (Report) - Original definition

Nguyen, Tran B.; Bateman, Adam P.; Bones, David L.; Nizkorodov, Sergey A.; Laskin, Julia; Laskin, Alexander (2010). "High-resolution mass spectrometry analysis of secondary organic aerosol generated by ozonolysis of isoprene". Atmospheric Environment. 44 (8): 1032–1042. Bibcode:2010AtmEn..44.1032N. doi:10.1016/j.atmosenv.2009.12.019.

"Any combination of atoms can serve as the base for calculating Kendrick mass (KM). The Kendrick mass defect (KMD) is then defined as the difference between the nominal mass and KM. For example, if formaldehyde is used as the base, KM_CH₂O and KMD_CH₂O are obtained by setting the molar mass of CH₂O to exactly 30 amu.

KM_CH₂O = mass x [mass_CH₂O]/mass_CH₂O

Square brackets refer to the nominal mass obtained by rounding the mass to the nearest integer. "

Primary Source- General definition for F=CH₂O; note amu is used incorrectly. This is a common error; the authors mean u or Da.

Lerno, Larry A.; German, J. Bruce; Lebrilla, Carlito B. (2010). "Method for the Identification of Lipid Classes Based on Referenced Kendrick Mass Analysis". Analytical Chemistry. 82 (10): 4236–4245. doi:10.1021/ac100556g. PMC 2875411. PMID 20426402.

"Kendrick mass = measured IUPAC mass × 14.0000"

Primary Source - Original definition

He, Huan; Emmett, Mark R.; Nilsson, Carol L.; Conrad, Charles A.; Marshall, Alan G. (2010). "High mass accuracy and resolution facilitate identification of glycosphingolipids and phospholipids". International Journal of Mass Spectrometry. 305 (2–3): 116–119. doi:10.1016/j.ijms.2010.10.014.

"Second, for lipids not included in the above databases, multiplication of each mass in Dalton by the factor, 14.00000/14.01565 yields so-called 'Kendrick mass'.

Kendrick mass = IUPAC mass × (1400000/14.01565)

Primary Source - Original definition and indication of what is meant by "IUPAC mass".

Taguchi, Vince Y.; Nieckarz, Robert J.; Clement, Ray E.; Krolik, Stefan; Williams, Robert (2010). "Dioxin Analysis by Gas Chromatography-Fourier Transform Ion Cyclotron Resonance Mass Spectrometry (GC-FTICRMS)". Journal of the American Society for Mass Spectrometry. 21 (11): 1918–1921. doi:10.1016/j.jasms.2010.07.010. PMID 20727785. S2CID 205704597.

"The industrial fire sample was expected to contain various polychlorinated compounds, so a mass scale reflecting the substitution of ³⁵Cl for H was chosen. This will implicitly make the mass change associated with this substitution equal to 34 Da, instead of 33.960128 Da, as it would be in the IUPAC mass scale. Therefore, the functional form of eq 1 used in this study can be found below, eq 2.

M_new = M_IUPAC · (34.000000/33.960128) = M_IUPAC · 1.001148 (2)

Primary Source - General definition for F=Cl; unit explicitly indicated as Da.

Lu, Mang; Zhang, Zhongzhi; Qiao, Wei; Wei, Xiaofang; Guan, Yueming; Ma, Qingxia; Guan, Yingchun (2010). "Remediation of petroleum-contaminated soil after composting by sequential treatment with Fenton-like oxidation and biodegradation". Bioresource Technology. 101 (7): 2106–2113. doi:10.1016/j.biortech.2009.11.002. PMID 19942431.

"Measured masses were converted from the IUPAC mass scale (CH₂ = 14.01565 Da) to the Kendrick mass scale (CH₂ = 14.00000 Kendrick mass units) (Kendrick, 1963)"

Primary Source - Per WP:WFTE, this source does not follow the Original Definition and seems to suggests a "different" unit. They do not use a symbol or shorthand and they do not mention "Kendrick mass units" elsewhere in the article.

Junninen, H.; Ehn, M.; Pet�j�, T.; Luosuj�rvi, L.; Kotiaho, T.; Kostiainen, R.; Rohner, U.; Gonin, M.; Fuhrer, K. (2010). "A high-resolution mass spectrometer to measure atmospheric ion composition". Atmospheric Measurement Techniques. 3 (4): 1039–1053. Bibcode:2010AMT.....3.1039J. doi:10.5194/amt-3-1039-2010. {{cite journal}}: replacement character in |last3= at position 4 (help); replacement character in |last4= at position 7 (help)

"Thus, it is possible to recognise patterns of compounds belonging to the same family by finding a series of peaks differing by 14.01565 Th. It simplifies the interpretation of a complex organic mass spectrum by expressing the mass of hydrocarbon molecules in Kendrick units (where m(¹²CH₂)=14 Ke) instead of Dalton (where m(¹²C)=12 Da) (Kendrick, 1963)."

Primary Source - Per WP:WFTE, this source appears to define a Kendrick unit with symbol Ke. The authors do not explicitly state that they are formally defining a new unit and it is not clear whether they mean Ke to be a shorthand notation or to stand side by side with Daltons, kilograms and meters.

D’andrilli, Juliana; Chanton, Jeffrey P.; Glaser, Paul H.; Cooper, William T. (2010). "Characterization of dissolved organic matter in northern peatland soil porewaters by ultra high resolution mass spectrometry". Organic Geochemistry. 41 (8): 791–799. Bibcode:2010OrGeo..41..791D. doi:10.1016/j.orggeochem.2010.05.009.

"This method assigns a Kendrick mass to all peaks on the mass spectrum, with a simple calculation converting the measured IUPAC mass (based on 12.00000 Da) to a new mass based on CH₂ = 14.00000 Da (Kendrick, 1963).

Kendrick Mass=IUPAC mass×(14/14.01565)"

Primary Source - Original Definition and Kendrick mass explicitly in Da.

Ohta, Daisaku; Kanaya, Shigehiko; Suzuki, Hideyuki (2010). "Application of Fourier-transform ion cyclotron resonance mass spectrometry to metabolic profiling and metabolite identification". Current Opinion in Biotechnology. 21 (1): 35–44. doi:10.1016/j.copbio.2010.01.012. PMID 20171870.

":Kendrick Mass=IUPAC mass×(14/14.01565)"

Secondary Source (Perspective) - Original Definition

Lee, Hyeyoung; An, Hyun Joo; Lerno Jr., Larry A.; German, J. Bruce; Lebrilla, Carlito B. (2010). "Rapid profiling of bovine and human milk gangliosides by matrix-assisted laser desorption/ionization Fourier transform ion cyclotron resonance mass spectrometry". International Journal of Mass Spectrometry. 305 (2–3): 138–150. doi:10.1016/j.ijms.2010.10.020. PMC 3158620. PMID 21860602.

"The measured masses were then converted from the IUPAC mass scale to the Kendrick mass scale by the multiplication of the mass values with 14.00000/14.01565, in which the mass of the CH₂ is taken as integer 14 mass units [37]. KMD was calculated by the subtraction of NKM from the Kendrick mass. Afterwards the calculated NKM and KMD were plotted and displayed.

Primary Source - Original definition in words.

Ehn, M.; Junninen, H.; Pet�j�, T.; Kurt�n, T.; Kerminen, V.-M.; Schobesberger, S.; Manninen, H. E.; Ortega, I. K.; Vehkam�ki, H. (2010). "Composition and temporal behavior of ambient ions in the boreal forest". Atmospheric Chemistry and Physics Discussions. 10: 14897. doi:10.5194/acpd-10-14897-2010. {{cite journal}}: replacement character in |last3= at position 4 (help); replacement character in |last4= at position 5 (help); replacement character in |last9= at position 7 (help)

"This is best done by changing to the Kendrick mass scale (Kendrick, 1963) where the mass of ¹²CH₂ is defined as 14.0000. In other words, the measured mass of an ion is divided by m(¹²CH₂)/14, and thus (CH₂)_n will always fall exactly on integer masses.

Primary Source - Inconclusive; this is the group of authors that "defined" the Kendrick unit above, yet they do not mention it in this article.

JURGEN H. GROSS (2010). Mass Spectrometry: A Textbook. Berlin: Springer. ISBN 978-3-642-07388-5.

"The Kendrick mass scale is based on the definition M(CH₂) = 14.0000 u. Conversion from the IUPAC mass scale to the Kendrick mass scale is achieved by multiplying each mass by 14.00000/14.01565 = 0.99888. The intention of the Kendrick mass scale is to provice an effective means of data reduction ..."

Secondary Source (Book) - Original definition; explicitly defines Kendrick mass with unit u, which is equivalent to Da per the above.

--Kkmurray (talk) 18:32, 13 January 2011 (UTC)[reply]

Please supply the source of this definition. Kendrick himself did not use this definition. Pleas ealso supply a definition of the term IUPAC mass. Kendrick did not use this term either Kehrli (talk) 13:19, 23 January 2011 (UTC)[reply]

The sources are those listed above. What is meant by "IUPAC mass" is clear: the measured mass in Da units. See Mopper 2007 above for example. The measured mass in Da units is multiplied by a number and the product is a quantity with units Da. --Kkmurray (talk) 21:51, 23 January 2011 (UTC)[reply]

Why the terminology of Kmurray contradicts VIM[edit]

In this section I will explain (once more) why the terminology proposed by Kmurray contradicts VIM. However, before I can do that I have to receive a proper definition of the term "IUPAC mass" and "Kendrick mass". I have asked for this multiple times but always got weasel answers. Once i have the definitions, I would like the sources of these definitions.

definition of IUPAC mass[edit]

definition of Kendrick mass[edit]

Proposed Compromise[edit]

Discussion has minimized for the past several days - so I have drawn up a compromise to discuss that will bring us into the result-oriented mindset.

Please state your willingness to support it and/or problems, concerns, with it.

Merge[edit]

1. The content of Kendrick (unit) will be merged into Kendrick mass.

2. Kendrick mass will use Daltons as it currently does but will note in a single sentence in the lead: "In other instances, scientists have used a 'Kendrick unit' in Ke to measure kendrick mass."

3. There may be another mention later in the article, citing the Junnien source.

Please discuss, Lord Roem (talk) 17:58, 19 January 2011 (UTC)[reply]

I support this compromise. Merging Kendrick (unit) into Kendrick mass will require removal of some original research, but the balance indicated by points 2 and 3 is appropriate. --Kkmurray (talk) 03:43, 21 January 2011 (UTC)[reply]

Support - This is essentially what should happen. Point one Strong Support given the removal of OR as suggested by points 2 and 3. Point two Weak Support - The use of the plural here is misleading. Yes, plural usage of the number of times it has been inferred (with generous interpretation) to be a unit is appropriate but use of 'Ke' is irrefutably a singular instance. Also this is generous weighting as it stands but reasonable and thus a compromise position. Point three Weaker Support - doesn't seem necessary but I guess generosity shows good faith. Overall I support the compromise, but I would actually like to see this be generalized and explained. I am not nearly as concerned about this issue as the next and the next and the next. An analysis by Kehrli of what is or is not "illegal" based on VIM should not be an issue in the future and quickly dismissed. If there is a primary or better a secondary reference or review that specifically points this out, a *mention* in Wikipedia *may* be merited. There are other edits in other related areas that fall within this wider scope that are currently outstanding. I would like to see a philosophical agreement here: "Violation of VIM or any other guidance document must be verifiable to be mentioned." That is sources specifically stating this fact, not the guidance document itself plus an argument about what was intended by primary sources and how to reconcile or interpret the two. In the absence of such verifiability the prevailing usage, units and abbreviations etc. as used in the literature of the field should be used. The above compromise on this one issue is within the scope of this as there is indeed at least one source that mentions Kendrick units as a concept. There may be some issues of weighting but not by miles. The weighting suggested on this particular issue is quite reasonable, if not absolutely accurate.--Nick Y. (talk) 04:48, 21 January 2011 (UTC)[reply]

why this so called "compromise" is not acceptable[edit]

To (1): "Kendrick mass" is a fuzzy concept. As far as I know the term "Kendrick mass" is nowhere properly defined. I have asked for sources of a definition of "Kendrick mass" multiple times and I have never received an answer. Until I get a properly sourced definition of the term "Kendrick mass" I cannot possibly agree to a merger. As a compromise we can have a redirect from "Kendrick mass" to the main article.

To (2): Redefinition of the official unit Dalton to a new value is something I will never agree to because it is not legal. In the same way I will never agree to a redefinition of the kg to a new value (unless it is backed by BIPM). I will not agree to illegal actions. Kehrli (talk) 12:33, 23 January 2011 (UTC)[reply]

Question to Lord Roem[edit]

My Lord, how on earth can you come to the conclusion that redefining the Da is a viable option? This blows my mind. It really makes me think that my skills for arguing for something need strong development. I am loosing here a very simple and obvious case, once again. Could you please give a detailed account of your line of thought? Kehrli (talk) 13:06, 23 January 2011 (UTC)[reply]

I would be glad to explain my thinking here.

You have demonstrated with the Junnien source that 'Ke' is something that is used for this measurement. The other parties agreed to this point. Then the question is what weight shall it be given? When compared to the vast literature base, it appears that usage of 'Ke' is far less used than Daltons for this type of measurement. To mesh these two ideas in a way that keeps their meaning 'alive' is keeping an article using Daltons while at the same time noting 'Ke' as usage in some other (and rarer) instances. From my neutral view, it appears both sides are somewhat right. But whether one source and an argument that Dalton usage is 'illegal' can justify using 'Ke' as the primary notation, strikes me as still difficult to understand. Maybe if you could cite where in the VIM and other 'constitutional' documents it indicates that Daltons/scaling can be illegal, I would better understand. And if you could you give an understanding of either a) where someone in the field calls Daltons illegal or b) more sources using 'Ke' as a measurement, I think everyone would be on better ground for discussion.

The compromise I offered I feel is fair with the discussions and sources presented. If you disagree with it, then we need more discussion. I ask that you read my paragraph above to help me better understand your case. Best regards, Lord Roem (talk) 18:02, 23 January 2011 (UTC)[reply]

Lord Roem, you seem to think that this discussion is about using Ke or Da. This is a oversimplification. There are many more aspects.

A) The question which units to use is only a minor aspect of the whole discussion

B) You seem to completely miss the point that even when it comes to the units, there are three different choices:

Kandrick mass units: consistent and used by approx 10 sources

Unitless: this is arguably the most common use, and half way consistent. Murray in the Kendrick mass article used this unitless terminology. It is only recently that he weaseled to Dalton mass unit.

Dalton mass units: is probably less common than unitless and not consistent at all

According to your arguments you would have to propose the unitless version. But it seems that you did not even consider this one. Why is this? Kehrli (talk) 18:52, 23 January 2011 (UTC)[reply]

The sources presented by the parties have been in usage of Dalton and Ke (Junnien). Your main problem with the current usage in the article is that it is 'illegal' scaling under VIM and other primary rules in this field. I am very interested in seeing the quote from VIM/source that says this. This is then the direction we should move the discussion. Lastly, you have seemingly proposed usage of Ke from the Marshall and Junnien source. I have just now heard about a unitless version. - Lord Roem (talk) 19:06, 23 January 2011 (UTC)[reply]

It is evident that I picked the sources in a way to show that "Kendrick mass units" are common usage. It is also evident that Murray has picked his sources to show that Dalton units are common. Murray, since he has an affiliation at an university, has easy access to all journals. His pick of papers, however, is highly biased. Not only the sample is biased. The portion he cites is also biased. He will cite the passage of a paper that supports Da usage, but will omit the passages that support other usages. Unfortunately most papers are not at all consistent in what they support. Hence, you should not be distracted by his biased sample of publications. You should make your own research and not trust the biased sample.

Just to illustrate my point: from Marshall, Fuel Chemistry Division Preprints 2003, 48(1), 14:

Analysis was performed by convertion of IUPAC measured mass to the Kendrick mass scale (CH2 = 14.00000 instead of 14.01565 Da) to facilitate identification of homologous series. Kendrick mass is obtained by multiplying the IUPAC mass with 14/14.0156.

Here the Kendrick mass of CH2 is dimensionless.

Here the same thing in another paper of Marshall (Can. J. Chem. 79: 546–551 (2001)):

In the Kendrick mass scale (18), each mass value is multiplied by (14.00000/14.01565), so that the Kendrick mass of CH2 becomes 14.00000.

No wonder Murray did not cite these two papers.

It is very evident that it is not legal to "scale" units. Imagine the following situation: you drive on a highway with 120 mph where only 80 mph are allowed. A police officer pulls you over and gives you a ticket for speeding. Now your response is: "Officer, I just scaled the miles to double their initial value. Therefore I was only driving 60 mph, not 120 mph." Do you think this would fly? No way. But this is exactly what what you do by scaling the Dalton. I am not an expert at law. You are. So you find out where exactly in the law it states that scaling of units is illegal. It must be somewhere. Otherwise not a single speeding ticket could be issued. I can give you a hint though: here you have an article about Metrology#National_standards. Every country maintains an agency that defined standards. In the US this agency is NIST. The definition of the Da by NIST is here: [15]. Now you show me where NIST defines the "scaled" dalton. I pay you a thousand buck if you can produce this scaled definition. It is as evident that you won't find it as it is evident that thee is no scaled mile that will save you from speeding tickets.

Once the term "IUPAC mass" and "Kendrick mass" is defined, I can show where it contradicts VIM. Is it not strange that I have to define and source all my statements, whereas from Murray you accept definitions without asking for any sources? Why is that? Kehrli (talk) 20:43, 23 January 2011 (UTC)[reply]

I asked him above, under "Da sources", which he listed. I did the same for you in the discussion over Marshall and Junnien. - Lord Roem (talk) 23:40, 23 January 2011 (UTC)[reply]

BTW: in his current article Kendrick mass Murray does not even use dalton units on the Kendrick mass. He uses the dimensionless notation. It is only during this mediation that he weaseled from unitless to Da. But I am sure he will weasel back to unitless as soon as we find that scaling Daltons is not acceptable. Kehrli (talk) 21:10, 23 January 2011 (UTC)[reply]

Daltons are not illegal per se[edit]

Lord, you wrote:

And if you could you give an understanding of either a) where someone in the field calls Daltons illegal ...

I never claimed that Daltons are illegal. I just said that it is illegal to scale them (= redefine them). When used according to the NIST standard (Da = m(¹²C)/12), daltons are perfectly ok. It is just not ok to change their definition. In the same way as it is not ok to change the value of a kg or a mile. Look, this is exactly my initial fear: your expertise in metrology is not sufficient to mediate this case. I can try to translate this into your field of expertise: I imagine that the term "murder" has an exact definition in the legal terminology. If now somebody comes and redefines the definition of "murder", the legal system would no longer work. Assume I would redefine DUI as murder. Can you imagine the mess? This is about what Murray is doing here. Kehrli (talk) 21:25, 23 January 2011 (UTC)[reply]

I am not pushing Ke as a primary notation[edit]

Lord Roem, you wrote:

And if you could you give an understanding of either b) more sources using 'Ke' as a measurement

I never stated anywhere that Ke should be used as a measurement.

But whether one source and an argument that Dalton usage is 'illegal' can justify using 'Ke' as the primary notation, strikes me as still difficult to understand.

If you or Murray or anyone else has a better symbol for the Kendrick mass unit I am happy to use it. The Ke is not at all my "primary" notation (whatever this should mean). It is the only symbol for the Kendrick mass unit that I found in the literature. If you found another one I would be excited to know about it. There is just one thing: we cannot use Da, because it is reserved for the Dalton mass unit which is defined differently. Kehrli (talk) 21:41, 23 January 2011 (UTC)[reply]

Please compare apples with apples[edit]

Lord Roem, you wrote:

The sources presented by the parties have been in usage of Dalton and Ke (Junnien).

If anything, you should compare the use of Kendrick mass units with the use of Dalton mass units. Not all people that used Kendrick mass units also used the symbol Ke. You have to search for Ke, Kendricks, Kendrick units, Kendrick unit, Kendrick unit of mass, and so on. These are all synonyms. Then do the same for Dalton mass unit. Kehrli (talk) 21:52, 23 January 2011 (UTC)[reply]

The story of little boy and the sloppy chemists[edit]

Lord Roem, it seems that you are missing my points completely. I will try to explain why the terminology used by Murray is fundamentally flawed. Please read the following story slowly until you understand it completely. Do not hesitate to ask questions if something is not clear.

Assume your mass is 80 kilograms = 176.36981 pounds. Now let us look how you would state this fact in formulas. One way to express this is:

m(Roem) = 80 kg = 176.36981 lbs

Here m is the symbol for mass, kg is the symbol for kilogram, and lbs is the symbol for pound. Please note that Roem has only one mass m(Roem) and this mass is the same whether it is expressed in kg or in lbs.

Now here is the way sloppy chemists express the same thing: first they create two masses for Mr Roem. The first one they call kg mass and write:

kg mass = 80 kg

Next they create a second mass and call it lbs mass. They then continue to write:

lbs mass= 176.36981 lbs

Next they forget that the two masses are actually the same. In other words, they forget that Roem's body does not actually change its mass when expressing it in kg or in lbs. Expressed in math they forget that

kg mass = lbs mass

Having forgotten this basic fact, they wonder: hmm - how do I get from lbs mass to kg mass? They then come up with the following formula:

kg mass = lbs mass * 80/176.36981

Now, magically, Mr Roem would have two different masses, the kg mass being only about half as much as the lbs mass. This, of course, is pure nonsense. Both masses need to be the same. As stated before:

kg mass = lbs mass

80 kg = 176.36981 lbs

What happens is the following: since the kg is approx. double the mass of a lbs, the numerical factor in front of the kg must be approx. half the factor in front of the lbs, so that the product on both sides are the same. So we already see that the sloppy chemists have it completely wrong. But it gets even worse:

For some reason the sloppy chemists decide that for simplicity they prefer to have a single mass unit only. Hence they decide to get rid of the kg and instead scale the lbs to the former value of the kg. Hence they write:

80 lbs = 176.36981 lbs

Proudly they pat each other on the back. That looks really simple. Then, a 6th grade pupil passes by. He looks at the equation and says: hey you guys, what are you doing? Every 6th grader can see that this formula is wrong. The chemists look at the equation and are stunned, at first. Then the brightest of the sloppy chemists gets it and answers: boy, you don't understand! The lbs on the left side are scaled. The boy goes: Scaled lbs? My teacher never mentioned such a thing. The chemists reply: well, do you have a source that forbids scaling lbs? The boy: no. The sloppy chemists: see? And if you still doubt we can also have a vote. The brightest of the sloppy chemists: this is so brilliant we should put it on Wikipedia.

Does this story sound familiar?

The important point is that there is a long chain of errors that the sloppy chemists commit:

1) they introduce two masses where there is only one

2) they name the two masses inadequately

3) they forget that the two masses are equal

4) they come up with a wrong formula to relate the two masses

5) they eliminate the second mass unit and replace it with a scaled unit

All papers except the Junninen paper make error 1) to 4). Many papers, but by far not all, then in addition make error 5). You are currently only looking at error 5). Note that the original Kendrick paper did not make any of these errors! Still, most papers cite Kendrick when they source their mistakes. That's how sloppy chemists are.

Kehrli (talk) 22:46, 23 January 2011 (UTC)[reply]

Let me respond. I think what Kkmurray and Nick are trying to say is that your argument that scaling is 'illegal' has not been shown support. You may be perfectly correct in every aspect, but it needs the appearance of being verifiable. For everyone's benefit, you need to explain where scaling is illegal. I completely understand your law hypothetical, but law and science are different organs in the body of the world. A sentence from VIM or some document to support your claim, I feel, is required to at least challenge the breath of evidence for the Dalton (or "scaled" dalton). - Lord Roem (talk) 23:48, 23 January 2011 (UTC)[reply]

Hello Lord Roem, I now have shown below what you requested, namely where the terminology of Murray contradicts the VIM and the IUPAC rules.

On a second note: this is not about science vs. law. This is about terminology and metrology. It is about the question what terminology should be used on Wikipedia. Should we use a terminology that is verifiably wrong, based on fuzzy math and not understandable to the general public or should we use terminology that is well sourced, according to the consensus of science, law, trade and commerce and in accordance to the laws of physics and math. This is a no-brainer. Kehrli (talk) 01:15, 25 January 2011 (UTC)[reply]

The problem comes from the incorrect assumption that Kendrick mass is a measured quantity rather than a quantity obtained by multiplying a measured quantity by a number. The definition indicated in the majority of the sources indicates that Kendrick mass is not a measured quantity, thus the fallacies suggested by Kehrli are not applicable. The Da unit is obviously not "scaled" and the Kendrick mass is not intended to indicate a quantity that can be measured thus no false equivalence is suggested. --Kkmurray (talk) 02:13, 24 January 2011 (UTC)[reply]

Here goes the weasel again. Suddenly the Da is no longer "scaled". Fact is: you are using two mutually incompatible definitions for the same thing. The Da cannot possible be at the same time m(C)/12 and m(CH2)/14. This is a no-brainer. Kehrli (talk) 01:15, 25 January 2011 (UTC)[reply]

I would reiterate here that in all likelihood even a reasonably supportive quote from VIM or other such document for this supposed illegality would probably not be sufficient verifiability since we will have to interpret it and then apply it to this particular situation. What is really needed to tip the scales in the other direction would be a direct statement actually saying that the Kendrick Mass is "illegal" in the literature, perhaps in a review etc., so that someone else is doing the interpreting and applying. Also with respect to Kkmurray's supposed biased sampling of the literature I have similar access and even a quick search comes up with similar results. With respect to the unitless notation: perhaps there is room to mention that this is also used on occasion as Kehrli has done a good job of pointing out these sources. Lord Roem - Kehrli will continue to persist in trying to push for "truth" which is a neat clean internally and externally consistent definition that is everything it should be despite what the current usage is. You need to clarify what the purpose of Wikipedia is and is not and what verifiability means. You have made it quite clear what the problem is here and the hurdles needed to forward his/her argument along but have not explained why. The arguments now being put forward by Kehrli are reasonable arguments in another venue, but here what matters is verifiability. Wikipedia is not a primary source. It is not a secondary source. We summarize and report, thats it. No improvements in the process please. The place for improvement and arguments for improvements is out there in the body of the scientific literature not here on Wikipedia. --Nick Y. (talk) 03:10, 24 January 2011 (UTC)[reply]

Nick, all my terminology is 100% verifiable. There is not a single term that does not have a source. Give me an example of what you think is not verifiable and I will show you the source. Also, as I have shown below, my terminology is in line with Kendrick's original paper, whereas your's is not. Kehrli (talk) 01:15, 25 January 2011 (UTC)[reply]

Talking about verifiability: I have still not received a definition of the term IUPAC mass and the Kendrick mass from you, not to mention a source for this definition. My terminology is therefore more verifiable than yours. Kehrli (talk) 01:15, 25 January 2011 (UTC)[reply]

Sloppy chemistry uncovered[edit]

Here is a definition given by Murray:

The Kendrick mass is obtained by multiplying the observed mass by the ratio of the nominal mass of CH₂ divided by the exact mass of CH₂:

Kendrick mass = IUPAC mass x (14/14.01565)

He indicates Kendrick himself as source for this definition. Let's have a look at what Kendrick actually wrote:

THE CH2 MASS SCALE: Masses on the O¹⁶ scale (atomic mass units) and C¹² scale (U) can be converted to the CH₂ scale by dividing by 1.0014361 and 1.0011178, respectively.

Now let's compare the two definitions based on the chain of errors that I have given above:

1) they introduce two masses where there is only one

2) they name the two masses inadequately

3) they forget that the two masses are equal

4) they come up with a wrong formula to relate the two masses

5) they eliminate the second mass unit and replace it with a scaled unit

1) Murray introduces two masses, IUPAC mass' and Kendrick mass, whereas Kendrick does not.

2) Murray names the two masses in an inadequate way. Kendrick did not use the term IUPAC mass' nor Kendrick mass

3) Murray forgets that the two masses are equal. Kendrick does not.

4) Murray presents a formula that Kendrick has never written in this way.

5) Kendrick never scaled an existing unit, Murray did.

Even though Murray makes more or less the exact opposite of Kendrick, he claims Kendrick as his source!! Is this not amazing? Roem, what do you say about this sloppy way of sourcing?

What did Kendrick really say and mean?[edit]

Kendrick says:

Masses on the O¹⁶ scale (atomic mass units) and C¹² scale (U) can be converted to the CH₂ scale by dividing by 1.0014361 and 1.0011178, respectively.

Murray's interpretation of this sentence is the following:

Masses on the O¹⁶ scale (atomic mass units) and C¹² scale (U) can be converted to the CH₂ scale by dividing the mass by 1.0014361 and 1.0011178, respectively.

My interpretation of Kendrick's definition is:

Masses on the O¹⁶ scale (atomic mass units) and C¹² scale (U) can be converted to the CH₂ scale by dividing the numerical factor by 1.0014361 and 1.0011178, respectively.

Quite obviously, Kendrick made an ambiguous statement. A statement that, unfortunately can easily be misunderstood by sloppy chemists with lack of knowledge in metrology.

Here is a short insert about ambiguous statements: Look at the statement "Tom smells like a dog". This might mean: "Tom has the ability to smell like a dog" [his sense of smell is as good as a dog's] and it also might mean: "Tom's body smells like a dog". The statement for itself is quite ambiguous. However, in 99% of the cases the context will make it clear. For example, if Tom is returning all sweaty from a workout, it is obvious that the second meaning was intended. On the other hand, if the statement is made after Tom just discovered a truffle, the first meaning was intended.

Hence, let's look at the context of the Kendrick definition. Then the case becomes clear. If interpreted in Murray's way, the Kendrick statement becomes meaningless and leads to FIVE really bad errors that all contradict basic principles of metrology. If interpreted in my way, the statement makes sense and is in line with almost all metrology rules. Now go figure what the correct interpretation is.

Conclusion: Kendrick's paper is NOT a source for Murray's statement. It is actually the exact opposite: Kendrick's paper is backing my interpretation as it is written in the article Kendrick (unit)

Where exactly is the contradiction to metrology literature ?[edit]

1) the error of the two masses[edit]

Unfortunately, Murray still has not supplied a proper definition of the terms Kendrick mass and IUPAC mass. For whatever reason Roem does not ask him for this definition either. On the other hand I need to have a definition in order to prove it wrong. So here are my definitions:

IUPAC mass is the mass of a molecule indicated in daltons or unified atomic mass units.

Kendrick mass is the mass of a molecule indicated in Kendrick mass units or what Kendrick called the CH2 scale.

Do we really have two masses? NO, of course not. In the same way as Roem's mass does not change when indicated in kg or lbs, the mass of any molecule does not change when indicated in IUPAC scale (Daltons) or CH2 scale (Kendricks). THERE IS ONLY ONE MASS. Period. This single mass can be indicated in different units. That's trivial. Having two masses, or for that matter, for any unit a different mass contradicts the VIM which says:

1.24

quantity calculus

formalism for algebraic manipulation of symbols representing quantities

NOTE

In this formalism, equations between quantities have the advantage over equations between

numerical values of being independent of the choice of units (see ISO 31-0:1992, subclause 2.2.2).

In other words: using two different masses IUPAC mass and Kendrick mass for indicating the same mass is not according to VIM.

2) the error of inadequate names[edit]

The IUPAC Green Book states the following:

The value of a physical quantity can be expressed as the product of a numerical value and a unit:

physical quantity = numerical value x unit

Neither the name of the physical quantity, nor the symbol used to denote it, should imply

a particular choice of unit.

Hence, the term IUPAC mass is against the rules of IUPAC because it is meant to imply dalton units. The same argument holds for the Kendrick mass. We don't need these two names because there is only one mass and we can call it just mass. Note that Kendrick did not have two masses, nor did he use these silly names.

3) the error of making the two masses unequal[edit]

If you you are introducing two masses (which is wrong, as we have seen above) you could still avoid damage by realizing that the two masses are equal. Then you would only contradict rules of terminology, but not rules of logic, of physics and of basic math. Unfortunately sloppy chemists did not cut this corner. They came up with the interpretation that a molecule changes its mass only by indicating the mass in a different unit. What Kendrick actually meant is that the numerical factor in front of the unit is changing. This factor must change if the unit changes, because the product of the factor and the unit must remain the same if the mass is required to be the same. Having the mass of an object change by just applying different units is of course absurd. It contradicts physics. I am not increasing the solar mass by a factor of 1000 just by By indicating the mass of the sun in g instead of kg. I do not loose weight just by using a different unit. That would be nice, but not realistic. I do not get richer by indicating my savings in cents instead of dollars. That is all very obvious nonsense. But it is exactly what is claimed by Murray and all other sloppy chemists producing the formula:

Kendrick mass = IUPAC mass * (14 Da / 14.01565 Da)

The same sections cited above from VIM and IUPAC green book contradict this view.

4) error of wrong formula[edit]

If you you are introducing two masses (which is wrong, as we have seen above), the correct formula would be:

Kendrick mass = IUPAC mass

The following formula is definitely wrong, as we have already argued above:

Kendrick mass = IUPAC mass * (14 Da / 14.01565 Da)

Conclusion[edit]

Murray's misinterpretation of Kendrick's statement makes the statement completely meaningless. Therefore it is safe to believe that Kendrick's ambiguous statement should be interpreted in the way explained in the article Kendrick (unit)

Kehrli (talk) 22:33, 24 January 2011 (UTC)[reply]

Again, the problem comes from the incorrect assumption that, in the "Original Definition", Kendrick mass is a quantity that can be measured rather than a quantity obtained by multiplying a measured quantity ("IUPAC mass") by a number (14/14.01565), hence the notation "Kendrick mass = IUPAC mass x (14/14.01565)" seen in the multiple sources above. The quantity calculus of this approach is consistent with VIM/Green Book/Red Book, etc. One source, Junien, seems to indicate that Kendrick mass is a quantity that can be measured and is reported in a new kendrick unit with symbol Ke. The "Junien Definition" quantity calculus is also consistent VIM/Green Book/Red Book, etc. However, the "Junien Definition" is not consistent with the "Original Definition". Because of this, if one starts with Junien's assumption that Kendrick mass is a quantity that can be measured and applies this assumption to the "Original Definition", one ends up with the "two mass" or "scaled unit" problems pointed out by Kehrli above. This merely points out the fundamental difference in the two starting assumptions: Kendrick mass is either a measured quantity ("Junien Defintion") or Kendrick mass is obtained from a measured quantity ("Original Definition"). The two definitions are internally consistent but inconsistent with each other. Both are sourced, thus the issue is what weight to give to each in the Kendrick mass article. Over the past decade, dozens of peer reviewed primary and secondary source articles in the top scientific journals in the world have used the Kendrick mass = IUPAC mass x (14/14.01565) definition and have explicitly indicated that the unit associated with Kendrick mass is Da. This definition cannot be given zero weight and remain true to the principles of WP:VERIFY. --Kkmurray (talk) 04:16, 25 January 2011 (UTC)[reply]

Do you have any source that states that the quantity "Kendrick mass" cannot be measured? I don't think so. Kehrli (talk) 21:22, 25 January 2011 (UTC)[reply]

Do you have a definition of the term "IUPAC mass"? As long as "IUPAC mass" is not defined, Kendrick mass is not defined either. Kehrli (talk) 21:22, 25 January 2011 (UTC)[reply]

Here: [16]. --Kkmurray (talk) 23:14, 25 January 2011 (UTC)[reply]

That is what I thought: no viable source for the "IUPAC mass" and therefore no source on "Kendrick mass" because it relies on the definition of the IUPAC mass. Thereby we have answered the question which terminology has better sources.Kehrli (talk) 08:39, 26 January 2011 (UTC)[reply]

I agree that we have answered the outstanding questions regarding the sources and clarified some issues regarding their relation to the Kendrick mass article. This being the case, we can return to the issue of assigning due weight to the sources per WP:NPOV. --Kkmurray (talk) 16:06, 26 January 2011 (UTC)[reply]

Kkmurray, what exactly is "IUPAC mass" when referenced in your sources? -- Lord Roem (talk) 17:15, 26 January 2011 (UTC)[reply]

The "IUPAC Mass" is the observed mass (sometimes called the measured mass): the mass that is measured in the experiment. The procedure reported in the sources above is to use a mass spectrometer to obtain a mass spectrum. Peaks are identified in the mass spectrum and associated with masses that are typically reported in the mass unit Da. The sources that use the "Original Definition" typically call this set of observed masses "IUPAC mass". The sources that use the "General Definition" typically call this the "observed mass". There are other equivalent notations. For each of the set of measured masses, the "IUPAC mass" (or equivalently the observed mass) is multiplied by a number. For the -CH₂ functional group (F= CH₂) this number is (14/14.01565). For other functional groups F in the "General Definition" this number is the (nominal mass F)/(exact mass F). The sources define "Kendrick mass" as the product of the observed mass, which they typically call the "IUPAC mass", and the number (14/14.01565), hence the equation "Kendrick mass = IUPAC mass x (14/14.01565)".

The definition of "IUPAC mass" is indicated several places above. For example.

[17] - The definitions and many of the above quoted sources clearly indicate what is meant by "IUPAC mass":

Kim 2003 is explicit: "Kendrick mass (F) = observed mass × [(nominal mass of F)/(exact mass of F)]"