Appendix 7 of Anti-Wikipedia 2: The Rise of the Latrines

Supplementary information to accompany Nature news article "Internet encyclopaedias go head to head" (Nature 438, 900-901; 2005)

Nature, 22 December 2005

Here is more detailed information about how our survey was carried out and the errors that were identified. This includes a description of how the peer review worked, some of the specific questions that have been put to us, and a full list of all the errors identified, for both Encyclopaedia Britannica and Wikipedia. The reviewers originally participated under condition of anonymity, but a few have subsequently agreed to being identified, and we have added their identities alongside their comments below.

No test is perfect and we acknowledge that any of our reviewers could themselves have made occasional errors. But by choosing reviewers who were highly qualified in the specific area described by each entry, we aimed to subject the encyclopaedia entries to the fairest and most stringent test that we could.

We would like to thank all of our reviewers for their contribution.

HOW THE PEER REVIEW WORKED

We chose fifty entries from the websites of Wikipedia and Encyclopaedia Britannica on subjects that represented a broad range of scientific disciplines. Only entries that were approximately the same length in both encyclopaedias were selected. In a small number of cases some material, such as reference lists, was removed to bring the length of the entries closer together.

Each pair of entries was sent to a relevant expert for peer review. The reviewers, who were not told which article came from which encyclopaedia, were asked to look for three types of inaccuracy: factual errors, critical omissions and misleading statements. 42 useable reviews were returned. The reviews were then examined by Nature's news team and the total number of errors estimated for each article.

In doing so, we sometimes disregarded items that our reviewers had identified as errors or critical omissions. In particular, as we were interested in testing the entries from the point of view of ‘typical encyclopaedia users', we felt that experts in the field might sometimes cite omissions as critical when in fact they probably weren't – at least for a general understanding of the topic. Likewise, the 'errors' identified sometimes strayed into merely being badly phrased – so we ignored these unless they significantly hindered understanding.

FREQUENTLY ASKED QUESTIONS

Q: How did you select the reviewers?

A: Each of the reporters involved with the study contacted whomever they thought best-placed to do the reviews. We are unable to reveal the identities of all of the reviewers as they originally participated in the study on an anonymous basis.

Q: Without divulging their identities, can you describe their qualifications?

A: We chose reviewers in academic positions who have worked in a relevant field for a long time and are highly regarded by their peers as an expert in the topic in question. Most choose to retain the anonymity of peer review although a small number of reviewers have agreed to be identified. Two examples are Michael Gordin at Princeton, a historian of science who has written what is widely regarded as the definitive text on Mendeleev, and Roald Hoffmann, one of the chemists who worked most closely with Robert Burns Woodward.

Q: Were the reviewers told that the articles were either from Encyclopaedia Britannica or Wikipedia?

A: They were told that the two entries were from Britannica and Wikipedia, but they did not know which was which. Entries were stripped of metadata and formatting to leave only raw text, to preserve the blind as much as possible.

Q: Were the reviewers required to provide backup for their decisions?

A: No. It would have been simply too time consuming. The quality of the reviews varied, from brief to particularly zealous, but since the same reviewer tackled the same entry in both encyclopaedias, we felt that the same standards were at least being applied to both pieces. We did however disqualify a few reviews for being too brief, because there wasn’t enough information to identify the errors concerned.

Q: How were the articles selected?

A: Each of the reporters that worked on the survey chose 10 to 15 scientific terms that were roughly in their scientific beat – the sorts of things we ourselves would check in an encyclopaedia. We had not looked at any of these entries in either encyclopaedia when we selected them. Then we weeded out the terms that did not have any entry in Britannica (they all appeared in Wikipedia), and any for which the entries were vastly different in length. Sometimes the lengths were balanced by amalgamating two or three Britannica entries into one coherent piece – for example, 'ethanol' was done this way. We felt this represented 'everything Britannica had to say on the subject' – at least, everything we could find by a quick search of Britannica online, exactly the way a user would approach it.

Q: Were the various titles also seen to represent a cross section of science?

A: Yes, deliberately so. We tried to have a reasonable spread of Biology, Physics, Chemistry, Environment and Others. We also tried to have a good mix of People, Things, Events, Ideas / Processes and Places.

ERRORS IDENTIFIED: ENCYCLOPAEDIA BRITANNICA

Acheulean Industry

I would not use the term 'early Homo sapiens'. Instead, use Homo heidelbergensis.

Agent Orange

A very minor error is that Agent Orange is considered by the Vietnamese to be the cause of the diseases listed in the second paragraph from the 1970s to the present, not just from the 1970s to the '90s.
The entry should include the statement that other mixtures containing dioxin were also sprayed, including Agents Purple, Pink and Green, albeit in lesser amounts.

Aldol

The aldol REACTION is not the same as the aldol CONDENSATION.
Sodium hydroxide is by no means the only base to be used in the aldol and acid catalysed aldol reactions also occur (usually with concomitant loss of water).
The reaction steps in the second reaction sequence should be equilibria up to the dehydration step.
In particular, there is no mention of the acid catalysed process and scant mention of related reactions

Archimedes Principle

Reviewer: Prof. Timothy J. Pedley, G. I .Taylor Professor of Fluid Dynamics, University of Cambridge, UK.

In the fourth sentence the word 'floating' is used to mean 'at rest', and does not necessarily mean that in common parlance.
The very last sentence is true only for an object at rest; when a body is moving there are pressure forces, as well as viscous stresses, associated with the motion.

Australopithecus africanus

Dart did not find the fossil. It was brought to him by others.

Bethe, Hans

It should say that Bethe was dismissed from his post in Germany in 1933 because his mother was Jewish.

Cambrian Explosion

“Numerically dominant” [and in passing note this is not defined: species?, individuals?] forms in the Cambrian are arthropods and sponges; neither phylum “became extinct”.
The onychophoran Aysheaia may have grazed/scavenged sponges, but it is not a parasite in any generally accepted sense.
The Ordovician extinctions were not at the “end” of the Period, but in the Ashgill.
Geological dates: base of Cambrian is 543, not 540
Geological dates: base of Ordovician is at 488, not 505
Geological dates: base of Silurian is 444, not 438, (if we take early Silurian as Llandovery then its time span is 444-428)
Geological dates: 421 is definitely Ludow.
Evolution of hard parts at beginning of Cambrian involved much more than development of calcium carbonate.
Role of oxygen in Cambrian explosion may well have been important, but it involved much more than the evolution of hard parts.
Many suspension feeders, e.g. bryozoans, brachiopods, radiated in Ordovician, not Silurian.

Cavity Magnetron

In para. 2 sentence 3, it is stated that the power is coupled out through a slot. Although this is one method, the more common method today is to couple it through a loop or wire to an attached waveguide.
In para. 3, sentence 6, the description of electron travel is not strictly accurate. No electrons stop, but bunches of electrons do sweep around the cavity from slot to slot, although this path is not necessarily taken by every electron.

Chandrasehkar, Subramanyan

Nobel Prize in Physics for key discoveries which have led to the currently accepted theory … [not for formulating the theory itself]
From 1933 to 1936 Chandra was a Fellow of Trinity College, Cambridge.
Chandrasekhar joined the staff of the University of Chicago, rising from assistant professor of astrophysics (1937) to Morton D. Hull etc.
Books: Principles of Stellar Dynamics (1943).

Creutzfeldt-Jakob Disease (CJD)

The presumed risk to humans was from high titre bovine tissues and not meat.
The statement about mutations leading to increased susceptibility to infection is speculative. There is no evidence that mutations lead to sporadic CJD.

Cloud

' As a mass of air ascends, the lower pressures prevailing at higher levels allow it to expand. In expanding, the air cools adiabatically (i.e., without heat exchange with the surrounding air) until its temperature falls ~~below~~ [to] the dew point
upon which the air becomes ~~supersaturated~~ [saturated].
The presence of cloudiness marks smaller diurnal temperature variations. A low overcast layer of cloud acts like a blanket, preventing the temperature from dropping much at night. A clear [night] ~~evening~~ sky, on the other hand, often leads to rapid cooling, with dew, frost, or even fog forming the following morning as a result.

Colloid

Any substance consisting of particles substantially larger than atoms or ordinary molecules but ~~much~~ too small to be visible to the unaided eye. True, if the particles are spherical; but most people now consider a colloidal particle as having any shape so long as at least one-dimension is in the ‘colloidal domain’. Thus, soap films (e.g., foams) and biological membranes fall into this category, and these can be easily seen by the light reflected from them.
Such particles range in size from about 10^-7 to 10^-3 centimetres and are linked or bonded together in various ways. No, they are not necessarily linked or bonded. Indeed, in most cases they repel each other in the medium (usually liquid) they are in.
In a system of this kind, the colloidal material may have a high molecular weight, with single molecules of colloidal size, as in polymers, polyelectrolytes, and proteins, or substances with small molecular weights may associate spontaneously to form particles (called micelles) There are other names, such as vesicles, microemulsion droplets, liposomes, etc.

Dirac, Paul

Dirac retired from Cambridge in 1969 (not 1968)
He was a professor at FSU, not an Emeritus Professor.
He took a degree in applied mathematics at Bristol, straight after his engineering degree.
There is nothing here about Dirac’s work on the monopole – an important omission.
I was surprised to see nothing at all about Dirac’s large number hypothesis (1937)
Fowler was not a ‘collaborator’ of Bohr and he certainly didn’t work with Bohr on the famous Bohr model of the atom.
Dirac’s vision of the spinning electron was much less derivative than this entry says: it was pretty much the unique product of his mind.
Dirac co-invented QM independently of the Göttingen group after he read Heisenberg’s paper. It is therefore misleading to say that he was behind them, except in that first paper.
Dirac produced his transformation /before/ he wrote his book.
It does not mention his discovery of the least action formulation of QM – an extremely important contribution

Dolly the Sheep

Mitochondria would have been contributed by the donor mammary gland cell, though these do not appear to have survived (much in the way that sperm mitochondria do not contribute to those in the adult animal)

Epitaxy

Reviewer: Max G. Lagally, Erwin W. Mueller Professor and Bascom Professor of Surface Science, University of Wisconsin, Madison, USA.

Line 1: Not sure what is meant by “crystalline substance”. Actually, atoms are deposited. The atoms adopt the crystalline arrangement of the substrate. “Epitaxy” is from epi (akin) and taxos (arrangement)
Line 2: does not have to be the surface of another substance. In fact “epitaxy” strictly means the same substance and heteroepitaxy is used if the substance on which the atoms are deposited is different
Line 2: the process almost certainly involves a chemical reaction, but it need not – you can do epitaxy with marbles – so correctly this should state “need not”
The last sentence in the first paragraph is misleading and vague - very little of integrated circuits requires epitaxy, and then usually only the starting material and that would be the same material on itself to make a better starting surface for device processing.
Paragraph 2. total mishmash. Chemical vapor deposition and doping are separate issues; you would not use generally gallium or arsenic with silicon or germanium, but rather boron and phosphorous.

Ethanol

(from 'alcohol' entry in student encyclopedia)

The word ‘alcohol’ is derived from the Arabic ‘al kuhl’ but I think the linking of this ‘kuhl’ with the traditional eye-makeup ‘kohl’ is dubious.
The author is misunderstanding the term ‘methylated spirits’ and seems to think that this is alcohol to which methanol has been deliberately added to render it undrinkable. This does not happen. It is called ‘methylated’ because it still contains traces of methanol that have not been removed.
Hexahydric alcohols have six OH groups, not four.

Field Effect Transistor

In the first paragraph, it is suggested that “This change in polarity is called the field effect.” This refers to the statement within the first sentence which describes the change from n-type material to p-type material when a negative voltage is established close to a long strip of n-type material. This is not the definition of field effect.
Also the statement does not include the words “electric field” from which the effect takes its name.
The second paragraph is wrong in that it does not describe the operation of a known transistor. Some aspects appear correct but the underlying principle described is wrong.

Haber Process

It really should include an equation that shows N₂ + 3 H₂ -> 2 NH₃

Kinetic Isotope Effect

Reviewer: Daniel Singleton, Associate Professor of Chemistry, Texas A&M University, College Station, USA.

"Such effects, called kinetic isotope effects, operate when only one bond is concerned in such a way that bonds involving the heavier isotope are broken with more difficulty than those involving the lighter isotope." I simply don't understand what it is trying to say.

Kin Selection

Reviewer: Chris Barnard, Professor of Biology, University of Nottingham, UK.

It’s stretching things a bit to say in the last para that ‘A queen typically mates with a single male during her lifetime…’ This is true of some ants, but is not a general rule for social insects
Yes, (unclear) in using the language of individual-level fitness and selection; but this was also a shortcoming of Hamilton’s original formulation. Thus to say ‘They all carry the same genes…’ (para 1) is misleading because what matters is not the totality of genes shared but the probability that relatives share a specific gene (strictly allele), in this case the one coding for the altruistic trait. By the same token, ‘individual fitness’ is a proxy for allele fitness, again, in this case, specifically the allele for the altruistic trait. Kin selection is THE paradigm of the gene selection argument; it actually makes no sense when couched at the level of individual fitness. The problem cascades through the piece, thus: Par2, lines 4-5 – should be 'A parent has a probability of 0.5 (or a half) of sharing any given gene (again actually allele) with each progeny …' and last line – should be '…because it increases the probability of transmission of the parental gene for caring.'
Para 4, first sentence – I’d say instead that ‘Altruism also occurs among unrelated individuals when the benefit of reciprocal cooperation is greater than the average benefit from refusing to cooperate.’ [ not ' when the altruist's costs are smaller'] which are the conditions for the Prisoners’ dilemma model to predict mutual cooperation as a stable alternative to defection

Lipid

Reviewer: Stephen High, Professor of Biological Sciences, University of Manchester, UK.

No mention of “saturated” and “unsaturated” fats, or more precisely fatty acids, is made.
There is no mention of the propensity of lipids to “self assemble” which is the basis of their ability to form membranes
The article uses outdated nomenclature only and fails to use the new more logical system such as phosphatidylcholine in place of lecithin.

Lomborg, Bjorn

t might have done better to qualify Bjorn's Greenpeace past as not true to call him "a committed Greenpeace environmentalist". I think the "committed" is overstating it.

Lymphocyte

Unclear or misleading: T cells also transform into memory cells.

Mayr, Ernst – no errors identified

Meliaceae

So short as to be of very little help in identifying the family: it could apply to any of about ten other families, or more.

Mendeleev, Dmitry

Reviewer: Michael Gordin, Assistant Professor of History of Science, Princeton University, New Jersey, USA.

In the first paragraph: M's 1871 version of the table is not final. He keeps revising it his entire life.
Declaring him the 17th child is either incorrect or misleading. He is the 13th surviving child of 17 total.
M's sister does *not* go with him to Moscow on the trip with his mother. She has already married into a Petersburg family.
M's mother does not have good connections, but the reason she doesn't enroll him in Moscow University has little to do with some fictionalized quota system for the regions of Russia. It is simply very hard to get into university in this period without connections, and people from the provinces tend not to have them.
He never applied to Medical School in St. Petersburg. The reason why he got into the Chief Pedagogical Institute is that his father was an alumnus.
Odessa is not in the Crimea, but on the Black Sea coast of Ukraine.
The presentation of Mendeleev as a political radical is highly misleading.
misleading statement about his role in the 1867 Paris Expo pavilion. He was a participant, but he was hardly sent to "organize" it. (He was an untenured chemistry prof at the time.)

Mutation

“Mutations occur when one base is substituted for another or when one or more bases are inserted or deleted from a gene. Substitution mutations affect only one codon …” No, you can also substitute, 2 bases, or 3 bases, or any other number of bases.
And actually, not bases are inserted, but nucleotides.
“Harmful genes eventually may be eliminated from a population …” That would be a very exceptional case. Usually “alleles” are eliminated, i.e. substituted by other alleles of the same gene.
“Whereas only one codon is affected by a substitution mutation, base insertions and deletions alter the reading frame of the entire gene”: this applies only if the mutation is in the coding region.
“assume that the end of a gene reads TAG GGC ATA ACG ATT”: a gene never ends with codons. There is always a 3’ untranslated region (at least).
“When this does occur, the percentage of organisms with this gene will increase until the mutated gene becomes the norm in the population.” No, this is not generally true. Due to genetic drift even beneficial mutant alleles might be eliminated, or even slightly deleterious alleles might become fixed.
“Mutations occur when one base is substituted …” The whole treatment is focused on point mutations or small-scale mutations affecting protein coding regions. What about chromosome mutations or genome mutations? What about mutations in non-coding regions, such as introns, promoters, or even in functionally irrelevant DNA?
Unclear or misleading: “Mutations take place in the genes”: defining genes is quite a problem, but almost all useful definitions imply that there is also non-genic DNA in genomes, which is, of course, also subject to mutation. So I would say that “Mutations take place in the DNA”.

Neural Network

The following sentence is misleading: "If the total of all the weighted inputs received by a particular neuron surpasses a certain threshold value, the neuron will send a signal to each neuron to which it is connected in the next layer." This suggests that the described procedure is the only one used, which is not the case.
The following sentence is also misleading: "First, a network can be equipped with a feedback mechanism, known as a back-propagation algorithm, that enables it to adjust the connection weights back through the network, training it in response to representative examples." Once again, there are many other training algorithms available in addition to backpropagation.

Nobel Prize

1. Bibliography lacks the two most important works on the subject, Crawford’s The Beginning of the Nobel Institution (1984) and Friedman’s The Politics of Excellence (2001), as well as the classic paper in Nature (1981).

2. Omission: That the Nobel Committee for Peace is appointed by the Norwegian Storting (Parliament). Although the committee is allegedly non-political, the appointments are very political.

3. Unclear/misleading: The 1935 Peace Prize to Ossietzky was awarded in 1936 (it had been reserved in ’35). This makes more sense when referring to Hitler’s ban on German participation in ’37.

4. “Several thousand people are engaged in the committees’ efforts to determine the originality and significance of each nominee’s contribution, and outside experts are frequently consulted….” Misleading – thousands participate in the nomination process, and by no means are all those who send in nominations impartial, but the actual determination of originality and significance remains with the committee. Use of outside experts is relatively recent and probably not ‘frequent’, at least in the sciences. The entry gives the impression that the process of evaluation entails a huge communal effort; this is not correct. More correct would be several thousand participate in the process of proposing candidates whose works are claimed to be of highest originality and significance. But evaluation of these candidates remains largely confined to the Swedish or Norwegian committees.

Pheromone

Reviewer: Olle Anderbrant, Professor of Ecology, Lund University, Sweden.

One might get the impression that a pheromone is a substance, while it usually consists of several in a blend.
Pheromones are not restricted to insects and vertebrates, but also occurs in e.g. crustaceans and fish.
Entomologists use not only sex pheromones, but also aggregation pheromones for trapping (e.g. bark beetles)

Prion

The conclusion that Alzheimer disease or Parkinson disease may arise from molecular mechanisms similar to those that cause prion diseases is not valid. All these disease may share common pathways leading to neurodegeneration but AD or PD are not transmissible diseases (a hallmark of prion diseases)
It should be more clearly stated that prion proteins exist in a normal isoform which is present in all cell types of the body and may adopt a pathogenic conformation that is deleterious to neuronal cells and thus associated with the disease. (Both proteins are called prion proteins, the use of the term "prion protein" to refer only to the pathogenic form is misleading).
The entry should refer to Griffith and Alper as the 1st scientists to propose that the infectious agent responible for TSE may be solely composed of proteins. Prusiner then purified the prion protein form the infectious agent.

Punctuated Equilibrium

Reviewer: Professor Henrik Jensen, Department of Mathematics, Imperial College, London, UK.

I think this misleads the reader by using terms like "The punctualists maintain..." giving a negative impression of proponents of PE. It seems that the entry is organised as an argument against PE – and doesn't bother much to explain what PE is about.

Pythagoras’ Theorem

Reviewer: Geoff Smith, Senior Lecturer in Mathematics at the University of Bath, UK.

The Italian town is Crotona, not Crotone.

Quark

Fifth paragraph: The theory of QCD was formulated in 1973, not 1977.
Sixth paragraph: The statement "At a distance of approximately 10-13 cm - about the diameter of a proton - quarks behave as through they were free" is incorrect. In fact, at distances of about the proton diameter, quarks interact very strongly. It is at distances much smaller than the diameter of a proton that quarks behave as approximately free.
Quarks possess other quantum properties, not discussed here, which are as fundamental as those which are described. In particular, quarks possess "charges" which give rise to their weak interactions.
Second paragraph: The following statements are misleading: "Quarks appear to be truly fundamental. They have no apparent structure; that is, they cannot be resolved into something smaller." The prevailing view is that quarks are unlikely to be truly fundamental. While no experiment has to date revealed any substructure to quarks, there are strong theoretical reasons to believe that quarks are not fundamental entities, and enormous experimental effort (including the multi-nation program of the Large Hadron Collider at CERN, in Geneva) is currently being devoted to the search for smaller or more fundamental constituents of matter.
Last paragraph, the statement: "Although QCD cogently explains the behaviour ... it does not account for the flavours of "charm" and "bottom"" is misleading. The origin and number of quark flavours is a question that lies entirely outside the framework of QCD. In particular, QCD can accommodate almost any number of quark flavours (technically, the theory requires only that the number of "light" quark flavours must be less than about 16).

Royal Greenwich Observatory

It was the oldest observatory, or the oldest astronomical institution NOT the oldest scientific institution (that was the Royal Society, est.1666).
Nautical Almanac was first published in 1766 with data for 1767
Omission: The role of Astronomer Royal is not mentioned,

Royal Society

There are some major errors in the first few sentences, including:

The identification of the 1645 London group with the ‘Invisible College’ mentioned in Boyle’s letters,
And the statement that the Society was ‘largely composed of Puritan sympathisers’.
In para. 2, Newton’s election was in 1672 new style.
In para. 3, some of the information about current publications is wrong.
The reference in the opening paragraph to ‘a number of small academies’ is misleading: I can’t think quite what the author is thinking of here.
Right at the start, if the society had been defined as a national institution (which it was) it is the oldest in Europe, not one of the oldest

Synchrotron

1. From 'synchrotron' entry: “The highest-energy electron synchrotron is at CERN in Geneva; it reaches 50 GeV (50 billion electron volts).”. It accelerated electrons and positrons to 104 GeV.

2. From the 'Electron Synchrotron' section: “At CERN the Large Electron-Positron collider (LEP) accelerates electrons and positrons to 50 GeV in a ring with a circumference of 27 kilometres, which is probably the practical limit for such machines.” LEP ceased operation in 2000 and accelerated electrons and positrons to 104 GeV.

Thyroid

Does not contain the information that most thyroid hormone is in the form of thyroxine and this is how it is most easily transported e.g. across the blood/brain barrier. However T3 is the biologically active form of the hormone and is produced, partly directly, but also by de-iodination of thyroxine which occurs in tissues.
The description of thyroid disorders should include hyperthyroidism (overactivity), hypothyroidism (under activity) and the fact that these are common affecting about 2% of the population.
It does not mention the importance of iodine intake
It does not mention the newborn screening for congenital hypothyroidism

Vesalius, Andreas

Reviewer: Neidhard Paweletz, German Cancer Research Centre (retired), Heidelberg, Germany.

The name of Galen is mentioned and essential for Vesal ´s achievements therefore it should be mentioned that he lived from 129/130 to 199/200 A D , long before the age of Vesal and nearly nobody had dared for centuries to doubt Galen´ s results.
We do not know, what Vesal ´s goal was, therefore “ Vesalius had attained his goal” should be omitted it is a speculation.

West Nile Virus

Although the virus is present in the bloodstream it must replicate in cells. Actually, most data now suggest that virus replication in lymphoid tissues (spleen, lymph node) leads to virus getting in the blood. It is unclear if it actually replicates in any of the leukocytes in the blood

Wolfram, Stephen

Paragraph 1, line 5 has an error. Wolfram does believe in math-based science, but not in TRADITIONAL math, so change “math-based science” to “science based on traditional mathematics”
Last paragraph: delete "corporate sellout and" (not true) and change "surely" to "may have"

Woodward, Robert Burns – no errors identified

Reviewer: Roald Hoffmann, Frank H. T. Rhodes Professor of Humane Letters, Cornell University, Ithaca, New York, USA.

ERRORS IDENTIFIED: WIKIPEDIA

Acheulean Industry

Cro-Magnons (early Homo sapiens) did not use the Acheulean!!
Date range is off, its about 1.5 my to 200 ka
The following statement is inaccurate and poorly written: 'The period during which these these tools were innovated is usually thought to be the early Paleolithic era or the beginning of the middle Paleolithic era.'
I have no idea what this following statement means: 'However, the Acheulean industry continued to be used by some primitive hominid cultures up until 100,000 years ago.' It’s not correct.
This is an awful set of sentences: 'by efficient scavengers, who were still preyed upon frequently by larger animals and often bewildered by their environment. Adversely, Acheulean tools gave their masters the ability to hunt and defend themselves successfully and gave them the distinction of being equally as deadly as the greatest predators of the prehistoric Earth.' Early hominins were probably hunting and scavenging. Acheulean hominins also likely scavenged and hunted. Acheuelean tools are often associated with large carcasses, suggesting that they had access to large quantities of meat. The sentence about Acheulean hominins abilities is overstated.
Regarding Asia, I would say West and Southern Asia. Acheulean hominins did not spread to Eastern Asia.
The statement 'It flourished roughly 400,000 to 100,000 years ago in Eastern Europe and Northern Asia.' has nothing to do with the Acheulean, I am not sure what it means.

Agent Orange

This entry implies that it was the herbicides that are problematic, which is not the case. It was dioxin, a byproduct of manufacture of 2,4,5-T that is of concern. Dioxin is persistent in the environment and in the human body, whereas the herbicides are not. In addition, there was a significant amount of dioxin in Agents Purple, Pink and Green, all of which contained 2, 4, 5 - T as well. However, we have less information on these compounds and they were used in lesser quantities.
The entry is on the verge of bias, at least. By use of the word "disputedly" in the second sentence there is at least an implication that the evidence of harm to exposed persons is in question. That is not the case, and the World Health Organization has identified dioxin as a "known human carcinogen", and other organizations such as the US National Academy of Sciences has documented harmful effects to US Air Force personnel.

Aldol

The mechanisms of base and acid catalysed aldol reactions should have every step as an equilibrium process
The acid catalysed process should include the dehydration step, which occurs spontaneously under acid conditions and, being effectively irreversible, pulls the equilibrium through to product.
The statement that LDA is avoided at all possible as it is difficult to handle is rubbish. Organic chemists routinely use this reagent – which they either make as required or use commercially available material.

Archimedes Principle

Reviewer: Prof. Timothy J. Pedley, G. I. Taylor Professor of Fluid Dynamics, University of Cambridge, UK.

In the section on acceleration and energy, which discusses how a body moves when it is not neutrally buoyant, it is rightly stated that the acceleration of a body experiencing a non-zero net force is not the same as in a vacuum, because some of the surrounding fluid has to be accelerated as well. However, it is implied that the mass of fluid that has to be added to that of the body, in using Newton's Law to calculate the acceleration, is equal to the mass of fluid displaced. This is not in general true - for example, the added mass for an immersed sphere is half the mass of fluid displaced.
The entry is rather imprecise. In line 3, for example, the object is said to "float" if the buoyancy exceeds the weight, so here "float" must mean "rise" and not "stay at the same level", which is probably not what was intended because the word has the other meaning in the second paragraph of the section on "Density".

Australopithecus africanus

The contribution of Broom in the 1930s should be mentioned.

Bethe, Hans

It is not really accurate to say that Bethe discovered "stellar nucleosyntheis" He showed now nuclear reactions accounted for the energy output from stars.
Robert Wilson was not at Cornell before WWII; he came in 1947

Cambrian Explosion

“Prior to the discovery of the Burgess Shale ….”. Absolutely wrong! The existing fossil record clearly demonstrated the existence of triploblasts, e.g. trilobites.
Diploblasts are much more complex, and to write “every cell …[is]… in contact with its watery mineral-rich environment” is basically wrong.
Diploblastic/triploblastic; actually refers to germ layers, not “layers” in adult animal.
Diploblasts have “internal organs” e.g. gonads.
Evidence for Ediacaran triploblasts was available long before discovery of phosphatized embryos.
Ediacaran fauna is known to span c. 565-540 Ma, i.e. much more than 10 Ma before Precambrian-Cambrian boundary.“
“Sexual reproduction” almost certainly evolved long before “Snowball Earth”.
Ediacaran faunas are no older than c. 570 Ma; no convincing trace fossils occur at 600 Ma (or earlier)
Cloudina is misspelt.
Cloudina is effectively Ediacaran in age, and is not know to extend into the Tommotian.
Cambrian fish “unlike any fish alive today”: highly misleading.

Cavity Magnetron

Microwave ovens were not completely unanticipated before World War II. Radio-frequency heating of foods had been tried on an experimental basis, and I have heard anecdotally that Germans were experimenting with microwave cooking before 1940.
While the mass production of magnetrons was of great benefit to the Allies, German and Japanese radars were also developed. If the history section contains material on the Allied effort, mention should be made of the Axis work (at least a sentence).

Chandrasehkar, Subramanyan – no errors identified

Creutzfeldt-Jakob Disease (CJD)

The hereditary forms are always associated with mutations of the PrP gene. The sporadic forms are by definition not associated with mutations.
The risk from HGH was only removed when this was medication was withdrawn in the USA in 1985.
The original case from Jakob's papers have been re-examined and two were judged to have been suffering from CJD and at least two from other conditions. This did lead to confusion about definitions but it is wrong to state that the patients all had a different disorder.
Although recent work has shown that PrPSc can be found with highly sensitive methods in some cases of sporadic CJD in muscle and spleen, the important point is that these tissues are negative using conventional tests in contrast to variant CJD in which LRS tissues are uniformly positive. This distinction is critically important for public health.
The section on pentosan polysulphate gives an overly optimistic impression of the efficacy of this treatment.

Cloud

Under 'Cloud formation and properties', cloud formation happens when air is cooled below its saturation point, not to its saturation point.
Under 'Cloud formation and properties': 'The air stays the same temperature but absorbs more water vapour into it until it reaches saturation'. No. Droplet or ice particle formation requires supersaturation. Water vapour can only be added to bring the air to saturation.
Omission: Cloud can however be formed by the mixing of two subsaturated air masses. Examples of this are “breath” condensation on a cold day, arctic sea-smoke and aircraft contrail formation.
'This method of raindrop production … typically produces smaller raindrops and drizzle'. Tradewind and tropical cumulus clouds are capable of producing drops of several millimetres in diameter.
Under 'clouds in family A': A contrail is a long thin cloud which develops as the result of the passage of a jet airplane at high altitudes. (any type of aircraft is capable of forming a contrail – not just jets. They result when mixing of the engine exhaust which contains unsaturated water vapour mixes with the unsaturated environmental air to produce a mixture which becomes temporarily saturated).

Colloid

'In general, a colloid or colloidal dispersion is a two-phase system of matter'; No, a uniform dispersion of particles in a liquid is a one-phase system of two or more components, no matter how large the particles are. A two-phase system requires there to be two distinct phases separated by an interface. If all the colloidal particles coalesced into one large particle, only then would it be a two-phase system, and the original colloid would be considered to have been in a meta-stable state
In a phase colloid, small droplets or particles of one substance, are dispersed in another substance, the continuous phase. In a molecular colloid, macromolecules are dispersed in a continuous phase (or dispersion medium). I’ve never heard of this division of colloids into phase colloids and molecular colloids.
Colloids can be classified as follows: ß Inconsistency: What follows is a very different classification than given in the opening two paragraphs. à

		Dispersed ~~phase~~ material
		Gas	Liquid droplets	Solid particles
Dispersing ~~phase~~ Medium	Gas	None: all gases are mutually soluble	Liquid aerosol, Examples: fog, mist	Solid aerosol, Examples: Smoke, dust
	Liquid	Foam, Examples: Whipped cream	Emulsion, Examples: Micelles, milk, mayonnaise, hand cream, vesicles, blood	Sol, Examples: Paint, pigmented ink
	Solid	Solid foam, Examples: Aerogel, Styrofoam, Pumice	Gel, Examples: Gelatin, jelly, cheese, Opal	Solid sol, Examples: Cranberry glass, Ruby glass

Misconception: van der Waals forces: These are due to dipole-dipole interactions (permanent and/or induced). Even if the particles don't have a permanent dipole there ~~could be~~ are always quantum mechanical fluctuations of the electron gas giving rise to an instantaneous ~~a temporary~~ dipole. So these types of forces are always present.
Omission in 'interactions' section: * Steric forces between polymer-covered surfaces or in solutions containing non-adsorbing polymer can modulate interparticle forces, producing an additional repulsive steric stabilization force or attractive depletion force between them.
The charge on the dispersed particles can be observed by applying an electric field: all particles migrate to the same electrode ß Only if the sign of their charge (positive or negative) is the same and therefore must all have the same charge. ß The same sign, not necessarily the same charge. The logic of this sentence is backwards.

Paul Dirac

1. Dirac never worked as an engineer for a living (all he did was a few weeks’ research one summer, directly after his engineering degree).

2. His PhD thesis did not mention Schrodinger’s quantum theory, so the characterization of Dirac’s early QM is not correct.

3. Dirac first became interested in general relativity as a student in Bristol, not at Cambridge.

4. His role in the discovery of field theory is not mentioned.

5. Nor is his extremely important work in the least-action formulation of QM, now very important in modern field theory.

6. I was surprised to see nothing at all about Dirac’s large number hypothesis (1937)

7. Dirac did speak publicy about his early family life in his interview to the Archives of the History of Quantum Physics.

8. He did not ‘derive’ the Dirac equation – he guessed it.

9. He was not a committed atheist in later life. I’d describe him as agnostic.

Dolly The Sheep

1. Somatic cell nuclear transfer involves transfer of an intact cell into an enucleated egg and subsequent fusion of the cell within a cell rather than transfer of the nucleus per se.

2. Cloning ‘will not bring back to life replicas of pets’.

3. Work is not progressing on cloning the mammoth or other prehistoric animals and will not be possible –shades of Jurassic Park here.

4. Similarly portraying the prospects for making the ‘controversial practice of genetic engineeering of children more acceptable’ perpetuates several media myths.

Epitaxy

Reviewer: Max G. Lagally, Erwin W. Mueller Professor and Bascom Professor of Surface Science, University of Wisconsin, Madison, USA.

Third paragraph: I’m not sure that “outgassing” is the proper word. I think “diffusion” is meant.

2. The big problem with this one is that it really hardly says anything about epitaxy, but more about manufacturing the starting point for Si device manufacture. It fails to mention epitaxy in GaAs and other III-V compounds, where it is much more important, and it fails to mention why epitaxy occurs at all and in what systems it is possible.

Ethanol

Para 6: It is said of the traces of benzene in purified alcohol that ‘consumption by humans lead to distinctive liver damage’. Such industrial alcohol is never drunk by humans and I think the author is confusing this with cirrhosis of the liver caused by excessive alcohol consumption over many years.
Para 9: the name of the ‘unpleasant’ agent is denatonium benzoate, better known as Bitrex.
Page 10: the term antifreeze is generally used for ethylene glycol not ethanol. Ethanol has a low melting point but this is not given.
Para 12: Ethanol is not commonly used as a disinfectant, although it has disinfectant properties.
Para 26*: Seems rather jumbled, mixing alcoholism, cirrhosis of the liver, and unproven claims that alcohol consumption is linked to various forms of cancer.

Field Effect Transistor

1. In the section on USES, CMOS is the acronym for Complementary Metal Oxide Semiconductor.

2. The first sentence of the section “FET Operation” mentions a “potential voltage” which is misleading. In electrical terminology “potential” and “voltage” tend to mean the same and hence both are not normally used together. It is best to use the word VOLTAGE alone for the purposes of describing how the FET works.

3. There are many types of FET but the section on FET Operation describes a “normally-on” or “depletion mode” type of MOSFET. However, it is usual to employ a “normally-off” MOSFET for CMOS devices which are described in the section on USES.

Haber Process

1. The statement "The process was developed by Fritz Haber and Carl Bosch in 1909 and patented in 1910." is slightly misleading. There are early patents, one in 1908 by Haber meant to protect his process, which was discovered independent of Bosch by Haber and his co-workers, one of whom was Le Rossignol. To be honest, the word "developed" does cover this aspect since it was Haber who "discovered" the process while it was Bosch as BASF who made it industrially viable.

2. In the last sentence, 'about half' is vague enough to be misleading.

Kinetic Isotope Effect

Reviewer: Daniel Singleton, Associate Professor of Chemistry, Texas A&M University, College Station, USA.

1. When it says "In still other cases, the rate change may be due to subtle differences in the electronegativity of the two isotopes," the best scientists in the area would say that there is no convincing example of this. The statement is controversial at best, and I believe it to be simply wrong.

2. The final part of the discussion regarding relative mass versus absolute mass confuses issues. The discussion ultimately gives the wrong impression that the issue is the use of reduced masses rather than the fact that (1/1)^.5 differs from (1/2)^.5 much more than (1/12)^.5 differs from (1/13)^.5 Still, I find that the discussion is useful for the facts it presents in building its misleading argument.

Kin Selection

Reviewer: Chris Barnard, Professor of Biology, University of Nottingham, UK.

It’s not true to say kin selection was first suggested by Darwin. Darwin certainly recognized the problem posed by altruism, specifically in the form of sterile castes, but his solution owed more to group selection than kin selection. The modern concept of kin selection stems from informal comments by Haldane, later formally refined by Hamilton (but, to be pedantic, Hamilton did not use the term kin selection - he defined inclusive fitness; it was Maynard Smith who coined the term ‘kin selection’)
On the gene selection/individual selection issue, this starts off on a better footing than the previous definition, but slips a bit where it says ‘…siblings share 50% of an individual’s genes…etc’ – should say ‘has a 50% chance of sharing the individual’s gene for self-sacrifice etc’
In the third para from the bottom, I’d change the text from the second sentence on to: ‘This may be through recognizing some attribute of an individual that correlates with kinship, such as familiarity through having grown up together, or it may come about indirectly; for instance young tiger salamanders avoid cannibalizing other young salamanders and their eggs until they have left their natal vicinity thereby reducing the damage they would do to the survivorship of their kin.’ As it is the text perpetuates distinctions between forms of ‘kin recognition’ that have been shown to be misleading in the critical literature.

Lipid – no errors identified

Reviewer: Stephen High; Reviewer: Stephen High, Professor of Biological Sciences, University of Manchester, UK.

Lomborg, Bjorn

The Copenhagen Consensus project is mentioned but with no explanation of what it actually was.

Lymphocyte

Lymphocytes are larger than red blood cells and plasma cells have a large cytoplasm to nucleus ratio, not vice versa.
The function of T cells is omitted and there is no mention of cytokine secretion.

Mayr, Ernst

The entry says that Mayr solved the species concept - but, take it from me, there are still dozens of people arguing about it: this is a bit misleading.
Mayr was not sent to PNG by Rothschild, but by the American Museum of Natural History.
The statement that "He continued to reject the view that evolution is the mere change of gene frequencies in populations, maintaining that other factors such as reproductive isolations had to be taken into account" is a bit odd; in that reproductive isolation presumably depends on the evolution of a genetic barrier - ie a change in gene frequencies.

Meliaceae

1. Actually flowers are usually cryptically unisexual although they do indeed look bisexual and much of the literature refers to them as such.

2. Most species are evergreen, only a minority are deciduous.

3. Inaccurate geography (e.g. S. macrophylla is not the Honduras mahogany and it does not occur in C America, just in S. America; the Honduras mahogany is S. humilis and that is what occurs in C. America; Khaya ivorensis is the "Ivory Coast Mahogany", but this is not a trade or common name that I have ever come across.

Mendeleev, Dmitry

Reviewer: Michael Gordin, Assistant Professor of History of Science, Princeton University, New Jersey, USA.

1. They say Mendeleev is the 14th child. He is the 13th surviving child of 17 total. 14 is right out.

2. Between 1859 and 1861 Mendeleev spent no time in Paris beyond a brief visit. He was in residence the entire time in Heidelberg.

3. He also did not work on gases at all, but instead the capillarity of liquids in this period.

4. He did not study the spectroscope with Kirchhoff.

5. He got the job at the Technological Institute in 1864, not 1863.

6. His first wedding is in 1862, not 1863.

7. Mendeleev was not actually dismissed from the University because of political activities. This contention has been invalidated by recent research.

8. M did not work out the 40% by volume standard for Russian vodka (it was established earlier by the British for gin), and he certainly never patented it.

9. Newlands published his work first in 1864, not 1866.

10. Mendeleev's work was also produced in the course of writing a textbook, and not originally a classification of the elements, as Newlands was. The classification emerged by accident, not as the result of a deliberate search for a system.

11. Also, Meyer's table was indeed a categorization by both weight and valence in 1864, not just by valence alone. (All 2-dimensional tables include weight as one axis in the 1860s.)

12. In the paragraph on the chemical ether, they make it sound like the lighter of the two proposed new elements was meant to be chemically inert. Actually, the other proposed, slightly heavier element (coronium), was *also* supposed to be chemically inert.

13. The paragraph on solutions research gets M's position exactly backwards: he is trying to show that Dalton's laws *don't* apply, not that they do.

14. M's version of gunpowder is "pyrocollodion," not "pyrocollodium."

15. It was not in fact adopted by the Russian navy, which commissioned it.

16. Omission: No mention at all of his importance as a public intellectual in late Imperial Russia. There is also no discussion of his role as an economic thinker, his work on the theory and practice of protectionist trade, his work on agriculture, etc.

17. In the first paragraph, the entry states that there were two competing versions of the periodic table. There were at least five competing variants by different people during the 1860s. Throughout the entry, there is a collapse to just M's and Lothar Meyer's. These are the last two and the most complete, but it is an unfair reduction of the historical picture, and it tends to overdramatize the story (as this entry often does).

18. This first paragraph also makes it sound like the correction of the atomic weights was more radical than the prediction of new properties of elements. It was the latter which was far more controversial. Essentially all periodic systems proposed revisions of existing accepted atomic weights, which were much less fixed than the entry suggests.

19. M's weddings are presented a bit misleadingly. He was indeed married to two women, but for a period of time (a few months) was married to both of them, leading to accusations of bigamy -- although no prosecution.

Mutation

“Neutral mutations do not affect the organism's chances of survival in its natural environment and can accumulate over time, which might result in what is known as punctuated equilibrium, a disputed interpretation of the fossil record.” Evolution at DNA sequence and phenotypic level have been seriously confused here.
“+ silent mutations: codes for the same amino acid, so has no effect”: “so” not justified; a silent mutation could e.g. affect the splicing and if so, could even be lethal.
“; C → U, or A → HX (hypoxanthine).” This is not the full story, because e.g. a U in DNA would be recognized by the cell’s repair system and eliminated. But now the U pairs with A … (imagine replication). Or, the C is methylated, then you could get mC à T indeed.
“There are three kinds of point mutations, depending upon what the erroneous codon codes for:” This applies only to coding regions (open reading frames), but only a very small fraction of e.g. the human genome represents coding regions.
“Most insertions in a gene can either alter splicing of the mRNA, or cause a shift in the reading frame (frameshift),” How do the authors get to the “most”; my feeling is that this is not correct. The statement may also depend on the definition and composition of a gene; e.g., if it has large introns, it might be quite robust towards insertions or deletions.
“* Loss-of-function mutations are the result of the protein encoded by the gene having less or no function.” Genes encoding only RNA, or nothing, can also lose their function.

Neural Network

The term "linearly independent" has a specific mathematical meaning, and the author has misused it. He/she appears to mean "linearly separable", which is a different concept entirely.
It is claimed that in connectionism neurons compute a monotonic function of the sum of products of their inputs with weights. This is not always the case. In fact the article mentions radial basis functions, which are a perfect counterexample.
Neural networks are divided by the article into supervised and unsupervised. No mention is made of reinforcement learning.
It is claimed that the Cognitron was the first multilayered neural network. While one might make the case for it being the first with a training algorithm, it is very likely that one could find a proposal for a multilayered neural network considerably earlier.
It is claimed that backpropagation is the most common learning algorithm. While this might be true in terms of its frequency of appearance in textbooks, it is in fact a very problematic algorithm in its simplest form, and it is probably misleading to suggest that it is the most commonly used algorithm in actual practice.
It is misleading to suggest, in presenting AI and cognitive modelling, that "approaching human learning and memory is the main interest in these models". In fact much work in AI has no interest in this whatsoever: the aim is to better solve certain technological problems.
It is misleading to suggest that what real neurons do is "simple". Similarly, the question of whether the brain is Turing-equivalent is at present entirely unresolved.

Nobel Prize

“The prize is occasionally awarded to those who preserved through critical moments in a process despite the risk of failure.” Not sure what this is supposed to mean, but if it implies that the committees take this criteria into account when deciding upon who shall get a prize, there is no evidence for this. This is part of the mythology and relates to Nobel’s own romantic vision, but not to the actual working of the prizes.
The reasoning for why no mathematics prize with respect to mathematics not considered a practical science is historically wrong. We do not know why Nobel chose not to include mathematics; evidence points to issues not mentioned in the entry, which repeats popular mythology and not work of those who studied the issue in detail.
Final date for receiving proposals is 31 January not 1 February.

4. Unclear/misleading: Those invited to nominate is unclear. Process of evaluating is unclear. The discussion of criticisms seems haphazardly slapped together; where useful information was found, it was included, but no clear thesis or vision for what should be included seems present. No perspective on why the prizes became significant; no perspective on general use of NP or other prizes for determining the alleged ‘Best’.

5. Omission: The location of the ceremonies has changed over time.

Pheromone

Reviewer: Olle Anderbrant, Professor of Ecology, Lund University, Sweden.

1. One might get the impression that a pheromone is a substance, while it usually consists of several in a blend.

2. 2nd paragraph. The fact that the confusion acts on the ability to find a mate, not to lay eggs per se, is missing

Prion

1. It should first be clearly stated that prions replicate through conversion of the host normal prion protein (and not any other host protein).

2. It is untrue that prion domains are flexible and lack a defined structure. On the contrary, prion domains are fold into structures called alpha helices in the normal conformation and are stretched into flat structures called beta strands when in the "prion" state.

3. Unclear: Regarding the normal cellular prion protein, its precise location is at the surface of all cells. It is untrue that its function is not known, rather it is not completely resolved.

4. Unclear: Concerning propagation of prions, it is not the disease which is propagated but the infectious agent (prions).

5. The sentence linking prions to memory and cellular differentiation is extremely misleading. The normal function of cellular prion protein in mammals is not fully understood, but it may take part to cell adhesion mechanisms, cell signaling, copper homeostasis, and protection against insults such as oxidative stress.

6. Bias; A very (too) long part of the entry is about yeast prions, as compared with mammalian prions. The occurrence of prions in yeast is interesting in so far as it gives credence to the protein only hypothesis.

7. It also has allowed to shed some light on the prion domains (i.e. regions in the protein involved in the conversion) and on the mechanisms of conversion. However, it is untrue that prion-like proteins are found in "many" plants or animals (we just do not know). The word "useful" is also confusing, while it is true that not all prions are associated with a "disease" state.

Punctuated Equilibrium – no errors identified

Reviewer: Professor Henrik Jensen, Department of Mathematics, Imperial College, London, UK.

Pythagoras’ Theorem

Reviewer: Geoff Smith, Senior Lecturer in Mathematics at the University of Bath, UK.

1. “This means that knowing the lengths of two sides of a right triangle is enough to calculate the length of the third-something unique to right triangles.'' is misleading. If you know two sides of a triangle and the included angle then you can always calculate the length of the third side.

Quark – no errors identified

Royal Greenwich Observatory

‘The last time that all departments of the RGO were at Greenwich was before World War II. Many departments were evacuated along with the rest of London to the countryside (Abinger, Bradford, and Bath) in 1939.’ – in fact, Magnetic & Meteorological Dept moved to Abinger in 1924 after the arrival of the railway at Greenwich which affected readings. Then in WWII many of the instruments were put into storage for their safe keeping, with work at Greenwich scaled back to the bare minimum.
'The castle now houses the International Study Centre …' – Herstmonceux Science Centre is housed in the Observatory buildings next to the castle, on the castle grounds, not in the castle itself.
‘built as a workplace for the Astronomer Royal’ - not really, it was built to provide data for navigators, the AR was appointed to use the observatory as a means of creating that data.
‘the Prime Meridian, to which longitude refers, went through the observatory’ suggests the Prime Meridian existed before the Observatory, when in fact it is a creation of the observatory.
The meridian line in the courtyard is marked by a stainless steel strip now, not brass.

Royal Society

1. Sprat’s name misspelt in References.

2. The timeline implies that the Society stayed at Arundel House from 1666 to 1710, whereas in fact it moved back to Gresham College (not mentioned), where it was based from its foundation till 1666.

Synchotron

1. Motivation for building the things in the first place - no mention of high energy particle physics, although synchrotron light sources are mentioned.

2. electron acceleration power should be electron beam energy