Arrow

Just in case you didn't know what an arrow was, this sign on a Kitchener street helpfully explains it.

Logo Fail

Whenever I pass by this dry cleaner's, I am always struck by the logo. The arrow through "speedy" is obviously meant to convey speed, but for me it just looks like the word "speedy" has been struck out. They used to be speedy, it says to me, but aren't any longer. Logo fail!

Christian Science Peddled at the University of Waterloo

Yesterday I attended a talk by Christian Scientist Barbara Fife entitled "The Power of Prayer", held at the University of Waterloo in the building where I work, the Davis Centre. Although the room can hold about 250 people, I would estimate that no more than about 25 people were present.

For those who don't know much about it, Christian Science is a sect of Christianity that maintains unsupported claims about "spiritual healing". (For a critical look at Christian Science claims, see my article here.)

Supposed evidence for Christian Science claims is nearly always anecdotal, and Barbara Fife did not disappoint there. She started with an anecdote about her husband who wanted to quit smoking. She prayed for him, and he was able to quit. This was offered in support of the idea that prayer can bring about change. From a scientific point of view, however, this kind of claim is essentially worthless, since it does not have any control. What if she had not prayed? Maybe her husband would have quit even sooner! Without a control, it is impossible to conclude that prayer was effective.

Ms. Fife discussed various definitions of prayer. In one definition, a prayer is a petition. Prayer, she claimed, is more effective if it is for self-improvement rather than material gain. Her prayer for her husband was unselfish and so it was answered.

Ms. Fife discussed various aspects of Mary Baker Eddy's life. She claimed Ms. Eddy was "scientific", when in fact Eddy conducted no experiments, had no scientific training, and was completely unfamiliar with the notion of double-blind study.

Ms. Fife related the story of her son, who had a bike accident and hit his head while at Principia College, the only Christian Science institution of higher learning in the world. Afterwards he threw up. Although his face was gouged, he was only treated with prayer and cleaning and bandaging of the wound and quickly recovered. Three weeks later at graduation his wounds were hardly visible. Again, this was offered as proving the power of prayer. But it is not surprising at all that one can naturally recover, without prayer, in three weeks from a wound like that. And it is certainly irresponsible, after a head injury with vomiting, that one does not get checked out by a competent neurologist.

She said that "God had a divine purpose" for everyone and nothing could change that, certainly not a bike accident. It makes me wonder, what was the divine unchangeable purpose behind Pol Pot?

Prayer, Ms. Fife claimed, helps us see and think differently. It is not to help God hear us; it is for us to be close to God.

She told the story of a woman who had uterine fibroid tumors. After she took up Christian Science the tumors shrank and disappeared. She did not mention the fact that fibroid tumors often shrink spontaneously, and this is perhaps due to changes in estrogen levels.

Ms. Fife claimed that Mary Baker Eddy's book Science and Health actually heals; there is a 130-year history of healings. Mary Baker Eddy "proved everything she wrote". There is a law of God underlying Creation. Anyone can pray and find healing.

All told, it was a fairly typical Christian Science performance: vague stories of healings, usually with no names given; claims of miraculous healing following prayer; no controlled studies ever referred to. After tepid applause, Ms. Fife did not take questions from the audience.

I went up afterwards and asked her, if Christian Science healing is effective, why is Principia College one of the very few universities in the US that has recurring measles epidemics? Why did Mary Baker Eddy need glasses? Why didn't she heal herself of poor vision? Why do Christian Scientists live shorter lives than non-Christian Scientists? Fife had no answers to any of these questions, saying only that Christian Science healers "need to do better". She said she had not read Simpson's study comparing longevity of Christian Scientists and non-Christian Scientists and she also said she was uninterested in reading it. Clearly, Ms. Fife is a woman whose mind is not open to evidence against her point of view.

Why was the University of Waterloo chosen as the venue for this talk? Possibly it was due to a wildly optimistic forecast of the number of attendees, but I would guess it was partly to give a "scientific" veneer to the claims made.

Canadian "Journalist" Sinks to New Low

Denyse O'Leary is a local Roman Catholic pro-intelligent-design, anti-evolution "journalist" whose writing is typically at the grade six level -- perfect for her audience. Based on what I've seen, she seems impervious to actual argument, preferring instead to slam what she delightfully calls "Darwinbots". In her writing, she rarely interviews people who disagree with her, and she elevates people who agree with her to the status of authorities. For example, she routinely refers to creationist David Tyler as a "physicist"; I guess that sounds better than admitting that he is a professor of "clothing design and technology".

But today she has sunk to a new low, by attempting to blame the recent murder at the Holocaust museum on Darwin's theory of evolution. Nearly all the commenters point out how insane this is, but, as usual, O'Leary is completely impervious to their reasoning.

If O'Leary were consistent, she'd also be blaming the crash of Air France 447 on Newton's theory of gravity.

Update: no surprise here - O'Leary's claimed "breaking story" isn't original with her; it comes from the odious David Klinghoffer.

Reviews that Hurt

Mathematical Reviews is a journal that attempts to provide a brief review of every legitimate paper published in the mathematical literature. Reviews are intended to summarize the content of the paper and put it into context, but sometimes the opinion of the reviewer shows through.

Here is one that I stumbled on today: "In the paper under review, ... performs elementary manipulations to produce several equations. The first few of these formulas involve P_r(n,k), the number of partitions of n into k relatively prime parts, while the last few involve R(n,k), the number of decompositions of n into k relatively prime parts. These formulas do not provide insight into the behavior of P_r(n,k) and R(n,k) so much as they demonstrate what sort of formulas result from certain elementary manipulations."

Ouch, that one's gotta hurt.

I have to admit, I wrote a review like that once, too. Here's an excerpt: "Their main result, Lemma 2.1, is equivalent to the statement that multiplication of 2 × 2 matrices is associative."

Jason Brown on Mathematics and Music

At the recent Canadam conference on discrete and algorithmic mathematics, Jason Brown of Dalhousie gave a great talk on mathematics and music. He accompanied his talk on the guitar, playing excerpts from jazz and rock standards to illustrate his points.

Jason was featured in the Wall Street Journal, among other places, for his work on using the Fourier transform to decode the mysterious opening chord in the Beatles song "A Hard Day's Night" (it turns out that the key ingredient is an F played on the piano).

Jason used his analysis of the mathematical underpinnings of Beatles songs to compose a song in the style of the Beatles, which he then recorded in the studio with musicians Scott Ferguson, Alex Vaughan and vocalist Hal Bruce. There's a great video of the performance of "A Million Whys" here.

Dejean's Conjecture Solved!

Dejean's conjecture is one of the oldest conjectures in combinatorics on words. Yesterday, at the CANADAM conference in Montréal (where I also gave a talk), James Currie and my former Ph. D. student Narad Rampersad announced the final step in the proof of this famous conjecture. That's Narad at the left and James on the right. (Photo courtesy of Amy Glen.)



Dejean's conjecture concerns repetitions in infinite words. A square is a repetition of the form xx, where x is a nonempty word. We can write this in shorthand as x². Examples of squares include the English word hotshots and the French word chercher. A cube is a repetition of the form xxx; the only example I know of in English is the sort-of-word shshsh. About a hundred years ago, the Norwegian mathematician Axel Thue gave examples of an infinite word over a 2-letter alphabet containing no cubes and an infinite word over a 3-letter alphabet containing no squares. It is easy to see that there are no infinite words without squares over a 2-letter alphabet, or cubes over a 1-letter alphabet.

More generally, one can try to avoid rational powers, not just integer powers. We say a string w is a p/q power if it can be written in the form x^kx' where x' is a prefix of x and the length of w is p/q times the length of x. For example, the French word entente is a 7/3 power, as it can be written in the form (ent)²e. Similarly, entanglement is a 4/3 power.

Dejean's conjecture concerns the largest possible exponent e such that there exists no infinite word over a k-letter alphabet avoiding powers of exponent e or greater. We write this exponent as RT(k), where RT stands for "repetitive threshold". Thue proved that RT(2) = 2. In 1972, Françoise Dejean proved that RT(3) = 7/4. She conjectured that RT(4) = 7/5 (which was later proved by Pansiot) and RT(k) = k/(k-1) for k ≥ 5.

Over the last 35 years the range of exponents for which Dejean's conjecture was known to hold slowly increased. Moulin Ollagnier proved the conjecture for 5 ≤ k ≤ 11; Mohammad-Noori and Currie proved it for 12 ≤ k ≤ 14. A real breakthrough occurred a couple of years ago, when Carpi proved the conjecture for all k ≥ 33. Currie and Rampersad then improved Carpi's construction to resolve k ≥ 27, and more recently they used Moulin Ollagnier's techniques to resolve the remaining cases 15 ≤ k ≤ 26. This competely resolves Dejean's conjecture. You can read Currie and Rampersad's paper here.

At the conference we also learned that (as is often the case in mathematics and computer science) nearly simultaneously, a proof of the remaining cases along different lines has been described by Michaël Rao of the Université de Bordeaux.

So congratulations to James Currie, Narad Rampersad, and Michaël Rao for finally resolving this famous conjecture!

Poll Confirms It: The More Religious You Are, The More Immoral You Are

Here's a link to a fascinating poll conducted by the Pew Forum on Religion and Public Life.

According to the results, 62% of white evangelical Protestants say torture against suspected terrorists can "often" or "sometimes" be justified. But only 40% of the "unaffiliated" agreed with that.

Among those who attend religious services at least weekly, 54% agreed that torture can "often" or "sometimes" be justified. But only 42% of those who "seldom" attend religious services agreed with that.

In other words, the more you are drenched with God-talk, the more you are likely to okay the abhorrent practice of torture.

The next time some theist rails about the immorality of atheists, point them to this poll.

What a Drag!

I just discovered last night that the slow leak we had in the kitchen sink leaked through the kitchen floor to the basement below. Unfortunately this was exactly where I was storing my issues of Skeptic (I had a complete collection starting with Vol. 1 No. 1) and Skeptical Inquirer, with the result that nearly all of the issues I had been saving have been destroyed by water and mold. I am now, with mask over mouth, removing all the issues and dumping them. Too bad -- I had planned to donate my complete collection of Skeptic to the local public library.

Michael Egnor Misses the Point

Whenever the Discovery Institute wants to hire a new spokesman, I imagine a conversation like this:

"Who can we get who is abysmally ignorant, illogical, and not afraid to show it?"

"Casey Luskin?"

"No, we already hired him. How about Michael Egnor?"

"Great idea. He has the added bonus of the arrogance of a surgeon. I'll send the invitation off right away."

Michael Egnor read my recent piece criticizing Margaret Somerville's article in Academic Matters. Somerville claimed that when parents decide to abort a child with Down's syndrome, that is a "eugenic" decision. "Only the decision not to abort when the fetus has Down's syndrome", Somerville claimed, "is not a eugenic decision". I pointed out that Somerville was doing here exactly what she decried earlier: labeling a decision she doesn't like as "eugenic", and therefore bad, without explaining why it is bad. I also pointed out that many parental decisions, such as choosing whom to have children with, could be considered "eugenic" in exactly the same way, yet I imagine Somerville would consider those acceptable. Following Somerville's logic, only picking someone at random for your mate "is not a eugenic decision."

But of course, Egnor missed the point entirely (and also managed to misspell my name). The point was not about eugenics, or Down's syndrome children at all; it was about Somerville's hypocrisy.

There are lots of other fallacies in Egnor's piece; you may enjoy spotting them all. Here are a few:

Here is how Egnor defends religion: "The existence of God is not a “ridiculous and unverifiable claim;” it's the conclusion reached by the vast majority of human beings living today and who have ever lived, and is a viewpoint held by most of the best philosophers, ethicists and scientists in history." Here he is using both the Fallacy of Appeal to Belief and the Fallacy of Appeal to Authority. Two fallacies in one sentence; truly a remarkable achievement.

Next, he claims there are thoughtful arguments for atheism (but doesn't provide a single example of an argument he believes is "thoughtful"). Then he dismisses the arguments of "Dawkins, Dennett, Harris, Myers, and Hitchens" as "puerile". (Of course, like Somerville, he doesn't give a single reason why he thinks this.) This is the Fallacy of Appeal to Ridicule.

He then invents an argument against Christianity -- ‘some bad things have been done by Christians, therefore Christianity is untrue’ -- and implies it is something that I believe (or that Dawkins et al. believe). This is the Fallacy of the Straw Man.

Next he goes on to smear Planned Parenthood, the National Organization of Women, and the Pro-Choice Resource Project as "eugenic". There's no denying that the word "eugenic" has a nasty reputation in our society, and Egnor doesn't hesitate to exploit it. (For the same reason, creationists love to associate "Darwinism" with both fascism and communism; they know how effective a smear can be to incite the Fallacy of Appeal to Emotion.) I can't resist pointing out that along the way, Egnor confuses "inference" with "implication".

Why does "eugenics" have a nasty reputation? It is not because the goal - to have healthy offspring - is something any parent would disagree with. After all, parents of Asheknazi Jewish heritage get tested for the Tay-Sachs gene, but I don't see Egnor labeling Dor Yeshorim as "eugenic" (but he would have to if he were consistent). No, it is because "eugenics" is equated in many people's minds with the centrally-directed, government-enforced, coercive eugenics advocated by the Nazis. It is one thing - and I think entirely acceptable - for parents to decide to not have a child with Tay-Sachs; it is another thing entirely for the government to murder or sterilize people perceived to have defective genes. Labeling both as "eugenic" is facile -- par for the course for Egnor -- but misses an essential difference.

Egnor goes on to say "In the atheist/Darwinian view, eugenics is moral, even virtuous." Here he is committing yet another fallacy: the Fallacy of Is-Ought. Darwinists (more properly, any scientist or person who understands the theory of evolution) are what they are because they hold to a scientific theory, not a description of ethical behavior.

Egnor then gives three reasons against parental choice. Unfortunately, none of them are very good. His first is "I have fairly traditional Christian beliefs, and I find the assertion that people should be bred and culled like farm animals to be repugnant." But when partners decide not to have children because (say) they both carry a gene like Tay-Sachs, or decide to abort a fetus that will have the disease, that has nothing to do with "be[ing] bred and culled like farm animals", unless the farm animals Egnor is thinking of are breeding themselves. By equating government-enforced eugenics with parental choice, Egnor commits the Fallacy of Equivocation. Furthermore, since 80% of pregnancies end unsuccessfully, with about half that figure attributed to genetic defects, it may be fairly said that Egnor's god is the Great Eugenicist in the Sky.

The second is "eugenics has stained my profession". But again, the eugenics that stained the medical profession consisted of, e.g., forced sterilization, not parents deciding whether to have children or to abort a fetus with a severe defect.

The third reason is that Egnor knows children with cognitive defects and finds they have value. That's nice, but nobody's claiming that these children should be killed or their parents made a mistake. What Egnor misses entirely, because of his sectarian religious viewpoint, is that for many parents, the decision is not between "having this child who will die a painful and gruesome death from Tay-Sachs before age 4" or "not having any child at all", but rather "having this child who will die of Tay-Sachs" or "not having it, and having a healthy child later on".

Finally, recall that my original question was "Why, exactly, would the world be better off with more Down's syndrome children?" Egnor says in response "The world is made better by every person." Even if we ignore the fact that Egnor's Pollyanna claim is clearly untrue (how was the world made better by Hitler or Pol Pot?), his response doesn't address the question. Parents are faced with limited resources. If they choose to raise a healthy child instead of an unhealthy child, why does Egnor want to refuse them that choice?

If Egnor really believes that the world would be better off with more Down's syndrome children, he should be doing everything he can to promote their production. As a medical doctor, he should be counselling couples to postpone having children until the wife is at least 40; after age 45, that increases the chances of having a Down's syndrome child to 1 in 19. Similarly, he should be encouraging older men to have more children, since paternal age is apparently a factor, too. Since he does not, it is clear that even Egnor does not believe that the world would be better off with more Down's syndrome children.

About 90% of parents decide to abort after a Down's syndrome diagnosis. If I shared Michael Egnor's fondness for logical fallacies, I would say that is evidence he is wrong. Instead, I will simply point out that most parents do not view having a Down's syndrome child as a good way to spend their limited parental resources. I don't demand that parents choose the way I would under the circumstances; I have great sympathy for parents faced with such a difficult decision, and I support their right to choose, no matter how they decide. Despite his attempt to tar me with the eugenic brush, it is his viewpoint that has more in common with totalitarian thinking.

And like the totalitarian, Egnor chooses to attack me from a forum that does not allow comments. What is he afraid of?

Monty Hall is out

A pleasant surprise arrived in the mail today: Jason Rosenhouse's new book, The Monty Hall Problem. I read a first draft of the book and found it excellent.

Alf van der Poorten says that the definition of a good book is that it mentions you. Under that criterion, this is a very good book indeed, as I appear on the back cover, giving the book an endorsement.

I recommend this book to anyone interested in probability.

Weird Google Maps Error

If you search for 2212 Line 34, Shakespeare, ON on Google Maps, you get a location that is something like 50 km from the true location. Shakespeare is actually between New Hamburg and Stratford, Ontario.

Google Maps seems quite unreliable for Southern Ontario. It used to be that when you searched for the Waterloo-Wellington
airport, you would get a location about 25 km from the true one.

It would be interesting to understand what about the data or algorithm results in such a bizarre error. It would also be nice if it were easier to report errors in Google maps.

Acknowledging Priority

One of the principles of publishing in mathematical and scientific journals is that, generally speaking, you cannot publish results that are already known.

Of course, publishing known results happens all the time anyway, because authors and referees cannot know the entire literature, and different authors use different terminology and notation. I once rediscovered a simple way to provide a lower bound on the size of nondeterministic finite automata, and published it, but later found out the result had already appeared in the literature -- indeed, the author had even sent me a reprint which, to my chagrin, I found languishing in my files. The point is that

1. Authors should not knowingly attempt to republish known results;

2. Referees should make at least some attempt to verify that the claimed results are new;

3. Editors should not agree to publish papers containing known results presented as if new.

There are some exceptions to these rules, however. Often one needs to state other researchers' results because the statement is crucial to the exposition. In this case, authors must be careful to provide the attribution and correct citation to the literature. In a "survey paper", one often brings together a large number of known results and tries to tie them into an overarching theme. Again, authors must be careful to provide the correct citations.

It is a violation of scientific/mathematical ethics to knowingly publish as new, results that are already known.

Recently a paper was submitted to a journal I edit. I sent it out to a referee, who observed that he/she had already refereed the paper for another journal, and the referee sent me the old report. That report pointed out that several of the results claimed as new were actually already in the literature. The authors had resubmitted the paper to me without making the required changes, acknowledging priority to others. This is a violation of mathematical ethics.

Margaret Somerville in "Academic Matters"

Here's a piece by McGill philosopher Margaret Somerville in the OCUFA publication Academic Matters. (OCUFA is the Ontario Confederation of University Faculty Associations.) I found it very shoddily argued.

For example, she rightly decries the suppression of speech on campus (something that I have also done; see here). But she then says "some people are going even further: they want to force physicians to act against their conscience under threat of being in breach of human rights or subject to professional disciplinary procedures for refusing to do so". I think these cases are not remotely comparable. The latter question revolves around whether physicians have the right to shirk their professional duty and engage in discrimination simply by calling their view "religious". Would Somerville also support the right of a physician to refuse to treat black patients, because the physician belongs to an Aryan church that views blacks as subhuman? I doubt it. Then how can she support the "right" of physicians to treat lesbian couples differently from heterosexual couples?

She says, "Political correctness operates by shutting down non-politically correct people's freedom of speech. Anyone who challenges the politically correct stance is, thereby, automatically labeled as intolerant, a bigot, or hatemonger. The substance of their arguments ... is not addressed ..." But then, just a few paragraphs later, she labels Richard Dawkins, Sam Harris, and Christopher Hitchens as "fundamentalists". I do not know exactly what she means by "fundamentalist" in this context, but it seems to me she is doing here exactly what she decried previously: applying a label to them without addressing the substance of their arguments.

Later she says "Only the decision not to abort when the fetus has Down's syndrome is not a eugenic decision". But here she is begging the question: why are decisions that she labels as "eugenic" necessarily bad? Why, exactly, would the world be better off with more Down's syndrome children? By her reasoning, positive assortative mating would be considered "eugenic"; yet most of us practice some form of it.

She seems to imply that religion deserves an equal place at the table as science. But she doesn't say why, other than to point out the obvious fact that many people hold religious views. Many people believe that 9/11 was a US government conspiracy, too, but I don't see why we are obligated to take their views seriously. With respect to religion, why should religious dogma, which maintains ridiculous and unverifiable claims, be treated in the same way as science and rational thinking?

Probably you can find more examples of shoddy argument in this piece. Academic Matters has a history of publishing anti-science and anti-rationalist screeds.

Fake Journal Publishing Scam

Here is an interesting scam that I hadn't seen before. Someone is sending out mail purportedly from the academic publisher Elsevier soliciting professors to submit papers to vaguely described journals. The scam is apparently that your paper gets "accepted" and then you are asked to pay "processing fees", which go to the scammers without any article ever appearing anywhere.

Then again, anyone who could be fooled by the ridiculous message below probably deserves what they get.


From: Elsevier Journals

*ELSEVIER*

*BUILDING INSIGHTS; BREAKING BOUNDARIES*
------------------------------

* *

*MANUSCRIPTS SUBMISSION*

Dear Colleague,

On behalf of all the Editors-in-chief of Elsevier Journals, we wish to
Communicate to you that we are currently accepting manuscripts in all Fields
of human Endeavour.

All articles published will be peer-reviewed. The following types of papers
are considered for publication:

- Original articles in basic and applied research.

- Critical reviews, surveys, opinions, commentaries and essays.

Authors are invited to submit manuscripts reporting recent developments in
their fields. Papers submitted will be sorted out and published in any of
our numerous journals that best Fits. This is a special publication
procedure which published works will be discussed at seminars (organized by
Elsevier) at strategic Cities all over the world. Please maximize this
opportunity to showcase your research work to the world.

The submitted papers must be written in English and describe original
research not published nor currently under review by other journals.
Parallel submissions will not be accepted.

Our goal is to inform authors about their paper(s) within one week of
receipt. All submitted papers, if relevant to the theme and objectives of
the journal, will go through an external peer-review process.

Prospective authors should send their manuscript(s) in *Microsoft Word or
PDF format* to *elsevierissues@live.com* and should Include a cover sheet
containing corresponding Author(s) name, Paper Title, affiliation, phone,
fax number, email address etc.

Kind Regards,

Emily Robinson(Prof.)

PS: Pls. show interest by mailing *elsevierissues@live.com* if your
Manuscript is not ready but will be ready soon.


I love the claim that "Papers submitted will be sorted out and published in any of
our numerous journals that best Fits."

I Feel Sorry for This Student

Here is some (redacted) e-mail I received today:


Dear Professor Jeffrey Shallit,

I am a Ph.D. student in the University XXX in XXX . I passed the theoretical courses and comprehensive exam and plan to defend my Ph.D. thesis proposal in next few months.
I would like to have your scientific support in my Ph.D. program as a co-supervisor. My Ph.D. thesis is about Cryptography Protocols.
In fact my research interest is about the following topics:
1. Distributed Cryptography Protocol such as Threshold Cryptography, secret sharing, ...
2. Security and Privacy Issue (specially Location Privacy)
3. Desinging and Evaluating Interactive Protocol
4. Digital Signatures

Please let me know if you could help me to define a research probelm or to define a project on any of the above topics to do it co-operatively.
I should mention that my M.Sc thesis was about XXX under the supervision of "Dr. XXX".

I do not need any finantial support. I'm looking forward to hearing from you.

I have attached my CV to this e-mail.


This student seems quite misinformed about the process. Finding a topic for a Ph. D. thesis is the job for the student and supervisor together; the supervisor suggests possible problems to work on, and the student surveys the literature and attends conferences to get ideas about others. But sending e-mail to request good topics is very likely to fail because (a) the number of really good problems is small (b) they tend to be jealously guarded by professors in order to distribute to their own students and colleagues. By a "really good problem" I mean one that few have thought of or worked on before, or a new approach to an old problem, and one that is likely to be interesting and have impact, and yet solvable in 2-4 years.

Finally, the student chose me to ask for topics, even though I have never published in any of the topics he/she listed.

This student is not getting very good advice from his/her advisers.

9/11 "Truthers" Meet their Waterloo - The Ron Craig Talk

The UW 9/11 Research Group, which previously sponsored two presentations by truthers, has finally gotten around to hearing the other side.

Ron Craig, a professor at Ryerson University with extensive training and experience in explosives, gave a talk Friday night in the Arts Lecture Hall at the University of Waterloo. Here's a brief summary:

He started by asking, "How many people here believe the WTC buildings were brought down by explosives?" Sadly, about half the people in the audience of approximately 100 raised their hands.

He then showed clips of the WTC buildings collapsing, some eyewitness testimony, and excerpts of last year's appalling presentations by A. K. Dewdney and Graeme MacQueen. He then asked rhetorically, "After seeing all this, how could you not believe the towers were brought down by explosives?"

Briefly, his answer was "expectation bias": investigators reach a premature conclusion without examining all the relevant data.

9/11 "Truthers" start with a presupposition, then look for data to support it. By contrast, real fire investigators start with documents such as NFPA 921, which outlines a scientific basis for investigating these incidents.

Craig pointed out that the WTC buildings used an innovative design for lightweight construction. They were the first super-high buildings to use this kind of construction, without heavy girders. The buildings weighed only 1/2 of what a conventional building would have weighed.

When demolition experts want to bring down a building, he said, they drill into columns and place the explosives. But no cement columns were used in the WTC. Furthermore, maintenance at the buildings reports that core beams above the 84th floor were inaccessible.

He then examined one claimed scenario for controlled demolition: in this scenario, explosives were placed on every floor. He then estimated how much explosive would be needed in this scenario, and came up with 1300 pounds of TNT-equivalent per floor, for a total of 143,000 pounds. Clearly this would be infeasible to set up without someone noticing.

Furthermore, such a large amount of explosive would have blown out windows in other buildings for blocks around. But this did not occur. In an explosive detonation, the typical inury is from flying glass, but there is no evidence that this occurred, nor evidence of other kinds of projectile injuries.

Explosives create heat of as much as 7000 degrees. Thermal injuries will be accompanied by primary blast injuries caused by pressure when the shockwave progesses through the body (e.g., middle ear injuries). "Blast lung" can occur at 50 to 150 psi. But not a single person in NY exhibited any symptoms of PBI.

Claims that thermite was used is undermined by the fact that no barium nitrate was found in the debris. He estimated that 61,000 pounds of thermite would have been needed. Again, it would have been impossible to set this up without someone noticing. Claims that sulfur was a signature of thermite/thermate are silly, because both the elevator shafts and stairwells were constructed with drywall, which is gypsum (calcium sulfate with 18% sulfur content).

Claims that molten steel was still flowing 21 days after the attacks are implausible. He showed one slide that supposedly depicted white-hot metal being observed by workers; it was actually just a worklight, as a video showed.

There is no good evidence that there were pools of molten steel. Many metals were at WTC, and low-temperature alloys could easily have formed. NFPA 921 says "if this occurs it is not an indication that accelerants were used or were present in the fire."

He then addressed the claim that "no other steel frame building has ever collapsed because of fire". He addressed other fires, such as this one at Delft. During the fire there was a partial collapse with "squibs" visible just as in the WTC.

He compared the WTC fire to other fires, such as the one in Madrid and One Meridian Plaza in Philadelphia. Both of these buildings had designs quite different from WTC.

Overall, I'd rate this part of the presentation as an A-. I think his points were very effective, although he could have also referenced the 1967 McCormick Center fire in Chicago, and he could have pointed to the lack of seismic evidence for explosions.

After the talk, there were some questions from the audience. One questioner asked him if he considered the "geo-political context" for 9/11. To his credit, Craig said that this was not his area of expertise; he is a fire and explosives expert, and his job is to look at the hard evidence, not speculations about motives.

Another questioner suggested that the Towers were brought down by some high-tech explosive invented by the government but unknown to everyone else. Craig found this suggestion (and a similar suggestion that "lasers" were used) ridiculous, saying that he regularly attends explosives conferences and such a thing could not be kept secret from experts.

Another questioner brought up the collapse of WTC 7. Craig said that he did not know for sure the cause of the collapse of that building, because not enough evidence was gathered yet. He said that he expects we will eventually know, because there is a strong motivation by architects, engineers, and insurance companies to understand the reasons behind the collapse, and many people are working on it.

I'd rate the question-answering portion as B+. Sometimes he simply reiterated previous points, instead of attempting to address the question from another angle, but overall he was generally effective.

Overall, I thought Ron Craig did a good job of demolishing the bizarre and unsupported claims by truthers that explosives brought down the World Trade Center buildings. Regrettably, it is unlikely to have much impact on truthers, who typically hold their beliefs with a religious fervor.

The Mother of All Rejection Letters

The Humanist Association of Canada Spring 1992 Newsletter contained the following item. Perhaps it is apocryphal, but it's funny even if not true.

"For writers only -- Every writer has received rejection slips; too many of them for most. The "Financial Times" has quoted the "mother of all rejection slips", translated from a Chinese economic journal. It goes like this:

We have read your manuscript with boundless delight. If we were to publish your paper, it would be impossible for us to publish any work of lower standard. And as it is unthinkable that in the next thousand years we shall see its equal, we are, to our regret, compelled to return your divine composition, and to beg you a thousand times to overlook our short sight and timidity."

A Conference I Won't Be Attending

Here is some conference spam I recently received:


Re: INVITATION for oral presentation at ICCE-17th Hawaii, USA

Upon review of your expertise in composite and nanotechnology of materials or physics/chemistry of materials/devices, and metals and concrete research, it gives me pleasure to invite you to orally present a paper at the coming 17th Annual International Conference on Composites or Nano Engineering, ICCE-17, July 26-31, 2009 in Hawaii, USA.. This is a truly “international” conference held in the USA, where the majority of the participants are from outside USA. The topic is broad to include almost all science and engineering, due to the emphasis of interdisciplinary research in nanotechnology.

The ICCE-17 Hawaii Call for Papers has received overwhelming responses of over 600 abstracts. The emphasis of the conference is to

(1) to learn the state of the art in hot topics where funding exists, such as Biomedical and Nano research on multifunctional materials and structures,

(2) provide a forum of exchange of ideas between Chemists, Physicists, Biologists, Engineers, mathematicians and mechanicians, to promote interdisciplinary approach to Nano/Biomedical/ Composites Technology,

(3) encourage participants to conduct interdisciplinary joint research and write joint research proposals

The venue hotel rate is being negotiated (prices falling due to recession), and the venue hotel and the island will be announced soon. The conference web is,

www.uno.edu/~engr/composite

These ICCE-17 detailed abstracts will be reviewed and appear as short papers in World Journal of Engineering, upon payment of registration fee and attendance of ICCE-17. Further, “all” full length version of these short papers, with paper title change, will be reviewed and published in WJOE or in Composites B journal. Thus, all participants will have two journal papers as a benefit of coming to ICCE-17 Hawaii. Due to budgetary constraints, we are unable to offer financial assistance.

Looking forward to seeing you in Hawaii.

Yours sincerely,

David Hui, Ph.D.,
Chairman ICCE-17 Hawaii, USA
Professor of Mechanical Engineering Univ of New Orleans
Editor-in-Chief, Composites Part B:
Doctor Honoris Causa (Italy, Nov. 2008, Vietnam, Dec. 2006, Ukraine, Nov. 2004)
dhui@uno.edu


This invitation has many signs of bogosity:

1. It was sent to an old address I set up 15 years ago for a conference and have not used since, a clear sign the author has used some spam service.

2. It falsely claims that I have been invited because of my "expertise in composite and nanotechnology of materials or physics/chemistry of materials/devices, and metals and concrete research", all fields that I have never done any research in. Also note the wide variety of unrelated topics listed as the theme of the conference -- this is quite unusual for a legitimate conference.

3. It has random grammatical errors and punctuation inconsistencies, such as capitalizing "Chemists" but not capitalizing "mathematicians", and putting "all" in quotes.

4. The author lists his honorary doctorates.

Sorry, I won't be going to this conference.

The Whininess Quotient

The Whininess Quotient (or WQ) of a class of students is defined to be the dimensionless quantity

(number of questions asked about how marks are assigned)
---------------------------------------------------------
(number of questions asked about content of the course)

The WQ can be classified as follows:

WQ < 1/2: Your class really cares about the material! Congratulations!

1/2 ≤ WQ < 2: Caution: whiners are beginning to dominate the conversation.

2 ≤ WQ < &infin: It's going to be a long semester.

WQ = ∞: Time to look for another university.