Wednesday, 23 March 2016

Philip Morse's imaginary glass tube

I've been reading a lot of acoustics textbooks to try to overhaul my ideas about how acoustics can and should be taught in the twenty-first century and today I settled down with Philip Morse's Vibration and Sound (2nd ed. McGraw-Hill, 1948). Morse was really driving the subject: Leo Beranek's description of his first research project at MIT was that Morse had developed the idea of impedance as a way of characterising walls and wanted someone to measure it for the first time (sorry, I don't have the exact quote from his memoirs to hand; they're well worth reading too). No wonder Morse's own memoirs were called In at the Beginning; though I've not had a chance to read them yet.

There's lots about Vibration and Sound that shows how the attempt to explain flows from the attempt to understand; even though it's avowedly mathematical it's also full of thought-experiments. One that particularly struck me introduces wave motion on a stretched string, something I talk about a lot when lecturing on Musical Instrument Acoustics, both to engineers and musicians. What he imagined was a string passing through a glass tube bent into the shape of a plane curve with its ends co-axial. The string is under tension and is being wound from one spool to another at a constant speed, and it travels through the tube without friction (as in all the best mechanics textbook problems). He works out the centrugal force on a short curved section of string (which varies with the square of the string's speed) and the force on the side of the tube on the inside of the curve due to tension (which is independent of speed). He then shows that when the string is spooling at a particular speed the resultant force between string and tube will vanish and:
"...we can carefully break away the tube from around the string and leave the string moving with velocity c, still retaining the original form of the tube, a wave form standing still in space."
  1. Before we had tape recorders we had wire recorders, my father used one when he did his national service with the Royal Signals. Could they have inspired this? Their 'brief heyday', according to that article I just linked was from 1946 to 1954. My copy's a 2nd edition from 1948, the first was published in 1936. If anyone has a first edition could they tell me if this is in it?
  2. The tone implies that the calculation of the forces on the tube is an elementary matter. Maybe so for students drilled on endless mechanics sets but maybe less so now. Much as I like this example I don't know that it would help my students as much. In those days acoustics was a graduate subject, often for students who'd learned electronics in the army and were, like Philip Doak, studying on the GI Bill. It might make a nice exam question though.
  3. Someone's got to do this experiment, it would be so cool. Not with a glass tube but the wire could run between rollers which could be withdrawn once the wire's up to speed. Then you could adjust the tension and move the wave back and forth.

Sunday, 28 February 2016

Slowness limits

A stretch of road that I regularly drive along recently had its speed limit reduced from 60 miles per hour to 50. No complaints from me, but I would like to know how much extra time to allow for my journey. A glance at the odometer tells me that the section with the new limit is two miles long so that means it'll take an additional ... err ... well ... an amount of time that I found rather tricky to work out in my head while driving.

Perhaps I'm just lousy at mental maths? For a week or so I annoyed my friends with this puzzle. Some worked it out sooner than others but none got it straight away and quite a few couldn't be persuaded/shamed into working it out without using pen and paper, or in some cases at all. Why is such a simple question so hard to answer?

The problem is speed, which is distance per unit time. If you're travelling at a speed of x 'distance measures per time measure' then, if you keep doing so for a whole time unit you'll have travelled x distance units. Hardly clear, I realise, and it doesn't help that I'm using 'unit' in two senses:in 'per unit time' it means with a value of one; in 'a whole time unit' it means the amount we use to measure time, be it hours, seconds or whatever.

The size of those measurement units determines the numerical value of the quantity - the Young's modulus of a material is an enormous number in SI units because it is the stress necessary to cause unit axial strain (i.e. doubling of axial length) and stress is force per unit area (in SI units a square metre). So the Young's modulus of steel is the force that would have to be applied to opposite faces of a one metre steel cube to stretch it till it was two metres long. No wonder it's a big number.

The measurement units might determine the numerical value, but the definition determines the meaning. With stress and strain there's a clear cause-and-effect: the stress causes the strain and the higher the material's modulus the more stress will be needed to cause the same strain. Is that the case with speed?

How often do you get in a car knowing how much time you intend to drive for but with an open mind about how far you're going to travel? In that strange situation knowing your speed is useful, because it tells you how many more miles each of the remaining seconds will add to your total distance. But what we almost always do is travel a set distance and want to know how long it will take. You might have a time constraint as well as a distance constraint but the distance constraint always wins: "Sorry, I couldn't drive fast enough so I got to the meeting five minutes late" might annoy your colleagues, but "Sorry, I couldn't drive fast enough so I stopped a mile away when it was time for the meeting to start" will annoy them more.

So we adjust speed in order to control arrival time, hopefully subject to speed limits. When you're running late it's tempting to go faster in order to get there sooner, but do you have a clear idea of how much journey time you save for a given increase in speed? I'd say no for two related reasons: as we've seen above it's a hard calculation to do, and the effect on journey time depends on how fast you're already going. As a result I suspect that some drivers who break speed limits do so because they overestimate the time it will save them. That's a testable proposition and I'd be interested in knowing if anyone's tested it, but for now I'm just going to assume it's true.

We could avoid the whole situation if we switched from speed to slowness, the reciprocal of speed. A speed of 60 miles per hour is a slowness of one sixtieth of an hour per mile, or 60 seconds per mile. If I tell you that a two-mile stretch of road has had its slowness increased from 60 seconds per mile to 72 seconds per mile the additional journey time will be obvious, and it'll also be clear that it's not a big deal; the additional 24 seconds is down in the noise compared to the uncertainties in my journey time.

The slownesses corresponding to our current speed limits mostly come out to whole numbers of seconds per mile because the number of seconds in an hour, 3600, is highly composite (thanks, Babylonians). So 10, 20, 30, 40, 50, 60 and 70 mph correspond to 360, 180, 120, 90, 72, 60 and 51.43 spm (oh well Babylonians, you did your best). Let's round that last one up up 52 spm, or 69.23 mph, rather than down to 51 spm, or 70.59 mph.

If we're going to argue that using slowness could reduce the perceived advantages of going faster when you're already going fast then we should consider what the effect will be when you're going slowly. Schools on main roads, which already have 30 mph speed limits, quite rightly have signs saying "Twenty is Plenty" - might motorists be less willing to increase their slowness from 120 spm to 180 spm than they are to reduce their speed from 30 mph to 20 mph? They might be, but the remedy is to address what they care about, journey time, with a sign saying "Take an extra 10 seconds [say] to go past our school at 180". OK it's not as snappy as "Twenty is plenty", nor does it rhyme, but someone can work on that.

You might be wondering what this has to do with acoustics: when we use rays to find approximate solutions to short-wavelength wave problems it's very common to calculate the slowness along a ray, when can be integrated over the ray's path to give its total travel time. This usage started in seismology (i.e. low-frequency short-wavelength solid acoustics) but shows up in plenty of other areas of acoustics.

Rays, however, have an important difference from cars: they don't stop at traffic lights. If we're calculating journey time by integrating slowness with respect to distance and the car stops we'll have a singularity, where slowness is infinite for an infinitely short section of the journey. Fortunately most cars have clocks and time proceeds untroubled when the car stops, so the time spent stopped can just be added to the journey time. As a bonus your slow-ometer (the old speedometer with a new dial) would have an infinity symbol on it which would a) look cool and b) encourage mathematical literacy.

Unlikely though this is to happen there's a more serious point here: the fact that speed and slowness are mathematically equivalent does not mean that they are psychologically, sociologically or political equivalent and there are plenty of similar choices to be made. Sticking with cars do you measure its mileage or its fuel consumption? Which map projection should you use when you plan an international trip? There are arguments to be made in each such case; I don't intend to make them here but my overarching point is that engineering is, or should be, a person-centred discipline and engineers have to think about these things - getting the maths right is necessary but not sufficient.

Postscript: There's an important case in acoustics where reciprocal quantities are less equivalent than they seem. When I first learnt that admittance was the reciprocal of impedance my reaction was to wonder why I was being asked to, effectively, remember a new name for something I already knew, and the fact that the real and imaginary parts of each had a special name didn't change my mind. It was much later that I encountered the multi-channel case where the admittance matrix is the inverse of the impedance matrix that I appreciated the value in having both concepts, so I try to explain that when introducing the concepts to my students.

Saturday, 26 September 2015

Memories of Geoff Lilley

On Monday morning I got a phone call telling me that Professor Geoffrey M Lilley had died the previous day at the age of 95. The news, though sad, wasn't entirely unexpected; he'd been quite frail for some time and several planned excursions to visit him earlier in the year had had to be put off as he hadn't been feeling up to it. This obituary, posted by the University of Southampton refers to his 'wit and skill as a raconteur', and when I emailed some of his former friends and associates I wrote "Doubtless lots more will be written about him in due course - everyone who met him came away with a story'.  I thought I ought to write down my 'Geoff stories'while I remember them and here seems as good a place as any to make a start - he takes a while to make his appearance in this one, I'm afraid.

Non-Standard Analysis

 My first paid work (as opposed to study) at the ISVR was on boundary-layer suction. I needed to brush up my knowledge of boudary-layer theory - the fluid dynamics lectures I'd had from the formidable Professor P O A L Davies as a BEng Engineering Acoustics and Vibration student in the late 80s, while fascinating and challenging, hadn't given me as solid a grounding as our current MEng Acoustical Engineering get nowadays.

Around the same time I read The Problems of Mathematics by Ian Stewart and was intrigued by the chapter about Abraham Robinson's Non-Standard Analysis. During my PhD Joe Hammond, my supervisor, had encouraged me to make contact with David Chillingworth in the Maths department and take his course on Advanced Calculus with Applications. Another fascinating course, this one from a pure mathematician (the 'application' turned out to be that if we were to cut out two particular cardboard shapes, glue them together with cork spacers, stand the result on its side and persuade a heavy enough beetle to walk along one of the perpendiculars, the structure would topple over when the beetle crossed a particular curve) and it introduced me to rigourous methods while showing me how little I, an engineer, knew about that whole area. Non-Standard Analysis seemed to offer a way to formalise the way engineers thought about infinitesimals and, Stewart suggested, allowed results to be obtained that would be much harder to derive by standard methods - 'canards' for instance.

The chapter's last section was called Logic for engineers (no offence, eh?) and mentioned some areas of perturbation theory where it had been applied, one of which was boundary layer flow! This was exciting - perhaps I'd stumbled across a skeleton key that would enable me to unlock wonderful new results in boundary layer theory that couldn't be found any other way? I had to find out more, but all the references for the chapter seemed to be mathematical expositions of the method rather than applications, none more so than Robinson's original book on the subject which I flicked through but found very dense after Stewart's gentle introduction. I asked David Chillingworth if he knew who had applied Non-Standard Analysis to boundary layers. He didn't know but asked Ian Stewart. He couldn't remember where he'd got the boundary layer story from. I searched for references to Non-Standard Analysis in the engineering literature and found that Feri Farassat at NASA had been using them for infinitesimal shock thicknesses, which looked promising but the next time I met Feri I asked him about not only did he not know the boundary layer reference he warned me against using it for perturbation problems at all.

I'd run out of leads when I met Geoff in the staff dining room. (In those less crowded days every table had paper napkins arranged alternately white and coloured - it was understood that the coloured ones were absorbent and were for mopping up spills, while the white ones were for sketching graphs and equations.) Geoff asked what I was up to and I told my tale, somehat surprised by the delight he seemed to be taking in it as I really wouldn't have expected him to have much interest in that sort of thing. His broad grin made it clear he knew something I didn't. The story soon unfolded: when he was at Cranfield College of Aeronautics Geoff had been friends with the inventor of Non-Standard Analysis Abraham Robinson who in the 1940s, despite his main field being logic and analysis, had thrown himself into aerodynamic theory as a contribution to the war effort and become a senior lecturer there. Geoff explained that they used have endless arguments about the importance of rigour and that Geoff had teased him that his ideas were all very well but irrelevant to anything he was interested in. So when 'Abie' published his comprehensive book Non-Standard Analysis he took great delight in giving Geoff a copy and telling him "I've even put in a boundary layer example, just for you!". I went back to the Library and there it was hidden away at the back, a derivation of the basic equations in one paragraph. And if it hadn't been for Geoff it wouldn't even have been there at all.

Sunday, 31 May 2015

Passive Resistance

Professor Lorena A Barba is one of my academic heroes; her 12 Steps to Navier-Stokes changed the way I think about CFD, coding and teaching all at once. If you haven't seen it or its successors then finding out about them is more important than anything that follows in this blog post. Anyway, recently she tweeted something I disagreed with:
but I made a fairly bad job of explaining why on twitter - this post is an attempt to do better.

First I have to refer to another of my academic heroes, Professor Geoffrey K Pullum, whose writing has changed the way I think about language and grammar (and who's no slouch at computer science either), for a thorough explanation of what the passive voice is.  It's far from straightforward and GKP rightly contends that the PV is often misidentified, with both Type I and Type II Errors common (not that I'm suggesting LAB makes either).

So what's wrong with the PV? One complaint is that they obscure agency, as in "decisions were made". Obscuring agency is usually bad, though there are times when it can be done out of sensitivity rather than evasiveness and there are times when the actor is unknown or irrelevant. At one time teachers and editors alike insisted that scientific reports be written entirely in the PV because scientific writing was supposed to be dispassionate - all actions were taken to be the author's, but since procedures should be reproducible it shouldn't matter who performed them, they should be described in enough detail that anyone could do them. This produced plenty of dull writing and the anti-PV movement is, at least in part, a reaction to that.

But as GKP shows there are numerous ways to obscure agency without using the PV. Conversely the PV doesn't have to obscure agency:
Gentlemen, the autopsy reveals that Sir Edgar's face was eaten by zombies!
doesn't leave any doubt about who is being accused.

Another complaint about the PV is that by postponing the revelation of the actor it forces readers to hold images in their heads until that revelation makes sense of them. LAB tweeted a typical example:
The first visible-light snapshot of a planet circling another star has been taken by NASA's Hubble Space Telescope.
That sentence is doing quite a lot of work, as is the way with such journalistic announcements, and one could quibble that it's not clear whether the snapshot is the first ever taken of that phenomenon, or just the first that NASA's HSC has managed to take. But I'm just as happy to be told that

  1. There's a snapshot.
  2. It's of a planet.
  3. The planet is circling another star
  4. The snapshot's been taken (rather than, say, sold).
  5. It was taken by the HSC.
in that order as I am to be told that
  1. The HSC has done something.
  2. It's taken something.
  3. The thing was a snapshot.
  4. The snapshot was of a planet.
  5. The planet was circling another star.
by the active recasting:
NASA's Hubble Space Telescope has taken the first visible light snapshot of a planet circling another star.
By the way, the ambiguity  about the firstness has gone, but now there's a possibility that the HSC is circling another star rather than, or as well as, the planet. But accepting that delayed revelation can be bad there are ways to do it without using the PV; see Kingsley Amis's 'gorged-snake construction':
'Looks like we're out of the woods for a bit', laughed the tall dark sun worshipper as he dubbined with his own hands the boots that...
My real concern about the anti-PV position is that it teaches a rule (don't use the PV) instead of a reason (obscuring agency can withhold useful information; delaying revelations can make reading hard work), and as academics we should be dealing in reasons rather than rule-following. Following the reason would probably result in less use of the PV, whereas following the rule would leave all the ways of achieving the same bad results without using the PV unexamined. There's an analogy with coding; my students often write bad code by using try and catch statements to enclose error-prone routines. Rather than impose a rule (don't use try and catch statements) I prefer to teach a reason (if your routine sometimes produces an error you probably aren't sure it's doing the right thing) as I'm sure most others would.

The problem is that because we have such a tradition of prescriptive, rather than descriptive, grammar we put up with rules far more than we would in other spheres, the most notorious example being the so-called split infinitive. Here the rule is "don't" and the reason is "because I say so" with various cod arguments about imagined derivation from Latin retrofitted. It became a self-fulfilling prophecy and generations learnt to do without this occasionally useful construction and to use alternatives, often clumsier, instead. Now they genuinely find SIs awkward and ugly because they've been conditioned to do so*.

Take coding again: if you don't declare all your variables before using them in a statically-compiled language like Fortran you'll get into trouble, so programmers were taught to always begin a program with declarations for all variables and lost marks when they didn't. When dynamically-typed languages like MATLAB and Python became popular the reason no longer applied but plenty of lecturers still insisted on the zombie rule. Indeed I remember being told that we shouldn't use MATLAB for teaching because it let students get away without writing 'proper' programs, i.e. ones that pre-declared variables. Of course there are other reasons to set up or list some variables at the start of a program (and reasons not to teach MATLAB**).

Now I'm starting to see the PV rule go the way of the SI rule, some people frown when they read a certain clause not because the PV has made it unclear or awkward, it's the passive construction itself that bothers them. And that in turn means that their students are avoiding them because their professors don't like them and for no other reason. It diminishes the language when parts of it are walled off, and it diminishes our students if we tell them to avoid things we don't like. Will the same people who winced or tutted at Star Trek's 'to boldly go' soon do the same when I sing 'These words were composed by Spencer the Rover'?

* I once hurriedly wrote something like "this University's internationally leading research..." to the dismay of a colleague. Had he said no more than that it was inelegant I wouldn't have disagreed, but he insisted that it was grammatically incorrect to separate a possessive from the thing possessed by both an adverb and an adjective, and made dark allusions to split infinitives and the poor state of teaching in my homeland. I assumed, since he was not without a sense of humour, that he was parodying the typical grammar buffoon so I composed a response in the same vein starting "my frightfully dear fellow" and finishing "your humbly obedient servant" with as many other examples of the dreaded construction as I could cram in between. It turned out that he was completely serious. I wish I'd offer to donate money to a charity of his choice if he could find any authority for his 'rule' as long as he reciprocated when he found he couldn't. I just hope his enjoyment of Charlie Brown wasn't spoiled too much when Frieda talked about "my naturally curly hair".

** Or, indeed, to not teach it. For what it's worth I invite you to imagine the content of two public information films, the first entitled "How Not To Paint Your House", the second "How To Not Paint Your House". The first would show an enthusiastic but inept person doing the job very badly; the second would show another snoozing in s hammock while the house in question peels and rots.

Sunday, 11 August 2013

An engineer's approach to the Instant Insanity puzzle

Last month we had the pleasure of a visit from my old friends Colm Mulcahy and Vicki Powers, both US maths professors. Vicki had been attending a meeting at the Isaac Newton Institute and Colm was giving talks based on his new book Mathematical Card Magic including one, at my suggestion, at Winchester Science Festival where I was speaking on "How Science Shaped Music". It was great to catch up and for my family to meet them, and Colm kindly brought several puzzles for David, including the one I want to write about here. 

Instant Insanity is the usual name for a set of four cubes with each face having one of four colours. The challenge is to pile them up so that each side of the stack shows each colour once. When I'd first heard of it as a child I'd mistaken it for Charles Hinton's four colour cubes, which he claimed helped develop intuition about four-dimensional shapes, mentioned in Martin Gardner's Mathematical Carnival. Gardner quotes a correspondent who claims Hinton's cunes drove him to the edge of madness; I must have heard that a four-colour cube puzzle was called Instant Insanity and conlcluded that this was it. But it isn't.

There's an analysis here (ppt) by Patrick K Asaba that uses a decomposition pronciple and graph theory to find a solution and show that it's unique for a particular set of cubes (how many different sets are out there, I wonder?) I've nothing against it, but not being a graph theorist I preferred to attack it with more basic tools and, possibly, more of an engineering approach.

First, how hard is the puzzle? As Asaba observes, each cube has 24 symmetries, though rotating the stack about its axis doesn't destroy a solution so I'd count the configurations to be chosen from as 82,944 rather than 331,776. That's still a lot, and suggests that brute force won't be any use so some thing elegant (like graph theory) will be needed. On the other hand, imagine that each cube had been drilled through, and a rod inserted through them. From that point, it would be fairly easy to either turn the cubes so that they solved the puzzle or to conclude that the wrong faces had been drilled and that no solution is possible. In fact here's a short piece of Mathematica code that allows you to 'turn' the (unfolded) cubes, and to reverse them, since they can be slid onto the rod either way up.

s = {{0, 0}, {0, 1}, {1, 1}, {1, 0}};
cols = {Red, Blue, Green, Yellow};
f = {{2, 3, 1, 4}, {3, 2, 4, 1}, {1, 4, 4, 2}, {2, 3, 1, 3}};
  Module[{q = j}, {Button["<", f[[q]] = RotateLeft[f[[q]]]],
     Dynamic@Table[{cols[[f[[q, i]]]],
        Translate[Polygon[s], {i, 0}]}, {i, 1, 4}]],
    Button[">", f[[q]] = RotateRight[f[[q]]]],
    Button["<>", f[[q]] = Reverse[f[[q]]]]}], {j, 1, 4}]]

So how many ways of drilling and sliding the cubes are there? Each cube can be drilled three ways, and once the first one is on the rod each subsequent one can be oriented two ways, so 3 x 6 x 6 x 6 = 648. Still more than I'd care to try individually but a lot less daunting than 82,944. Here are the four sets of three choices for our set of cubes:





(the set Colm gave us had yellow faces rather than white ones.) Our task, then, is to pick one line from each group, each of which can then be flipped and rotated until a solution is found. There are only 81 ways of doing this; can we exclude some at this stage?

Once we've chosen our four rows there have to be four of each colour, and that's by no means guaranteed with a random choice. We can exclude the Y G Y Y row from the second row from further consideration, because that would mean that only one other row can have a Y in it, so that the first and fourth cubes would have to show B G R R and B G R G. The remaining row from the third cube would have to one Y and no G, which none of them do. 

We can tabulate the number of times each colour appears on each row:

B G R Y 1 1 1 1
G G R Y 1 0 2 1
B G R R 2 1 1 0

Y B Y R 1 1 0 2
Y G Y Y 0 0 1 3
G B Y R 1 1 1 1

R Y G B 1 1 1 1
R R G Y 2 0 1 1
R Y Y B 1 1 0 2

B B R Y 1 2 0 1
B G R G 1 1 2 0
G B G Y 0 1 2 1

We can't choose four lots of 1 1 1 1 because the fourth cube doesn't have any. We could interpret rows of numbers as the digits of single numbers and try the 54 remaining ways of adding them up to see how many give 4444. As it happens there are five. This might be a little too much brute force for your tastes but the chances you'd go insane before you found them are reasonably slender.

[to be continued]

Friday, 19 October 2012

Skeptics in the Pub: forum or echo chamber?

Unless you've been living under a rock you'll have heard of Skeptics in the Pub; it's a brilliant idea where (as the name implies) a bunch of skeptics meet once a month or so in a pub or other convivial location for an address by a guest speaker. Mobility and other commitments haven't let me get to nearly as many sessions as I'd like, and no one seems to have invited me to speak at one though I've given skeptical talks elsewhere in the past based on my Short History of Bad Acoustics as well as more cafe scientifique type stuff. But most of those I've been to I've greatly enjoyed and I'm grateful to their organisers for doing something I wish I'd done when I was younger and  had the energy. I just think they might be missing a trick.

All the speakers I've heard of being invited to SITP sessions are skeptics themselves, and many of them are fine speakers with important things to say. A few, and I won't name names, seem to be there to tell skeptics to be skeptics, which strikes me as 'preaching to the choir' (though as an atheist ex-choirboy that's not as pointless as it sounds).

Recently a SITP group announced that one of their future speakers would be Rupert Sheldrake, proponent of 'morphic resonance', the idea that you can tell when you're being looked, and that dogs can tell when their owners are coming home. Not many people take these ideas seriously, and  disabusing those who do doesn't seem to me to be the world's most important job. But for the record I disagree with all his conclusions and dispute the reasoning that leads him to them. So is his appearance at a SITP meeting a good thing or a bad thing?

Several twitterers made it clear that they thought it was a bad thing. I'm not so sure, but don't find it easy to condense my reasons into twitter-length, hence this blog-post. The thing is, regardless of how wrong I think his conclusions are, I find the process of identifying and articulating the flaws in his reasoning useful. I'm also aware that I'm not as good as I'd like to be at calmly and lucidly expressing and explaining my opposition to some ideas.

It's a sadness to me that the last time I saw an old friend before his death it was over a cheeseboard and our conversation went from Shropshire Blue to organic farming to homeopathy where it became clear we had a difference of opinion that I allowed to escalate into an unproductive slanging match. I don't suppose I had much if any chance of changing his mind but I could have expressed my reasons better than I did, and maybe influenced some of the other people present if any of them were on the fence. As it happened neither of us was much of an advertisement for our viewpoint, not helped by the fact that we were both in wheelchairs, so a bystander wouldn't have seen either of us as an example of healthy living.

So I'm prepared for the possibility that, as predicted by my twitter-chums, Rupert's SITP session will descend into a 'slagging match'. But I hope it doesn't, because if we Skeptics can't disagree with someone without losing our individual or collective rags then we've got a problem. And frankly I think we can do with the practice, myself included. Some have suggested that this is like the 'false balance' that programmes like Today are often accused of. Maybe it is, but sometimes false balance is all you've got: suppose Today asked you to come on and discuss Rupert's views with him and a presenter who imagines that the truth must lie somewhere between your viewpoint and Rupert's. Opt to stay in bed and he'll go unchallenged. Appear and employ all the withering scorn you like at whichever preposterous idea he's pushing this week but I guarantee that he'll come across as more reasonable and persuasive than you will. Are you quite sure you don't wish you'd come to his SITP session and tried out a few counter-arguments before getting in the Radio Car?

Dog telepathy and so on  is all very well, but homeopaths who provide malaria 'prevention' are potential killers, that should make any self-respecting skeptic's blood boil, shouldn't it? No disagreement from me, but remember when Simon Singh  took them on on Newsnight; each time he was firm and eloquent but he was also calm and respectful. I know too many skeptics who just couldn't manage it, and could do with some practice.

Has the SITP group that invited Sheldrake inadvertently endorsed his views by inviting him to speak? I don't think so, but it would be a lot easier to counter that claim if he weren't seemingly the only non-skeptic ever to be invited to such an event. By the way I'm struggling to find a word for the type of speaker I mean; 'woo' is nice and short for twitter purposes but doesn't really capture it, and non-skeptic has the drawback that everyone considers themselves to be skeptical. Anyway, whatever you call them I'm not for a moment suggesting that they'd all make appropriate SITP speakers. Many are so incoherent and or deluded that debating with them is impossible and an attempt would probably just exacerbate mental health problems. The only place I want to see 'Jasmuheen' is in prison, possibly a psychiatric one.

But that's not the case with all of them and there's a difference between someone with whom debate is impossible and someone who's opinion it's impossible to change by debate. I don't for a minute think that Rupert Sheldrake is going to change his mind during his SITP session, or that any skeptics are going to come around to his views, but debate is worthwhile even so. I'd suggest that my University of Southampton colleague Professor George Lewith would be an ideal candidate for an SITP invitation. I don't agree with his conclusions but I'm sure he can respond to counter-arguments without blowing his top, and I wish I could be surer that the same could be said of a SITP audience.

One last point: you might think that this class of invitee would be unlikely to accept such an invitation (though apparently Sheldrake did). Fine. Being able to say "We invited X to present his case for alien abduction/crop triangles/etc to an audience of skeptics but he/she declined" is not without value. In the meantime, debate is too important to be left to the Institute for Unspeakable Ideas.

Wednesday, 30 November 2011

US National Academy of Sciences announces new patron: Jenny McCarthy

 For immediate release

Jenny McCarthy to be next Patron of US National Academy of Sciences

Washington DC: At a crowded press conference today a spokesperson for the US National Academy of Sciences confirmed that its next patron would be noted actress, author and activist Jennifer McCarthy. Reading from a prepared statement the spokesperson explained that the role of patron is principally that of a ceremonial figurehead and is traditionally given to a figure from the entertainment industry whose public profile and connections would allow them to showcase the work of the Academy. The spokesperson continued:
"Ms McCarthy is Hollywood Royalty, and will attract the sort of attention that we could never hope to on our own. We look forward to strengthening our relationship with her, which began when she was awarded honorary Membership of the Academy under the special rules that allow us to admit selected showbusiness legends, though without voting rights."
Responding to questions from reporters the spokesperson dismissed as 'malicious gossip' the suggestion that Ms McCarthy's record of statements claiming a link between vaccination and autism and sustained criticism of the scientific community might conflict with the Academy's stated aims, stating that "As I already said, the role is ceremonial, her views are her own, and anyone who thinks they disqualify her from playing a role in the Academy's mission is obviously nursing some kind of anti-showbusiness grudge." Asked to confirm that the appointment was for life the spokesperson reminded reporters that Ms McCarthy would only take up the post after the death of the current incumbent, Shirley MacLaine.


[The above press release is, of course, both fictitious and absurd. I wish the Royal Society (the UK Academy of Science) the best of luck when the time comes for them to issue an announcement that, while equally absurd, will sadly be all too real.]