Looking Out To Sea

Comment of the century, on the wonders of herbal medicine:

The great thing about British herbal medicine, of course, is that it’s automatically geared to be very compatible with your physiology.

That’s foreign herbs bad, native herbs good for those still boggling.

Monday night’s Cafe Scientifique was magnificent and I feel very sorry for all those people who didn’t come. It was about synaesthesia and given by Julia Simner from Edinburgh University.

Synaesthesia seems to be about as fascinating a subject as anything to study, with all sorts of revealing facts about language, learning and development, neuroscience, memory and childhood lifestyles being wrapped up in the heads of synaesthetes.

So what is synaesthesia? Essentially, it is “creation” of sensations when unrelated parts of the brain are activated. For instance, tastes might also give the sensation of texture on the back of the hand, or words might activate tastes or colours. The pairings are related to the proximity in the brain for the different sensations — associated pairs always turn out to be adjacent in the brain. For a particular stimulus the sensation will always be the same for that person — “William” will always taste of potato for that person.

So, some interesting facts:

• If you get a colour sensation when reading letters then the colours will not be arbitrary, though any two synaesthetes may disagree on the particular colours. The commonest letters and commonest colours often pair up: ‘A’ is often red and so on.
• Forcing non-synaesthetes to choose colours for the letters of the alphabet tends to produce very similar links between the commonest colours/letters.
• Word/taste synaesthetes have a similar distribution of tastes, according to their childhood diet. So there will be many sweets and sweet-flavoured words, and few or no alcoholic ones.
• Synaesthesia is a heritable condition because it is caused by a hyper-connecitivity in the brain. I asked whether this has any effect on prevalence of epilepsy, though she didn’t know. She was aware that many synaesthetes seemed to complain of migraine.
• The extra sensations can be useful in test situations — letter-colour synaesthetes tend to perform better in spelling tests. People who see colours when hearing words are better at transcribing voices when listening to noisy signals like a badly tuned radio.
• Most synaesthetes seem to have only one form of synaesthesia though it can happen that many sensations can kick off many others, which can be quite discomfiting.
• Some synaesthetes see a ‘ticker tape’ transcription in front of them as they hear voices — literally like their own private subtitles.

There were loads of other fascinating things that we spoke about that evening. To get a little taste of the subject why not read up on Dr Simner’s appearance in Nature — she was on the podcast which has a transcript online as well as in the journal. (I think I made her day by mentioning that I remembered her on the podcast from two years ago. She thought I was the only person who must have listened to it. So go listen!)

Let this be a salutary lesson on the dangers of impulse buying. If you don’t spend a few minutes reading reviews on Amazon you might accidentally buy Amir Aczel’s The Artist and the Mathematician, the “story of Nicolas Bourbaki, the genius mathematician who never existed”. And that would be a mistake.

Nicolas Bourbaki was the pseudonym of a group of French mathematicians who attempted to formalise mathematical thinking in the early to mid-twentieth century. In the author’s opinion Bourbaki’s publications had important influences on the structuralist movement that would spread from linguistics and anthropology to many disparate areas of science.

Well, I wouldn’t know about that; and I still feel like I don’t know about it. The book is filled with tedious and trivial details where it should provide only impressions — and sketchy and vague where it should be exact and clear. In fact it exemplifies everything the Bourbaki group were pushing against. Aczel takes whole chapters to explain the minute detail surrounding the early life of one mathematician (including the life of his parents when they were young…) though this has no real relevance to the work he did. In fact, now I think on it I can’t even remember which mathematician gets all the boring backstory.

Whatever: the point is that the writer doesn’t bother telling you why any of this matters. He name-drops mathematical ideas without context or explanation. They have no more relevance to the reader than the endless litanies of people and parents’ occupations and meetings and so on. Amir Aczel insists that Bourbaki was incredibly influential in whatever it was they did, without bothering to reveal whatever it was they did. And that many other fields borrowed these ideas to do whatever it was that they did, again without explanation or detail. And then eventually we find that Bourbaki became less relevant — though again, without explanation.

It’s quite satisfying to say that an author who talks about abstract algebras and category theory is “over-generalising”. If only the book were as satisfying. Instead, I can heartily recommend Mario Livio’s The Equation That Couldn’t Be Solved — a proper tribute to genius mathematics.

Today’s crazy thought was inspired by Scott Aaronson’s lecture notes/discussion on The Emperor’s New Mind. He notes that, for human thought to be computable then it must be equivalent to a Turing machine. So, the author of The Emperor’s New Mind, Roger Penrose, must be equivalent to a particular machine M.

Does M output the following sentence?

“Roger Penrose will never output this sentence.”

Well, we don’t know what that means — for a person to “output a sentence”. For a classically defined Turing machine we know what it means, but not for humans. I’m sure Roger Penrose could say the above sentence but that’s not what the statement means. I certainly don’t know, though I can talk nonsense as much as anyone.

It did bring to mind a discussion with Nick in a previous comment thread, about believing one’s own opinions. From the accusation that “you always believe your own opinions are right” it seems reasonable there must be people who believe their own opinions are wrong. Why would one hold opinions that you acknowledge to be wrong? Is it even possible?

I suggest that one of the limitations of the Turing machine M, which we call Roger Penrose, is that it cannot believe things it doesn’t believe. Obviously! The fact that I thought it worth writing a blog post about is probably what makes this crazy.

There was a man on the bus this evening who was furiously scribbling little mathematical notations on a grubby piece of paper. I was so curious to find out what he was doing! He was really going for it — several lines of closely-written squiggles. The only things I could make out properly were the long division lines separating numerator from denominator, and some Σs.

Was it maths? Physics? Engineering? I want to know! :-) It makes such a change from people reading Jackie Collins or talking loudly on their phones.

I got a phone call this afternoon from my aunt and uncle asking if my parents were okay in China. They are fine, though there might be difficulty getting out of the country now? I’m not sure, maybe there is not much disruption. It’s a very large place, after all.

A wee while back Rowan Williams got in a bit of trouble with large parts of the thinking world for, amongst other things, saying evolutionary biology was some kind of Dawkinsian cult which wanted to kill all believers. Well, something absurd was certainly reported in the press (which is the same thing, right?).

I’ve given up trying to decide if accurate reporting by newspapers is just a hoped-for ideal that has never been attained, or whether we currently just have a fine crop of journalists who (to paraphrase Terry Pratchett) use truth more as a reference point than as a shackle. Instead, what I can do is find out what he actually said. All the archbishop’s speeches, essays and similar productions appear on his official website eventually. And the official transcript (and the original audio recording) for this Faith and Science speech is now available.

First I’d like to present what Rowan Williams said on the day:

First of all there is the extension of Darwinian theory beyond straightforward biology and genetics. The heart of the conflict between faith and science as it’s frequently presented these days is no longer a simple stand-off between what people might regard as two rival accounts of how the world came to be.

Immediately we can see that, though he later refers to neo-Darwinism, he is not talking about “straightforward biology and genetics”. A curious claim, like saying “I’d like to talk about ice cream — by which I don’t mean the frozen cream dessert or non-dairy equivalents”.

Rowan Williams may be guilty of many things, but clarity is not one of them.

The transcript, however, includes a small aside intended to clarify the matter of his poor wording. I just wanted to leave it out first in order to give you a good idea of what the original audience would have heard. This is what the transcript says, with my emphasis:

First of all there is the extension of Darwinian theory beyond straightforward biology and genetics. [Note: This extension of the theory is sometimes loosely called ‘Neo-Darwinism’; but this is potentially confusing, as this term is more strictly applied to the fusion of Darwin’s original theory with Mendelian genetics. I did not avoid this confusion in the original version of this lecture.] The heart of the conflict between faith and science as it’s frequently presented these days is no longer a simple stand-off between what people might regard as two rival accounts of how the world came to be.

So, in this small aside he has admitted to being foolish and unclear, by redefining perfectly good terms. Fair enough. He goes on:

In spite of all the fuss about creation science versus evolution, that’s actually not where the intellectual energy of the debate lies. The real issue is in this extension of Darwinian principle and theory into an entire theory of culture and intellectual life. This is a vision fairly regularly reiterated by Professors Dawkins and Dennett and it deserves a moment’s explication.

What he’s talking about here is memetics. That’s what it looks like. (Richard Dawkins came up with the word, though he hasn’t done much research into it since it was mentioned in The Selfish Gene. I’m not sure about Daniel Dennett but in the couple of lectures of his I have seen he mentioned memes a bit.) Why Williams ever thought “neo-Darwinism” was a good label for this I’ll never understand. He may have been thinking of Universal Darwinism but I don’t think that’s accurate either.

He suggests that “science” (or maybe just that evil Dawkins fellow) have been concocting fairy stories about the world and letting the stories run away with themselves. They have not paying attention to the evidence. This is a curious argument since it doesn’t reflect the reality of (visible) academic research into memes or the attention that is paid to them. As far as I can tell, memetics as an active research area is dead at the moment. The only Journal of Memetics — not even a paper one at that, just an online publication — has been closed for business for at least three years now. This is not quite the threatening body of science the archbishop makes it out to be.

The whole speech seems rather pedestrian in the end. If you were to replace every instance of ‘Darwinism’ with ‘memetics’ then it would make more sense but it still wouldn’t say more. Susan Blackmore, who is mentioned in the speech as a “follower” of Dawkins (ah, the science-as-religion canard, where would we be without you?), raises most of these arguments in her own book on memes. They are not new to the people interested in the field. The remainder seem to be ordinary philosophical musings about reductionism and so on, or the realisation that popular views of genetics (a “gene for X”) are not very accurate. In any case, there is nothing actually show-stopping in his speech, and no obvious connection to faith.

Anyway, I’m getting a wee bit off the point. In short, Rowan Williams did not call biology a fairy story: he called memetics a fairy story. Though in the process he did admit that Christianity was a fairy story, which was a surprising point. Why did the press not quote that bit so widely? Maybe it’s old news by now.

Last night’s Café Scientifique was a special outing to the Edinburgh Camera Obscura (which I think is a great place to visit anyway). The talk was given by Will Hossack from the University of Edinburgh.

It was a very good talk (they’re so variable it’s impossible to recommend from one week to the next) — just a shame that the room was too small and too hot for the purposes. It was a windowless room on the fourth floor full of optical illusions and bright lights. Good fun to wander round and play with the exhibits but not great when sitting cheek to jowl on little seats.

But anyway. He explained the general process of laser cooling, by trapping particles with beams of light. Then he went on to describe the work he does with fairly large objects (yeast and fungal spores as well as latex spheres) using the trapping effect to create optical tweezers which can move objects up to a dozen microns in size.

They’ve been wiring up these computer-controlled optical tweezers to some 100x microscopes, and he had some fascinating videos of the things one can do. Apart from getting latex spheres to dance an eightsome reel, he also had a streamer of DNA anchored at one end by the tweezer. The other end was being forced out by the flowing solution it was all bathed in. You could see the long streamer collapse in a flash into a tight little ball when they added some enzyme. Very cool.

It looks like the Edinburgh Café Sci has had a little injection of fresh ideas from teaming up with the post-graduate science communication team (this jolly to the Camera Obscura was their idea) so I hope they follow through with more interesting visits.

The weather has been shockingly warm and sunny since the weekend. I’ve been leaving the flat in the morning without a dozen layers of clothes. I know people who have been sunburned. It gets quite stifling sometimes, though the sea breeze down at the shore makes up for that.

I’m still reading The Meme Machine but I should be finished reasonably soon. On Monday I went for a walk to look at furniture for the new flat, and popped into a bookshop on the way back. I bought The Artist and the Mathematician: The Story of Nicolas Bourbaki, the Genius Mathematician Who Never Existed. It’s quite a small book but seems like it will be quite interesting.

Also just heard that two of my old flatmates are making a brief visit (to Scotland, I guess, since they live in London) on the weekend of the 17th. We won’t be in to the new flat by that point — not until the 23rd — but will still probably be overcome with excitement.

Tomorrow night is a Café Scientifique Special at the Camera Obscura. It will involve lasers, so obviously we’re both right in there. Lasers! Don’t know when we’ll get a chance to eat. I would suggest grabbing a quick bite from Wannaburger but Helen’s been pretty late out of work lately and it starts at 7 o’clock. We may have to eat afterwards.

This is written with the inspiration of Simon Peyton Jones’ talk about pudding combinators. (He may also have mentioned financial contracts.)

Imagine we have a board game, with two opposing sides. To make things easy, this board game only has one type of piece on each side — there are no rooks and bishops and cuddies.

A Strategy is a mapping from the circumstances you find your players in to a move you can make.

type Strategy = Situation -> Direction
type Situation = (Location, [Location], [Location])

The situation for any one piece is its location, the location of the pieces on its side and the location of pieces on the opposing side.

The base Strategy is to not move at all. This is no way to win, so we need to improvise a few strategies. We could move all of our pieces towards the enemy in a mindless deathmarch:

attractfoes :: Strategy
attractfoes (me, _, foes) = attraction me foes

We can do the same for friends (so that pieces can clump together) and with repulsion (so pieces avoid their team-mates, for example).

repelfriends :: Strategy
repelfriends (me, friends, _) = repulsion me friends

Brief diversion: Attraction and Repulsion

So far I’ve assumed the existence of a few things. Some of them you can guess at (eg, Location is just a tuple of x and y co-ordinates). The functions attraction and repulsion need some more explanation. From the given type signatures we can infer that their type is:

attraction, repulsion :: Location -> [Location] -> Direction

The first argument is the piece under study and the second argument is all the pieces it is attracted to/repelled from. Between each pair of locations (pieces) there is a force — either toward or away:

attract, repel :: Location -> Location -> Direction

It seems to me that these should be the “primitives” of this system. (In a sense they are, but not in any formal way. That’s just what these strategies ultimately rely on.) Maybe working up from these functions would reveal a nicer system. (I say “these functions” but really there is only one: each is the negation of the other, so either could be implemented in terms of the other.)

Now where was I? Combining strategies

Assuming we have four simple strategies (attracted to and repelled from both friends and foes) we probably want to combine them. The simplest means is by addition:

(<+>) :: Strategy -> Strategy -> Strategy
s1 <+> s2 = \x -> s1 x + s2 x

Let’s say that s1 is attracted towards enemy pieces but s2 is repelled from them. (This is a silly example, but instructive.) The combinator shown above allows these two urges to neutralise each other — since as I’ve already mentioned, attraction and repulsion are negations of each other anyway.

Of course we may decide that some urges are more important than others. The urge to clump with friends is more important than the urge to avoid the enemy. So we want a scaling system, to increase or reduce the importance of a particular strategy compared to others.

(<*>) :: Double -> Strategy -> Strategy
n <*> s = scale n . s

(The scale function scales a Direction tuple by its first argument.) We can then increase or decrease the importance of a strategy by scaling it:

(0.7 <*> attractfriends) <+> attractfoes :: Strategy

So far we’ve assumed that one strategy is applicable in all cases. This is never the case — there are always corner cases and special situations which we should test for and evaluate accordingly. Let’s say we want our pieces to clump together until the crowd reaches a certain critical point. Then they march out to war or something.

I imagine we would run such a system a bit like the ?: operator from C.

condition <?> consequent <:> alternate :: Strategy

Let’s break it down. The part after <?> is a choice of two strategies, only one of which is applied. The choice is as simple as a tuple of (Strategy, Strategy) — so <:> is essentially an alias for the tuple constructor.

(<:>) :: Strategy -> Strategy -> (Strategy, Strategy)
(<:>) = (,)

The condition is slightly more intricate. What kinds of things would the predicate test? I guess anything that can be determined by looking at the circumstances of this player.

(<?>) :: (Situation -> Bool) -> (Strategy, Strategy) -> Strategy
predicate <?> choices = \x -> if predicate x
                                    then fst choices
                                    else snd choices

The conditional combinator is brand new for this post — I haven’t implemented it in the code yet. So I don’t know how horribly wrong it is! More on that later.

And because my post yesterday was mostly about baking but slightly about Haskell, I suppose I should balance things up by noting that yesterday’s loaf tasted even better this morning. Slightly moister and very tasty. But I’m going outside into the sunshine now!

At the moment I’m reading The Meme Machine by Susan Blackmore and quite enjoying it. It’s deeper and more thought-provoking than I had originally thought it would be.

The idea that seems most appealing is expansion on the notion of memes as parasitic replicators that Dawkins first uses in his description in The Selfish Gene. It’s certainly true that many ideas are both extremely common and dangerous to our survival. Genetic evolution on its own doesn’t seem to explain the popularity of these ideas.

To what genetic end, for example, do men and women lock themselves in big buildings away from the public and the opposite sex? And yet monks and nuns are a fairly common occurrence throughout history. There are many other examples — honour killings come to mind as being a particularly absurd one. Infanticide is fairly common in the wild if a parent can’t spare resources to keep a new-born alive. But killing your own offspring because they have the audacity to become independent?

And yet there are plenty of examples in biology where one life form can pervert the actions of another to its own end. We sneeze out the cold virus because that helps the virus spread. Ants can be infected by fungus and made to climb to the highest point around before dying. The fungus then bores its way out of the dead ant’s head and spores from this vantage point. Why did the ant climb? Because the fungus did something — I don’t know what — to make it.

It helps the genes of the parasite if the host can be controlled to do its bidding — and these actions may be dangerous to the host. And so the notion of memes as parasites seems all the more compelling — as replicators which don’t care about your survival or that of your line. It only matters that the meme spreads to the population.

And so the meme for shutting yourself away from other people spreads for its own sake and not for yours (or your genes’). Or the meme for killing your daughters spreads (by imitation, by oppression, by proxy) even though it frustrates the efforts of your genes to propagate themselves.

Some memes, like some parasites or infections, can probably be too dangerous. They could kill off the host before spreading. Think about the shortest-lived but most violent infections which inspire books and movies — viruses like Ebola and Marburg. They tend to debilitate their hosts before the infection can spread very far (though not as quickly as in the movies, of course…). And so, I think, might some very powerful memes. Maybe a suicide cult could be considered in this category — a meme-infection with a predefined cut-off point. (Also note that the general concept of suicide cults outlives the active participants, by being recorded in books, films or oral history. Like Ebola has a reservoir of carriers outside the human population, waiting to reinfect at any opportunity, so might the right type of person start another suicide cult.)

The idea seems interesting — I’m keen to see how the idea can be applied to other concepts in the rest of the book. I will definitely see if such a memetic approach can reveal anything new about people.