Do The Right Thing

December 6, 2013

Like millions of others, I have been welling up listening to people on radio and TV recount their memories of Nelson Mandela. I’ve never even been to South Africa, but during my youth and early manhood, the struggle against apartheid was the great cause for anybody with a heart and a political head, the rotten thing in the world that needed fixing. A short but vivid memory from a few years before Mandela was released is of watching TV and seeing Soweto youths burst across a field, with sticks. I can remember being exhilarated, and thinking yes, they are bursting from their chains – it will all change now. Then moments later I felt guilty. Oh, surely, violence is bad? What we need is peace, love, and understanding? Well mostly yes, I do believe that peace and love is best. But sometimes … sometimes …

Everybody on the Beeb is stressing that Mandela was a great man because he resisted revenge : he emerged from decades of injustice with a message of co-operation and peace. He did the right thing. He did the right thing again five years later when he stepped down, visible proof of the democratic transfer of power. Sometimes we hear that during his time in prison he changed, and realised that he had to reach out to his gaolers.

Just occasionally it is mentioned that he did indeed plan acts of sabotage. In the beginning, in the early 1950s, he believed in non-violent direct action. But he saw it didn’t work, and 65 of his brothers were massacred by police. He decided he had to take up arms, and began forming a guerilla army. I am still waiting to hear somebody on the BBC say this : that too was the right thing.

I love the Beeb, but it is really a branch of the state. The message we are taught is that violence is bad. But the truth is that it is only bad if you ordinary people try to use it. The state needs a monopoly on violence, to maintain civil order. Mostly I believe this is correct : brutal but necessary. But sometimes … sometimes… I have never had to fight. I like to think that in the First World War I would have been a conscientious objector, and in the Second World War I would have signed up. You shouldn’t fight for power, but you should fight evil. But who knows.

So … taking up arms in the late 1950s was the right thing. Rejecting revenge in the 1990s was also the right thing. Having the strength of character to do both, to have the judgement to know what is right for the time – now that is wonderful. Lets not airbrush the violent past. Its part of why the reconciliation was so amazing.


Marginal solution

November 27, 2013

Okey dokey. Better reveal the solution to the stat-geek marginalisation quiz. There were sixty two votes.

The popular winner was the economics/marginal profits idea, with 31 votes. Plausible but wrong.

The second most popular was the “marginal interest” idea. Well… this is what the term has more or less drifted into meaning, because (almost) everybody has forgotten the true origin. So… wrong.

Nobody voted for “lost in the mists of time”, which proves you all care. How nice.

Only two people voted for EB Margin being the pseudonym of WR Gossett. This disappointed me, both because it is funny and because it was supposed to be a cunning false trail. WS Gosset in fact published his papers under the name of “Student”, which is why we have the “Student’s t test’.

So of course the correct answer was other. Sorry if that was an annoying tactic, but I think if I’d made the right answer one of the choices, it would have been too obvious. Amongst the 6 suggestions, two were for our amusement :

“I’d write the reason here but there’s not enough room in the margin”
“To marginalise those who don’t know”

and four were were spot on or more or less right

“Refers to margins of a contingency table”
“thought it was to do with averaging rows, with answer stuck in the margin”
“your are projecting the 2D pdf onto the “margin” of the plot”
“Sweeping the probability to the edge (=margin) of the paper?”

Sounds like the first two people knew, and the second two deduced the right answer. If you were one of those people, award yourself an extra biscuit at coffee time, and feel free to announce yourself.

Just to it spell out..  As physicists, we nearly always think in abstract mathematical terms, so we think of  “marginalisation” as a calculus problem – an integral. Even when thinking visually we picture a joint probability distribution as a smooth surface in three dimensions. But early statisticians were often concerned with tables of numbers, and worked on paper. Think of a joint frequency distribution as a grid of numbers in cells. Then  add up a row, and write the answer in the margin. When you have done this for all the rows, read down that margin, and – voila – the marginal distribution for y.

Don’t start me on regression…


A quiz of marginal interest

November 20, 2013

Two things we know.

(1) Scientific terminology is burdened with the baggage of history, which now makes no logical sense. So… early type galaxies are the ones with late type stars? Errr… And which of these terms relates to a sequence in time? Neither. Right. Very helpful.

(2) When you have to teach something, you finally figure out things that have been bugging you for years.

(3) Nobody expects the … oh. Anyway. Often (1) and (2) combine to make a particularly thick fog.

For some time the term “marginalisation” had been nagging at me, but I ignored it because I had other stuff to get on with. I am referring to the term in statistics. You have a probability density function of two variables, f(x,y), but decide that y is “interesting” and x is “uninteresting”. You then integrate over x to get a PDF p(y) for y alone. This known as “marginalising over x”.

So here is the quiz. My guess is only about seven people will want to take it, but I can’t resist it.

Rule (a) Andrew Liddle is not allowed because I already told him the answer in the pub. Rule (b) No Googling. Rule (c) Never talk about  Stats Club.


Borders Meltdown

October 25, 2013

I do like to keep up to date. So here is a link to a 2009 blog post about the US Republican Party. George Djgovsiki Dvosrgksji Djorgiojski me old mate George from Caltech just posted a link to this on Facebook. It’s based on a book called Albion’s Seed which I have been fond of since ex-SLAC chum Jack Singal bought me a copy as a present. I wrote a connected blog post about Puritan Sex back here.

Short version. Appalachian/backwoods/redneck culture comes from the borders of Scotland and England. This was a war-torn lawless region that bred a culture that had no trust in authority and believed only in family and clan. Fiercely stubborn and violent. The traditional aristocratic slave-owning south on the other hand sprang from a Cavalier culture from Southern England. These two cultures – borderers and cavaliers – have traditionally made up the Republican party, with the aristos keeping the rednecks in check. What has happened over the last decade is that the rednecks have taken over, and are now holding America hostage at the same time as they are a diminishing part of American culture.

Pretty convinced myself, and its a strangely optimistic vision. This is not a crisis of American political culture. Its a crisis of conservatism. It cannot persist. It will implode. It just needs a few old-fashioned Republicans to start rebelling.

I just hope it happens before the Capitalist World System collapses.

Or do I?


The Art of Scientific Knowledge

October 16, 2013

I find myself musing again on the links between Art and Science. No, not the fact that the latest Booker prize winner apparently has an astrological structure, sigh. No, not even The Falling Sky, intriguing blend though it is of academic angst and lesbian lust. No. Umm. Where was I? Oh yes. Art. Grayson Perry has been delivering the first ever cross-dressing Reith Lectures  and very fine they are too. Yesterday’s was about how you judge quality in Art, a famously heated topic. (Can you have a heated topic, rather than a heated debate? Ed.)

There is no objective formula. The choices seem to be (a) The Market. (b) The Club – curators, critics and successful artists. (c) Public Opinion. All the tension seems to come from (c) disagreeing with (b). I have always been fascinated by the way folk are not content to just not like something; they get angry with Art. “My Johnny can do better than that” etc. Oh. Right. How come your Johnny ain’t famous then? I saw this in action the previous summer when visiting a Tracey Emin exhibition at the lovely Turner Gallery in my old home town of Margate. (An art gallery! In Margate!!!) Tracey is not quite my cup of tea but I was giving it a go. Suddenly there were staff scurrying around because a small child had drawn on one of the sculptures. The crowd was instantly split into the horrified bourgeoisie and the cheering polloi. Pardon my mongrel language approach.

So. Thats Art. Science? When we try get all philosophically rigorous we also find it really hard to pin down an objective assurance of truth. Cue pub argument about Hume, Popper, Feyerabend etc. But day by day the situation is the opposite. We know in our guts that the whole point of science is the search for objective knowledge, and that we have found a strange paradoxical but reliable method of getting at it; knowledge comes from honest scepticism.

We also take for granted that the arbiters of good science are us gals and guys in the club. (More gals please.) We don’t think the public should vote on whats true and whats not. There is no market in science. You can’t simply proclaim yourself an expert (though some try). There are not even any gentleman amateur scientists any more. You pass your exams, convince an interview panel, take the Government Shilling or the University Penny, expose your work nervously at conferences full of other club members, and try to decide whether you want to play the Herd Member route or the Lone Wolf route. They can both work, as long as you keep publishing, although the latter is a harder trick to pull off.

But public opinion? You will note its called Public Outreach, not Public Insertion. We generously give them the benefit of our wisdom. Oh, but please, do explain again why you personally believe Einstein was wrong because public opinion is very important to us.  Yeah, right.


Specially for Tim

October 9, 2013

I have been putting on the nosebag tonight. The ESO Committee of Council is here in Edinburgh; the first time we have hosted it for ten years I believe. Anyhoo, I am not on said august body, but as a local astro-big-wig was invited to the nosh. All the chat was about ELT and Brazil of course. Much optimism. Honest. Also a bit of Higgsteria spin-off with Wommers and Jim The Dunlop later in the pub. (The Bow Bar. Some of my readers will know it well.)

Anyhoo, found myself chatting to the Danish rep on the government side. Very cogent woman called Cecilie Tonroe. I think. I was probing her about Danish astronony when Tim De Zeeuw leaned over and said “careful what you say to this man, Cecilie, he has a blog and anything interesting will appear there”.

Anyway. The entire point of this post is to prove Tim right.

Except of course you don’t know what I am not telling you.


Higgsteria : tension builds

October 7, 2013

We’re all a bit tense here in Edinbrrr.  Peter H is understood to be in hiding and quite right too. He’s done more than his duty over many months waving the flag for Physics in general, for UK science, and for Edinburgh University. Adrian Bird didn’t get the Medicine Prize today, so the Edin.Univ. Powers will crossing all possible fingers and toes for tomorrow. Check here. Apparently we expect the announcement to be at 10:45 UK time, but it will initially be in Swedish, so there will be an extra minute or two of hypertension.

Well, we will know soon enough. If you want to entertain yourselves meanwhile, you could try Telescoper’s Poll. Or you could watch Frank Close’s wonderful seminar, which is the clearest explanation I have seen/heard of what its all about, and why a prize specifically for Peter is appropriate. The CERN version seems to be broken, but there is a recording of a version at SISSA that’s audible but bvisually murky. Fascinatingly, Close makes a case for Phil Anderson being an overlooked man, and shows how different parts of Physics can cross-fertilise.

Or if you really want some entertainment, you can see how you can make chocolate from nothing.


Update : Englert and Higgs get it ! But no CERN mega-prize.. Anyway, well done Peter and big cheers in Edinburgh


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