Thursday, 23 February 2012

Digging for the truth

I have long thought that it is going to be nearly impossible to get to the truth - if anything can be defined as the 'truth' - of the AGW debate. Partly this is because of the problems of modelling the future in a system as complex and little understood as Earth's, and partly because our actions and other effects can combine to make those models redundant.  For this reason, it will always be a best-guess estimate.

However it is interesting to see how both sides (*) are fighting each other. The AGW-proponents do themselves a disservice by lumping all critics into a 'global warming denier' grouping, where the spectrum of sceptic views are far more varied than that. Likewise, some sceptics tend to extrapolate from small problems rather than look at the big picture.

First, I would like to make a big proviso: the events in this blog post are recent and events are moving fast; I have had to look at many different sources to produce it, some of which are contradictory. I have tried to be as even-handed as possible, but that is not always possible. The links I have added should allow you to do your own research and form your own opinions.

'Climategate', the release of rather embarrassing emails from the Climate Research Unit at the University of East Anglia, was well covered in the media. At best they showed the researchers at the CRU as being obstructive and more interested in the politics of climate change than getting to the truth, which they seem to have predetermined. As part of that crisis, allegations of hacking led to an expensive criminal inquiry by the police. This was despite it being distinctly possible that the documents came from a publicly-accessible server (i.e. they had essentially been published). As far as I am aware, no charges have been bought with regards to the 'hacking'.

Last week some documents were released from an American anti-global warming group called the Heartland Institute (HI). The documents made some claims that some AGW proponents jumped on, claiming shadowy organisations funded the HI (**). However, pretty soon some people, notably at Watts up with That and elsewhere, noticed that the document that showed the HI at it worst was stylistically different from the others. There is also some doubt about the contents of some of the other documents, although HI have only claimed one is an out-and-out forgery.

The HI soon said that one of the documents had been faked; strangely enough this was the one that others had noted as being different. Further research by sceptics showed that aspects of the faked document were stylistically similar to those produced by Peter Gleick, the head of the American Geophysical Union's Task Force on Scientific Ethics. Strangely, Gleick stood down from that position shortly afterwards.

A few days later Gleick admitted that he had got the confidential documents by deception: the accusation is that he impersonated a member of HI's board to get them. Instead of then doing an analysis under his own name, he then leaked them to a pro-AGW website. Although he denies it, he is also accused of faking the most damaging document.

The AGU do a great deal of good work; coincidentally I read several of their excellent blogs on geology and geography; I respect them far more than I do the CRU. However it is staggering that a scientist working for such an august and well-respected body can use deception to steal documents, then publish them. AGUs reaction has, so far, been good.

When the CRU emails were leaked the pro-AGW groups used (unproved) accusations of hacking to divert attention from the embarrassing contents. The HI scandal (and it s a scandal) involves impersonation and likely fakery. Potentially worse, allegedly some of the documents contained personal information about HI's employees.

Richard Black on the BBC has behaved disgustingly. When the CRU emails were released he refused to discuss the contents; in contrast he jumped on the HI's leak with gusto. Even his latest blog entry (on the BBC website) tries to paint over what Gleick did; instead he concentrates his fire on the HI. Black is purposefully missing the real story: one of deception and forgery, and instead attacks the victim. Well done, BBC.

It does not have to be this way. Judith Curry is an unusual scientist - she takes a rather different line to most, and gets shot at from both sides. She believes in AGW, but dislikes the way her fellow proponents are treating the science. Her blog post on this topic is far better, and compares Gleick's actions with his previous words as head of Scientific Ethics. BBC: get rid of Black and hire someone like Curry instead.

The truth matters. All Gleick and his supporters have done is make the truth harder to discern.

(*) Both sides is actually a misnomer - there are many different aspects and opinions in the debate.

(**) I find this interest in the funding of the HI funny - they have a small budget of $5 million a year, a tiny fraction of what pro-AGW organisations spend each year.

Wednesday, 22 February 2012

The elegance of FM stereo

FM radio is going to die. Slowly, inevitably, it is going to be overtaken by digital radio that squeezes many more stations into the same frequencies. Which is a shame, as FM exhibits what is, for me, an elegant engineering solution to a problem.

Originally FM was mono-only. That is, the stations broadcast just one signal that was fed to all speakers on the radio. In the 1950s it was realised you could broadcast stereo signals easily on FM. However this required sending two signals; one for the left-hand speaker and one for the right. An obvious approach would be for the left-hand signal to be broadcast on the mono frequency, and the right-hand on a frequency broadcast a short distance away.

However by this stage there were many mono FM radios in homes, and this approach would have made these useless as they would only get the left-hand signal (try listening to only one speaker of a stereo system to hear the problem).

To solve this, they came up with a simply cunning solution.

They broadcast a sum signal (left + right) on the main (mono) frequency and, a short frequency hop away, a difference (left - right). From these, both the left-hand and right-hand signals can be retrieved using simple analogue circuitry, and the mono signal maintains the qualities of the combined stereo channels.

Say at any one period the left-hand signal is at 5, and the right-hand at 7 (they are really sine waves, but the maths works well enough for discrete digital values).
This means 12 (5+7) is broadcast on the sum frequency, and -2 (5-7) on the difference.

To obtain the original left and right stereo values, you simply:
1) To get the left-hand signal, you add the difference and sum values, i.e. 10, then divide by 2 to get 5
2) To get the right-hand signal, you subtract the difference from the sum, i.e. 14, then divide by 2 to get 7

Of course there are other complexities, but the basic approach is simple: what is even better, it was easy to perform in 1950s-era electronics.

It is an utterly elegant solution. It also explains why, if you have poor signal quality, the radio degrades to mono, which is broadcast on the main frequency.

Digital radio has many interesting engineering and mathematical tricks, (for instance the magnificent Fast Fourier Transforms), but nothing beat the simple elegance of the FM stereo solution.

As usual Wikipedia has much more information and this page goes into more detail than almost anyone will want...

Sunday, 19 February 2012

Impressive friends

Aeons ago, whilst at university in London, I had a friend who was studying aeronautical engineering. For the purposes of this post, I shall call him 'Gopher' (*).

Gopher was a great bloke. Imagine Ace Rimmer in a flying jacket. I used to go to Club E1 and other places with Gopher - he was a great bloke (**). One night we got talking to a couple of girls in the student union bar.

"What do you do?" they asked Gopher
"Well, I fly light aircraft, gliders, and race cars."
They turn to me: "And what do you do?"
"I'm on a geological engineering course, and I work freelance as a programmer."
They turn back to Gopher. "So, how often do you fly?"

I did not get a look-in all night.

One of my oldest friends, another aeronautical engineer, is getting married in May. He is an Iron man triathlete, a marathon runner, and, to add insult to injury, a literal rocket scientist. I am seriously in awe of this guy. And he is marrying a beautiful lady.

I have spent most of my life surrounded by people who are incredibly active and sporty. I spent quite a time at school with a leg in casts;during sports periods I was given the only jobs I could do: timing people on the cross-country runs or recording the completed swimming lengths. In comparison to these lovely people I am a laggard, a positive couch potato. And now my wife has taken up running, and is doing rather well.

My walking is a small attempt to at least partially replicate the highs that these people routinely achieve.

Walking is boring: you tell someone that you have walked 1,000 miles and their eyes glaze over; walking is boring, literally pedestrian. Running is interesting. Flying is sexy. Motor racing is doubly sexy. Iron man triathletes are Gods. Walkers are... well, boring.

I have lost contact with Gopher; I last talked to him ten years ago. A Google search has yielded no results. But I hope that he is still racing, doing amazing things.

I raise my glass of Laphroaig to him, wherever he is. (***)

(*) Why 'Gopher'? The answer: he goes for this, goes for that, goes for anything in a skirt!

(**) One day we were sitting outside the Atrium of the university, talking about this newfangled thing called the Internet. We chatted about the possibility of an on-line encyclopaedia that contained all the world's information at different levels of complexity. You could select a topic and see basic information, then drill fractally down into near-infinite detail. We realised that two men could not possibly assemble that much information, and it would have to be a collaborative effort. We envisaged a combination of the Hitch Hikers Guide to the Galaxy, the Encyclopaedia Britannica and the Dynabook that would render paper libraries redundant. Microsoft Encarta was launched later that same year, and seven years later Nupedia was launched, which spawned Wikipedia. That is the difference between the entrepreneur and the dreamer. We dreamed, they did.

(***) Technically it should really be a glass of Glenmorangie. I have happy memories of drinking the best part of half a bottle of that lovely liquid with him in that famous pedestrian bridge over Aspen Way in Poplar.

Tuesday, 14 February 2012

Education, education, education

The Times Education Supplement recently published an article which has spread rather rapidly over the web. It is well worth a read:

We were both shocked by the article. Talk about a lack of ambition for the pupils under his care.

I find the first couple of paragraphs staggering:
It is 4pm. My weary colleagues and I are slowly unwinding in the maths office, when there is a knock on the door.
"Could I have a quick word with Jonny, please?" says Michael in a bright, nervous voice. I don't sigh, but inwardly I think, "Is that my 'quick' or yours?"
The Michael in question is a pupil, and Jonny his maths teacher. Michael is concerned that he will not get an A-grade, and Jonny thinks he is worrying unnecessarily. Perhaps a justifiable concern; but what follows is, in my opinion, utterly unprofessional. Instead of encouraging the pupil he chooses to so exactly the opposite, and gives a spiel *against excellence* that would dishearten and discourage many bright children.

The idea that a teacher reacts this way to an inquisitive pupil is flabbergasting. Then again, it was at 16.00, and no-one works past that hour, do they?

I think that the author has a kernel of an idea that he articulates particularly badly - that children are being put under too much pressure. Yet his article goes much further and shows a worrying lack of concern for the pupil.

I can only hope that few teachers think like the author. And I am amazed that the Times Education Supplement published it - it reflects so badly on the teacher in question and the profession.