Saturday 20 June 2009
When is a conversation public, an act of performance, and when is it private? This problem rears its head with greater frequency in the age of the internet, as more discussions are publicly accessible without necessarily, in the minds of the participants, being for the public.
In everyday life, the Scottish Daily Express recently sent one of its reporters onto Facebook. There she found embarrassing photos and descriptions of drunkeness and snogging among children from Dunblane. They had seen their schoolmates massacred before them, some had sustained horrific injuries themselves, but freshly turned 18 they were now fair game: this normal adolescent behaviour was somehow a public scandal. Bloggers were outraged, but mainstream media kept silent.
There are parallels from the world of science, in the form of preprint archives.
“Oceans charge up new theory of magnetism” said the Times last Sunday. As always, it wasn’t enough that a theory was interesting and new: it had to be transgressive, turn the world on its head, and have all the answers.
“Earth’s magnetic field, long thought to be generated by molten metals swirling around its core, may instead be produced by ocean currents, according to controversial new research published this week.” [Note: since I contacted them, they have changed the text of the online version of this article, although this change is not flagged, see below]. That is what science correspondent Jonathan Leake’s article said. But it is not what the new research said.
Pay attention. The earth, as you know, has a magnetic field, which is how compasses work. Where this field comes from is a bit of a mystery. Things that are “permanent” magnets, like the iron horseshoe ones you’ve played with, tend to lose their magnetic field after a while.
The earth’s magnetic field keeps on going, but it also fluctuates a tiny bit. And every now and then – like about 780,000 years ago – it flips, so that the North and South poles change place.
Nobody really knows what causes the flips, but the fluctuations have been taken as evidence of the movement of the molten iron core in the earth, slooping and spinning around, and this movement forms the basis of the dynamo theory for the origin of the earth’s magnetic field.
The Times said that Professor Ryskin from Midwestern University has a new paper out, which is true, and that he had shown that the fluctuations in the magnetic field are due to the movement of oceans, which he also did say.
The Times goes further. It suggests that the poles flipping is due to the movement of water in the oceans. “One idea is that changes in ocean circulation may explain the curious reversals shown by Earth’s magnetic field, in which the north and south magnetic poles suddenly flip over.” This idea is not in Prof Ryskin’s paper. I contacted Prof Ryskin: he says he does not think his ocean theory explains the flip.
The Times also says Ryskin’s paper claims that the whole of the earth’s magnetic field is produced by the movement of oceans. The paper does not make this claim. I contacted Prof Ryskin: he says he does not think the oceans create the earth’s magnetic field.
He says he wanted to stick to the subject of the published paper, didn’t want to speculate on the questions of the field origin or its reversals, and objected to such speculations being included. The Times journalist meanwhile says that Prof Ryskin has confirmed that everything in the Times article was correct.
What explains this disparity? It is partly a practical issue, and partly, perhaps, a question of tolerating mystery.
A long time ago, several years back, Prof Ryskin put a paper up for discussion on a preprint server. These do not constitute publication, they are a place – not properly peer-reviewed – where academics can post ideas for discussion and criticism. Ryskin does not stand by everything he said in this paper, and many of his ideas have changed. Like the teenagers from Dunblane, he is alarmed that it should suddenly be seen as a formal reflection of his views, and feels it was never meant for public consumption, or popularisation. When he posted his thoughts for discussion among academics, it never occurred to him that anybody else would want to read it.
But there is also an emotional issue. I don’t know what explains the disparity between the academic’s account, and the journalist’s: but I will tolerate that mystery, because “I don’t know” is often the correct answer for many questions.
Prof Ryskin is clear on this too: the variation in the earth’s magnetic field has always been seen as evidence of hydrodynamic flow in the iron core. If he’s right, and this variation is actually produced by the ocean flow, he says, then there’s no evidence of flow in the core of the earth, so the dynamo theory becomes entirely hypothetical.
You can see the earth’s magnetic field with a compass. “In my view it may be good, in some respects, to have this as a mystery again,” he says. “That can be stimulating: it may be good for people to think that there are mysteries to be solved.”
The paper is here:
And there’s a good blog entry on Ryskin’s work here:
I’m amused to see that since I contacted them, the Times have changed their copy, and “produced by” has been replaced with “linked to”.
Read the original here
No clarification or correction, just a silent change.