Dark Matter?

Every time I read back over my list of publications, I am struck by how most of the good ones seem to have sunk without a trace. Most of the ones where I thought I had discovered something interesting and novel about the universe, or had hit upon an interesting and novel way of looking at something we already knew about, have very few citations, or none at all. Perhaps I should do a series of posts on my top five papers with no non-author citations? Hmm, I have been neglecting this blog lately, and a theme like that might help.

Anyway, a few years ago a colleague gave me a weighty chapter he had written, entitled A Quantum Approach to Dark Matter, which I was slack (It is 63 pages long) and never got around to reading (It *is* 63 pages long). Remembering it today, I thought I would first check to see what other people thought of it- I am a mere chemist, and can only identify very dubious theoretical physics as dubious at a glance. I found my colleague had four published articles in the area over the past half-decade, and none of them had been cited at all. This is a tragedy. It is dreadful to spend years wrestling with an idea, to hone and shape it into a form you think is fit to present to the world, expound it with all the energy and clarity at your command, shepherd it into print, and then see it be ignored completely. Hence, I thought I would put a link to the chapter here. And I really will read it myself, I promise. And put an ignorant chemist's critique here on the web, at the very least, so Google can find it.

Some time ago I was asking the question: ‘How good are these climate models? What sort of predictive value have they shown in modelling future climate? After all, we’ve been doing them for a few decades now.’

A nice person on realclimate.org (there are some, not all of them treat people who disagree with them as the demonised other) directed me to a classic paper by Hansen et al.

"If you want an indication of how well these models do you can go get (J. Geo Res. 93 (1988) 9341) the Hansen GCM paper that people talk about, and compare their results with observed patterns of warming and other things."

Here is the plot from that paper showing the response of overall global temperature (which the authors argue convincingly is a much better parameter than any subset of the data, e.g., whether it snowed at my house or not in a given year) for three different scenarios- A being continued exponential growth, B being a more subdued form of business as usual, and C if drastic cuts are implemented starting a few years ago.

I went and got the Hadcrut3 data set and plotted it on top of this one, as near as I was able, and got this.

There are other data sets out there. I shall plot some of the others and put them up for you.

The Hansen et al. model predicts the greatest degree of warming at high latitudes, fitting observations, but the model also reproduces another feature of observed weather, that those latitudes have the highest natural variability from one year to another.

In which I place myself beyond the pale of civilised discourse

Firstly, an observation on scientific models, coagulated in the enthralling world of emulsion polymerisation:

Whenever you are trying to model some complex phenomenon, the fit of the model to the data can be improved by adding more adjustable parameters. A complex phenomenon will usually be dependent on a large number of factors, but the fact that the model fits the data better when you incorporate an additional factor may or may not mean that new factor is important: it might just mean that the additional parameter(s) you have incorporated are improving your fit. This is another thing the David Sangster told me: ‘With enough adjustable parameters, you can fit a camel.’

So there is a tension between the complete model, which contains all the factors that ought to be physically important – but might be meaningless because of all the guesstimated parameters you have put in to quantify these factors- and the simple model, which ignores things that might be physically important, but also avoids adjustable parameters. If you go too far in one direction, you get a model that can fit any possible data; too far the other, you get the well-known ‘assume a spherical horse’ punchline.

This also means that when you are modelling a complex phenomenon, you will tend to base your model on the processes that are best known, where you don’t have to pick numbers out of the air for your adjustable parameters, and you will ignore if you possibly can the role played by processes that are less understood, which would force you to bring in rubbery parameters.

Now to place myself beyond the pale. Some time ago I made the assertion:

‘Anthropogenic global warming is a fact, but we shouldn’t do anything about it.’

The second part of this statement is a considered opinion, based on facts and reasoned deductions from them. The first part of this statement, I have realised over the last few months, is based on an irrational mood.

That is: in the laboratory, and considering the atmospheres of the planets in toto, there is a perfectly splendid mechanism by which increasing the concentration of atmospheric carbon dioxide should increase temperatures. It is a really good mechanism, based on rock-solid physics. But is there any evidence that this mechanism is responsible for observed temperature change globally? Evidence, in the scientific sense, is where a model has predictive value: it does not just fit the data we have, but tells us what future data is going to look like. I did not examine this question before I made the statement above. Instead, I relied on the irrational mood that it seemed like wishful thinking that there was some sort of feedback mechanism providentially cancelling out this Greenhouse warming effect.

Let us consider these two famous graphs:

What do they tell us? They show us a correlation between carbon dioxide concentration and average global temperature. They also tells us, very clearly, that there are factors other than carbon dioxide which contribute to the world’s temperature.

We could also draw graphs that show some sort of a correlation between sunspot activity and global temperature, and earthshine and global temperature, and the number of pirates and global temperature. The last of these three graphs would be a joke circulated by the Church of the Flying Spaghetti Monster. The other two are graphs where it is easy to construct a testable mechanism for how the correlation might work. These mechanisms are not as solid or as well understood as the Greenhouse mechanism. They rely on more rubbery adjustable parameters. If we ignore them, do we have a spherical horse? If we include them, do we have a camel?

What is signal, and what is noise, in the Hadcrut3 temperature curve?

An idea that was in fashion when I was an undergraduate was the Gaia hypothesis of James Lovelock. You don’t hear much about it nowadays. You might remember that it was all about negative feedbacks keeping the global ecosystem in balance, life keeping things tickety-boo for life. I bring it up here as a hand-waving justification for a recent shift in my irrational mood: given that there is a grain of truth in Lovelock’s ideas, it now seems to me reasonably likely that there would be a negative feedback mechanism tending to minimise the effects of any carbon dioxide we add to the air.

I must now revise my assertion:

‘Anthropogenic global warming is a conjecture with limited predictive value, and we shouldn’t do anything about it.’

And I have to apologise for some of the slighting references to global warming denialists I have made previously.

And unfortunately I have nerfed one of the major motivations for establishing this blog, which was to use any perceived authority associated with my real name to push the line that we shouldn’t take any action to stop anthropogenic global warming. By denying AGW to be a fact, I have placed myself outside the pale of civilised discourse and disqualified myself from making any statements on the issue that will be taken seriously.

Son cosas de la vida…

14% more First Year students agree balancing redox equations is fun!

In a striking improvement over last year's already high student enthusiasm for balancing redox equations, the proportion of students agreeing that balancing redox equations is fun has risen to 83%!

Googling Professor Ronald Laura? Part Five.

“It is foolish, generally speaking, for a philosopher to set fire to another philosopher in Smithfield Market because they do not agree in their theory of the universe. That was done very frequently in the last decadence of the Middle Ages, and it failed altogether in its object. But there is one thing that is infinitely more absurd and unpractical than burning a man for his philosophy. This is the habit of saying that his philosophy does not matter, and this is done universally in the twentieth century, in the decadence of the great revolutionary period.”
- G. K. Chesterton




Here is part of an email I received last Friday which contains the gist of my correspondent's remarks:

I am requesting that you remove the abstract on nurturing gifted students from your blog, also remove any reference to Professor Laura (including his name) and I'd like that done as soon as possible please, today if feasible. I do not want to take further action but I will if the comments are still there next week. I feel I have to do this before any more damage is done to others that don't deserve it.


Here is another bit:

Considering you did not stay for the whole of Prof Laura's presentation, and that those who have posted on your blog have not even attended
any of or only one of his talks how can you justify comments like 'I have met the enemy!' That's disgusting! considering all the amazing
work that Professor Laura has done for others. How can you defame someone like that?


I think it is rather more disgusting that I could have googled Ronald Laura and not immediately found any criticism of his ideas or the way he presents them. If you have ideas that you believe are worthwhile, and you are at all interested in truth- as I am- then you hunger and thirst for criticism, for it is in responding to criticism that your ideas are tested and improved. If you are interested in convincing other people of the truth of your ideas- as I am- then you also welcome criticism of the way you present them, because this enables you to present them better. Even if you are not interested in truth, but only want to be transgressive in an adolescent way- as I hope I am not- then you have a positive need for reactionaries to jump up and down criticizing you. Otherwise, what would be the point?

I do not need to send my criticism explicitly to Ronald Laura, because I know he will find it. The beauty of the web is that all this criticism can take place in a completely public forum, and anyone can join in. Anyone who can find value in our competing visions of truth can derive value from it. Anything stupid I say is open to the world, as anything stupid he says is open to the world.

Users of the Web are perfectly capable of taking on board conflicting opinions and making up their own mind. If I told people to look up something Noam Chomsky wrote, they would find plenty of material on the Web written by other people who bitterly disagree with Noam Chomsky. If I told them something by Cardinal Pell could be useful to them, they would find plenty of harsh words directed against Cardinal Pell and his ideas. If I directed them to the work of Richard Dawkins, they would find no end of web-pages saying he was talking rubbish. If I asked them to google ‘string theory’ they would immediately find people claiming it is fraudulent drivel. If I asked them to google ‘global warming’ they would find pages claiming it is a vast left-wing conspiracy to abolish property rights, and pages claiming anyone opposing extreme measures to combat it must be a knuckle-dragging shill of Big Oil.

What is so uniquely fragile about Ron Laura that he should be shielded from all this? If he does not want to be part of this world, he should not post stupid things on the Web. My friend Klaus Rohde asserts on his blog that it is ‘common sense’ that John Howard should be put on trial for war crimes. This is vastly more insulting than anything I have written about Ron Laura, yet Klaus is yet to tell me of any good friends of Mr Howard writing him to demand he not 'defame' our former Prime Minister.

I do not intend to take down any of these posts. That said, should any readers with a legal background have the opinion that anything said could be likely to be construed as defamation, please let me know, as I have no wish to be sued by a rich and powerful Professor!

Update: I found a version of Ronald Laura's analogy about the Garden of Eden on the ABC website. It is not entirely clear whether he really thinks clothes are a bad idea, but that would explain his concern with developing washboard abs:

If there is a single defining characteristic of the modern age, then as I see it, it's probably the mindless commitment we have to technology as the panacea for virtually all our ills. In fact we have committed ourselves and been so bedazzled by technology if you like, that we have essentially theologised technology. We've turned it into a way of, I suppose, taking on the pretence of playing God ourselves. In the Garden of Eden story the serpent tempts Eve to eat of the Tree of Knowledge. She then in turn tempts Adam to eat of the Tree of Knowledge. When he does, they suddenly become shamed and conscious of what seems surprising in itself, their nakedness.

Now within that context, occurs the first act of technology if you like, namely the sewing of the figleaf. They sew the figleaf and turn to technology to do that, as a way of covering their external nakedness. I want to suggest that the problem at the outset was never their external nakedness, it was their internal nakedness. Their shame in respect of alienation from God, their disobedience, their failure to live by way of honouring the beauty of the garden, the gift of the garden, the gift of their life in relation to God.

So in essence what I'm saying is that by virtue of sewing the figleaf, and covering their external nakedness, what they actually really do is turn away from the deeper problem, and what it does is to apply or appeal to technology as a way of avoiding having to confront the wages of their actual sin. The sin of disobedience, the sin of alienation, the sin of not living as God would have them live in the garden.

So for me the story is very powerful as I've recast it as a way of saying that first of all the Garden of Eden story, in this sense, needn't be construed as a past and defined event which occurred long ago in time. I see it as a dynamic event, unfolding constantly in history in the way it reproduces itself through our interactions with nature and each other. We're constantly as a race, a group, humankind, presented in beautiful garden scenarios which unfortunately we continuously despoil.

In fairness I also read the hardcopy text of this article, from 1986, which is actually quite reasonable. His theology of transcendence is not particularly new- I'm sure I've read C. S. Lewis saying essentially the same thing, and before him, St. Augustine (So possibly it goes back to Plato- what did they teach me in those schools?)- but it appears that once upon a time Prof Laura was doing intellectual work of some value, before he went off the rails into a technology-is-evil obsession.

A little note about chain transfer to butyl methacrylate

For good or evil, this paper, which I began writing in 1999 at the request of Professor Bob Gilbert, is finally published. It is a tremendous pleasure to finally be a co-author with David Sangster, the eminence d'or of Australian polymer science. He is the source of the quote which informs my every waking action:

'Just because the model fits the data, it doesn't mean the model is true.'

Royal Society Discussion Paper, Ocean acidification due to increasing atmospheric carbon dioxide. Part Two.

The RSC discussion paper explains the division of ocean waters between an upper zone, where calcium carbonate formation is possible, and a colder lower zone, where it is not possible. The fact that mass transport between these zones is very slow is stressed. The paper does not actually give a pH profile of the ocean, but here is one:

(The little dark dots are the data from today; the big circles are attempts to figure out the situation at various times in the past, which is what the paper I sourced this from is about.)

Note that the vast majority of the volume of the ocean is cold, and relatively acidic. This deep ocean is where an enormous amount of carbon is stored. Transport of carbon dioxide out of or into this layer will not be controlled by thermodynamics (i. e., where carbon dioxide it would most dearly love to be), but by kinetics (i. e., how fast it can get there). Thus, it does not matter to this zone whether or not we are adding carbon dioxide to the atmosphere at a rate unparalleled in Earth’s history or not, because that will not control how fast it gets there. It has to run the gauntlet of the warm water- where it may or may not be converted into calcium carbonate- first.

Remember the figures in the last post on how the carbonic acid equilibria change with temperature. I am now going to make the assertion- which I should now go out and try to verify- that the deep ocean is more acidic *because* it is cold.

To qualify this as-yet-unverified assertion of mine, I should say that I have not yet found any data on the pressure dependence of the pKa values in solutions of reasonable ionic strength, which is also likely to be important.

I suggest that the temperature gradient of the ocean is probably what generates the pH profile, and because transport of carbon dioxide into or out of the ocean is slow compared to how much is already there, it is the temperature dependence of the carbonic acid equilibria which control the speciation observed. Note also that the boundary between the carbonate-forming zone and the non-carbonate forming zone, from our figures below showing what the equilibria do, is going to be dependent both on the pH of the upper layers and their temperature.

Now… if climate change means anything, it means the oceans warming up. Heating the ocean and reducing the pH will pull the carbonate/bicarbonate equilibrium in different directions. I don’t know which is likely to be more significant.

Because the historical record does not show carbon dioxide spouting out of the ocean immediately as temperature increases, but lagging about 1000 years, I am not at all worried about degassing of carbon dioxide starting some feedback loop of badness : until that cold lower ocean where most all of the carbonic acid species are sitting warms up, there is no reason for significant amounts of carbon dioxide to leave the ocean. That is, if degassing of the ocean *is* the reason for the increase in carbon dioxide lagging historical temperature changes. It might not be.