vrijdag 17 augustus 2012

Anthropic Water

Water, plain and simple water, is an intriguing substance. Its chemical formula is H2O. A water molecule is composed of one oxygen atom and two hydrogen atoms. A simple chemical structure indeed. But the spatial structure of water is not as simple as we might imagine. The most ‘straightforward’ structure is the most symmetrical one, with the two hydrogen atoms opposite of each other and the oxygen atom in the middle, the three atoms nicely on a straight line. Like the three atoms in carbon dioxide, CO2, for example. No, in water the three atoms form a triangle. The angle at the vertex where the oxygen sits is 104.5 degrees. And this is of vital importance. Literally.

It makes water a polar molecule, with the negative charge (the electrons) closer to the oxygen than to the hydrogen. Its bent structure and the charge distribution determine the properties of water as a solvent. They also make water a liquid at standard temperature and pressure, which is quite exceptional for such a light molecule. (Even H2S, which has a similar structure but a smaller dipole moment, is a gas, even if it is heavier than water.) Without water and its properties, largely determined by its bent shape, there would be no life.

The structure of water can be understood by describing its electron orbits as determined by quantum mechanics. The radii of these orbits (the distance from the relatively heavy and immobile oxygen and hydrogen nuclei) and the velocity of the electrons are such that their product is of the order of one (in so called ‘natural units’). Through the ‘uncertainty relations’ we know that in this case we enter the ‘quantum domain’ and quantum mechanics is the theory we need to describe the physical reality.

It would go too far to call quantum mechanics a straightforward theory. It is quite an amazing theory, but once you have accepted it, its use is straightforward. This does not mean it is easy: water consists of three nuclei and ten electrons and even if you simplify the nuclei to pointlike particles it is impossible, for now and always, to exactly solve the quantum mechanical equation (the Schrödinger equation) for this many body system. It is, however, possible to make acceptable approximations and to resort to the use of computers and the result is that the structure of water, vital for life, follows compellingly from quantum mechanics, a perhaps counter-intuitive but profound construct of the human mind and an accurate description of the physical world.

All this was known when I went to university in 1967 and it was exciting, very exciting, to ‘rediscover’ this during the initial years of university training. There was more to be discovered and personally I was (and I am) attracted by the challenges of elementary particle physics. In recent years a connection between particle physics and another field really catching the imagination, cosmology, has been made. In the beginning there was particle physics... Our understanding of the beginning of the universe, of the very initial phases of the Big Bang, is hampered by our lack of understanding of gravity. It must have played an important role at the quantum level, initially, when the energies involved were very high. A lack of understanding of quantum-gravity does not mean a lack of candidate theories for including gravity in the description of the elementary world. Based on the principles of the theories of relativity and quantum mechanics (a ‘minimal’ condition for candidate theories) and with the notion of ‘elementary particle’ replaced by ‘elementary string’ in fact a practically infinite number of theories can be chosen from. Even if we assume, perhaps somewhat naively, that the right ‘theory of everything’ has been found in principle, no one is capable of singling it out from the huge number of possible theories.

I will now tread on slippery ground. Cosmologists have invoked the ‘anthropic principle’ to explain, or rather to be absolved of explaining why the universe and the laws that govern it are as they are. According to the ‘anthropic principle’, the universe we observe and the laws we find must be consistent with ‘us’, with conscious life – if not, we would not be there to make observations and find explanations in the first place. So only universes compatible with conscious life (is this well-defined?) can ‘exist’. The ‘anthropic principle’ may be interesting philosophically, but, as far as I can see, it is not useful to help us find the right ‘theory of everything’ amidst the huge number of possible theories. Neither is it able to explain the structure of water, but quantum mechanics is, and was so long before anyone felt the need for an anthropic principle!

Jos Engelen
August 17, 2012

maandag 13 augustus 2012

Nature, an open book?

Open Access (OA) to scientific publications is generally considered to be the desirable standard. In particular publications resulting from publicly funded research should not be obstructed by a (pay)wall and should be accessible easily by researchers, cross-disciplinary, by researchers in the private sector, including SME’s, and by the general public. Sharing scientific information widely is clearly beneficial for science itself, for facilitating applications and for involving and informing the public.

The transition to OA publishing is rather straightforward in principle but the practical implementation requires certain obstacles to be overcome. Publishing is a professional activity concerned with standards of quality control and editorial policies that have led to a body of scientific journals that has an important and recognized role in scholarly communication. This, or such a body of qualified scientific journals should be preserved under the transition to OA. Ideally the important publishers should stay on board by adapting their business models.

The highest standard of excellence is implied when reference is made to articles published in ‘Nature or Science’.  Or in a few other similarly highly ranked journals. Nature and Science are not OA journals, but they have a very strong position and researchers are keen to get their results published in them. So, in a sense, ‘Nature and Science’ are an obstacle to reaching the desired OA standard.

Let us look in somewhat more detail at Nature, as an example. Let me stress from the outset: my purpose is not to question the high quality that is attributed to Nature, my purpose is to understand whether it is possible to make it part of the ‘OA world’.

Nature’s Editor in Chief repeated recently, during a panel discussion at the European Science Open Forum conference in Dublin, that Nature has adhered to the same editorial policy ever since its foundation in 1869. Namely: in order to qualify for acceptance by Nature an article should report on new results, present ‘a first’, not reported on before. I do not find this very helpful, because every research article published in the scientific literature should satisfy such criteria. So what makes Nature so unique? What has changed since 1869 is the intensity and diversity of scientific research: the volume of excellent research has increased by orders of magnitude. The role of research has also changed: from a rather esoteric activity of a rather small elite to a societal necessity for competitiveness and sustainability. The number of manuscripts submitted to Nature for publication has increased enormously during its existence and the fraction of manuscripts actually accepted for publication has plummeted dramatically. This fact alone has contributed considerably to Nature’s almost mythical status. It is not Nature’s fault. Nature employs a staff of full time, professional editors, who, helped by reviewers (scientists, ‘peers’ of the authors submitting articles) do the utmost to select the best manuscripts for publication. But how do you define ‘the best’? There is a danger here of getting caught in a tautological illusion. To find clues I invite you to have a look at a number of recent issues of Nature. A first observation is that only about half of the published pages is dedicated to original scientific results (a small fraction of that half to fully fledged articles, the rest to ‘letters’). The remaining half is filled with news, views, advertisements, announcements, recruitment pages. I now ask myself again: how are ‘the best’ scientific articles defined. ‘The best’ for attracting the right audience for ‘the rest’?

Let us return to the scientific articles, 50% of Nature’s business. It remains a problem that the overly prolific submission of manuscripts to Nature puts a very heavy burden on the editorial staff. It comes at a cost that makes a transition to an Open Access business model for Nature prohibitive. At least, that is what Nature says. But why would that be so? The relatively few articles that are published in Nature can easily be paid for once the ‘author pays’ (means: research funding organization pays) model would be generally accepted. It is perfectly possible to maintain the highest scientific quality standards whilst adopting Open Access publishing as the new standard. This is true in general, this is true for Nature. It requires a critical attitude of the scientists, of the research funders and of those ‘measuring’ the quality of research and its practitioners. Nature should follow the scientific community, not the other way around.

(This 'blog' appeared, translated in Dutch and slightly edited, in 'NRC Handelsblad' of July 31, 2012)

Jos Engelen
July 28, 2012