blogjou

Theory tends to emerge as a profession as a science matures...

Theory tends to emerge as a profession as a science matures and as the depth and power of theoretical methods increase. But the roles of theory and observation should be regarded as distinct whether or not there are separate classes of practitioners for the two activities.

Similarly, in the will of the Swedish dynamite magnate Alfred Nobel...

Similarly, in the will of the Swedish dynamite magnate Alfred Nobel, who established the Nobel prizes, the science prizes are listed with physics first, chemistry second, and physiology and medicine third. As a result, the physics prize is always awarded at the beginning of the ceremony in Stockholm. If there is just one physics prize winner and that winner is a married man, it is his wife who comes into dinner on the arm of the King of Sweden. (When my friend Abdus Salam, a citizen of Pakistan and a Muslim, received a share of the physics prize in 1979, he turned up in Sweden with his two wives, np doubt causing some problems of protocol to arise.) The winner or winners in chemistry rank second in protocol, and those in physiology and medicine third. Mathematics is omitted from Nobel’s will for reasons that are not really understood. There is a persistent rumor that Nobel was angy with a Swedish mathematician, Mittag-Leffler, for stealing the affections of a woman, but, as far as I know, it is only a rumor.

But is the information obrained from the outside world...

But is the information obtained from the outside world, for example from a parent who speaks the language in question, sufficient to construct such an internal grammar? That question has been answered in the negative by Noam Chomsky and his followers, who conlcude that the child must come already equipped at birth with a great deal of information applicable to the grammar of any natural human language. The only plausible source of such information is a biologically evolved innate proclivity to speak languages with certain grammatical features, shared by all natural human languages. The grammar of each individual languange also contains additional features, not biologically programmed. Many of those vary from language to language, although some are probably iniversal like the innate ones. The additional features are what the child has to learn.

It is not at all atrivial matter that there are such things as species...

It is not at all a trivial matter that there are such things as species; and they are not just artifacts of the biologist’s mind, as has sometimes been claimed. Ernst Mayr, the great ornithologist and biogeographer, likes to recount how, as a young researcher in New Guinea, he counted a hundred and twenty-seven species of birds nesting in the valley where he was working. The members of the local tribe counted a hundred and twenty-six; the only difference between their list and his was that they lumped together two very similar species of gerygone that Ernst, with his scientific training, was able to distinguish from each other. Even more important than the agreement among different sorts of people is the fact that the birds themselves can tell whether or not they belong to the same species. Animals of different species are not usually in the habit of mating with one another, and in the rare cases where they do, the hybrids they produce are likely to be sterile. In fact, one of the most successful definitions of what constitutes a species is the statement that there is not effective exchange of genes by ordinary means between members of different species.

Nietzsche introduced the distiction between...

Nietzsche introduced the distinction between “Apollonians,” wo favor logic, the analytical approach, and a dispassionate weighing of evidence, and “Dionysians,” who lean more toward intuition, synthesis and passion. These traits are sometimes described as correlating very roughly with emphasis on the use of the left and right brain respectively. But some of us seem to belong to another category: “Odysseans,” who combine the two predilections in their quest for connections among ideas.

Today the network of relationships linking the human race to itself...

Today the network of relationships linking the human race to itself and to the rest of the biosphere is so complex that all aspects affect all others to an extraordinary degree. Someone should be studying the whole system, however crudely that has to be done, because no glueing together of partial studies of a complex nonlinear system can give a good idea of the behavior of the whole. Chapter 22 describes some efforts just getting under way to carry out such a crude study of world problems, including all the relevant aspects, not only environmental, demographic, and economic, but also social, political, military, diplomatic, and ideological. The object of the study is not just to speculate about the future, but to try to identify among the multiple possible future paths for the human race and the rest of the biosphere any reasonably probable ones that could lead to greater sustainability. Here the word sustainability is used in a broad sense, including not only the avoidance of environmental catastrophe, but of catastrophic war, widespread long-lasting tyranny, and other major evils as well.

The fate and transit time of carbon in a tropical forest

The paper is on means and quantiles of transit times of C in the Porce forest (Columbia). Furthermore, the concept of $\mathrm{NPP}/\mathrm{GPP}$ as $\mathrm{CUE}$ is questioned and an interpretation as $\mathrm{NPP}/\mathrm{GPP} = R_h/\mathrm{GPP}$ is suggested.

• The time that C fixed as $\mathrm{GPP}$ spends in an ecosystem is relevant to understand feedbacks between ecosystems and the climate system.
• Plot level estimates of
• Used average of parameters from a parameter set obtained by MCMC.
  • Average okay for linear models?
  • What about nonlinear models?
• autotrophic pools: foliage, wood, fine roots, coarse roots
• heterotrophic pools: fine litter, CWD, soil carbon
• Most metabolic processes operate on an intra-annual time-scale.

We obtained an average value of 0.3 for the ratio NPP:GPP for the forests at equilibrium, a ratio that is often called carbon use ef- ficiency ($\mathrm{CUE}$) (Chambers et al., 2004; DeLucia et al., 2007; Gifford, 2003; Malhi et al., 2015). According to common interpretation, this ratio would suggests that 30% of the photosynthetically fixed car- bon is used for biomass production. Similar values for $\mathrm{CUE}$ with simi- lar interpretations are also given by Chambers et al. (2004) and Malhi et al. (2013), although larger variability in $\mathrm{CUE}$ is reported in Doughty et al. (2018). However, we believe that this common interpretation of $\mathrm{CUE}$ has problems since, as our transit time distribution showed, au- totrophic respiration is composed of carbon that spends some time in biomass before being respired. The amount of time carbon stays in plant cells can vary from hours to decades, but photosynthates have to be metabolized from living cells (biomass) for CO2 production to occur. Thus, autotrophic respiration originates from biomass already produced; however, most of this metabolism occurs very quickly as the transit time distribution suggests, giving the false impression that a large proportion of carbon was not used to produce biomass. As other authors have shown (DeLucia et al., 2007; Gifford, 2003), estimates of $\mathrm{CUE}$ depend largely on whether estimates are made on short or long periods of time, and the transit time distribution pro- vides good support for avoiding an interpretation of this ratio out of the context of the time-­scales involved.

\begin{equation} \nonumber \frac{\mathrm{NPP}}{\mathrm{GPP}} = \frac{\mathrm{GPP}-R_a}{\mathrm{GPP}} = \frac{R_e}{\mathrm{GPP}} \end{equation}

• $\mathrm{NPP}/\mathrm{GPP} = 0.3$ means that 70% of total photosynthates are respired by autoptrophs and only 30% by heterotrophs.
• no relation to biomass production (as $\mathrm{CUE}$), but interpretation in terms of different pathways of fixed C

It doesn't seem to me that this fantastically marvellous universe...

It doesn’t seem to me that this fantastically marvellous universe, this tremendous range of time and space and different kinds of animals, and all the different plants, and all these atoms with all their motions and so on, all this complicated thing can merely be a stage so that God can watch human beings struggle for good or evil - which is the view that religion has. The stage is too big for the drama. So I believe it’s not the right picture.

I think I entered MIT in Math...

I think I entered MIT in Math (course XVIII). After a bit I went to Franklin (then head of Math Department) to ask “what is the use of higher mathematics beside teaching more higher mathematics.” He answered, “if you have to ask that then you don’t belong in mathematics.”

It appears the Greeks take their past very seriously...

It appears the Greeks take their past very seriously. They study ancient Greek archeology in elementary school for six years, having to take 10 hours of that subject every week. It is a kind of ancestor worship for they emphasize always how wonderful the ancient Greeks were - and wonderful indeed they were. When to encourage them by saying yes and look how modern man has advanced beyond the acient Greeks (thinking of experimental science, the development of mathematics, the art of the renaissance, the great depth and understanding of the relative shallowness of Greep philosophy, etc., etc.) - they say, “What do you mean - what was wrong with the ancient Greeks?” They continually put their age down and the old age up, until to point out the wonders of the present seems to be an unjustified lack of appreciation for the past. They were upset when I said that the thing of greatest importance to mathematics in Europe was the discovery by Tartaglia that you can solve a cubic equation - which, altho it is very little used, must have been psychologiclly wonderful because it showed a modern man could do something no ancient Greek could do, and therefore helped in the renaissance which was the freeing of man from the intimidation of the ancients - what they are learning in school is to be intimidated into thinking thet have fallen fo far below their super ancestors.