Missing the Point

“What would happen if we thought of Darfur as we do of Iraq, as a place with a history and politics—a messy politics of insurgency and counterinsurgency?” (§4). This is the most telling question posed by Professor Mahmood Mamdani in “The Politics of Naming: Genocide, Civil War, Insurgency.” The implication is that the growing public demand for strong international action—military or otherwise—to halt the atrocities in Darfur is somehow unwarranted because people have failed to understand that the systematic crimes against humanity committed against civilians in Darfur (and indeed Iraq) are an inevitability of “the messy politics of insurgency and counterinsurgency.

Laws of Form: Why Spencer Brown is missing the point

What Spencer Brown wants to rationalize out of existence is alternation itself – the prerequisite of his whole operation. By that he simplifies (identifies) more than he says. And he does not say all that is important

Studying Abroad, Toilet Paper, and Other Exercises in Missing the Point

I have been in Ghana only for a few days, and I can already tell I am going to love the place­—the people, the food, the environment, all remind me of my home country, Sierra Leone. However, I don’t think I can adjust to the constant uttering by some of my peers about how this experience “makes them appreciate how much they have.” In the past four days, I have heard that same phrase over and over again. [excerpt

Missing observations and additive outliers in time series models

The paper deals with estimation of missing observations in possible nonstationary ARIMA models. First, the model is assumed known, and the structure of the interpolation filter is analyzed. Using the inverse or dual autocorrelation function it is seen how estimation of a missing observation is analogous to the removal of an outlier effect; both problems are closely related with the signal plus noise decomposition of the series. The results are extended to cover, first, the case of a missing observation near the two extremes of the series; then to the case of a sequence of missing observations, and finally to the general case of any number of sequences of any length of missing observations. The optimal estimator can always be expressed, in a compact way, in terms of the dual autocorrelation function or a truncation thereof; is mean squared error is equal to the inverse of the (appropriately chosen) dual autocovariance matrix. The last part of the paper illustrates a point of applied interest: When the model is unknown, the additive outlier approach may provide a convenient and efficient alternative to the standard Kalman filter-fixed point smoother approach for missing observations estimation

Comment on "Spatio-temporal filling of missing points in geophysical data sets" by D. Kondrashov and M. Ghil, Nonlin. Processes Geophys., 13, 151–159, 2006

Kondrashov and Ghil (2006) (KG hereafter) describe a method for imputing missing values in incomplete datasets that can exploit both spatial and temporal covariability to estimate missing values from available values. Temporal covariability has not been exploited as widely as spatial covariability in imputing missing values in geophysical datasets, but, as KG show, doing so can improve estimates of missing values. However, there are several inaccuracies in KG’s paper. Since similar inaccuracies have surfaced in other recent papers, for example, in the literature on paleo-climate reconstructions, I would like to point them out here

Missing the point in noncommutative geometry

Noncommutative geometries generalize standard smooth geometries, parametrizing the noncommutativity of dimensions with a fundamental quantity with the dimensions of area. The question arises then of whether the concept of a region smaller than the scale - and ultimately the concept of a point - makes sense in such a theory. We argue that it does not, in two interrelated ways. In the context of Connes’ spectral triple approach, we show that arbitrarily small regions are not definable in the formal sense. While in the scalar field Moyal-Weyl approach, we show that they cannot be given an operational definition. We conclude that points do not exist in such geometries. We therefore investigate (a) the metaphysics of such a geometry, and (b) how the appearance of smooth manifold might be recovered as an approximation to a fundamental noncommutative geometry

Missing the point in noncommutative geometry

Noncommutative geometries generalize standard smooth geometries, parametrizing the noncommutativity of dimensions with a fundamental quantity with the dimensions of area. The question arises then of whether the concept of a region smaller than the scale - and ultimately the concept of a point - makes sense in such a theory. We argue that it does not, in two interrelated ways. In the context of Connes’ spectral triple approach, we show that arbitrarily small regions are not definable in the formal sense. While in the scalar field Moyal-Weyl approach, we show that they cannot be given an operational definition. We conclude that points do not exist in such geometries. We therefore investigate (a) the metaphysics of such a geometry, and (b) how the appearance of smooth manifold might be recovered as an approximation to a fundamental noncommutative geometry