Two views of conceptual realism

Thesis (M.A.)--Boston UniversityThe problem of the thesis is to compare critically the major ontological questions which serve to distinguish two outstanding schools of philosophy representing the realistic development of thought. These schools are referred to as Platonic Realism and Neo-Realism. Some of the questions treated- deal with such matters as ontological extensity, novelty, linguistics, the subordinate character of epistemology, and the nature of error--for each of which distinct explanations are offered by both realistic schools. More precisely, these problems became prominent as a consequence of the latter-day Neo-Realist's refusal to accept the ontological limitations imposea by the theory of the earlier Platonic Realists. In the light of this, ontological speculation stands as a decisive cleavage between the Platonic Realist and Neo-Realist. Accordingly, the particular theory of ontology expressed by each of these schools must come under examination for purpose of evaluating their claims. Upon the basis of such an examination, certain important qualifying conditions are found to be necessary in order to determine the value of conceptual realism. In the last analysis, the thesis is designed to highlight these qualifying conditions. Plato's theory of Ideas was seen to give an early, but comprehensive, statement of one dimension in the realistic view of reality. This dimension was composed exclusively of Ideas. These Ideas, which later became known as universals, were imputed to have certain important qualities: abstractness, individuation, and eternality. None of these qualities may be omitted when speaking of the various divisions by which the Platonic Ideas may be divided into classes; these classes consisted of Ideas of qualities and relations, Ideas of negative notions, and Ideas of sensible objects. The account given by Plato of the relation between the Ideas and the actual physical world led to a view of immanence which Plato most often preferred to call "participation." This account was never sufficiently or adequately explicated by Plato for his readers to have a clear and distinct understanding of such a relation. In its broadest form, Plato's ontology was inclusive of three definite dimensions--Being, the Ideas, and phenomena--which, taken collectively, exhaust the content of the Platonic universe. The Neo-Realist movement began as a polemic against both idealism and subjectivism, and as a polemic it sought to show the difficulties with the positions that it condemned. From this polemic, however, there emerged a definite and positive commitment. This commitment included such aspects of the Neo-Realistic thesis as a theory of independence in cognition, epistemological monism, logical analysis, a pluralistic ontology, and an external view of relations. These positive features were seen in operation through the Neo-Realist's presentative theory of perception that sought to uphold a relational theory of consciousness based upon a universe of being best described as a "neutral mosaic." The basis for such a theory of reality was found to center in the Neo-Realist's doctrine of subsistents which was seen to be expressive of an all-pervasive logical atomism. A direct comparison of the two schools of realism gave light to certain differences between them due to the modification imposed upon Platonic Realism by the Neo-Realist's doctrine of possibility. Most important, the content of the Platonic Realm of Ideas was affected, and thus limited, due to mathematical and moral qualifications, whereas the Neo-Realist's Realm of Possibility was unrestrictively membered by logical constructs. An explanation of novelty as it is effected by the theory of Ideas was seen to be restricted in application to the level of phenomena, however, the Neo-Realist's theory of possibility readily accounted for novelty at any level. The nature of the propositional structure in the Neo-Realist's theory of possibility was found to be more inclusive in accounting for reality than the Platonic treatment of general terms which demanded a relation of identicalness between the Idea and the general term. Whereas Plato's account of error was epistemological, the Neo-Realist awarded error an ontological status based upon their theory of possibility. Certain objections to a theory of possibility must be registered which have the collective force of placing the ontological value of such a theory in question. These objections indicate that a theory of possibility is suspect due to: (1) the failure of the Neo-Realists to provide an adequate definition; (2) the violation of all sense of aesthetic proportion; (3) the failure in providing an effective test upon which to base or warrant their assertions about conceptual reality; and, (4) the failure to justify their position in light of the criticism based upon Russell's theory of types. From such considerations, the thesis seeks to highlight an inconclusiveness which obtains in the two Realistic views presented here. To give a picture of reality within the framework of the realistic tradition, a reliance upon a theory of universals was fully in evidence in both the Platonic and Neo-Realistic views. If one accepts a theory of universals, the question then arises as to what extent one is willing to be committed. On the one hand, a question of inconsistency and incompleteness arose concerning the strict Platonic position due to a circumscription of the universals accepted. On the other hand, a dissatisfaction resulted on the grounds of non-economy if one accepted the uncircumscribed theory of possibles recognized by the Nee-Realists. Yet if one is going to accept a theory of universals, but reject both the Platonic and Neo-Realistic interpretations of this theory for reasons of being too narrow and too broad, respectively, the question then remains as to exactly what sort of reconciliation between these two views, if any, would constitute an acceptable position. As yet, no such reconciliation has found general acceptance, however, at least certain important qualifying conditions--consistency, completeness, and economy--are seen to structure any such acceptance. Hence, only to the extent to which such conditions adequately qualify the two Realistic positions, may acceptance of those positions, complete, or partial, be found

Identifying and Modeling Spatio-temporal Structures in High Dimensional Climate and Weather Datasets with Applications to Water and Energy Resource Management

Weather and climate events are costly to society both financially and in terms of human health and well being. The costs associated with extreme climate events have motivated governments, NGOs, private investors, and insurance companies to use the data and tools at their disposal to estimate the past, present, and future hazards associated with a wide range of natural phenomena in an effort to develop mitigation and/or adaptation strategies. The nonstationary nature of climate risks requires the use of numerical climate models, often general circulation models (GCMs), to project future risk. The climate risk field, however, currently finds itself in a predicament because GCMs can be biased and do not provide a clear way to credibly estimate their uncertainty with respect to simulations of future surface climate conditions. In response to this predicament, I lay the groundwork for a set of GCM credibility assessments by identifying the large-scale drivers of surface climate events that evolve over a range of timescales ranging from daily to multi-decadal. I specifically focus on three types of climate events relevant to the water and energy sectors: 1) seasonal precipitation, which impacts drinking water supplies and agricultural productivity; 2) extreme precipitation and the costly associated riverine flooding; and 3) temperature, wind, and solar radiation fields that modulate both electricity demand and potential renewable electricity supply. In chapter I, I derive a set of atmospheric indices and investigate their efficacy to predict distributed seasonal precipitation throughout the conterminous United States. These indices can also be used to diagnose the impact of tropical sea surface temperature heating patterns on conterminous United States precipitation. This is particularly of interest in the aftermath of the unexpected precipitation patterns in the conterminous United States during the 2015-2016 El Niño event. I show that the set of atmospheric indices, which I derive from zonal winds over the conterminous United States and portions of the North Atlantic and Pacific oceans, can skillfully predict precipitation over most regions of the conterminous United States better than previously recognized mid-latitude atmospheric and tropical oceanic indices. This work contributes a set of intermediate atmospheric indices that can be used to assess the efficacy of forecasting and simulation climate models to capture signal that exists between tropical heating, mid-latitude circulation, and mid-latitude precipitation. In chapter II, I first show that the frequency of regional extreme precipitation events, which are predictive of riverine flooding, in the Ohio River Basin are poorly simulated by a GCM relative to historical precipitation observations. I then illustrate that the same GCM is much better able to simulate the statistical characteristics of a set of atmospheric field-derived indices that I show to be strongly related to the precipitation events of interest. Thus, I develop a statistical model that allows for the simulation of the precipitation events based on the GCM's atmospheric fields, which allows me to estimate future hazard based on credibly simulated GCM fields. Lastly, I validate the fully Bayesian statistical model against historical observations and use the statistical model to project the future frequency of the regional extreme precipitation events. I conclude that there is evidence of increasing regional riverine flood hazard in the Central US river basin out to the year 2100, but that there is high uncertainty regarding the magnitude of the trend. This work suggests that the identification of atmospheric circulation patterns that modulate the probability of extreme precipitation and riverine flood risk may improve flood hazard projections by allowing risk analysts to assess GCMs with respect to their ability to simulate relevant atmospheric patterns. In chapter III, I present the first comprehensive assessment of quasi-periodic decadal variations in wind and solar electricity potential and of covariability between heating and cooling electricity demand and potential wind and solar electricity production. I focus on six locations/regions in the conterminous United States that represent different climate zones and contain major load centers. The decadal variations are linked to quasi-oscillatory variations of the global climate system and lead to time-varying risks of meeting heating + cooling demand using wind/solar power. The quasi-cyclical patterns in renewable energy availability have significant ramifications for energy systems planning as we continue to increase our reliance on renewable, weather- and climate-dependent energy generation. This work suggests that certain modes of low frequency climate variability influence potential wind and solar energy supplies and are thus especially important for GCMs to credibly simulate. All of the investigations are designed to be broadly applicable throughout the mid-latitudes and are demonstrated with specific case studies in the conterminous United States. The dissertation sections represent three cases where statistical techniques can be used to understand surface climate and climate hazards. This understanding can ultimately help to mitigate and adapt to climate variabilities and secular changes, which impact society, by assisting in the development, improvement, and credibility assessment of GCMs capable of reliably projecting future climate hazards

A Quarter-Century of Observations of Comet 10P/Tempel 2 at Lowell Observatory: Continued Spin-Down, Coma Morphology, Production Rates, and Numerical Modeling

We report on photometry and imaging of Comet 10P/Tempel 2 obtained at Lowell Observatory from 1983 through 2011. We measured a nucleus rotation period of 8.950 +/- 0.002 hr from 2010 September to 2011 January. This rotation period is longer than the period we previously measured in 1999, which was itself longer than the period measured in 1988. A nearly linear jet was observed which varied little during a rotation cycle in both R and CN images acquired during the 1999 and 2010 apparitions. We measured the projected direction of this jet throughout the two apparitions and, under the assumption that the source region of the jet was near the comet's pole, determined a rotational pole direction of RA/Dec = 151deg/+59deg from CN measurements and RA/Dec = 173deg/+57deg from dust measurements (we estimate a circular uncertainty of 3deg for CN and 4deg for dust). Different combinations of effects likely bias both gas and dust solutions and we elected to average these solutions for a final pole of RA/Dec = 162 +/- 11deg/+58 +/- 1deg. Photoelectric photometry was acquired in 1983, 1988, 1999/2000, and 2010/2011. The activity exhibited a steep turn-on ~3 months prior to perihelion (the exact timing of which varies) and a relatively smooth decline after perihelion. The activity during the 1999 and 2010 apparitions was similar; limited data in 1983 and 1988 were systematically higher and the difference cannot be explained entirely by the smaller perihelion distance. We measured a "typical" composition, in agreement with previous investigators. Monte Carlo numerical modeling with our pole solution best replicated the observed coma morphology for a source region located near a comet latitude of +80deg and having a radius of ~10deg. Our model reproduced the seasonal changes in activity, suggesting that the majority of Tempel 2's activity originates from a small active region located near the pole.Comment: Accepted by AJ; 29 pages of text (preprint style), 8 tables, 7 figure

Row Width and Hybrid Effects on Corn Yield in Iowa

In Iowa, corn historically has been grown in row widths of 30 inches or wider. During the last decade, many Iowa producers developed a renewed interest in the productiveness of corn in narrower rows. Much of this renewed interest was a result of the observed yield benefits of planting soybeans in rows narrower then 30 inches. In addition, the advancements made in farm machinery today have established effective means by which farmers can plant and harvest these narrow rows. As a result, research is needed to evaluate the effect of row spacing and related planting decisions on the yield of modern, high-yielding corn hybrids. The designed purpose of this study was to test the responses of different hybrids (based on relative maturity) to narrow row spacings. This study was conducted over three years, 1997-1999. In addition to this site, this study has been conducted at five other university research farms

Row Width and Plant Density Effects on Corn Yield in Iowa

During the late 90s, research in the northern Corn Belt comparing 15- and 30-inch row corn illustrated yield benefits to narrow rows. In addition, many Iowa producers found soybean yields were optimized when soybean row widths were decreased below 30-inches. As a result, Iowa producers questioned whether benefits to narrow row corn (\u3c 30 inches) existed in Iowa. To answer these questions, research was conducted to evaluate the effect of row spacing and related planting decisions on the yield of modern high-yielding corn hybrids. During the 1997, 1998, and 1999 growing seasons, the effects of row width and harvest plant density were evaluated. The objective of the study was to identify the optimum plant density for corn planted in 15-inch rows compared with 30-inch rows. In addition to this site, this study was conducted on five other university research farms

Starter Fertilizer, Row Width, and Planting Date Effects on Corn Yield in North Central Iowa

Delayed planting or replanting of corn can result in significant yield losses. Recently, planting date studies in Iowa have shown 3% yield loss comparing mid-May planting dates with late April planting dates and 20-30% yield loss comparing June planting dates with late April planting dates. These yield losses can be partially attributed to the hastened vegetative development from increased accumulation of thermal units at later planting dates, which contribute to lessened capture of light resources and thus less carbon fixation. In Iowa, it has been shown that starter fertilizer can increase the early growth of corn from stage V3 to V8. Narrow row spacing will also improve light interception during early vegetative development. During the 1999 and 2000 growing seasons, the effects of planting date, row spacing, and starter fertilizer on corn yield were evaluated. The objective of this study was to determine whether the use of starter fertilizer and row spacing at later planting dates would reduce the associated yield loss by improving early resource capture

Meteorology and climatology of historical weekly wind and solar power resource droughts over western North America in ERA5

Wind and solar electricity generation is projected to expand substantially over the next several decades due both to rapid cost declines as well as regulation designed to achieve climate targets. With increasing reliance on wind and solar generation, future energy systems may be vulnerable to previously underappreciated synoptic-scale variations characterized by low wind and/or surface solar radiation. Here we use western North America as a case study region to investigate the historical meteorology of weekly-scale “droughts” in potential wind power, potential solar power and their compound occurrence. We also investigate the covariability between wind and solar droughts with potential stresses on energy demand due to temperature deviations away human comfort levels. We find that wind power drought weeks tend to occur in late summer and are characterized by a mid-level atmospheric ridge centered over British Columbia and high sea level pressure on the lee side of the Rockies. Solar power drought weeks tend to occur near winter solstice when the seasonal minimum in incoming solar radiation co-occurs with the tendency for mid-level troughs and low pressure systems over the U.S. southwest. Compound wind and solar power drought weeks consist of the aforementioned synoptic pattern associated with wind droughts occurring near winter solstice when the solar resource is at its seasonal minimum. We find that wind drought weeks are associated with high solar power (and vice versa) both seasonally and in terms of synoptic meteorology, which supports the notion that wind and solar power generation can play complementary roles in a diversified energy portfolio at synoptic spatiotemporal scales over western North America

The Highly Unusual Outgassing of Comet 103P/Hartley 2 from Narrowband Photometry and Imaging of the Coma

We report on photometry and imaging of Comet 103P/Hartley 2 obtained at Lowell Observatory from 1991 through 2011. We acquired photoelectric photometry on two nights in 1991, four nights in 1997/98, and 13 nights in 2010/11. We observed a strong secular decrease in water and all other observed species production in 2010/11 from the 1991 and 1997/98 levels. We see evidence for a strong asymmetry with respect to perihelion in the production rates of our usual bandpasses, with peak production occurring ~10 days post-perihelion and production rates considerably higher post-perihelion. The composition was "typical", in agreement with the findings of other investigators. We obtained imaging on 39 nights from 2010 July until 2011 January. We find that, after accounting for their varying parentage and lifetimes, the C2 and C3 coma morphology resemble the CN morphology we reported previously. These species exhibited an hourglass shape in October and November, and the morphology changed with rotation and evolved over time. The OH and NH coma morphology showed hints of an hourglass shape near the nucleus, but was also enhanced in the anti-sunward hemisphere. This tailward brightness enhancement did not vary significantly with rotation and evolved with the viewing geometry. We conclude that all five gas species likely originate from the same source regions on the nucleus, but that OH and NH were derived from small grains of water and ammonia ice that survived long enough to be affected by radiation pressure and driven in the anti-sunward direction. We detected the faint, sunward facing dust jet reported by other authors, and did not detect a corresponding gas feature. This jet varied little during a night but exhibited some variations from night to night, suggesting it is located near the total angular momentum vector.Comment: Accepted by Icarus; 20 pages of text (preprint style), 5 tables, 7 figure

The Increasing Rotation Period of Comet 10P/Tempel 2

We imaged comet 10P/Tempel 2 on 32 nights from 1999 April through 2000 March. R-band lightcurves were obtained on 11 of these nights from 1999 April through 1999 June, prior to both the onset of significant coma activity and perihelion. Phasing of the data yields a double-peaked lightcurve and indicates a nucleus rotational period of 8.941 +/- 0.002 hr with a peak-to-peak amplitude of ~0.75 mag. Our data are sufficient to rule out all other possible double-peaked solutions as well as the single- and triple- peaked solutions. This rotation period agrees with one of five possible solutions found in post-perihelion data from 1994 by Mueller and Ferrin (1996, Icarus, 123, 463-477), and unambiguously eliminates their remaining four solutions. We applied our same techniques to published lightcurves from 1988 which were obtained at an equivalent orbital position and viewing geometry as in 1999. We found a rotation period of 8.932 +/- 0.001 hr in 1988, consistent with the findings of previous authors and incompatible with our 1999 solution. This reveals that Tempel 2 spun-down by ~32 s between 1988 and 1999 (two intervening perihelion passages). If the spin-down is due to a systematic torque, then the rotation period prior to perihelion during the 2010 apparition is expected to be an additional 32 s longer than in 1999.Comment: Accepted by The Astronomical Journal; 22 pages of text, 3 tables, 6 figure