All faculty talks are 90 minutes (talk + Q & A). Please find suggested readings below.
|Time||July 9th: MULTISCALE DAY||July 10th: CHEMISTRY / NANO DAY||July 11th: MODELING DAY|
|9:00-10:30||– free time –||Julia Bursten||Alisa Bokulich|
|11:00-12:30||Bill Bechtel||Robin Hendry||Collin Rice|
|1:30-3:00||Lab Visit||Reading/Discussion Group||Reading/Discussion Group|
|3:30-5:00||Sara Green||Dan Needleman||(4pm start) Patrick McGivern|
|5:00-5:30||Student abstracts & Daily Summary Session||Daily Summary Session||Daily Summary Session|
|6:00||Dinner: Bangkok Joe’s||Dinner: Paolo’s||(6:30pm) Dinner: Clyde’s|
Presentation Titles, Abstracts, and Suggested Readings
Patrick McGivern: Emergence for Active Matter
Sarah Green: Scaling-effects and biomechanical constraints in biology
My aim in this talk is to clarify the similarities and differences in the philosophical insights that can be drawn from multi-scale modeling in physics and biology. Modeling a system across different scales requires the combination different types of mathematical models because assumptions about how the system behaves, and about which details can be ignored, are scale-dependent. Yet, what is described as the “tyranny of scales” problem in physics has not yet received much attention from philosophers of biology. I draw on selected case examples that illustrate how this problem plays out in the biological domain and discuss their philosophical implications. Analyzing the ways in which different models are combined in multi-scale modeling also has interesting implications for discussions on reductionism, and on the relation between physics and biology. Whereas physical science approaches are often either taken to support a reductionist view, or to primarily offer background conditions for biological explanations. In contrast, I argue that inputs from physics often reveal the importance of macroscale models and explanations. Moreover, the case examples suggest that we take a more symmetrical view of physical and biological factors influencing biological matter.
Julia Bursten: At the Borders of Active Materials: Shape Memory Alloys
Abstract: One of the central questions of the Active Matter Project is what constitutes an active material. In AMP1, Needleman et al. identified two central material responses that characterize active materials: self-propelling behavior, and flocking/swarming behavior. These behaviors are exhibited across a wide range of organic and inorganic materials, and they are jointly sufficient for classifying a material as active. This criterion, while useful for centralizing discussion about the structure and behavior of active materials, leaves the boundaries of classification somewhat hazy, as there are a variety of collective responses in materials that fall short of the joint propelling/flocking threshold. In this talk, I consider a series of material responses that are typically classified as “smart,” namely the shape memory effect (SME) in alloys. The SME occurs when a metal is stressed, by heat or magnetism, above a particular threshold of deformation and then, upon cooling, “remembers” its original shape. I consider whether the SME is an example of an active material response as a means of surveying the borderlands of active materials.
Robin Hendry: Emergent (Sub-)Disciplines
Using the examples of chemistry and soft matter, I investigate what it takes for a discipline (or sub-discipline of physics) to be emergent, when it is also in some important sense a physical science. A discipline is emergent when (i) it is possible to study its subject matter without knowing the more fundamental entities and processes underlying it and (ii) it is necessary to study it this way because it is not possible to derive its central theoretical claims from more fundamental theories. Chemistry began as an autonomous science that developed theories concerning the elemental composition of substances at a time when physics offered no relevant theories of the structure of matter. From the beginning of the twentieth century, however, chemistry and physics were increasingly commensurated: a process in which the languages of the two sciences became linked systematically. By comparing and contrasting chemistry, soft matter and other supposedly emergent disciplines, I try to extract some lessons for debates on reductionism, emergence and the unity of science.
Dan Needleman: Active Matter and Cell Biology
Alisa Bokulich: Taming the Tyranny of Scales: Lessons from the Earth Sciences
Bill Bechtel: Life: Coordinating Mechanisms at Multiple Spatial and Temporal Scales
Biological organisms are often studied by situating them in a constant environment, perturbing them with a stimulus, and recording their responses. They are assumed to be at a state-state, with their responses determined by the stimulus. Variability, which is almost always observed, is treated as noise. However, when time series data is collected, biological organisms exhibit a multitude of endogenous oscillations at multiple frequencies and amplitudes. An important feature of oscillatory systems is their capacity to synchronize when an appropriate signal connects different oscillators, enabling coordinated behavior over extended spatial scales. Biological oscillations occur over a broad range of frequencies (from ultradian with periods from thousandths of a second to hours) to circadian (approximately 24 hours) and infradian (extending to years). Coupling also occurs between oscillations at different frequencies and these often serve to coordinate relatively independent mechanisms within organisms. Developing examples from bacteria to the human brain, I will explore how coordination of oscillators provides an important way in which biological organisms coordinate processes over many spatial and temporal scales.