The constructal law and the evolution of design in nature

The constructal law accounts for the universal phenomenon of generation and evolution of design (configuration, shape, structure, pattern, rhythm). This phenomenon is observed across the board, in animate, inanimate and human systems. The constructal law states the time direction of the evolutionary design phenomenon. It defines the concept of design evolution in physics. Along with the first and second law, the constructal law elevates thermodynamics to a science of systems with configuration. In this article we review the more recent work of our group, with emphasis on the advances made with the constructal law in the natural sciences. Highlighted are the oneness of animate and inanimate designs, the origin of finite-size organs on animals and vehicles, the flow of stresses as the generator of design in solid structures (skeletons, vegetation), the universality and rigidity of hierarchy in all flow systems, and the global design of human flows. Noteworthy is the tapestry of distributed energy systems, which balances nodes of production with networks of distribution on the landscape, and serves as key to energy sustainability and empowerment. At the global level, the constructal law accounts for the geography and design of human movement, wealth and communications.     

The physics and biology of fluorescence microscopy in the life sciences

The last decade has seen a renaissance in the use of fluorescence microscopy in biology. This development was fuelled by the discovery of autofluorescent proteins that, through simple genetic conjugation to virtually any protein of interest, allowed their investigation of living cells. Importantly, this also prompted the introduction of advanced fluorescence microscopy techniques of ever increasing sophistication that exploit the possibilities of this new labelling technique. The microscope became an analytical instrument, images became rich sources of quantitative information, and we obtained an unprecedented insight into the working of the molecular machines that operate in living cells. This new field is positioned at the interface between biology and physics. This review will provide an historic overview of this process, describing some of the most exciting developments, and mainly focusing on one of the most informative imaging techniques for the elucidation of the chemistry of life; Förster Resonance Energy Transfer microscopy.     

The emergence of design in pedestrian dynamics: Locomotion,self-organization,walking paths and constructal law

Gait is inherent to human life and hence its importance is often overlooked. But walking remains the most basic form of transportation and almost all journeys begin and end with a walk, regardless of the modes used in-between. Gaining a good understanding of pedestrian?s dynamics is thus a crucial step in meeting the mobility and accessibility needs of people by providing safe and quick walking flows.This paper presents a critical and integrative review of research on pedestrian?s dynamics and associated topics. The review focuses on comprehensive theories and models, with an emphasis on the advances made possible by the application of the constructal law. Constructal law points out that the emergence and evolution of design in pedestrian dynamics is analogous to that of animate flow systems. Most importantly, it also highlights that the basic features of pedestrian dynamics and supportive walking infrastructures can be optimally envisaged with the help of a few fundamental physics laws.