The evolution of airplanes

Airplanes Figure 1Abstract: The prevailing view is that we cannot witness biological evolution because it occurred on a time scale immensely greater than our lifetime. Here, we show that we can witness evolution in our lifetime by watching the evolution of the flying human-and-machine species: the airplane.

We document this evolution, and we also predict it based on physics principles. We show that the airplanes must obey theoretical allometric rules that unite them with the birds and other animals. For example, the larger airplanes are faster, more efficient as vehicles, and have greater range.

The engine mass is proportional to the body size: this scaling is analogous to animal design, where the mass of the motive organs (muscle, heart, lung) is proportional to the body size. Large or small, airplanes exhibit a proportionality between wing span and fuselage length, and between fuel load and body size. The animal-design counterparts of these features are evident. The view that emerges is that the evolution phenomenon is broader than biological evolution. The evolution of technology, river basins, and animal design is one phenomenon, and it belongs in physics.

 

The World Cup’s Light-Color Advantage

colorsAccording to Adrian Bejan and J. Peder Zane, authors of  “Design in Nature”, 83% of the winners after the group stage at the World Cup in Brazil wore lighter colors than their opponents – and this is neither an anomaly nor a coincidence.

Instead it reveals a deciding factor in all team sports that, funnily enough, is recognized but not seen. This factor provides surprising insight into the phenomenon of “home-field advantage” and how subtle physical advantages rooted in physics often mean the difference in closely contested matches.

The lighter colors are easier to see because light colors reflect more light than darker ones. This is an advantage, helping teams be united and in sync with the flow of the game.

For fast-flowing team sports like soccer, vision and cognition are as crucial to success as speed and conditioning. In soccer, where scoring chances are rare, the ability to spot your teammate a split second faster can mean the difference between a thread-the-needle pass for a goal or another just-miss.

blogtalkradio.com: A Kind Voice on Big Ideas & Philosophy

A Kind Voice

 

 

Inteview with Adrian Bejan, a former player on the Romanian national basketball team, who is currently a professor of Mechanical Engineering at Duke University.  We will discuss flows in nature and sports, as well as get to know Professor Bejan and his work.

Professor Bejan’s developed the Constructal Law, which is the law of physics that accounts for the universal phenomenon of generation of design (configuration, pattern, geometry) in nature.  The constructal law was stated by Professor Bejan in 1996 as follows: “For a finite-size system to persist in time (to live), it must evolve in such a way that it provides easier access to the imposed currents that flow through it.”

Convection Heat Transfer, 4th Edition

 

Convection Heat Transfer, 4th Ed.

A new edition of the bestseller on convection heat transfer

A revised edition of the industry classic, Convection Heat Transfer, Fourth Edition, chronicles how the field of heat transfer has grown and prospered over the last two decades. This new edition is more accessible, while not sacrificing its thorough treatment of the most up-to-date information on current research and applications in the field.

One of the foremost leaders in the field, Adrian Bejan has pioneered and taught many of the methods and practices commonly used in the industry today. He continues this book’s long-standing role as an inspiring, optimal study tool by providing:

  • Coverage of how convection affects performance, and how convective flows can be configured so that performance is enhanced
  • How convective configurations have been evolving, from the flat plates, smooth pipes, and single-dimension fins of the earlier editions to new populations of configurations: tapered ducts, plates with multiscale features, dendritic fins, duct and plate assemblies (packages) for heat transfer density and compactness, etc.
  • New, updated, and enhanced examples and problems that reflect the author’s research and in the field since the last edition
  • A solutions manual.

Complete with hundreds of informative and original illustrations, Convection Heat Transfer, Fourth Edition is the most comprehensive and approachable text for students in schools of mechanical engineering.advances in the field since the last edition.

Evolution: Why all plumes and jets evolve to round cross sections

Above a certain height, all turbulent plumes have round cross sections.This paper uses a common example of natural organization in order to demystify the phenomenon of evolution in nature. The example is inanimate: the evolution of all plumes and jets in one direction in time, from any cross-sectional shapes to round cross sections. The arrow of time points in one direction, and this direction is captured by the constructal law of design evolution in nature. 

The prevalent view in science is that evolution is a phenomenon of biology, and that it cannot be witnessed in our lifetime. This paper shows that in plumes and jets we witness evolution in real time. We also see the physics principle of evolution, which also allows us to predict turbulence as a phenomenon of physics.

 

Maxwell’s Demons Everywhere: Evolving Design as the Arrow of Time

Closed system in steady state, with heat flow in and out. (a) Without flow organization (design); (b) With flow organization;

Science holds that the arrow of time in nature is imprinted on one-way (irreversible) phenomena, and is accounted for by the second law of thermodynamics. In this article from Nature Scientific Report, Prof. Bejan show that the arrow of time is painted much more visibly on another self-standing phenomenon: the occurrence and change (evolution in time) of flow organization throughout nature, animate and inanimate. This other time arrow has been present in science but not recognized as such since the birth of thermodynamics.

It is Maxwell’s demon.

Translated in macroscopic terms, this is the physics of the phenomenon of design, which is the universal natural tendency of flow systems to evolve into configurations that provide progressively greater access over time, and is summarized as the constructal law of design and evolution in nature. Knowledge is the ability to effect design changes that facilitate human flows on the landscape. Knowledge too flows.