The Tortoise and the Hare

41598_2018_30303_Fig9_HTML.png “The fastest animals and vehicles are neither the biggest nor the fastest over lifetime” is the subtitle of A. Bejan, U. Gunes, J. D. Charles, and B. Sahin in their Nature Scientific Report published the 27 August 2018.

Thanks to their theory, in this article, the authors explained phenomena such as the emergence of animal “outliers”:  higher speed at smaller body mass.

They show that what accounts for the animal outlier also accounts for the vehicle outlier: military jet fighter are smaller and reach speeds higher than the biggest commercial aircraft. Yet, like the cheetah, the jet fighter spends most of its active life at rest, on the ground, out of sight.  This new view gives the word ‘outlier’ a different meaning: the jet fighter is the outlier because, during its overall lifetime, it is slower than the bigger commercial aircraft, which spend most of its time flying.

This new meaning is in fact the oldest, taught by Aesop in his fable “The Tortoise and the Hare”: what matters in the life of the mover is the movement – i.e. the territory covered, the speed averaged – over the whole lifetime.


生命的物理學 – 從生命到經濟消長

Professor’s Adrian Bejan’s book on the Constructal Theory, The Physics of Life: The Evolution of Everything, will be available in Chinese the 27 of July, 2018:

The book can be ordered on the following site:





Human innovation and enlightenment explained by Physics

 Ephrat Livni reviews, in this Quartz article, the application of Constructal theory to the physical description of innovation and human illumination. Livni article refers to a recent research paper on Social organization by A. Bejan  and other researchers: Social organization: The thermodynamic basis.

Simply put, the theory explains that “this theoretical framework also reveals the physical meaning of innovation: It is a local design change that liberates the flow over the entire territory inhabited by the organized movers”. In brief,  innovations open new pathways that generate opportunity for more movement for everyone around them.

And, as the local invention attract sudden movement, then the whole flowing area, or population, becomes wealthier than before. According to Bejan, “this is the tangible, or physical effect of a single idea, and why research, science, questioning, and tinkering benefit the whole of society”.

Read the full story by Ephrat Livni on Quartz: Physics can explain human innovation and enlightenment, June 30, 2018.


Personal Aircraft: Why The Revolution Won’t Happen

According to Prof. Adrian Bejan views, captured into this article published by Aerospace America, a fundamental law of physics will prevent the Personal Aircraft revolution to happen.

The passenger drones, sky taxis, and other personal aircraft names are buzzing and exciting the aviation industry – but Prof. Bejan explains us that flying is for faster travel over long distances, and not for short distances. In this last case, the economical movement is on land, and it is slower.



Design in Nature: the field and its future

These concluding observations presented by Prof. Adrian Bejan, were recorded at the end of the NSF workshop at Villanova University on “Constructal Theory: after 20 Years of Exploration and what the Future Holds”.

This video will guide you  through the decades of development of Constructal theory, since its very inception in Adrian Bejan student’s research work in buckling theory – and his, already, innovative understanding of, and approach to, this field of research.