• 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.

    Adrian Bejan: 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.
    Donald A. Nield, Adrian Bejan (2012). “Convection in Porous Media”, p.135, Springer Science & Business Media