Chapter 3
Mechanical Aspects of Biosystems
. . . those who rely simply on the weight of authority to make an
assertion, without searching out the arguments to support it, act
absurdly.
—Vincenzo Galilei, Galileo’s father
Summary The materials we are made from follow the same ‘laws’ of mechanics
that inorganic materials do. From the sizes of macromolecules to the sizes of whales,
these laws are those discovered by Isaac Newton back in 1665. We can understand
much of our construction, operations, and our physical limitations by studying these
Newtonian principles. The subject of the study is called mechanics, and the ideas in
this subject describe relationships between forces, accelerations, stress, strain, and
viscous flow. These connections will be applied to a number of biophysical systems.
Mechanics applied to macroscopic systems was the first successful science, and
not surprisingly, is close to everyday observation. Archimedes studied the behavior
of fluids, discovering a basic principle of buoyancy. Leonardo da Vinci invented
many new mechanical devices, and made a careful study of the human musculature,
blood flow, and anatomy. Galileo studied mechanical motion, realizing that massive
bodies retain their motion unless acted on. In the hands of Isaac Newton, our
understanding of the dynamics of particle systems extended far beyond planetary
systems, to any system of masses, including the matter of which we are made.
In what follows, we will see examples of the vast territory over which Newton’s
ideas can take us. However, when our vision reaches to the smallest scales of
biological interest, the atoms that make us, we will find that Newton’s ideas are
subsumed by those of quantum theory, or when we wish to become relativistic space
travelers or apply geosynchronous satellites for positioning, then we use the ideas
of Einstein to expand those of Newton.
© Springer Nature Switzerland AG 2020
W. C. Parke, Biophysics, https://doi.org/10.1007/978-3-030-44146-3_3
27
Mechanical Aspects of Biosystems
. . . those who rely simply on the weight of authority to make an
assertion, without searching out the arguments to support it, act
absurdly.
—Vincenzo Galilei, Galileo’s father
Summary The materials we are made from follow the same ‘laws’ of mechanics
that inorganic materials do. From the sizes of macromolecules to the sizes of whales,
these laws are those discovered by Isaac Newton back in 1665. We can understand
much of our construction, operations, and our physical limitations by studying these
Newtonian principles. The subject of the study is called mechanics, and the ideas in
this subject describe relationships between forces, accelerations, stress, strain, and
viscous flow. These connections will be applied to a number of biophysical systems.
Mechanics applied to macroscopic systems was the first successful science, and
not surprisingly, is close to everyday observation. Archimedes studied the behavior
of fluids, discovering a basic principle of buoyancy. Leonardo da Vinci invented
many new mechanical devices, and made a careful study of the human musculature,
blood flow, and anatomy. Galileo studied mechanical motion, realizing that massive
bodies retain their motion unless acted on. In the hands of Isaac Newton, our
understanding of the dynamics of particle systems extended far beyond planetary
systems, to any system of masses, including the matter of which we are made.
In what follows, we will see examples of the vast territory over which Newton’s
ideas can take us. However, when our vision reaches to the smallest scales of
biological interest, the atoms that make us, we will find that Newton’s ideas are
subsumed by those of quantum theory, or when we wish to become relativistic space
travelers or apply geosynchronous satellites for positioning, then we use the ideas
of Einstein to expand those of Newton.
© Springer Nature Switzerland AG 2020
W. C. Parke, Biophysics, https://doi.org/10.1007/978-3-030-44146-3_3
27