Chapter 6
Electric and Magnetic Fields in Life
Let us be neither drawn aside from the subject in pursuit of
analytic subtleties, nor be carried beyond the truth by a favorite
hypothesis.
—James Clerk Maxwell
Summary Humans wondered about sparks, lightning strokes and lodestones early
in our history, but we did not have a logical and full description of electric and
magnetic effects until James Clerk Maxwell’s work in the 1860s. The properties of
electromagnetism is of central importance in life systems on Earth. The very structure of atoms and molecules comes about through electromagnetic interactions of
electrons and protons. Our nervous system uses electric pulses to send signals. Our
cellular flagellae and cilia motors work through electric pumps. Electrodynamics is
a necessary subject within any serious study of life.
6.1 Importance of Electromagnetism to Life
Electromagnetism is the term used to label one of the four principal types of
interactions acting on clumps of matter. Just like gravity, electric forces diminish
as the square of the separation distance between a pair of interacting charges. 1 Both
gravitational and electromagnetic forces extend over a long range of space, and
are measurable for bodies separated by laboratory-size distances. 2 But, for small
charged chunks of material in our environment, the electric force acting on one
from another is far greater than the gravitational force. 3
1 F G = Gm 1 m 2 /r 2 ; F E = kq 1 q 2 /r 2 .
2 The nuclear force, which hold protons and neutrons together, and the weak force, which accounts
for radioactivity, diminish exponentially fast with distance, and have not been measured over
distances much larger than a few nuclear diameters.
3 Gravity from a nearby mass becomes important to life only when one or both of the chunks is of
planetary size!
© Springer Nature Switzerland AG 2020
W. C. Parke, Biophysics, https://doi.org/10.1007/978-3-030-44146-3_6
183
Electric and Magnetic Fields in Life
Let us be neither drawn aside from the subject in pursuit of
analytic subtleties, nor be carried beyond the truth by a favorite
hypothesis.
—James Clerk Maxwell
Summary Humans wondered about sparks, lightning strokes and lodestones early
in our history, but we did not have a logical and full description of electric and
magnetic effects until James Clerk Maxwell’s work in the 1860s. The properties of
electromagnetism is of central importance in life systems on Earth. The very structure of atoms and molecules comes about through electromagnetic interactions of
electrons and protons. Our nervous system uses electric pulses to send signals. Our
cellular flagellae and cilia motors work through electric pumps. Electrodynamics is
a necessary subject within any serious study of life.
6.1 Importance of Electromagnetism to Life
Electromagnetism is the term used to label one of the four principal types of
interactions acting on clumps of matter. Just like gravity, electric forces diminish
as the square of the separation distance between a pair of interacting charges. 1 Both
gravitational and electromagnetic forces extend over a long range of space, and
are measurable for bodies separated by laboratory-size distances. 2 But, for small
charged chunks of material in our environment, the electric force acting on one
from another is far greater than the gravitational force. 3
1 F G = Gm 1 m 2 /r 2 ; F E = kq 1 q 2 /r 2 .
2 The nuclear force, which hold protons and neutrons together, and the weak force, which accounts
for radioactivity, diminish exponentially fast with distance, and have not been measured over
distances much larger than a few nuclear diameters.
3 Gravity from a nearby mass becomes important to life only when one or both of the chunks is of
planetary size!
© Springer Nature Switzerland AG 2020
W. C. Parke, Biophysics, https://doi.org/10.1007/978-3-030-44146-3_6
183