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1.1  Motivation for Biophysics

twisting motions (which we will discuss in Chapter 6). It is not really a relevant fact. But it is

interesting.

However, the distinctions between the biology and physics disciplines today are often

a little contrived. More importantly though, they are often not terribly helpful. It is a tra­

gedy that the majority of high-​school-​level science students still need to make relatively early

choices about whether they wish to specialize primarily in the area of physical/​mathematical

biased science/​engineering or instead in the life sciences. This approach inevitably results in

demarcated structures within our higher education factories, faculties of physics, schools of

biology, etc., which potentially serve to propagate the distinction further.

Fundamentally, the laws of physics apply to all things, including biological systems, so the

need for a core distinction, one might argue, is an intellectual distraction. This distinction

between physics and biology also stands out as an historical anomaly. Key developments in

the understanding of the natural world by the ancient civilizations of Babylonia and Egypt

made no such distinction, neither did Greek or Roman or Arab natural philosophers nor did

even the Renaissance thinkers and Restoration experimentalists in the fifteenth to seven­

teenth centuries, who ultimately gave birth to the concept of “science” being fundamentally

concerned with formulating hypotheses and then falsifying them through observation. Isaac

Newton, viewed by many as the fountain from which the waters of modern physics flow,

made an interesting reference in the final page of his opus Principia Mathematica:

And now we might add something concerning a certain most subtle Spirit which pervades and

lies hid in all gross bodies; by force and action of which Spirit the particles of bodies mutually

attract one another at near distance, and cohere, if contagious; and electric bodies operate

at greater distances, as well repelling as attracting the neighbouring corpuscles; and light is

emitted, reflected, refracted, inflected, and heats bodies; and all sensation is excited, and the

members of animal bodies move at the command of the will, namely, by the vibrations of this

Spirit, mutually propagated along the solid filaments of the nerves, from the outward organs

of sense to the brain, and from the brain into the muscles. But these are things that cannot be

explained in few words, nor are we furnished with that sufficiency of experiments which is

required, to an accurate determination and demonstration of the laws by which this electric

and elastic Spirit operates.

This perhaps suggests, with a significant creative interpretation from our modern era, a pic­

ture of combined physical forces of mechanics and electric fields, which are responsible for

biological properties. Or perhaps not. Again, maybe this is not relevant. Sorry. But it’s still

very interesting.

We should try to not let disciplinary labels get in the way of progress. The point is that

the physical science method has been tremendously successful on a wide range of nonliving

problems all the way from nuclei to atoms to solid state to astrophysics. The fundamental

theories of quantum mechanics, thermodynamics, electromagnetism, mechanics, optics,

etc., are immensely powerful. On the other hand, these theories can sometimes appear to

be relatively toothless when it comes to life sciences: for example, a system as small as a

cell or as large as an ecosystem. The fact that these objects are emergent from the process

of evolution is a fundamental difference. They may be comprehensible, but then again they

may not be, depending on whether 4 billion years of life on Earth as we know it is sufficient

or not to reach an “evolutionary steady state.” So, the very nature of what we are trying to

understand, and our likely success in doing so, could be very different in the study of the

life sciences. That is the point underpinning the quote at the start of this chapter “physics

does not equal biology.” We are not trying to make any point about what we call the activ­

ities of these disciplines. But it is a point about the nature of the objects under study as

described earlier.

“Biophysics” in its current form is a true multidisciplinary science. A minimal definition

of biophysics is this: it is what biophysicists do. Say this and you are guaranteed a titter of

laughs at a conference. But it’s as good a definition as any. And the activities of biophysicists

use information not only from physics and biology but also from chemistry, mathematics,

engineering, and computer science, to address questions that fundamentally relate to how

living organisms actually function. The modern reblurring of the lines between biology and