Life’s Ratchet review and excerpts

Kirkus Reviews

September 15, 2012

How Molecular Machines Extract Order from Chaos

Author: Hoffmann, Peter M.

Publisher: Basic
Pages: 288
Price (Hardcover): $27.99
Publication Date: October 30, 2012
ISBN (Hardcover): 978-0-465-02253-3
Category: Nonfiction

A biophysicist examines the relationship between chance and necessity at the boundary between life and inanimate objects. Hoffmann (Physics and Materials Science/Wayne State Univ.) founded his university’s Biomedical Physics program in order to apply the latest advances in nanotechnology to probe the nature of life. Although his field of expertise is physics (he admits to having never formally studied biology), while still in graduate school, he became fascinated by the discrepancy between life at the level of atoms and molecules, where “chaos reigns,” and at the larger scale of human existence, where, for the most part, “order prevails.” With the development of the atomic force microscope, which can sense motion, scientists are now able to witness the action in living cells of molecular machines, “autonomously moving molecules performing specific tasks like tiny robots.”

The author applies Darwin’s profound insight into the evolution of species to the question of how life itself evolved. He shows how Darwin implicitly resolved the split between reductionism and vitalism with the discovery of natural selection. Hoffmann distinguishes between macroscopic machines created to serve a specific purpose and the “autonomous [molecular] machines” found in life. He believes that the key to their functioning is the relationship between different kinds of energy at the nanoscale level, where different kinds of energy (chemical, electrostatic, thermal, etc.) operate on the same scale. He speculates about the “exciting possibility that the molecules in our body can spontaneously convert different types of energy into one another.” By creating order from the chaotic storm of thermal energy through a process of natural selection, the mechanisms and enzymes necessary for a cell to live come into being. “Evolution is not random,” Hoffmann writes. “It is a collaboration between a random process (mutation) and a nonrandom, necessary process (selection)….all of nature is a result of this balance.”

A fascinating mix of cutting-edge science with philosophy and theology.

40 b/w figures




As we enter the microscopic world of life’s molecules, we find that chaos, randomness, chance, and noise are our allies. Without the shaking and rattling of the atoms, life’s molecules would be frozen in place, unable to move. Yet, if there were only chaos, there would be no direction, no purpose, to all of this shaking. to make the molecular storm a useful force for life, it needs to be harnessed and tamed by physical laws and sophisticate structures—it must be tamed by molecular machines. The fruitful interaction of chance and necessity also explains how these chaos-harvesting machines were “designed” by evolution. Chance and necessity may even explain how our minds work, how we have new insights, and why we have intuition. This book is a vindication for randomness, a much-maligned force. Without randomness, there would be no universe, no life, no humans, and no thought.

Chapter 1

Life is the dance of a bee and the roar of a lion. It is the tangle of a rainforest and the mortal battle between bacteria and host. Life is amoeba and elephant, evolution and extinction, and the power to transform a planet. The complexity and variety of life is staggering, but for physicists, life begins at a more basic level. All life started as a circle dance of molecules billions of years ago. The lion and the bee, the humble yeast and the mighty blue whale all share the same jittering molecules in their cells; we are all cousins.

But while life is based on molecules and energy, it seems to defy a purely physical explanation. When we look at a living being, we immediately recognize it as alive, as fundamentally different from a rock or a cloud. Yet, when we try to define life, we run into difficulties. There seems to be something indefinable, some special ingredient that separates inanimate matter from living flesh. When a loved one dies, we despair at not being able to recreate life. It is as though a special ingredient, a “life force,” has left the body. Life seems forever beyond our powers and understanding.

And yet, we know that modern science has the power to manipulate life. From genetic engineering to brain imaging, science has penetrated living matter to its very core. The dichotomy between our everyday experience of the purposefulness and magic of life, and the fact that when we go looking for the magic ingredient, we only find matter and mechanism, has occupied human minds for thousands of years. It has led to a drawn-out battle between those who see purpose and those who see mechanism. In this battle, sometimes one side gained the upper hand, sometimes the other. Has the battle finally been decided? And if yes, who won?

Chapter 2

Faint wisps of hydrogen and helium are swirling through the immensity of space. The cosmos is vast and empty. Suddenly, the visitors glimpse a tiny illuminated island: a galaxy in a sea of nothingness. Looking closer, they notice that the island is made of smaller points of light: little nuclear fireplaces called stars, sprinkled into the cold darkness of space. Around many of the stars, small sand grains and blobs of gas leisurely circle their star’s illumination. On one of the sand-grain planets, heated by its star to a comfortable 293 degrees Kelvin, white water vapor clouds beautifully set off the deep blue of saltwater oceans and the yellow-brown of continents. The tiny two-legged creatures inhabiting this little world, having just begun to glimpse a few feeble answers to the endless mysteries surrounding them, believe themselves to be the center of the universe. Chuckling, the visitors keep their giant spaceship cloaked, and move on.

Chapter 4

In a game of nanobaseball, however, inertia would be unimportant, as the ball would weigh next to nothing. Ditto gravity. But the relatively large surface area compared with the tiny bulk of the nanobaseball would make it difficult to get the nanobaseball off the nanobat…

Chapter 5

James Clerk Maxwell (1831–1879) left behind a distinguished scientific legacy. He unified electricity and magnetism, discovered electromagnetic waves and explained the nature of light, solved the riddle of Saturn’s rings, developed modern color theory, laid the foundations for engineering control theory, and cofounded statistical mechanics.

In addition to all this, he invented a demon…

© Peter M. Hoffmann, 2012 – 2018. All rights reserved.