Carl Zimmer - Lifes Edge: The Search for What It Means to Be Alive

She Has Her Mothers Laugh

A Planet of Viruses

Evolution: Making Sense of Life

The Tangled Bank

Science Ink

Brain Cuttings

The Descent of Man: The Concise Edition

Microcosm

Soul Made Flesh

Evolution: The Triumph of an Idea

Parasite Rex

At the Waters Edge

THE BORDERLAND

In the fall of 1904, the Cavendish Laboratory was full of curious experiments. Clouds of mercury shuddered with flashes of blue light. Lead cylinders pirouetted on copper disks. The ivy-covered building on Free School Lane, nestled in the heart of Cambridge, was the most exciting place for physicists to be, not just in England but in the entire world, a place where they could toy with the fundamental pieces of the universe. Amidst this forest of magnets and vacuums and batteries, it would have been easy to overlook one small experiment sitting forlornly by itself. It consisted of little more than a glass tube capped with cotton, half-filled with a few spoonfuls of brown broth.

But something was coming into being in that tube. In a few months the world would collectively gasp at it. Newspapers would celebrate the experiment as one of the most remarkable achievements in the history of science. One reporter would describe what lurked in the tube as the most primitive form of lifethe missing link between the inorganic and organic worlds.

This most primitive life was the creation of a thirty-one-year-old physicist named John Butler Burke. In photographs from around the time of the experiment, Burkes boyish face has a melancholy cast. He was born in Manila to a Filipino mother and an Irish father. As a boy he traveled to Dublin for schooling and ended up at Trinity College, where he studied X-rays, dynamos, and the mysterious sparks released by sugar. Trinity awarded Burke a gold medal in physics and chemistry. One professor described him as a man who is gifted with the power of exciting in others the enthusiasm which he brings to bear upon his own lines of investigation. After finishing his studies, Burke moved from Dublin to England to teach at a series of universities. His father soon died and his motheran old lady of very large means, as Burke later called hersupported him with a generous allowance. In 1898, Burke joined the Cavendish.

Nowhere on Earth had physicists learned so much in so little time about matter and energy. Their most recent triumph, courtesy of the labs director, Joseph John Thomson, was the discovery of the electron. In his first few years at the Cavendish, Burke followed up on Thomsons work by running experiments of his own on the mysterious charged particles, investigating how electrons could light up clouds of gas. But then a new mystery lured him away. Like many other young physicists at the Cavendish, Burke started experimenting with a glowing new element called radium.

A few years beforehand, in 1896, a French physicist named Henri Becquerel had discovered the first evidence that ordinary matter could cast off a strange form of energy. When he wrapped uranium salts in a black cloth, they created a ghostly image on a photographic plate nearby. It soon became clear that the uranium was steadily releasing some kind of potent particle. To follow up on Becquerels work, Marie and Pierre Curie extracted uranium from an ore called pitchblende. In the process, they discovered that some of the energy was coming from a second element. They named it radium and christened its new form of energy radioactivity.

Radium unleashed so much energy that it could keep itself warm. If scientists set a piece atop a block of ice, it could melt its own weight in water. When the Curies mixed radium with phosphorus, the particles unleashed by the radium made the phosphorus glow in the dark. As news of this rare, exotic substance spread, it became a sensation. In New York, dancers put on radium-coated outfits to perform in darkened casinos. People wondered if radium would become a mainstay of civilization. Are we about to realize the chimerical dream of the alchemistslamps giving light perpetually without the consumption of oil? one chemist mused. Radium also seemed to have a vitalizing power. Gardeners sprinkled it on their flowers, convinced it could make them grow bigger. Some people drank liquid sunshine to cure all manner of ills, including even cancer.

It was cancer that would eventually claim Marie Curies life in 1934, probably because of the radium and other radioactive elements she worked with on a daily basis. Now that we understand the deadly risk posed by radioactivity, its hard to imagine how anyone could think that radium could have vitalizing powers. But in the early 1900s scientists knew surprisingly little about the nature of life. The best they could say was that its essence lurked in the jellylike substance in cells, a material they called protoplasm. It somehow organized cells into living things and was passed down from one generation to the next. Beyond that, little was certain and all manner of ideas were viable.

To Burke, life and radioactivity displayed a profound similarity. Like a caterpillar becoming a moth, a radium atom could undergo a transformation that seemed to come from within. It changes its substancein a limited sense it livesand yet it is ever the same, Burke declared in a 1903 magazine article. The distinction, apparently insuperable, that the biologist holds to exist between living and so-called dead matter, should thus pass away as a false distinction... All matter is alivethat is my thesis.