The 100 Most Influential Scientists of All Time (2 page)

Jonas Edward Salk

Sir Fred Hoyle

Francis Harry Compton Crick

James Dewey Watson

Richard P. Feynman

Rosalind Franklin

Edward O. Wilson

Jane Goodall

Sir Harold W. Kroto

Richard E. Smalley

Robert F. Curl, Jr.

Stephen Jay Gould

Stephen W. Hawking

J. Craig Venter

Francis Collins

Steven Pinker

Glossary

For Further Reading

Index

In science the credit goes to the man who convinces the world, not to the man to whom the idea first occurs
.

—Francis Darwin (1848–1925)

F
rom the very first moment humans appeared on the planet, we have attempted to understand and explain the world around us. The most insatiably curious among us often have become scientists.

The scientists discussed in this book have shaped humankind's knowledge and laid the foundation for virtually every scientific discipline, from basic biology to black holes. Some of these individuals were inclined to ponder questions about what was contained within the human body, while others were intrigued by celestial bodies. Their collective vision has been concentrated enough to examine microscopic particles and broad enough to unlock tremendous universal marvels such as gravity, relativity—even the nature of life itself. Acknowledgement of their importance comes from a variety of knowledgeable and well-respected sources; luminaries such as Isaac Asimov and noted biochemist Marcel Florkin have written biographies contained herein.

The influence wielded by the profiled men and women within the realm of scientific discovery becomes readily apparent as the reader delves deeper into each individual's life and contributions to his or her chosen field. Oftentimes, more than one field has been the beneficiary of these brilliant minds. Many early scientists studied several different branches of science during their lifetimes. Indeed, as the founder of formal logic and the study of chemistry, biology, physics, zoology, botany, psychology, history, and literary theory in the Middle Ages, Aristotle is considered one of the greatest thinkers in history.

Breakthroughs in the medical sciences have been numerous and extremely valuable. Study in this discipline
begins with a contemporary of Aristotle's named Hippocrates, who is commonly regarded as the “father of medicine.” Perhaps Hippocrates' most enduring legacy to the field is the Hippocratic Oath, the ethical code that doctors still abide by today. By taking the Hippocratic Oath, doctors pledge to Asclepius, the Greco-Roman god of medicine, that to the best of their knowledge and abilities, they will prescribe the best course of medical care for their patients. They also promise to, above all, cause no harm to any patient.

The Greeks were not the only ones studying medicine. The Muslim scholar Avicenna also advanced the discipline by writing one of the most influential medical texts in history,
The Canon of Medicine
. Avicenna also produced an encyclopedic volume describing Aristotle's philosophic and scientific thoughts about logic, biology, psychology, geometry, astronomy, music, and metaphysics. This hefty tome was called the
Kitāb al-shifā
(“Book of Healing”). About 450 years later, a German-Swiss physician named Philippus Aureolus Theophrastus Bombastus Von Hohenheim, or Paracelsus, once again advanced medical science by integrating medicine with chemistry and linking specific diseases to medications that could treat them.

The Renaissance period brought to light the scientific genius of painter and sculptor Leonardo da Vinci. His drawings of presciently detailed flying machines preceded the advent of human flight by more than 300 years. What's more, da Vinci's drawings of the human anatomy structure not only illuminated many of the body's features and functions, they also laid the foundation for modern scientific illustration.

Anatomical drawings were also the purview of Flemish physician Andreas Vesalius. Unlike da Vinci's illustrations,
which were mainly for his own artistic education, Vesalius incorporated his sketches and the explanations of them into the first anatomy textbook. His observations of human anatomy also helped to advance physiology, the study of the way the body functions.

Other physicians took their investigation of anatomy off the page and onto the operating table. Ancient Greek physician Galen of Pergamum greatly influenced the study of medicine by performing countless autopsies on monkeys, pigs, sheep, and goats. His observations allowed him to ascertain the functions of the nervous system and note the difference between arteries and veins. Galen was also able to dispel the notion that arteries carry air, an idea that had persisted for 400 years.

Centuries later, in the 1600s, Englishman William Harvey built on Galen's theories and observations, and helped lay the foundation for modern physiology with his numerous animal dissections. As a result of his work, Harvey was the first person to describe the function of the circulatory system, providing evidence that veins and arteries had separate and distinct functions. Before his realization that the heart acts as a pump that keeps blood flowing throughout the body, people thought that constrictions of the blood vessels caused the blood to move.

Other groundbreaking scientists have relied on observations outside the body. A gifted Dutch scientist and lens grinder named Antonie van Leeuwenhoek refined the main tool of his trade, the microscope, which allowed him to become the first person to observe tiny microbes. Leeuwenhoek's observations helped build the framework for bacteriology and protozoology.

As several of the stories in this book confirm, science is a competitive yet oddly cooperative field, with researchers frequently either refuting or capitalizing on one
another's findings. Some ideas survive the test of time and remain intact while others are discarded or changed to fit more recent data. As an example of the former, Sir Isaac Newton developed three laws of motion that are still the basic tenets of mechanics to this day. Newton also proved instrumental to the advancement of science when he invented calculus, a branch of mathematics used by physicists and many others.

Then there are the numerous advances made in the name of science that began with the development of vaccines. Smallpox was a leading cause of death in 18th-century England. Yet Edward Jenner, an English surgeon, noticed something interesting occurring in his small village. People who were exposed to cowpox, a disease contracted from infected cattle that had relatively minor symptoms, did not get smallpox when they were exposed to the disease. Concluding that cowpox could protect people from smallpox, Jenner purposely infected a young boy who lived in the village first with cowpox, then with smallpox. Thankfully, Jenner's hypothesis proved to be correct. He had successfully administered the world's first vaccine and eradicated the disease.

More than fifty years later, another scientist by the name of Louis Pasteur would expand Jenner's ideas by explaining that the microbes, first discovered by Leeuwenhoek, caused diseases like smallpox. Today this idea is called the germ theory. Pasteur would go on to discover the vaccines for anthrax, rabies, and other diseases. He also came to understand the role microbes played in the contamination and spoilage of food. The process he invented to prevent these problems, known as pasteurization, is still in use today.

Other scientists, including Joseph Lister, Robert Koch, Sir Alexander Fleming, Selman Waksman, and
Jonas Salk, would build on Pasteur's germ theory, leading to subsequent discoveries of medical import. Anyone who ever needs to have an operation has Lister, the founder of antiseptic medicine, to thank for today's sterile surgical techniques. Koch, with his numerous experiments and meticulous record keeping, was instrumental in advancing the idea that particular microbes caused particular illnesses, greatly improving diagnostic medicine. Fleming was responsible for discovering the first antibiotic, penicillin, in 1928. Fleming's work was continued by Waksman, who systematically searched for other antibiotics. This led to the discovery of one of the most widely used antibiotics of modern times, streptomycin, in 1943. Less than 10 years later, Salk would develop a vaccine that could protect children from the debilitating and deadly disease poliomyelitis. Since that time, scientists have almost succeeded in eliminating polio worldwide.

Medical scientists are certainly not the only ones to build on one another's work. Discoveries of one scientist, no matter what field he or she works in, are almost always examined, recreated, and expanded on by others. Luigi Galvani, an Italian physicist and physician, for example, discovered that animal tissue (specifically frog legs) could conduct an electric current. Building on Galvani's observations, his friend, Italian scientist Alessandro Volta, constructed the first battery in 1800.

Expanding on Volta's work and that of Danish physicist Hans Christiaan Ørsted, who discovered that electricity running through a wire could deflect a magnetic compass needle, French physicist André-Marie Ampère founded a new scientific field called electromagnetism. The English physicist Michael Faraday would pick up the work from there, using a magnetic field to produce an
electric current. In turn, this enabled him to invent and build the first electric motor.

Reviewing Faraday's experiments and theoretical work allowed James Clerk Maxwell to unify the ideas of electricity and magnetism into an electromagnetic theory and to mathematically describe the electromagnetic force. Another physicist, Albert Michelson, determined that the speed of light was a never-changing constant. Using Maxwell's mathematical theories and Michelson's experimental data, Albert Einstein was able to develop his special theory of relativity, which resulted in what is arguably the most famous equation in the world: E=mc
²
. This elegantly simple but extremely powerful equation states that mass and energy are two different forms of the same thing. In other words, they are interchangeable. This idea has been indescribably important to the development of modern physics and astronomy.

Einstein suggested that his idea could be tested using radium, a radioactive element discovered shortly before he announced his special theory of relativity. Discovered by Marie Curie, a Polish-born French chemist, and her husband, Pierre, radium continuously converts some of its mass into energy, a process Madame Curie named radioactivity. Her studies would eventually result in her becoming the first woman to ever be awarded a Nobel Prize. She was awarded a second Nobel Prize in 1911 for the discovery of polonium and radium.

Building on the work of Curie and Einstein, future scientists would be successful—for better or worse—in harnessing nuclear energy. These concepts would be used to build fission reactors in nuclear power plants, producing electricity for towns and cities. However, the same concepts would also be used by a group of scientists, including Enrico Fermi, J. Robert Oppenheimer, Luis Alvarez, and many others, to develop nuclear weapons.

In 1675, Isaac Newton wrote a letter to Robert Hooke in which he said, “If I have seen further it is by standing on the shoulders of giants.” Thanks to the pioneering efforts of the scientists mentioned in this introduction, along with the other chemists, biologists, astronomers, ecologists, and geneticists in the remainder of this book, today's scientists have a solid foundation upon which to make astounding leaps of logic. Without the work of these men and women, we would not have computers, electricity, or many other modern conveniences. We would not have the vaccines and medications that help keep us healthy. And, in general, we would know a lot less about the way the human body functions and the way the world works.

Today's scientists owe a huge debt of gratitude to the scientists of days past. By standing on the shoulders of these giants, who knows how far they may be able to see.