George Wald

George Wald

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George Wald was an American
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...

A scientist in a broad sense is one engaging in a systematic activity to acquire knowledge. In a more restricted sense, a scientist is an individual who uses the scientific method. The person may be an expert in one or more areas of science. This article focuses on the more restricted use of the word...

 who is best known for his work with pigments in the retina
The vertebrate retina is a light-sensitive tissue lining the inner surface of the eye. The optics of the eye create an image of the visual world on the retina, which serves much the same function as the film in a camera. Light striking the retina initiates a cascade of chemical and electrical...

. He won a share of the 1967 Nobel Prize in Physiology or Medicine
Nobel Prize in Physiology or Medicine
The Nobel Prize in Physiology or Medicine administered by the Nobel Foundation, is awarded once a year for outstanding discoveries in the field of life science and medicine. It is one of five Nobel Prizes established in 1895 by Swedish chemist Alfred Nobel, the inventor of dynamite, in his will...

 with Haldan Keffer Hartline
Haldan Keffer Hartline
Haldan Keffer Hartline was an American physiologist who was a co-winner of the 1967 Nobel Prize in Physiology or Medicine for his work in analyzing the neurophysiological mechanisms of vision.Hartline began his study of retinal electrophysiology as a National Research Council Fellow at Johns...

 and Ragnar Granit
Ragnar Granit
Ragnar Arthur Granit was a Finnish/Swedish scientist who was awarded the Nobel Prize in Physiology or Medicine in 1967 along with Haldan Keffer Hartline and George Wald....



As a postdoctoral researcher, Wald discovered that vitamin A
Vitamin A
Vitamin A is a vitamin that is needed by the retina of the eye in the form of a specific metabolite, the light-absorbing molecule retinal, that is necessary for both low-light and color vision...

 was a component of the retina. His further experiments showed that when the pigment rhodopsin
Rhodopsin, also known as visual purple, is a biological pigment of the retina that is responsible for both the formation of the photoreceptor cells and the first events in the perception of light. Rhodopsins belong to the G-protein coupled receptor family and are extremely sensitive to light,...

 was exposed to light, it yielded the protein opsin and a compound containing vitamin A. This suggested that vitamin A was essential in retinal function.

In the 1950s, Wald and his colleagues used chemical methods to extract pigments from the retina. Then, using a spectrophotometer, they were able to measure the light absorbance of the pigments. Since the absorbance of light
Light or visible light is electromagnetic radiation that is visible to the human eye, and is responsible for the sense of sight. Visible light has wavelength in a range from about 380 nanometres to about 740 nm, with a frequency range of about 405 THz to 790 THz...

 by retina pigments corresponds to the wavelength
In physics, the wavelength of a sinusoidal wave is the spatial period of the wave—the distance over which the wave's shape repeats.It is usually determined by considering the distance between consecutive corresponding points of the same phase, such as crests, troughs, or zero crossings, and is a...

s that best activate photoreceptor cells, this experiment showed the wavelengths that the eye could best detect. However, since rod cell
Rod cell
Rod cells, or rods, are photoreceptor cells in the retina of the eye that can function in less intense light than can the other type of visual photoreceptor, cone cells. Named for their cylindrical shape, rods are concentrated at the outer edges of the retina and are used in peripheral vision. On...

s make up most of the retina, what Wald and his colleagues were specifically measuring was the absorbance of rhodopsin, the main photopigment in rods. Later, with a technique called microspectrophotometry, he was able to measure the absorbance directly from cells, rather than from an extract of the pigments. This allowed Wald to determine the absorbance of pigments in the cone cell
Cone cell
Cone cells, or cones, are photoreceptor cells in the retina of the eye that are responsible for color vision; they function best in relatively bright light, as opposed to rod cells that work better in dim light. If the retina is exposed to an intense visual stimulus, a negative afterimage will be...

s (Goldstein, 2001).


Wald was born in New York City
New York City
New York is the most populous city in the United States and the center of the New York Metropolitan Area, one of the most populous metropolitan areas in the world. New York exerts a significant impact upon global commerce, finance, media, art, fashion, research, technology, education, and...

 to Isaac Wald and Ernestine Rosenmann, Jewish immigrant parents. He was a member of the first graduating class of the Brooklyn Technical High School
Brooklyn Technical High School
Brooklyn Technical High School, commonly called Brooklyn Tech or just Tech, and also administratively as High School 430, is a New York City public high school that specializes in engineering, math and science and is the largest specialized high school for science, technology, engineering, and...

 in New York in 1922. He received his Bachelor of Science degree from New York University
New York University
New York University is a private, nonsectarian research university based in New York City. NYU's main campus is situated in the Greenwich Village section of Manhattan...

 in 1927 and his PhD in zoology
Zoology |zoölogy]]), is the branch of biology that relates to the animal kingdom, including the structure, embryology, evolution, classification, habits, and distribution of all animals, both living and extinct...

 from Columbia University
Columbia University
Columbia University in the City of New York is a private, Ivy League university in Manhattan, New York City. Columbia is the oldest institution of higher learning in the state of New York, the fifth oldest in the United States, and one of the country's nine Colonial Colleges founded before the...

 in 1932. After graduating, he received a travel grant from the US National Research Council. Wald used this grant to work in Germany with Otto Heinrich Warburg
Otto Heinrich Warburg
Otto Heinrich Warburg , son of physicist Emil Warburg, was a German physiologist, medical doctor and Nobel laureate. He served as an officer in the elite Uhlan during the First World War and won the Iron Cross for bravery. Warburg was one of the twentieth century's leading biochemists...

 where he identified vitamin A in the retina. Wald then went on to work in Zurich
Zurich is the largest city in Switzerland and the capital of the canton of Zurich. It is located in central Switzerland at the northwestern tip of Lake Zurich...

, Switzerland
Switzerland name of one of the Swiss cantons. ; ; ; or ), in its full name the Swiss Confederation , is a federal republic consisting of 26 cantons, with Bern as the seat of the federal authorities. The country is situated in Western Europe,Or Central Europe depending on the definition....

 with the discoverer of vitamin A, Paul Karrer
Paul Karrer
Paul Karrer was a Swiss organic chemist best known for his research on vitamins. He and Walter Haworth won the Nobel Prize for Chemistry in 1937.-Early years:...

. Wald then worked briefly with Otto Fritz Meyerhof
Otto Fritz Meyerhof
-External links:* *...

 in Heidelberg
-Early history:Between 600,000 and 200,000 years ago, "Heidelberg Man" died at nearby Mauer. His jaw bone was discovered in 1907; with scientific dating, his remains were determined to be the earliest evidence of human life in Europe. In the 5th century BC, a Celtic fortress of refuge and place of...

, Germany, but left Europe for the University of Chicago
University of Chicago
The University of Chicago is a private research university in Chicago, Illinois, USA. It was founded by the American Baptist Education Society with a donation from oil magnate and philanthropist John D. Rockefeller and incorporated in 1890...

 in 1933 when Adolf Hitler
Adolf Hitler
Adolf Hitler was an Austrian-born German politician and the leader of the National Socialist German Workers Party , commonly referred to as the Nazi Party). He was Chancellor of Germany from 1933 to 1945, and head of state from 1934 to 1945...

 came to power and life in Europe became more dangerous for Jews. In 1934, Wald went to Harvard University
Harvard University
Harvard University is a private Ivy League university located in Cambridge, Massachusetts, United States, established in 1636 by the Massachusetts legislature. Harvard is the oldest institution of higher learning in the United States and the first corporation chartered in the country...

 where he became an instructor, then a professor. He was elected to the National Academy of Sciences
United States National Academy of Sciences
The National Academy of Sciences is a corporation in the United States whose members serve pro bono as "advisers to the nation on science, engineering, and medicine." As a national academy, new members of the organization are elected annually by current members, based on their distinguished and...

 in 1950 and in 1967 was awarded the Nobel Prize
Nobel Prize
The Nobel Prizes are annual international awards bestowed by Scandinavian committees in recognition of cultural and scientific advances. The will of the Swedish chemist Alfred Nobel, the inventor of dynamite, established the prizes in 1895...

 for Physiology or Medicine for his discoveries in vision. In 1966 he was awarded the Frederic Ives Medal by the OSA
Optical Society of America
The Optical Society is a scientific society dedicated to advancing the study of light—optics and photonics—in theory and application, by means of publishing, organizing conferences and exhibitions, partnership with industry, and education. The organization has members in more than 100 countries...

. He was married twice: in 1931 to Frances Kingsley and in 1958 to the biochemist Ruth Hubbard
Ruth Hubbard
Ruth Hubbard is Professor Emerita of Biology at Harvard University, where she was the first woman to hold a tenured professorship position in biology. -Biography:...

. He had two sons with Kingsley—Michael and David; he and Hubbard had a son—the award-winning musicologist and musician Elijah Wald
Elijah Wald
Indeed, his first book was a collaboration with his biologist mother entitled Exploding the Gene Myth, in which they wrote that "The myth of the all-powerful gene is based on flawed science that discounts the environment in which we and our genes exist." "There are no definitive histories," he...

—and a daughter, Deborah.

Wald spoke out on many political and social issues and his fame as a Nobel laureate brought national and international attention to his views. He was a vocal opponent of the Vietnam War
Vietnam War
The Vietnam War was a Cold War-era military conflict that occurred in Vietnam, Laos, and Cambodia from 1 November 1955 to the fall of Saigon on 30 April 1975. This war followed the First Indochina War and was fought between North Vietnam, supported by its communist allies, and the government of...

 and the nuclear arms race
Nuclear arms race
The nuclear arms race was a competition for supremacy in nuclear warfare between the United States, the Soviet Union, and their respective allies during the Cold War...


Speaking at MIT in 1969 Wald bemoaned that "Our government has become preoccupied with death, with the business of killing and being killed."

In 1980, Wald served as part of Ramsey Clark
Ramsey Clark
William Ramsey Clark is an American lawyer, activist and former public official. He worked for the U.S. Department of Justice, which included service as United States Attorney General from 1967 to 1969, under President Lyndon B. Johnson...

's delegation to Iran
Iran , officially the Islamic Republic of Iran , is a country in Southern and Western Asia. The name "Iran" has been in use natively since the Sassanian era and came into use internationally in 1935, before which the country was known to the Western world as Persia...

 during the Iran hostage crisis
Iran hostage crisis
The Iran hostage crisis was a diplomatic crisis between Iran and the United States where 52 Americans were held hostage for 444 days from November 4, 1979 to January 20, 1981, after a group of Islamist students and militants took over the American Embassy in Tehran in support of the Iranian...


With a small number of other Nobel laureates, he was invited in 1986 to fly to Moscow to advise Mikhail Gorbachev
Mikhail Gorbachev
Mikhail Sergeyevich Gorbachev is a former Soviet statesman, having served as General Secretary of the Communist Party of the Soviet Union from 1985 until 1991, and as the last head of state of the USSR, having served from 1988 until its dissolution in 1991...

 on a number of environmental questions. While there, he questioned Gorbachev about the arrest, detention and exile to Gorki
Nizhny Novgorod
Nizhny Novgorod , colloquially shortened to Nizhny, is, with the population of 1,250,615, the fifth largest city in Russia, ranking after Moscow, St. Petersburg, Novosibirsk, and Yekaterinburg...

 of Yelena Bonner
Yelena Bonner
Yelena Bonner was a human rights activist in the former Soviet Union and wife of the noted physicist and dissident Andrei Sakharov. During her decades as a dissident, Bonner was noted for her characteristic blunt honesty and courage.-Youth:...

 and her husband, fellow Nobel laureate Andrei Sakharov
Andrei Sakharov
Andrei Dmitrievich Sakharov was a Soviet nuclear physicist, dissident and human rights activist. He earned renown as the designer of the Soviet Union's Third Idea, a codename for Soviet development of thermonuclear weapons. Sakharov was an advocate of civil liberties and civil reforms in the...

 (Peace, 1975). Wald reported that Gorbachev said he knew nothing about it. Bonner and Sakharov were released shortly thereafter, in December, 1986.

Wald died in Cambridge, Massachusetts
Cambridge, Massachusetts
Cambridge is a city in Middlesex County, Massachusetts, United States, in the Greater Boston area. It was named in honor of the University of Cambridge in England, an important center of the Puritan theology embraced by the town's founders. Cambridge is home to two of the world's most prominent...


External links

Two of George Wald's speeches can be read on-line: