www.britannica.com Open in urlscan Pro
104.18.4.110  Public Scan

Form analysis
6 forms found in the DOM

GET /search

<form method="get" action="/search" id="global-nav-search" class="md-search-form m-0 global-nav-search-bar-small">
  <div class="search-box position-relative col-100">
    <label class="sr-only" for="global-nav-search-query">Search Britannica</label>
    <input name="query" id="__2a27c02f-f2a0-4f28-836f-d1923eee7493" placeholder="Search Britannica..." class="form-control form-control-lg rounded-lg font-16 search-query pl-20 pr-70 shadow-sm" maxlength="200" autocomplete="off"
      aria-label="Search Britannica">
    <button class="search-reset-btn btn btn-link px-10 position-absolute top-0 h-100 d-none" type="reset">
      <em class="material-icons" data-icon="close"></em>
    </button>
    <button class="search-submit btn btn-link text-blue px-10 position-absolute top-0 right-0 h-100" type="submit" disabled="">
      <span class="sr-only">Click here to search</span>
      <em class="material-icons search-icon" data-icon="search"></em>
    </button>
  </div>
</form>

---

GET /search

<form method="get" action="/search" id="global-nav-search" class="md-search-form m-0 global-nav-search-bar-small global-nav-center search global-nav-center-search-container">
  <div class="search-box position-relative col-100">
    <label class="sr-only" for="global-nav-search-query">Search Britannica</label>
    <input name="query" id="__72cb5426-a3d5-41d4-ac3d-71844e8c1c9c" placeholder="Search Britannica..." class="form-control form-control-lg rounded-lg font-16 search-query pl-20 pr-70 shadow-sm" maxlength="200" autocomplete="off"
      aria-label="Search Britannica">
    <button class="search-reset-btn btn btn-link px-10 position-absolute top-0 h-100 d-none" type="reset">
      <em class="material-icons" data-icon="close"></em>
    </button>
    <button class="search-submit btn btn-link text-blue px-10 position-absolute top-0 right-0 h-100" type="submit" disabled="">
      <span class="sr-only">Click here to search</span>
      <em class="material-icons search-icon" data-icon="search"></em>
    </button>
  </div>
</form>

---

POST /submission/feedback/382827

<form method="post" action="/submission/feedback/382827" id="___id2" class="md-form2-initialized">
  <div class="my-20"> Corrections? Updates? Omissions? Let us know if you have suggestions to improve this article (requires login). </div>
  <div class="type-menu">
    <label for="feedback-type" class="label mb-10">Feedback Type</label>
    <select id="feedback-type" class="form-select mb-30" name="feedbackTypeId" required="">
      <option value="" selected="selected">Select a type (Required)</option>
      <option value="1">Factual Correction</option>
      <option value="2">Spelling/Grammar Correction</option>
      <option value="3">Link Correction</option>
      <option value="4">Additional Information</option>
      <option value="5">Other</option>
    </select>
  </div>
  <label for="feedback" class="label mb-10">Your Feedback</label>
  <textarea id="feedback" class="form-control mb-30" name="feedback" maxlength="3000" rows="7" required=""></textarea>
  <button class="btn btn-blue" type="submit" disabled="disabled">Submit Feedback</button>
</form>

---

POST /submission/feedback/619727

<form method="post" action="/submission/feedback/619727" id="___id7" class="md-form2-initialized">
  <div class="my-20"> Corrections? Updates? Omissions? Let us know if you have suggestions to improve this article (requires login). </div>
  <div class="type-menu">
    <label for="feedback-type" class="label mb-10">Feedback Type</label>
    <select id="feedback-type" class="form-select mb-30" name="feedbackTypeId" required="">
      <option value="" selected="selected">Select a type (Required)</option>
      <option value="1">Factual Correction</option>
      <option value="2">Spelling/Grammar Correction</option>
      <option value="3">Link Correction</option>
      <option value="4">Additional Information</option>
      <option value="5">Other</option>
    </select>
  </div>
  <label for="feedback" class="label mb-10">Your Feedback</label>
  <textarea id="feedback" class="form-control mb-30" name="feedback" maxlength="3000" rows="7" required=""></textarea>
  <button class="btn btn-blue" type="submit" disabled="disabled">Submit Feedback</button>
</form>

---

POST /submission/feedback/619727

<form method="post" action="/submission/feedback/619727">
  <div class="my-20"> Corrections? Updates? Omissions? Let us know if you have suggestions to improve this article (requires login). </div>
  <div class="type-menu">
    <label for="feedback-type" class="label mb-10">Feedback Type</label>
    <select id="feedback-type" class="form-select mb-30" name="feedbackTypeId" required="">
      <option value="" selected="selected">Select a type (Required)</option>
      <option value="1">Factual Correction</option>
      <option value="2">Spelling/Grammar Correction</option>
      <option value="3">Link Correction</option>
      <option value="4">Additional Information</option>
      <option value="5">Other</option>
    </select>
  </div>
  <label for="feedback" class="label mb-10">Your Feedback</label>
  <textarea id="feedback" class="form-control mb-30" name="feedback" maxlength="3000" rows="7" required=""></textarea>
  <button class="btn btn-blue" type="submit">Submit Feedback</button>
</form>

---

POST /print/article/619727

<form action="/print/article/619727" method="post" target="_blank" rel="noopener">
  <div class="print-box-items">
    <ul class="list-unstyled">
      <li><label><input class="mr-10" type="checkbox" name="sequence[]" value="0">Table Of Contents</label></li>
      <li><label><input class="mr-10" type="checkbox" name="sequence[]" value="1">Introduction</label></li>
      <li><label><input class="mr-10" type="checkbox" name="sequence[]" value="2">Background and early life</label></li>
      <li><label><input class="mr-10" type="checkbox" name="sequence[]" value="3">Deuterium and atomic bomb research</label></li>
      <li><label><input class="mr-10" type="checkbox" name="sequence[]" value="4">Origin of the solar system</label></li>
      <li><label><input class="mr-10" type="checkbox" name="sequence[]" value="5">Legacy</label></li>
    </ul>
  </div>
  <input type="submit" class="btn btn-blue md-disabled" value="Print">
</form>

---

Text Content

Search Britannica Click here to search
Search Britannica Click here to search
Login
Subscribe
Subscribe

Home Quizzes & Games History & Society Science & Tech Biographies Animals &
Nature Geography & Travel Arts & Culture Money Videos
Stanley Miller
Table of Contents
Stanley Miller

Table of Contents
 * References

Quizzes
 * Faces of Science


STANLEY MILLER

American biochemist
Actions
Share
External Websites
 * National Academy of Sciences - Biography of Stanley L. Miller

Share



LEARN ABOUT THIS TOPIC IN THESE ARTICLES:


INVESTIGATION OF LIFE-ORIGIN ATMOSPHERE

 * 
   In life: Hypotheses of origins
   
   Miller, under the guidance of his professor at the University of Chicago,
   chemist Harold C. Urey. A mixture of methane, ammonia, water vapour, and
   hydrogen was circulated through a liquid solution and continuously sparked by
   a corona discharge mounted higher in the apparatus. The discharge…
   
   Read More


MILLER-UREY EXPERIMENT

 * 
   In abiogenesis: The Miller-Urey experiment
   
   Urey and Stanley Miller tested the Oparin-Haldane theory and successfully
   produced organic molecules from some of the inorganic components thought to
   have been present on prebiotic Earth. In what became known as the Miller-Urey
   experiment, the two scientists combined warm water with a mixture of four
   gases—water…
   
   Read More


OPARIN-HALDANE THEORY

 * In Oparin-Haldane theory
   
   Urey and Stanley Miller tested the Oparin-Haldane theory and successfully
   produced organic molecules from some of the inorganic components thought to
   have been present on prebiotic Earth. This became known as the Miller-Urey
   experiment. Modern abiogenesis hypotheses are based largely on the same
   principles as the Oparin-Haldane…
   
   Read More



Harold C. Urey
Table of Contents
Harold C. Urey

Table of Contents
 * Introduction
   
 * 
   Background and early life
   
 * 
   Deuterium and atomic bomb research
   
 * 
   Origin of the solar system
   
 * 
   Legacy
   

Fast Facts
 * Harold C. Urey summary
 * Facts & Related Content

Quizzes
 * Faces of Science

More
 * More Articles On This Topic
 * Additional Reading
 * Contributors
 * Article History

Related Biographies
 * Robert Burns Woodward
   American chemist
 * Eric Betzig
   American physicist
 * Carolyn R. Bertozzi
   American chemist
 * Aziz Sancar
   Turkish-American biochemist
 * See All

Home Science Astronomy
Science & Tech


HAROLD C. UREY

American chemist
Actions
Cite
Share
Give Feedback
External Websites
Print Cite Share Feedback
External Websites
Also known as: Harold Clayton Urey
Written by
Richard E. Rice
Associate Professor, James Madison University, Harrisonburg, Virginia.

Richard E. Rice
Fact-checked by
The Editors of Encyclopaedia Britannica
Encyclopaedia Britannica's editors oversee subject areas in which they have
extensive knowledge, whether from years of experience gained by working on that
content or via study for an advanced degree. They write new content and verify
and edit content received from contributors.

The Editors of Encyclopaedia Britannica
Last Updated: Article History
Table of Contents
Category: Science & Tech
Born: April 29, 1893 Indiana ...(Show more) Died: January 5, 1981 (aged 87)
California ...(Show more) Awards And Honors: Nobel Prize ...(Show more) Subjects
Of Study: cosmogony deuterium radioactive isotope Solar System uranium-235
...(Show more) Role In: Manhattan Project ...(Show more)
See all related content →


Harold C. Urey, in full Harold Clayton Urey, (born April 29, 1893, Walkerton,
Ind., U.S.—died Jan. 5, 1981, La Jolla, Calif.), American scientist awarded the
Nobel Prize for Chemistry in 1934 for his discovery of the heavy form of
hydrogen known as deuterium. He was a key figure in the development of the
atomic bomb and made fundamental contributions to a widely accepted theory of
the origin of the Earth and other planets.




BACKGROUND AND EARLY LIFE

Urey was one of three children of Samuel Clayton Urey and Cora Rebecca Reinsehl.
The elder Urey, a schoolteacher and minister, died when the boy was six. His
mother remarried and had two daughters in that marriage.

Britannica Quiz
Faces of Science

After high school, Urey taught in rural public schools from 1911 to 1914, first
in Indiana and then in Montana. While teaching at a mining camp in Montana, Urey
decided to attend the University of Montana in Missoula, where he majored in
zoology with additional study in chemistry. After graduating in 1917, Urey
worked as a chemist during World War I, an experience that set his future in
chemistry. After the war, he returned to the University of Montana, where he
taught chemistry for two years before beginning graduate study at the University
of California at Berkeley. Under the direction of Gilbert N. Lewis, he received
a doctorate for his dissertation on electron distribution in the energy levels
of the hydrogen atom and thermodynamic calculations on gaseous molecules.
Although the necessary molecular properties were not then available, Urey
developed good approximate values. His work led to accepted methods for
calculating thermodynamic properties from spectroscopic data. With an
American-Scandinavian Fellowship, Urey spent 1923–24 with the Danish physicist
Niels Bohr at the Institute for Theoretical Physics in Copenhagen. Afterward,
Urey joined the faculty at Johns Hopkins University in Baltimore, Md., where he
emphasized the importance of quantum mechanics for students of chemistry and
directed his research toward the spectroscopic study of molecules. With the
American physicist Arthur E. Ruark, he published Atoms, Molecules and Quanta
(1930), an early discussion in English of the new field of quantum mechanics.

While visiting his mother in Seattle, Wash., in 1926, Urey met Frieda Daum, a
bacteriologist from Lawrence, Kan. They married and had four children.




DEUTERIUM AND ATOMIC BOMB RESEARCH

In 1929 Urey moved to Columbia University in New York City, where he continued
his work on the properties of molecules and atoms. The theory of isotopes—i.e.,
the idea that an individual element may consist of atoms with the same number of
protons but with different masses—had been developed by the English chemist
Frederick Soddy in 1913. The less-abundant isotopes of carbon, nitrogen, and
oxygen had been discovered by others by the end of the 1920s, and Urey remarked
that only the discovery of isotopes of hydrogen—the lightest element—could be
more significant. Urey had a systematic chart of the isotopes, both known and
predicted, on his office wall. This system included two additional isotopes of
hydrogen—both undiscovered—one with twice the mass (2H) and one with three times
the mass (3H) of ordinary hydrogen (1H). A letter to the editor from two
physicists in the July 1, 1931, issue of Physical Review discussed some indirect
evidence for the natural abundance of 2H—i.e., “heavy hydrogen” (which Urey
later named deuterium) as one atom for every 4,500 atoms of 1H. Within days of
reading this article, Urey devised an experiment to look for deuterium. After
obtaining samples of hydrogen expected to be enriched in deuterium, he detected
a spectrum that agreed with his predictions for deuterium from the Bohr atomic
model. In 1934 Urey received the Nobel Prize, as well as the Willard Gibbs Medal
from the Chicago Section of the American Chemical Society, for this discovery.
Shortly after winning the Nobel Prize, Urey wrote the entry on deuterium for the
1936 printing of the 14th edition of the Encyclopædia Britannica.



Urey continued to investigate isotopes of hydrogen, carbon, oxygen, nitrogen,
and sulfur. By 1939 he and his associates had developed successful methods for
separating the rarer isotopes of all these elements, making them readily
available for laboratory research. Urey wrote several papers on the separation
of isotopes, including those of the heavy elements, and during World War II he
was active in the U.S. government’s program for separating the fissionable
uranium isotope 235U from the more-abundant 238U for use in the atomic bomb.

Get a Britannica Premium subscription and gain access to exclusive content.
Subscribe Now

Urey served on various advisory committees for the Manhattan Project and
directed efforts to separate the isotopes with several techniques, including
gaseous diffusion. This was a huge and complex operation, beset by numerous
problems in the development of a suitable diffusion barrier for the uranium
hexafluoride. When the barrier that Urey had been working on was not chosen for
the diffusion plant being built at Oak Ridge, Tenn., he gave up his work on
diffusion. Although he remained nominal head of the project, he tried to
convince U.S. President Harry S. Truman not to drop the bomb on Japan. After the
war, Urey worked for civilian, rather than military, control of atomic weapons,
and he proposed an international ban on their production and stockpiling.




ORIGIN OF THE SOLAR SYSTEM

Two postwar events at the University of Chicago, where Urey became a professor
in 1945, dramatically altered the focus of his research. The Face of the Moon
(1949) by Ralph Baldwin, which presented scientific evidence that lunar craters
were formed by asteroid and comet impacts and that the lunar mares were formed
by lava flows, inspired an intense interest in the origin of the solar system
that lasted for the rest of Urey’s life. His book The Planets: Their Origin and
Development (1952) has been described as “the first systematic and detailed
chronology of the origin of the Earth, Moon, the meteorites, and the solar
system.” Initially, Urey rejected the hypothesis that the Moon and Earth had a
common origin, believing instead that the Moon arose independently, was older
than the Earth, and was only later captured by the Earth. Thus, Urey argued, the
Moon should provide clues to the early solar system that the Earth could not.
His ideas led to intense debates among scientists in the 1950s and ’60s, but he
was ultimately able to influence the U.S. National Aeronautics and Space
Administration (NASA) in undertaking the Apollo program of lunar exploration.
After retiring from the University of Chicago in 1958, Urey became
professor-at-large at the new campus of the University of California at San
Diego. There he continued his research program in the planetary sciences. When
Apollo 11 brought back rocks and dust from the Moon in 1969, Urey was one of the
six scientists who first examined them. Later examinations of these rocks showed
that his hypothesis about the Moon was wrong. Still the good scientist in his
late 70s, however, Urey revised his thinking on the basis of the new evidence.





LEGACY

Urey cared deeply about his fellow human beings, and he regarded the United
States’ major problem as “the proper education and inspiration of our youth.”
Politically active, he served as science advisor to the Democratic Party and to
president-elect John F. Kennedy. He received the U.S. National Medal of Science
in 1964. After retiring in 1970, Urey suffered from parkinsonism and cardiac
disease.

Richard E. Rice


Load Next Page



Feedback
Corrections? Updates? Omissions? Let us know if you have suggestions to improve
this article (requires login).
Feedback Type Select a type (Required) Factual Correction Spelling/Grammar
Correction Link Correction Additional Information Other
Your Feedback Submit Feedback
Thank you for your feedback

Our editors will review what you’ve submitted and determine whether to revise
the article.

Share
Share to social media
Facebook Twitter
URL
https://www.britannica.com
Share
Share to social media
Facebook Twitter
URL
https://www.britannica.com


Update Privacy Preferences
Feedback
Corrections? Updates? Omissions? Let us know if you have suggestions to improve
this article (requires login).
Feedback Type Select a type (Required) Factual Correction Spelling/Grammar
Correction Link Correction Additional Information Other
Your Feedback Submit Feedback
Thank you for your feedback

Our editors will review what you’ve submitted and determine whether to revise
the article.

Feedback
Corrections? Updates? Omissions? Let us know if you have suggestions to improve
this article (requires login).
Feedback Type Select a type (Required) Factual Correction Spelling/Grammar
Correction Link Correction Additional Information Other
Your Feedback Submit Feedback
Thank you for your feedback

Our editors will review what you’ve submitted and determine whether to revise
the article.

verifiedCite
While every effort has been made to follow citation style rules, there may be
some discrepancies. Please refer to the appropriate style manual or other
sources if you have any questions.
Select Citation Style
MLA APA Chicago Manual of Style
Rice, Richard E.. "Harold C. Urey". Encyclopedia Britannica, 25 Apr. 2023,
https://www.britannica.com/biography/Harold-Urey. Accessed 31 July 2023.
Copy Citation
Share
Share to social media
Facebook Twitter
URL
https://www.britannica.com/biography/Harold-Urey
External Websites
 * Academy of Achievement - Biography of Dorothy Hamill
 * The Nobel Prize - Biography of Harold Clayton Urey
 * National Academy of Sciences - Biographical Memoirs - Harold Clayton Urey

Britannica Websites
Articles from Britannica Encyclopedias for elementary and high school students.
 * Harold Clayton Urey - Student Encyclopedia (Ages 11 and up)

print Print
Please select which sections you would like to print:
 * Table Of Contents
 * Introduction
 * Background and early life
 * Deuterium and atomic bomb research
 * Origin of the solar system
 * Legacy

verifiedCite
While every effort has been made to follow citation style rules, there may be
some discrepancies. Please refer to the appropriate style manual or other
sources if you have any questions.
Select Citation Style
MLA APA Chicago Manual of Style
Rice, Richard E.. "Harold C. Urey". Encyclopedia Britannica, 25 Apr. 2023,
https://www.britannica.com/biography/Harold-Urey. Accessed 31 July 2023.
Copy Citation
Share
Share to social media
Facebook Twitter
URL
https://www.britannica.com/biography/Harold-Urey
External Websites
 * Academy of Achievement - Biography of Dorothy Hamill
 * The Nobel Prize - Biography of Harold Clayton Urey
 * National Academy of Sciences - Biographical Memoirs - Harold Clayton Urey

Britannica Websites
Articles from Britannica Encyclopedias for elementary and high school students.
 * Harold Clayton Urey - Student Encyclopedia (Ages 11 and up)