First Flight

On the morning of December 17, 1903, Wilbur and Orville Wright took turns piloting and monitoring their flying machine in Kill Devil Hills, North Carolina. Orville piloted the first flight that lasted just 12 seconds and 120 feet. On the fourth and final flight of the day, Wilbur traveled 852 feet, remaining airborne for 59 seconds. That morning, the brothers became the first people to demonstrate sustained flight of a heavier-than-air machine under the complete control of the pilot.

First Flight, December 17, 1903, John T. Daniels, photographer. Wright Brothers Negatives. Prints & Photographs Division

They built their 1903 glider in sections in the back room of their Dayton, Ohio, bicycle shop. That afternoon, the Wright brothers walked the four miles to Kitty Hawk and sent a telegram to their father, Bishop Milton Wright, back home in Dayton:

Success four flights thursday morning all against twenty one mile wind started from level with engine power alone average speed through air thirty one miles longest 57 seconds inform Press home Christmas.

Telegram, Orville Wright to Bishop Milton Wright, announcing the first successful powered flight, December 17, 1903. Words and Deeds in American History: Selected Documents Celebrating the Manuscript Division’s First 100 Years. Manuscript Division

Through their own research and experimentation, and by studying the attempts of other would-be pilots, the Wright brothers knew that heavier-than-air flight was possible. They corresponded frequently with engineer Octave Chanute, a friend and supporter of their work. On May 13, 1900, Wilbur wrote a letter to Chanute expressing his ambition to fly:

For some years, I have been afflicted with the belief that flight is possible to man. My disease has increased in severity and I feel that it will soon cost me an increased amount of money if not my life.

Letter, Wilbur Wright to Octave Chanute, concerning the Wright brothers’ aviation experiments, May 13, 1900. Octave Chanute Papers. Words and Deeds in American History: Selected Documents Celebrating the Manuscript Division’s First 100 Years. Manuscript Division

[Wilbur and Orville Wright with their Second Powered Machine, Huffman Prairie, Dayton Ohio]. May 1904. Wright Brothers Negatives. Prints and Photographs Division

The U.S. Army saw potential in the new technology and signed a contract with the Wright brothers in 1908. Their new Military Flyer was successfully tested in 1909. The Library of Congress is rich in resources on flight.

See The Wilbur and Orville Wright Papers at the Library of Congress for a look at digital images that document the lives of the Wright brothers including correspondence, scrapbooks, drawings, and their own collection of glass-plate photographic negatives.

The Octave Chanute Papers reside in the Library of Congress. View the finding aid for more information on this collection in the Manuscript Division.

Read Alexander Graham Bell’s June 26, 1906, letter to Mabel Hubbard Bell on “the flying machine of the Wright Brothers of Dayton Ohio.”

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Willard Frank Libby and the Radiocarbon Revolution

On December 17, 1908, Willard Frank Libby was born on a farm in Grand Valley, Colorado. Libby, a physical chemist, won the 1960 Nobel Prize in Chemistry for his development of the technique known as radiocarbon dating. This technique uses the decay of an unstable isotope of carbon, radioactive carbon-14 (C14), to determine the age of organic materials—anything composed of matter that was once living. Carbon-datable items, generally ranging from a few hundred to 60,000 years old, can be as varied as the sole of an ancient sandal, glacial ice cores, the Dead Sea Scrolls, or mummies from an Egyptian pharaoh’s tomb. Radiocarbon dating has had such a profound impact on many branches of the human sciences—including archaeology, geology, history, geophysics, and preservation—that its discovery has been called “the radiocarbon revolution.”

Sandal A
, Leather, Courtesy of the Israel Antiquities Authority, 1st century B.C.E.-1st century C.E. Scrolls From the Dead Sea: The Ancient Library of Qumran and Modern Scholarship

By the 1940s, researchers already knew that when cosmic radiation enters the earth’s upper atmosphere it collides with the gasses present there to produce neutron showers. They also knew that a few of these free-floating neutrons are in turn absorbed by nitrogen atoms, which in the process are transformed into C14 (the more common isotope is carbon-12). C14 is unstable and will decay back to nitrogen over time—the emission of beta particles during this second transformation is the process that makes it radioactive.

Libby’s achievement was to recognize that C14 moves from the atmosphere to the biosphere through a series of additional steps:

  • newly produced C14 oxidizes to form carbon dioxide (CO2), a common component of the atmosphere;
  • plants absorb carbon dioxide molecules through photosynthesis, converting the carbon atoms into sugar while releasing the oxygen back into the air;
  • plants, directly or indirectly, are digested by all living organisms.

Therefore, Libby concluded, all living organisms contain a small amount of C14. But he also recognized that carbon uptake ceases when an organism dies. Because C14 decays over time, organic items that are no longer living contain increasingly smaller percentages of C14 the older they get. Libby was able to compare the amount of C14 remaining in an item to the amount originally found in the atmosphere to determine that item’s age.

Enoch Scroll in Color
The Enoch Scroll. Parchment, courtesy of the Israel Antiquities Authority, ca. 200-150 B.C.E. Scrolls From the Dead Sea: The Ancient Library of Qumran and Modern Scholarship.

During the 1950s, Libby and others built increasingly sensitive Geiger counters to measure the radioactivity of organic objects. Age calculations were based on the half-life of C14: after 5,730 years about 50 percent of the original amount of C14 will still be present in an object. Among the items that Libby tested and successfully dated were prehistoric sloth dung, charcoal from Stonehenge, and the parchment wrappings of the Dead Sea Scrolls. Libby was able to further verify his theory by performing radiocarbon tests on items whose date was already known from other sources.

Willard Libby received a PhD in chemistry from the University of California, Berkeley, in 1933 and stayed on to teach there until joining the Manhattan Project when the U.S. entered World War II. Following the war, Libby became a professor of chemistry at the University of Chicago, where he conducted his groundbreaking research; his book Radiocarbon Dating was published in 1952. Libby was appointed by President Dwight Eisenhower to the Atomic Energy Commission in 1954. Shortly before winning the Noble Prize, he returned to teaching and research at UCLA; he died in 1980.

Jesse Younger in the Chemistry Lab. University of Nebraska, Lincoln. John Vachon, photographer, May 1942. Farm Security Administration/Office of War Information Black-and-White Negatives. Prints & Photographs Division

With additional research, scientists have continued to refine the techniques of radiocarbon dating. In reality, C14 levels in the atmosphere have been similar, but not fully constant, over time. Changes in the magnetic fields of the earth and sun can affect the intensity of cosmic radiation, while carbon dioxide levels in the atmosphere also fluctuate naturally or due to the burning of fossil fuels. Nuclear weapons testing in the 1950s and early 1960s raised the amount of C14 in the atmosphere to a high of almost twice its natural level. To account for such fluctuations, calibration curves based in dendrochronology (tree ring dating) have been created, going back thousands of years.

Developed in the 1980s, accelerator mass spectrometry External (AMS) is a method that separates the atoms of a sample of carbon by atomic weight. This means that the percentage of C14 in a sample can be measured directly, rather than on the basis of radioactive decay. AMS permits the measurement of very small samples, which allows for the dating of museum and library objects without destroying them.

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