John J. Hopfield (spectroscopist)

Hopfield was born Jan Józef Chmielewski in 1891 in Płock, Poland and was orphaned at an early age. He grew up in an orphanage in Poland and briefly stayed with a Pennsylvania Dutch family in the United States before running away. Despite little formal education, he supported himself by teaching at a district school.

Hopfield was admitted to Syracuse University around 1913, completed his A.B. degree in 1917, and then worked as an instructor through 1919. At Syracuse, he had worked as an assistant with Raymond Thayer Birge, who moved to University of California, Berkeley around this time. Hopfield was then admitted to Berkeley with a fellowship, and was awarded his doctorate for spectroscopic work in 1923. He became an instructor and assistant professor of physics at Berkeley, and was awarded a Guggenheim Fellowship in 1928 to work with Friedrich Paschen for a year in Berlin.

By the time he left Berlin in 1929, the stock market crash and depression had ended most new faculty hiring. Purdue University appointed him as a National Research Council Fellow for two years. He next was employed in creating the physics exhibit for the 1933 "Century of Progress" World's Fair in Chicago. This was followed by a position with the Libbey-Owens-Ford glass company in Toledo, Ohio. With the onset of the Second World War, physicists were again in great demand, and he moved to Washington, D.C., to participate in war-related research. The end of his career was spent at the Johns Hopkins University Applied Physics Laboratory and at the Naval Research Laboratory in the Optics Division in Washington, D.C.. On January 8, 1953, Hopfield died after a brief illness.{{cite journal |title=John J. Hopfield |journal=Physics Today |volume=6 |issue=3 |page=24 |date=1953 |doi=10.1063/1.3061184 |quote=John J. Hopfield, physicist at the optics division of the Naval Research Laboratory at Bethesda, Maryland, died after a brief illness on January 8th at the age of sixty‐one.}}

Hopfield's son, J. J. Hopfield, was born in 1933 and also became a noted physicist, receiving the 2024 Nobel Prize in Physics.{{Cite web |title=The Nobel Prize in Physics 2024 |url=https://www.nobelprize.org/prizes/physics/2024/press-release/ |access-date=2024-10-08 |website=NobelPrize.org |language=en-US}}

• Ultraviolet Absorption and Emission Spectra of Carbon Monoxide{{cite journal | title=Ultraviolet Absorption and Emission Spectra of Carbon Monoxide |author1=Hopfield, J. J. |author2=R. T. Birge | journal=Physical Review | date=1927 | volume=29 |issue=6 | pages=922|doi=10.1103/PhysRev.29.901|bibcode=1927PhRv...29..901. }}
• The Ultra-Violet Band Spectrum of Nitrogen{{cite journal | title=The Ultra-Violet Band Spectrum of Nitrogen |author1=Birge, R. T. |author2=J. J. Hopfield | journal=The Astrophysical Journal | date=1928 | volume=68 | pages=257 | doi=10.1086/143142| bibcode=1928ApJ....68..257B }}
• New Ultra-Violet Spectrum of Helium{{cite journal | title=New Ultra-Violet Spectrum of Helium | author=Hopfield, John J. | journal=The Astrophysical Journal | date=1930 | volume=72 | pages=133 | doi=10.1086/143271| bibcode=1930ApJ....72..133H | doi-access=free }}
• Absorption and Emission Spectra in the Region λ 600-1100.{{cite journal | title=Absorption and Emission Spectra in the Region λ 600-1100 | author=Hopfield, John J. | journal=Physical Review | date=1930 | volume=35 | issue=9 | pages=1133 | doi=10.1103/physrev.35.1133| bibcode=1930PhRv...35.1133H }}
• New Oxygen Spectra in the Ultraviolet and new Spectra in Nitrogen{{cite journal | title=New Oxygen Spectra in the Ultraviolet and new Spectra in Nitrogen | author=Hopfield, J. J. | journal=Physical Review | date=1930 | volume=36 | issue=4 | pages=789–790|doi=10.1103/physrev.36.783 | bibcode=1930PhRv...36..783. }}
• Preparation of Schumann plates{{cite journal | title=A Simplified Method of Preparing Schumann Plates |author1=Hopfield, J. J. |author2=E. T. S. Appleyard | journal=JOSA | date=1932 | volume=22 | issue=9 | pages=488–495 | doi=10.1364/josa.22.000488}}
• The Ultraviolet Spectrum of the Sun from V-2 Rockets{{cite journal | title=The Ultraviolet Spectrum of the Sun from V2 Rockets |author1=Hopfield, J. J. |author2=Clearman, H. E.| journal=Phys. Rev. |date=1948|volume=73 | issue=9 | pages=877–884 |

doi=10.1103/PhysRev.73.877|bibcode=1948PhRv...73..877H}}

• HOPFIELD{{cite book | title=HOPFIELD | publisher=U.S. Patent and Trademark Office | author=Hopfield, John J. | date=28 February 1933 | location=Washington, D.C. | volume=U.S. Patent No. 1,899,804}}
• Manufacture of multiple glass sheet glazing units{{cite book | title=Manufacture of multiple glass sheet glazing units | publisher=U.S. Patent and Trademark Office | author=Hopfield, John J. | date=3 September 1940 | location=Washington, D.C. | volume=U.S. Patent No. 2,213,395}}
• Uniting of glass to glass and metals to glass{{cite book | title=Uniting of glass to glass and metals to glass | publisher=U.S. Patent and Trademark Office | author=Hopfield, John J. | date=14 January 1941 | location=Washington, D.C. | volume=U.S. Patent No. 2,228,352}}
• Multiple glass sheet glazing unit and method of making the same{{cite book | title=Multiple glass sheet glazing unit and method of making the same | publisher=U.S. Patent and Trademark Office |author1=Haven, Charles D. |author2=John J. Hopfield | date=18 March 1941 | location=Washington, D.C. | volume=U.S. Patent No. 2,235,680}}
• Multiply glass sheet glazing unit{{cite book | title=Multiple glass sheet glazing unit | publisher=U.S. Patent and Trademark Office |author1=Haven, Charles D. |author2=John J. Hopfield | date=18 March 1941 | location=Washington, D.C. | volume=U.S. Patent No. 2,235,681}}
• Method of fabricating multiple glass sheet glazing units{{cite book | title=Method of fabricating multiple glass sheet glazing units | publisher=U.S. Patent and Trademark Office | author=Hopfield, John J. | date=14 December 1943 | location=Washington, D.C. | volume=U.S. Patent No. 2,336,544}}

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Category:1891 births

Category:1953 deaths

Category:Syracuse University alumni

Category:University of California, Berkeley alumni

Category:American spectroscopists

Category:20th-century American physicists

Category:Fellows of the American Physical Society

Category:Emigrants from Congress Poland to the United States