John Clauser

Clauser was born in Pasadena, California. His father, Francis H. Clauser, was a professor of aeronautical engineering who founded and chaired the aeronautics department at Johns Hopkins University. He later served as the Clark Blanchard Millikan Professor of Engineering at the California Institute of Technology (Caltech).{{Cite web |date=2022-09-20 |title=Proving that Quantum Entanglement is Real |url=https://www.caltech.edu/about/news/proving-that-quantum-entanglement-is-real |access-date=2022-10-06 |website=California Institute of Technology |language=en}} His mother, Catharine McMillan, was the humanities librarian at Caltech and sister of 1951 Nobel Prize in Chemistry laureate Edwin McMillan.{{Cite web |date=2022-10-04 |title=Caltech Alum Wins Nobel Prize in Physics |url=https://www.caltech.edu/about/news/caltech-alum-wins-nobel-prize-in-physics |access-date=2022-10-06 |website=California Institute of Technology |language=en}}

He received a Bachelor of Science in physics from Caltech in 1964, where he was a member of Dabney House.{{cite book|title=The Big T|date=1963|publisher=Associated Students of the California Institute of Technology}} He received a Master of Arts in physics in 1966 and a Doctor of Philosophy in physics in 1969 from Columbia University{{cite web |url=https://history.aip.org/phn/11504008.html |title=John F. Clauser |work=American Institute of Physics}} under the direction of Patrick Thaddeus.{{cite thesis |title=Measurement of the Cosmic Microwave Background by Optical Observations of Interstellar Molecules |date=1970 |institution=Columbia University |degree=Ph.D. |last=Clauser |first=John F. |id={{ProQuest|302516464}} |oclc=145659}}{{cite web |url=http://www.nasonline.org/publications/biographical-memoirs/memoir-pdfs/thaddeus-patrick.pdf |title=Patrick Thaddeus (1932–2017) |page=12 |series=Biographical Memoirs |publisher=National Academy of Sciences}}

From 1969 to 1975, he worked as a postdoctoral researcher at the University of California, Berkeley and Lawrence Berkeley National Laboratory. In 1972, working with Berkeley graduate student Stuart Freedman, he carried out the first experimental test of the CHSH-Bell's theorem predictions. This was the first experimental observation of a violation of a Bell inequality.{{cite journal|last1=Freedman|first1=Stuart J.|last2=Clauser|first2= John F.|date=April 3, 1972|title=Experimental Test of Local Hidden-Variable Theories|journal=Physical Review Letters|volume=28|issue=14|page=938-941|doi=10.1103/PhysRevLett.28.938 |bibcode=1972PhRvL..28..938F |doi-access=free}} In 1974, working with Michael Horne, he first showed that a generalization of Bell's Theorem provides severe constraints for all local realistic theories of nature (a.k.a. objective local theories). That work introduced the Clauser–Horne (CH) inequality as the first fully general experimental requirement set by local realism. It also introduced the "CH no-enhancement assumption", whereupon the CH inequality reduces to the CHSH inequality, and whereupon associated experimental tests also constrain local realism. Also in 1974 he made the first observation of sub-Poissonian statistics for light (via a violation of the Cauchy–Schwarz inequality for classical electromagnetic fields), and thereby, for the first time, demonstrated an unambiguous particle-like character for photons.{{cn|date=August 2024}}

Starting in 1973, Clauser published the newsletter Epistemological Letters, which was created because mainstream academic journals were relunctant to publish articles about the philosophy of quantum mechanics.{{cn|date=August 2024}} Clauser worked as a research physicist mainly at Lawrence Livermore and Berkeley from 1975 to 1997. In 1976 he carried out the world's second experimental test of the CHSH-Bell's Theorem predictions.{{cite news |title=Proving that Quantum Entanglement is Real |url=https://www.caltech.edu/about/news/proving-that-quantum-entanglement-is-real |access-date=October 6, 2022 |work=California Institute of Technology |date=September 20, 2022}}

Clauser was awarded the Wolf Prize in Physics in 2010 together with Alain Aspect and Anton Zeilinger. The three were also jointly awarded the 2022 Nobel Prize in Physics.{{Cite web |title=The Nobel Prize in Physics 2022 |url=https://www.nobelprize.org/prizes/physics/2022/summary/ |access-date=October 4, 2022 |website=NobelPrize.org |language=en-US}}

In May 2023, Clauser joined the board of the {{CO2}} Coalition, a climate change denial organization.{{Cite news |first=Seunghan |last=Cho |date=2023-06-26 |title=노벨물리학상 수상자 "정치인들, 잘못된 과학정보 만들어내"|trans-title=Nobel laureate in physics "Politicians create false scientific information" |url=https://www.hankyung.com/it/article/202306264943Y |access-date=2023-07-28 |work=The Korea Economic Daily|agency=Yonhap News Agency |language=ko}} Later that year, Clauser called himself a "climate denier" and claimed "there is no climate crisis".{{Cite news |last=Joselow |first=Maxine |date=2023-11-16 |title=He won a Nobel Prize. Then he started denying climate change. |url=https://www.washingtonpost.com/climate-environment/2023/11/16/john-clauser-nobel-climate-denial/ |url-access=subscription |url-status=live |archive-url=https://web.archive.org/web/20231118144100/https://www.washingtonpost.com/climate-environment/2023/11/16/john-clauser-nobel-climate-denial/ |archive-date=2023-11-18 |access-date=2023-11-17 |newspaper=The Washington Post |language=en-US |issn=0190-8286}} Clauser's views on climate change have been described as "pseudoscience". His belief that cloud cover has more of an impact on Earth's temperature than carbon dioxide emissions is contradicted by the overwhelming scientific consensus on climate change.{{cite journal|title=The Scientific Consensus on Climate Change|last=Oreskes|first=Naomi|author-link=Naomi Oreskes|journal=Science|date=2004-12-03|volume=306|issue=5702|page=1686|doi=10.1126/science.1103618|doi-access=free}}{{cite web|url=https://earthobservatory.nasa.gov/features/Clouds/clouds.php|title=Clouds & Radiation|last=Graham|first=Steve|publisher=NASA Earth Observatory|date=1999-03-01|access-date=2023-11-19|archive-url=https://web.archive.org/web/20231119072129/https://earthobservatory.nasa.gov/features/Clouds/clouds.php|archive-date=2023-11-19|url-status=live}}{{Cite web |date=4 September 2023 |title=John F. Clauser: the latest climate science-denying physicist |url=https://skepticalscience.com/clauser-latest-climate-denying-physicist.html |website=Skeptical Science}} Observational evidence shows the overall current cloud feedback amplifies global warming and does not have a cooling effect.{{cite journal|title=Observational evidence that cloud feedback amplifies global warming|last1=Ceppi |first1=Paulo |last2=Nowack |first2=Peer |editor1-last=Held |editor1-first=Isaac M. |editor1-link=Isaac Held |journal=PNAS|date=2021-07-19|volume=118|issue=30|doi=10.1073/pnas.2026290118|doi-access=free|pmc=8325336|bibcode=2021PNAS..11826290C }}

Clauser is an atheist. He has emphysema due to smoking cigarettes in his youth.

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{{Commons category|John Clauser}}

{{Scholia}}

• {{Nobelprize}}
• [https://www.aip.org/history-programs/niels-bohr-library/oral-histories/25096 Oral history interview transcript with John Clauser on 20, 21, and 23 May 2020, American Institute of Physics, Niels Bohr Library & Archives]
• [http://www.johnclauser.com John Clauser's homepage]

{{Wolf Prize in Physics}}

{{Nobel Prize in Physics}}

{{2022 Nobel Prize winners}}

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Category:1942 births

Category:Scientists from Pasadena, California

Category:20th-century American physicists

Category:21st-century American physicists

Category:Columbia Graduate School of Arts and Sciences alumni

Category:University of California, Berkeley staff

Category:Wolf Prize in Physics laureates

Category:Living people

Category:Nobel laureates in Physics

Category:American Nobel laureates