David Layzer

{{Short description|American astrophysicist and cosmologist (1925–2019)}}

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| name = David Layzer

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| birth_date = {{birth date|1925|12|31}}

| birth_place = Cleveland, Ohio, U.S.

| death_date = {{death date and age |2019|08|16|1925|12|31}}

| death_place = Belmont, Massachusetts, U.S.

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| fields = Astrophysics

| workplaces = Harvard University

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| education = Harvard University (A.B., 1947; Ph.D., 1950){{Cite book |url=https://trove.nla.gov.au/version/7367625 |title=Gravitational collapse, cosmic black-body radiation, and the origin of astronomical systems |last1=Layzer |first1=David |last2=Foundation |first2=Gravity Research |date=1968 |publisher=Gloucester, Mass. : Gravity Research Foundation |pages=12 |language=English}}

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| thesis_title = Two problems in the theory of atomic spectra: orbit-orbit interaction and central fields

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| thesis_year = 1950

| doctoral_advisor = Donald H. Menzel

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| notable_students = Carlos Varsavsky
Joseph Silk

| known_for = Cold Big Bang

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| awards = Member of the American Academy of Arts and Sciences

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David Raymond Layzer (December 31, 1925 – August 16, 2019) was an American astrophysicist, cosmologist, and the Donald H. Menzel Professor Emeritus of Astronomy at Harvard University.{{Cite web |url=https://astronomy.fas.harvard.edu/astronomy-alumni |title=Astronomy Alumni |website=Harvard University |language=en |access-date=2018-05-29}}{{Cite news |url=https://www.thecrimson.com/article/1983/3/3/course-lotteries-pthe-student-faculty-committee-on/ |title=Course Lotteries |date=1983-03-03 |work=Harvard Crimson |access-date=2018-05-29 |language=en}}{{Cite web |url=https://www.aip.org/history-programs/niels-bohr-library/oral-histories/33928 |title=David Layzer |date=2007-12-05 |website=American Institute of Physics |language=en |access-date=2018-05-29}}

He is known for his cosmological theory of the expansion of the universe, which postulates that its order and information are increasing despite the second law of thermodynamics.{{Cite web |url=http://www.informationphilosopher.com/solutions/scientists/layzer/growth_of_order/ |title=David Layzer - the Growth of Order in the Universe |website=The Information Philosopher |access-date=2018-05-29}} He is also known for being one of the most notable researchers who advocated for a Cold Big Bang theory.{{Cite book |url=https://archive.org/details/strangemattersun00sieg |url-access=registration |title=Strange Matters: Undiscovered Ideas at the Frontiers of Space and Time |last=Siegfried |first=Tom |date=2002-08-23 |publisher=Joseph Henry Press |isbn=9780309500586 |pages=[https://archive.org/details/strangemattersun00sieg/page/274 274] |language=en}}{{Cite book |url=https://books.google.com/books?id=Z_F0hhN3IrAC |title=The Silent Pulse |last=Leonard |first=George |date=September 2009 |publisher=Gibbs Smith |isbn=9781423611363 |pages=138 |language=en}} When he proposed this theory in 1966, he suggested it would solve Olbers' paradox, which holds that the night sky on Earth should be much brighter than it actually is.{{Cite news |url=https://www.thecrimson.com/article/1966/4/29/layzer-proposes-theory-explaining-why-the/ |title=Layzer Proposes Theory Explaining Why the Night Sky Is Not Bright |date=1966-04-29 |work=The Harvard Crimson |access-date=2018-05-29 |language=en}} He proposed a solution to the paradox of time's arrow. The fundamental laws of physics don't distinguish positive from negative time, and yet the Second Law of Thermodynamics (and our everyday life) tell us that time "flows" in one direction.{{Cite web |last=Layzer |first=David |date=1975 |title=The Arrow of Time |url=https://static.scientificamerican.com/sciam/assets/media/pdf/2008-05-21_1975-carroll-story.pdf |access-date=December 28, 2023 |website=static_scientificamerican.com}} He also published several articles critiquing hereditarian views on human intelligence, such as those of Richard Herrnstein and Arthur Jensen.{{Cite news |url=https://www.thecrimson.com/article/1976/10/30/faked-data-linked-with-herrnstein-iq/ |title='Faked' Data Linked With Herrnstein I.Q. Research |date=1976-10-30 |work=The Harvard Crimson |access-date=2018-05-29 |language=en}}{{Cite book |url=https://books.google.com/books?id=Nd9uAAAAQBAJ |title=Man's Most Dangerous Myth: The Fallacy of Race |last=Montagu |first=Ashley |date=2001-04-19 |publisher=AltaMira Press |isbn=9780585345482 |pages=157 |language=en}}

He became a member of the American Academy of Arts and Sciences since 1963,{{cite journal |jstor=3785442 |title=New Members Elected 8 May 1963 |date=1962 |journal=Records of the Academy (American Academy of Arts and Sciences) |issue=1962/1963 |pages=143–150 }} and was also a member of Divisions B and J of the International Astronomical Union.{{Cite web |url=https://www.iau.org/administration/membership/individual/3295/ |title=David Layzer |website=International Astronomical Union |access-date=2018-05-29}} He died in Belmont at the age of 93 in 2019.{{Cite web|url= https://www.swdfuneralhome.com/obituary/David-Layzer |title= David Layzer Obituary |website=Short, Williamson & Diamond Funeral Home|access-date= 2019-09-11}}