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Edward Norton Lorenz (1917-2008)

Research notes for NWP history series. Compiled from the National Academy of Sciences Biographical Memoir (Kerry Emanuel, 2011), the Royal Society Biographical Memoir (Tim Palmer, 2009), the MIT News obituary (April 2008), Britannica, MacTutor (St Andrews), the Kyoto Prize citation (1991), the Times of London obituary, The Tech (MIT) obituary, Physics Today obituary, the Lorenz Center website, and Lorenz’s own Kyoto Prize commemorative lecture “A Scientist by Choice” (1991).

1. Source disagreements and corrections to the brief

Before the biographical narrative, three points need flagging because the commissioning brief contains inaccuracies that recur in popular sources but are corrected by the primary record (Lorenz’s own 1991 Kyoto Prize lecture “A Scientist by Choice”, cited extensively by Emanuel in the NAS memoir).

Lorenz’s father was a mechanical engineer, not a dentist. Edward Henry Lorenz (1882-1956) attended Hartford High School and Trinity College, then majored in mechanical engineering at MIT (then located in downtown Boston). Emanuel: “He was small in stature but an excellent distance runner and held the record for the 2-mile run at MIT. It was from him that his son acquired an early knowledge of science, particularly mathematics.” (NAS Memoir, p. 1.) Wikipedia, Britannica, MacTutor and the NAS memoir all agree on this point. The “dentist” attribution appears nowhere in the primary literature.

Lorenz’s MIT doctoral advisor was James Austin, not Victor Starr. Emanuel: “Ed’s thesis, which was performed under the supervision of James Austin, earned him a doctorate of science degree in 1948.” (NAS Memoir, p. 10.) Wikipedia gives the advisor as “James Murdoch Austin”; Britannica gives “James Austin”; MacTutor agrees. Victor Starr was Lorenz’s postdoctoral mentor and lifelong collaborator on the general-circulation project that Lorenz joined immediately after finishing his ScD. The confusion is understandable – Starr was the more visible figure and Lorenz himself called him “next to his parents, the most important influence on my intellectual development” – but it is a confusion.

Lorenz had no documented siblings. The brief mentions “brothers”; neither Emanuel’s NAS memoir nor Palmer’s Royal Society memoir nor any obituary mentions siblings of Edward Norton Lorenz. (Emanuel does mention that Lorenz’s mother Grace had siblings, who moved to Chicago with her after her father’s early death; that is the only “siblings” reference in the record.) Treat Ed Lorenz as effectively an only child unless a primary source can be found that contradicts this.

Family residence: Cambridge, Boston area – with a Lexington interval. The brief says “family life in Lincoln, Massachusetts.” Emanuel: “Following their marriage they settled in Cambridge, Massachusetts, and lived in the Boston area for the remainder of their lives” (p. 10), and separately “During the years they lived in Lexington, Massachusetts, Ed was a member of the town’s choir” (p. 3). Lexington, not Lincoln. He died in Cambridge.

Thesis title – mild variation between sources. Wikipedia and Britannica both give: “A Method of Applying the Hydrodynamic and Thermodynamic Equations to Atmospheric Models” (1948, MIT, ScD). Emanuel paraphrases the content (“it described an application of fluid dynamical equations to the practical problem of predicting the motion of storms”) without quoting the title. The Wikipedia/Britannica title appears authoritative; the brief’s title is correct.

2. Birth, family, and West Hartford childhood (1917-1934)

Edward Norton Lorenz was born 23 May 1917 in West Hartford, Connecticut.

Father: Edward Henry Lorenz (Hartford 1882 – 1956). Hartford High School, Trinity College, then a mechanical-engineering degree from MIT (downtown Boston campus, before the move to Cambridge). “Small in stature but an excellent distance runner” – held the MIT 2-mile-run record. Source of his son’s early grounding in science and mathematics; the two would compete on jigsaw puzzles and record times on the inside covers of the boxes. (Emanuel NAS, p. 1.)

Mother: Grace Peloubet Norton (Auburndale, Massachusetts 1887 – 1943). Her father, Lewis M. Norton, developed the first course in chemical engineering at MIT in 1888; he died young, after which Grace’s mother moved the family to Chicago, where she founded the home-economics department at the University of Chicago (from which Grace ultimately graduated). Grace became a school teacher and was active in civic organisations. Ed’s own words, via Emanuel: she “fostered in him a deep interest in games, particularly chess, and… taught me more about life than anyone else.” (NAS Memoir, p. 2.)

Family meteorology trivia: the parents met at Waterville Valley, a summer resort in New Hampshire, were married in 1916, and continued to summer there. Ed spent many summers at Waterville Valley throughout his life. The White Mountains were a fixture from the cradle.

Grandfather (maternal): Lewis M. Norton – pioneer of chemical engineering education at MIT. (So both Lorenz’s father and his maternal grandfather had MIT connections; Ed himself eventually spent his entire career there. Three generations.)

Siblings: none mentioned in any biographical source.

Childhood traits (mostly from Lorenz’s own 1991 Kyoto lecture, via Emanuel):

  • Mathematically precocious. Read out house numbers from his go-cart for his mother; after learning multiplication, memorised all perfect squares between 1 and 10,000; learned the longhand method for square roots and cube roots.
  • Chess: captain of his high-school and college chess teams.
  • Loved crossword and jigsaw puzzles; kept his childhood jigsaw collection for life.
  • Map-making: at seven, drew maps of imaginary places “with inset enlargements.” That same summer (visiting friends on a farm east of Hartford) he opened an atlas, saw illustrations of the planets, was struck by the rings of Saturn, and was launched into a lifelong love of astronomy.
  • Aged eight: witnessed a total solar eclipse on “a bitterly cold day in Hartford, with shadow bands shimmering across fields of snow.” (Emanuel quoting Lorenz, NAS p. 3.) This was the 24 January 1925 eclipse, the great urban-east-coast eclipse whose path of totality crossed Connecticut and southern New England. The shadow-bands-on-snow detail is verifiably unusual and is the kind of physical observation that probably stayed with him.
  • Musical: had a good ear; began violin at nine, concluded he lacked manual dexterity for a pleasing sound, but kept a lifelong passion for concert music. Later attended student-orchestra concerts at MIT with Jane; sang in the Lexington town choir.
  • Small for his age and a year younger than his classmates, so he was bad at team sports. By high school he could swim underwater further than anyone. Light weight made him fast up White Mountain trails. “Mountains and music were his greatest spare-time interests” (paraphrase of his own later characterisation).

The flavour throughout is of a quiet, intellectually self-sufficient New England boyhood centred on books, numbers, board games, and the White Mountains – which then continued, essentially unmodified, for ninety years.

3. Education: Dartmouth and Harvard (1934-1942)

Dartmouth College, BA in Mathematics (1934-1938). Entered 1934, already committed to mathematics. Emanuel’s telling detail: of about 700 entering students that year, only seven would major in mathematics. Lorenz “preferred the logical clarity of math to any of the other courses he encountered, including history, physics, and geology.” Graduated 1938.

Harvard University, AM in Mathematics (1938-1940). Entered the Harvard maths graduate school in 1938 “delighting in being able to focus exclusively on math.” Studied group theory, set theory, combinatorial topology under Saunders Mac Lane, Marshall Stone, and James Van Vleck (the last later a Nobel laureate in physics). His master’s thesis advisor was George Birkhoff, the eminent mathematician best known for his proof of Poincaré’s Last Geometric Theorem. The thesis itself was not on dynamical systems but on a problem in Riemannian geometry. AM awarded 1940.

The Birkhoff connection is one of the great curiosities of Lorenz’s intellectual genealogy: through Birkhoff he is just one step from Poincaré and the three-body problem – whose sensitive dependence on initial conditions Lorenz would, two decades later, rediscover in atmospheric form and reformulate as modern chaos.

He remained at Harvard for further doctoral work in mathematics 1940-1942 (the AM was 1940). Then came the war.

4. World War II: Army Air Corps weather forecasting (1942-1946)

In Lorenz’s own words, repeated from his 1991 Kyoto lecture and quoted verbatim by Emanuel (NAS p. 4):

It soon became evident that we were studying to be meteorologists. The distinction is one that I was slow to appreciate.

Path into meteorology. In early 1942, “just months before he expected to receive his doctoral degree” in mathematics from Harvard, Lorenz chose between being drafted and entering an Army Air Corps weather-forecaster training programme. He chose the latter. In March 1942 he enrolled as a cadet in an Army-sponsored eight-month accelerated master’s programme at MIT, just across the Charles. The faculty included Hurd Willett, Henry Houghton, and Bernard Haurwitz – effectively the first generation of American academic meteorology.

Our faculty in meteorology was as outstanding as any in the world, and it was natural that they should want to teach real science to their students. This was probably compatible with the Army’s philosophy that an officer is a gentleman. – Lorenz, “A Scientist by Choice”, quoted Emanuel p. 4.

He took an MIT SM in meteorology in 1943. November 1942: he and four classmates were retained at MIT to teach the next year’s intake; this gave him time to take advanced classes.

A telling early frustration, in his own words (Emanuel p. 5):

Not only were we never shown how to use the dynamical equations to make weather forecasts, which I had naively assumed was the reason for our studying dynamic meteorology, but we were not even told whether they could be used in this manner. I also learned that some outstanding meteorologists at other universities believed that it was impossible.

This explicit gap between dynamical theory and forecasting practice became, twenty years later, the core problematic of his career.

Pacific theatre. After completing the final MIT training course, Lorenz shipped out: two more months of tropical-meteorology training in Hawaii, then Saipan in October 1944. He helped set up a weather-forecasting operation supporting bombing raids against Japan. His specific role: chief of upper-level-winds forecasting. Observation density between Siberia and Saipan was wretched – US aircrew were essentially the only observers, and Lorenz complained that “the pilots, to save time, would often simply repeat the forecast as the observation. This made for excellent forecast verification but hardly helped the forecasters make the next forecast.” (Emanuel p. 6.)

The military-meteorology context of those months included Halsey’s Typhoon Cobra (December 1944), the catastrophe Emanuel cites as proof of how casually the Air Corps treated weather data: Admiral Halsey, refusing to divert reconnaissance aircraft, sailed the Third Fleet into the typhoon’s core and lost 3 ships and 790 men.

Spring 1945: weather operation moved (per Lorenz’s own memoir, to Okinawa; per his colleague Patrick Suppes, to Guam – Emanuel flags this disagreement explicitly in footnote 2 of the NAS memoir, noting that the Battle of Okinawa did not end until mid-June 1945 and Suppes is probably right that the group moved to Guam, though Lorenz himself may subsequently have gone to Okinawa). Lorenz was appointed head of the upper-air section. The forecasting operation continued for several months after Japan’s surrender.

Patrick Suppes on Lorenz in uniform (NAS p. 6, from August 2008 personal communication):

Although Ed was not a strongly outgoing individual, it turned out that he rather liked conversation on many topics, and of course as those who knew Ed will find unsurprising, he knew a lot and was prepared to talk about a great many different subjects.

Suppes and several Weather Central colleagues including Lorenz were nominated (unsuccessfully) for a Bronze Star. The nomination citation (Suppes’s, “similar to” Lorenz’s per Suppes) reads:

Through high order technical skill and resourcefulness, he utilized scientific principles to adapt known techniques and to devise new techniques of analysis and forecasting in the institution of a successful combat weather forecasting service.

5. The switch to meteorology and the MIT PhD (1946-1948)

At the end of the war, Lorenz had two paths: return to Harvard and finish the mathematics doctorate, or switch fields entirely. He consulted Henry Houghton, head of the MIT meteorology department, and chose meteorology. His own justification, again from the 1991 Kyoto lecture:

Mathematicians seem to have no difficulty in creating new concepts faster than the old ones become well understood, and there will undoubtedly always be many challenging problems to solve. Nevertheless, I believed that some of the unsolved meteorological problems were more fundamental, and I felt confident that I could contribute to some of their solutions.

MIT ScD in Meteorology, 1948. Advisor: James Austin (full name James Murdoch Austin per Wikipedia). Thesis title: “A Method of Applying the Hydrodynamic and Thermodynamic Equations to Atmospheric Models” – a power-series-in-time expansion of the governing equations applied to storm motion. By the time the thesis was finished, the Princeton (IAS) team under von Neumann was already mounting the rival approach – finite-difference numerical integration on the ENIAC – and Lorenz judged in retrospect that his own technique was “more cumbersome than some others that were currently being developed” and was probably never actually used. (Emanuel p. 10, quoting “A Scientist by Choice”.) But the work showed, Emanuel notes, that Lorenz was “an innovative and independent thinker.”

6. Marriage, family, and home life (1948-2001)

Jane Loban (Dayton, Ohio 1919 – 2001). Raised mostly in Cedar Falls, Iowa. Her dominant interest as a young woman was flying – she flew small aeroplanes before she was old enough to drive. The path from aviation to meteorology was natural, and she came to MIT as a research assistant in the meteorology department, where she met Ed.

Wedding: 1948, “a few weeks after [Ed] received his doctorate” (Emanuel p. 10).

Children, in order: Nancy, Edward (“Ned”), Cheryl. All three inherited their parents’ love of puzzles and games, and all three became first-class downhill skiers. Lorenz’s own description (Emanuel p. 10):

Many of my winter weekends were spent taking one or all of them, usually with my wife as well, to some ski area north of Boston; this, of course, was just what I had hoped would happen.

By the time of his death there were also four grandchildren (per The Tech obituary).

Residence: Cambridge after the wedding; at some point a stretch in Lexington, Massachusetts (where Ed sang in the town choir); and Cambridge again for his last years (he died at home in Cambridge in 2008). Not Lincoln, MA.

Children’s later locations (from The Tech 18 April 2008 obituary): Nancy in Roslindale (a Boston neighbourhood); Edward H. Lorenz (MIT class of ‘75) in Grasse, France; Cheryl in Eugene, Oregon.

Summers: Waterville Valley, New Hampshire (the family resort going back to his parents’ courtship), and Chautauqua resort in Boulder, Colorado. At Chautauqua he and Jane were regular concert-goers.

Jane’s last years and death. From the late 1990s Jane suffered “a series of debilitating illnesses.” Ed set aside his research and devoted himself to her care. Jane died in late 2001. After her death he returned to research and published roughly nine further papers.

7. Personality, hiking, and skiing

This is the section worth quoting at length, because everyone who wrote about Lorenz returned to the same themes: a man almost painfully reserved with strangers; warm, slyly funny, and intensely loyal with intimates; and physically extraordinarily durable, walking and skiing into his ninth decade.

Reserve. Emanuel (NAS p. 22): “Those of us privileged to have known Ed Lorenz will remember him as a gentle, quiet soul, almost painfully shy and modest to a fault. But engage him on a favorite topic – a fine point in atmospheric or dynamical systems theory, the virtues of a particular mountain trail, or anything to do with his extended family – and with a twinkle of his bright blue eyes he would come to life; at such times one always felt as if he were inwardly smiling at life.”

Kerry Emanuel to the MIT News obit (2008): Lorenz was “a perfect gentleman” who “through his intelligence, integrity and humility set a very high standard.”

Physics Today obituary: “extremely modest” – the author imagines Lorenz’s response to the worldwide tributes as: “I just don’t see what the fuss is about.”

Humour. The Tech (MIT student paper, 18 April 2008) preserved one specific Emanuel anecdote that doesn’t make the more formal obituaries: on a desert hike Lorenz “imitated coyotes” until actual coyotes responded. Treat the bright-blue-eyed twinkle as backed by primary evidence.

Outdoor activity. Emanuel called him “like a mountain goat” who “knew every trail” in both the White Mountains of New Hampshire and the Rockies. The Lorenz Center website’s photo archive documents specific places: the Flatirons near Boulder; White Mountains of NH; Mt. Battie in Camden, Maine. The Times of London obit: “a very keen outdoorsman who enjoyed hiking and cross-country skiing until well into old age.” Multiple sources confirm he was skiing in his eighties and “managed to continue most of his regular activities until only a few weeks before his death.”

Work habits at MIT. Emanuel: “generations of students and colleagues at MIT will remember many occasions when Ed would appear silently in their office, as if by magic, and enthuse over some feature of the current weather map.” The forecasting interest – born in the Army Air Corps – never left him. Lunch hours at the MIT faculty club were often spent playing chess with colleagues, including Norbert Wiener (who played simultaneous games against several colleagues at once).

Devotion to family. Emanuel: “Although a reticent man, there were a few topics that were sure to get him going: hiking in the mountains, and his family.” He showed “an old-fashioned sense of chivalry toward Jane.” When visiting colleagues with families he would arrive with mathematics-based toys for the children.

Teaching. “Much beloved as a teacher and for many years running won the prize awarded by MIT graduate students for the best teacher of the year” (Emanuel p. 23).

On free will, from The Essence of Chaos (1993), much-quoted as a representative bit of late Lorenz Pascal-wagering:

We must wholeheartedly believe in free will. If free will is a reality, we shall have made the correct choice. If it is not, we shall still not have made an incorrect choice, because we shall not have made any choice at all, not having a free will to do so.

(Emanuel calls this “characteristic Lorenzian fashion” and explicitly frames it as Pascal’s wager applied to determinism.)

8. MIT career timeline

Compiled from Emanuel, MIT News, Wikipedia, MacTutor, Britannica, the Times obituary, and The Tech. The titles are essentially consistent across sources; only minor year disagreements exist (e.g. Britannica says “assistant professor 1954” while MIT News and Wikipedia say 1955).

Year Position
1942 Cadet, Army Air Corps weather-forecaster training, MIT
1943 SM Meteorology, MIT
1948 ScD Meteorology, MIT (advisor: James Austin)
1948 Research scientist, MIT Department of Meteorology (Starr’s general-circulation project)
1953-54 Visiting year at UCLA (filling in for a faculty member on leave)
1955 Assistant Professor (Britannica gives 1954)
1962 Professor
1977-1981 Department head (the department by then = Earth, Atmospheric and Planetary Sciences)
1987 Emeritus (some sources, including Lorenz Center, give 1988 as the retirement year)

Visiting/leave stints across his career: Lowell Observatory (Flagstaff, Arizona, 1951); UCLA (1953-54); Norwegian Meteorological Institute (Oslo); NCAR (Boulder); the European Centre for Medium-Range Weather Forecasts (multiple visits).

9. Awards and honours

Compiled and dated from Emanuel’s NAS memoir, Wikipedia, Britannica, the Lorenz Center, the Times obituary, and the Kyoto Prize site. Sources disagree on a handful of years (e.g. Wikipedia gives the Revelle Medal as 1992; the brief says 2003; the answer is below).

  • 1961 Fellow, American Academy of Arts and Sciences
  • 1969 Meisinger Award and Carl-Gustaf Rossby Research Medal, American Meteorological Society – the AMS’s highest scientific honour
  • 1973 Symons Memorial Gold Medal, Royal Meteorological Society (UK)
  • 1975 Elected to the US National Academy of Sciences
  • 1981 Foreign Member, Norwegian Academy of Science and Letters
  • 1983 Crafoord Prize, Royal Swedish Academy of Sciences, shared with Henry Stommel. The Crafoord was awarded for the first time in 1982 (to Vladimir Arnold and Louis Nirenberg, in mathematics); Lorenz and Stommel were the second-year laureates, in geosciences, in 1983. The brief’s “first awarded” is true in the geosciences category, since 1983 was the first year geosciences was the rotating subject – worth checking before asserting flatly that Lorenz won “the first Crafoord.” Prize value $50,000 per Emanuel; $54,000 per The Tech (after exchange-rate appreciation between announcement and award).
  • 1984 Honorary Member, Royal Meteorological Society
  • 1989 Elliott Cresson Medal, Franklin Institute
  • 1991 Kyoto Prize in Basic Sciences (Earth & Planetary Sciences, Astronomy and Astrophysics), Inamori Foundation. Citation: “Outstanding Contribution to Earth Science and Mathematical Science by the Development of Theoretical Basis of Numerical Study in Meteorology and the Discovery of Deterministic Chaos.” Commemorative lecture: “A Scientist by Choice” – a key autobiographical primary source for everything in this file.
  • 1992 Roger Revelle Medal, American Geophysical Union. (The brief says 2003; Emanuel and Wikipedia both give 1992. The brief is wrong on year.)
  • 2000 International Meteorological Organization Prize (the WMO’s highest award)
  • 2004 Buys Ballot Medal, Royal Netherlands Academy of Arts and Sciences; and Lomonosov Gold Medal (Russian Academy of Sciences)
  • 2008 Felice Pietro Chisesi e Caterina Tomassoni Award

Honorary degrees: multiple, including the listing on Wikipedia.

The Lorenz Center. Founded at MIT in 2011 by Dan Rothman and Kerry Emanuel of the Department of Earth, Atmospheric, and Planetary Sciences, with support from the School of Science under Dean Marc Kastner. Mission per the Center’s website: “a climate think tank that would restore to climate science that mode of curiosity-driven free scientific inquiry.” Named for Lorenz as “an inspiring example of what it means to be a scholar, free to pursue the most fascinating aspects of our physical environment.” After Emanuel’s retirement, Raffaele Ferrari became co-director. The Center is conceived as a “scientific oasis… free of financial and political pressures” where leading scientists can pursue novel ideas about climate.

10. Death

16 April 2008, at home in Cambridge, Massachusetts, age 90, of cancer (he had had a bout in the 1980s and a recurrence in 2007). Emanuel: “He died at home in April 2008, surrounded by his family and having worked on proofs of his latest paper just a few days earlier.” That paper – “Compound windows of the Hénon map”, Physica D 237:1689-1704 – was published posthumously in 2008. He published a substantial bibliography after Jane’s death in 2001, including:

  • 1986: “On the existence of a slow manifold”, JAS 43:1547-1557 (the pre-Jane-illness landmark paper)
  • 1990: “Can chaos and intransitivity lead to interannual variability?”
  • 1991: “Dimension of weather and climate attractors”, Nature 353
  • 1993: The Essence of Chaos (book, University of Washington Press)
  • 1998 (with Emanuel): “Optimal sites for supplementary weather observations” – the adaptive-sampling paper
  • 2006: “Regimes in simple systems”
  • 2008 (posthumous): “Compound windows of the Hénon map”

11. Key quotes and primary-source fragments worth keeping handy

These are the ones likely to be reusable in a long-form post.

On the gap between dynamic meteorology and forecasting (Army Air Corps, 1942-43):

Not only were we never shown how to use the dynamical equations to make weather forecasts, which I had naively assumed was the reason for our studying dynamic meteorology, but we were not even told whether they could be used in this manner. I also learned that some outstanding meteorologists at other universities believed that it was impossible. – Lorenz, “A Scientist by Choice” (1991)

On choosing meteorology over mathematics (1945-46):

Mathematicians seem to have no difficulty in creating new concepts faster than the old ones become well understood… Nevertheless, I believed that some of the unsolved meteorological problems were more fundamental, and I felt confident that I could contribute to some of their solutions. – Lorenz, “A Scientist by Choice”

On Victor Starr (his postdoctoral mentor 1948-c.1973):

In a day when there was still much confusion in meteorology, Starr’s clear and deliberate analyses of some of the fundamental problems proved highly refreshing, and they removed any lingering doubts as to the desirability of my change from mathematics to meteorology. The things I remember best and cherish most, in looking back over my scientific career, are the almost daily conversations with Victor Starr during the more than twenty-five years that I worked with him, first as a protégé and then as a colleague. – Lorenz, Kyoto Prize questionnaire response, quoted Emanuel p. 11.

On the LGP-30 (the Royal McBee desktop computer in his MIT office on which he discovered chaos, 1958):

Suddenly I realized that my desire to do things with numbers would be fulfilled. – Lorenz, “A Scientist by Choice”

On the moment of discovery (1961, the famous coffee-break re-run):

At this point, I became rather excited. – Lorenz to Emanuel (NAS p. 16)

On precision of initial conditions (Emanuel, MIT News obit, paraphrasing Lorenz):

Any imprecision will throw you off. Even the thickness of the pen line on a graph can be enough.

On the seagull (the prototype of the butterfly), from “Deterministic Nonperiodic Flow”, 1963:

One meteorologist remarked that if the theory were correct, one flap of a sea gull’s wings would be enough to alter the course of the weather forever. The controversy has not yet been settled, but the most recent evidence seems to favor the gulls. – Lorenz (1963,2), quoted Emanuel footnote 6.

The butterfly itself was probably introduced by Joseph Smagorinsky in 1969 (Emanuel cites Smagorinsky’s 1969 BAMS article on extended-range forecasting); Lorenz’s famous 1972 AAAS talk “Predictability: Does the Flap of a Butterfly’s Wings in Brazil Set Off a Tornado in Texas?” then made it canonical.

Earlier ancestor of the butterfly: Emanuel traces the lineage back to Franklin’s grasshopper, 1898:

Long range detailed weather prediction is therefore impossible, and the only detailed prediction which is possible is the inference of the ultimate trend and character of a storm from observations of its early stages; and the accuracy of this prediction is subject to the condition that the flight of a grasshopper in Montana may turn a storm aside from Philadelphia to New York! – W. S. Franklin (1898), reviewing Duhem in Phys. Rev. 6:170-175, quoted Emanuel footnote 6.

On free will, from The Essence of Chaos (1993):

We must wholeheartedly believe in free will. If free will is a reality, we shall have made the correct choice. If it is not, we shall still not have made an incorrect choice, because we shall not have made any choice at all, not having a free will to do so.

Emanuel summing up (NAS, closing paragraphs):

Ed’s scientific legacy will no doubt focus on his work on chaos in forced dissipative systems and his discovery of the fractal nature of the state spaces of such systems… history may well record that Ed Lorenz had begun the process of hammering the last nail into the coffin of Laplace’s daemon.

12. Scientific itinerary in compressed form (for cross-reference)

For the NWP-series post we will mostly want the biography, but here is the research arc compressed, since the science is the reason for the biography. All dates are publication dates.

  • 1948 ScD thesis: power-series-in-time integration of fluid-dynamical equations applied to storm motion. (Already obsolescent given Princeton finite-difference work.)
  • 1950 “Dynamic models illustrating the energy balance of the atmosphere”, J. Meteorol. 7:30-38.
  • 1951 Visits Lowell Observatory, publishes paper on the depth of the Jovian atmosphere.
  • 1953-54 UCLA visit. Meets Bjerknes, Holmboe, Eliassen (the last becomes a lifelong friend).
  • 1955 “Available potential energy and the maintenance of the general circulation”, Tellus 7:271-281. Lorenz’s first landmark contribution; APE is still the standard energetic framework used in general-circulation analysis.
  • 1958 Acquires the Royal McBee LGP-30 desktop computer in his MIT office.
  • 1960 “Maximum simplification of the dynamic equations”, Tellus 12:243-254. Step toward the chaos work.
  • 1961 Coffee-break re-run: chaos discovered on the LGP-30 from a 12-variable model. Then reduced to a 3-variable system via Barry Saltzman’s 7-variable convection model.
  • 1963 “Deterministic Nonperiodic Flow”, J. Atmos. Sci. 20:130-141 – the chaos paper. Plus “The mechanics of vacillation” (with the sea-gull remark) in the same volume.
  • 1967 Book/treatise on the general circulation of the atmosphere (WMO). Still a teaching reference.
  • 1969 “The predictability of a flow which possesses many scales of motion”, Tellus 21:289-307 – the “predictability horizon” paper arguing that fine-scale errors cascading upscale create a finite prediction limit even with vanishing initial error.
  • 1972 AAAS talk: “Does the Flap of a Butterfly’s Wings in Brazil Set Off a Tornado in Texas?”
  • 1986 “On the existence of a slow manifold”, JAS 43:1547-1557 – the late landmark.
  • 1991 “Dimension of weather and climate attractors”, Nature 353
  • 1993 The Essence of Chaos (book)
  • 1998 With Emanuel: “Optimal sites for supplementary weather observations” – the adaptive-sampling paper
  • 2006 “Regimes in simple systems”
  • 2008 Posthumous: “Compound windows of the Hénon map”

13. Bibliography of sources actually consulted

  • Emanuel, Kerry. 2011. Edward Norton Lorenz, 1917-2008: A Biographical Memoir. National Academy of Sciences, Washington DC. PDF at https://texmex.mit.edu/pub/emanuel/PAPERS/Lorenz_Edward.pdf. The primary biographical source for this file. Draws extensively on Lorenz’s own 1991 Kyoto Prize lecture “A Scientist by Choice”, a WMO interview (1996), Patrick Suppes (personal communication, 2008), and Lorenz’s son and daughter (Ned and Nancy).
  • Palmer, Tim N. 2009. “Edward Norton Lorenz. 23 May 1917 – 16 April 2008.” Biographical Memoirs of Fellows of the Royal Society 55:139-155. HTTP 403 from royalsocietypublishing.org when fetched; cited by Emanuel as a key source.
  • MIT News. “Edward Lorenz, father of chaos theory and butterfly effect, dies at 90.” 16 April 2008. https://news.mit.edu/2008/obit-lorenz-0416. Includes Emanuel quotes.
  • The Tech (MIT student paper). “Edward N. Lorenz ScD ‘48.” 18 April
    1. https://thetech.com/2008/04/18/lorenzobit-v128-n20. Source for children’s locations and the coyote-imitation anecdote.
  • Physics Today obituary (online): Lorenz “extremely modest” and “I just don’t see what the fuss is about” line.
  • The Times of London obituary (republished on MacTutor): https://mathshistory.st-andrews.ac.uk/Obituaries/Lorenz_Edward_Times/
  • MacTutor History of Mathematics biography: https://mathshistory.st-andrews.ac.uk/Biographies/Lorenz_Edward/
  • Britannica biography: https://www.britannica.com/biography/Edward-Lorenz
  • Wikipedia, “Edward Norton Lorenz.” Most useful for award dates, thesis title, and family-detail cross-checking.
  • Kyoto Prize, Edward Norton Lorenz laureate page: https://www.kyotoprize.org/en/laureates/edward_norton_lorenz/ – citation and category.
  • Lorenz Center, MIT. https://www.lorenz.mit.edu/edward-n-lorenz and /about and /meet-the-founders. Founding history, mission, hiking photo archive.
  • WMO. 1996. “The Bulletin interviews Professor Edward N. Lorenz.” WMO Bull. 45:111-120. Primary-source interview; cited by Emanuel.
  • Lorenz, E. N. 1991. “A Scientist by Choice.” Kyoto Prize Commemorative Lecture. The single most important autobiographical source; Emanuel quotes it throughout.
  • Lorenz, E. N. 1993. The Essence of Chaos. University of Washington Press. Source for the free-will quote.
  • BAMS. Lorenz, E. N., interviewed November 2007: “Revisiting the Limits of Predictability and Their Implications: An Interview From 2007.” Bull. Amer. Meteor. Soc. 95(5):681-687, May 2014. Probably Lorenz’s last published interview.

14. Quick-reference fact box for the post

  • Born 23 May 1917, West Hartford, Connecticut
  • Father: Edward Henry Lorenz (1882-1956), MIT mechanical engineer (NOT dentist)
  • Mother: Grace Peloubet Norton (1887-1943), Auburndale MA -> Chicago, Univ. of Chicago alumna, school teacher; her father Lewis M. Norton founded chemical engineering at MIT
  • No documented siblings
  • Dartmouth AB Mathematics 1938
  • Harvard AM Mathematics 1940 (master’s advisor: George Birkhoff; thesis in Riemannian geometry)
  • Army Air Corps cadet from March 1942; MIT SM Meteorology 1943; Pacific theatre 1944-45 (Saipan, then Guam/Okinawa); upper-air section chief
  • MIT ScD Meteorology 1948; advisor James Austin (NOT Victor Starr); thesis “A Method of Applying the Hydrodynamic and Thermodynamic Equations to Atmospheric Models”
  • Married Jane Loban 1948; children Nancy, Edward “Ned”, Cheryl; four grandchildren
  • Settled in Cambridge MA; intermediate period in Lexington MA (NOT Lincoln); died at home in Cambridge
  • Victor Starr was his postdoctoral mentor (1948-c.1973), not his thesis advisor
  • MIT faculty 1948-1987; assistant prof 1955, full prof 1962, department head 1977-1981, emeritus 1987
  • Key papers: 1955 (APE), 1963 (“Deterministic Nonperiodic Flow”), 1969 (predictability), 1986 (slow manifold)
  • Major awards: Rossby 1969, Symons 1973, NAS 1975, Crafoord 1983 (with Henry Stommel), Kyoto 1991, Revelle 1992, Buys Ballot 2004
  • Lorenz Center founded MIT 2011 by Dan Rothman and Kerry Emanuel
  • Died 16 April 2008, Cambridge MA, age 90, of cancer
  • Hiked and cross-country skied into his eighties; “like a mountain goat” (Emanuel); knew “every trail” of the White Mountains and Rockies; was working on proofs of his last paper days before his death