Raymond Grégoire (?-1960)

A great pedagogical physicist
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Ambiguity about the year of his birth
  Raymond Grégoire was born on January the 1st, 1906 at dawn but his father decided to register the birth for the previous day, December the 31st 1905. Babies were delivered at home in those days and registering a son a year earlier meant for a boy doing his military service a year earlier so that he could enter active life a year earlier.

A difficult childhood and brilliant studies
   The young Raymond knew little of his father who was an employee of the famous Wagram Hall in Paris, and who was called up in 1914, and who came back gassed in 1918. His internal and external injuries lead to his death in 1920 after long and painful suffering. Raymond was then raised along with his younger twin brother and sister by two years with his mother who had to find a job to feed her three children. Becoming a post woman, she had to buy the necessary bicycle for her job with the little means she had. Raymond would have started earning his living at the age of 14 as most boys of his age were doing if his teacher had not noticed his great potential and had convinced his mother to let him carry on his studies. Hence, Raymond went on studying at the higher primary superior school Turgot which is today the Lycée Turgot in Paris

Archives ESPCI 42th promotion de l'ESPCI R.Grégoire in locket

He was admitted after his first attempt to l'École Supérieure de Physique et Chimie Industrielles de la ville de Paris (ESPCI). This school which trains the scientific elite of France has provided 18 members of the Institut de France, 5 Nobel prizes and many professors at the College de France. Raymond was the youngest when he joined this school at only 17. After graduating from this prestigious school where he got second place, he could have pursued a brilliant career in industry but decided to put his skills into research. He was immediately hired by Marie Curie under the recommendation of Paul Langevin, director of the school and also the real but modest pioneer of relativity theory and became her personal laboratory assistant.

His military obligations   In 1927, he joined the army reserve officer school (officier de réserve de l'armée de terre) at Poitiers where his fellow officers were remonstrated with him on how tall he was (nearly two meter high).

Collection privée

A career entirely dedicated to Research and Teaching

Archives Musée Curie In the lecture hall of Curie laboratory Paris

He spent most of his professional life at the Curie Laboratory in Paris. In 1933, he graduated with a PhD in α ray emission, which with the β and γ rays form the rays of radioactive elements. His PhD supervisor was Madame Marie Curie and the members of the jury were André Debierne who discovered the Actinium and who succeeded to Madame Curie as head of the Laboratory and also Jean Perrin, the famous physicist (Nobel Prize winner for Physics in 1926). Raymond dedicated his PhD to Madame Curie whom he admired and deeply respected and to his mother to whom he was deeply grateful for the great sacrifices she had made in order for him to pursue his higher education. Here is the judgement of Madame Curie quoted by her daughter Eve in her book "Madame Curie" (p355, éditions Folio): « I am really very well pleased with my young Grégoire, I knew he was very gifted! »   Raymond taught theoretical electricity at Charliat school where he succeeded to Frederic Joliot-Curie. He was also in charge with the electronic laboratory operations at ESPCI.

  In 1937, Jean Perrin asked him to manage the exhibition rooms dedicated to natural and artificial radioactivity in The Science Museum (Palais de la découverte) of Paris, where he presented several original experiments. He presented the Mendeleïev table in 18 columns for the first time where normally it was represented in 8 columns. It is still presented nowadays with 18 columns. In 1939, he took measurements of cosmic rays near the equator and the pacific ocean. In 1948, he was in charge of the laboratory works in CEA (Commissariat à l'Energie Atomique) for the training of expert engineers in radioactivity. He often gave lectures in the Science Museum of Paris (Palais de la découverte) on the different aspects of contemporary physics, especially in radioactivity.

A great teacher   His students recognised unanimously his great qualities of teaching because he knew how to make the most difficult parts of physics easily understood. Most of his students became great scientists, some of whom joined the Science Academy (académie des sciences) such as Marguerite Perey, the first woman to be accepted into this famous institution. The ESPCI library keeps the text of one of his lectures that he made on December the 18th, 1944, during which he presented very clearly, relativity theory. Raymond died of a heart attack, in front of his students, chalk in hand, while teaching at Charliat in 1960. He was 54.

A group of his students measuring radioactivity along the "Grands Boulevards" in Paris

Brief Biography

- Note on the mass number of the stable isotops of the elements 43, 61, 85, 87. - Publications in the Journal of Physics and Radium on "stable and radioactive nuclei"
- Note on the trajectory of alpha rays in air – Actual knowledge on the constitution of matter -" General review of Electricity, of June the 24th , 1939, t. XLV, p. 833-844"
-On the number of ion pairs emitted by an alpha ray of polonium in the air " CRAS, t.193 (1931), p. 41-44 "
-Sur la courbe de Bragg des rayons H." CRAS 1935, p.1-3 "
-Sur le nombre de masse des isotopes stables des éléments 43, 61, 85 et 87 " CRAS, 1938 ", p.1477-1478
-Stable and radioactive nuclei " Journal de Physique et le Radium, 1938, n°10. p.419-427 "
-Fifty years of nuclear physics " Atomes Review, January 1951, n°58. p.12-15 "

Film making as a hobby

Raymond loved making 16 mm films as a hobby. The ESPCI library keeps one of his films taken at the school in 1945. Another one of his films is in Curie Museum. It was taken during the PhD viva of Marguerite Perey and Jean Teillac, who would become the high commissionaire at the atomic energy. In this film, one also recognises several famous people such as Madame Razet who was Madame Curie's loyal PA, Frédéric and Irène Joliot-Curie, André Debierne, Francis Perrin who was an eminent physicist like his father, Jean Perrin.

His mariage and children

Raymond married Jeannine Bret in 1935 who was working as the personal assistant of her father Georges Bret, CEO of Presses et Cisailles Bret factory in Normandy. Jeannine who was also an excellent pianist, dedicated her life to raise her four children born in 1936, 1941, 1944 and 1946. The youngest child called Patrice died at the age of two and half.
Frédéric Joliot Curie on his way with his wife to Stockholm to receive the Nobel Prize of chemistry, stopped over in Verneuil sur Avre, a small town in Normandy to be the witness of his friend and colleague Raymond at his wedding.

Surrounded by celebrities

Raymond Grégoire worked daily with people of very high reputation :

-André Debierne, who discovered Actinium,
-Fernand Holweck who improved with Maurice de Broglie and under the supervision of Paul Langevin, ultra sound scanning in water. He also improved the power of T.S.F devices. He was tortured to death by the Nazis in 1941.
-Irène-Joliot Curie, daughter of Pierre et Marie Curie, who received the Nobel prize for chemistry for the discovery of artificial radioactivity. She often asked Raymond to give lectures on her behalf in la Sorbonne whenever she was unavailable,
-Frédéric Joliot-Curie who received the exceptional honour of a national funeral,

-Madame Curie, Paul Langevin and Jean Perrin are three all resting in the Panthéon where are buried the famous people who marked the history and identity of France.