Ştefan Procopiu

Ştefan Procopiu (January 19, 1890 - August 22, 1972) was a great Romanian physicist.

Ştefan Procopiu was born in Bârlad. He attended the Gheorghe Roşca Codreanu High School in Bârlad from 1901 to 1908, continuing his studies at the Faculty of Sciences of the "Alexandru Ioan Cuza" University of Iaşi from 1908 to 1912. After graduation he became assistant to professor Dragomir Hurmuzescu.

In 1919 he obtained a scholarship to continue his studies in Paris, attending courses of famous scientists, such as Gabriel Lippmann, Marie Curie, Paul Langevin, Aimé Cotton. On 5 March 1924, Procopiu obtained the title of doctor in physics with the thesis "On the electric birefringence of suspensions" presented to a commission including professor Aimé Cotton as coordinator and Charles Fabry and Henri Mouton as cross-examiners.

After his return to Romania in 1925, he was professor of the gravitation, heat and electricity department of the "Alexandru Ioan Cuza" University of Iaşi, replacing his former teacher Dragomir Hurmuzescu, who had retired. Procopiu coordinated the department until his retirement in 1962. At the same time he was appointed professor at the "Gheorghe Asachi" Polytechnic Institute of Iaşi. In 1939 Ştefan Procopiu published his treatise on "Electricity and Magnetism", followed in 1948 by his monography on “Thermodynamics”.

On June, 1948 he was appointed corresponding member of the Romanian Academy, being promoted to full membership on July 2, 1955. In 1964 he was awarded the Romanian State Prize. He was also decorated with the Order of Work (Ordinul Muncii), Order of the Star of Romania and the Order of Scientific Merit. Procopiu was also selected twice as member in the Commission for the award of the Nobel Prize.

Ştefan Procopiu was also deeply involved in the cultural life of the city of Iaşi. He was an active member of the Board of Directors of the National Theatre “Vasile Alecsandri” of Iaşi. Ştefan Procopiu died on August 22, 1972 in Iaşi age 82.


Scientific activity

Ştefan Procopiu started scientific research even before graduating. He continued this activity while he was assistant professor.

The magnetic moment of electrons
The first important paper by Ştefan Procopiu is "Determining the Molecular Magnetic Moment by M. Planck’s Quantum Theory". After studying Planck’s quantum theory and Langevin’s magnetism theory, established the magnetic moment and determined the physical constant of magnetic moment, named magneton. Ştefan Procopiu published his results two years before Niels Bohr made the same discovery independently. The magneton is now known as Bohr-Procopiu magneton. Continuing his studies, in 1954 he established a method for the experimental determination of the magneton, which he improved in 1963.

Other research before and during World War I
Ştefan Procopiu also worked on wireless communications and in 1913 published a paper on “Experimental Research on Wireless Telegraphy”. In 1916 he invented a device for locating and establishing the depth of bullets in the bodies of the wounded soldiers.

Longitudinal depolarization of light
In 1921, Procopiu discovered and analyzed in the Physics Laboratory of Sorbonne University a new optical phenomenon which consisted in the longitudinal depolarization of light by suspensions and colloids. In 1930, the occurence was designated as "Procopiu Phenomenon". Part of this reasearch was included in Procopiu's doctoral thesis.

Electromotive force of galvanic elements
Thus, in 1930, studying the Barkhausen effect, Ştefan Procopiu discovered a circular effect of magnetic discontinuity. In 1951, this effect was named "Procopiu Effect". This discovery had important applications in the development of the memory of computers.

Studies of the earth magnetism
Earth’s magnetism was a continuos concern of Stefan Procopiu, For 25 years he studied this phenomenon in Romania and developed the magnetic maps of the country. He also identified the magnetic anomaly located on the Iasi-Botoşani. In 1947, Procopiu identified a variation of the earth's magnetic field, with a periodicity of cca, 500 years, indicating that, starting 1932 earth’s magnetic moment increases from the Ecuator to the poles.

Henri Coanda

Henri Marie Coandă (June 7, 1886 – November 25, 1972) was a Romanian inventor, aerodynamics pioneer and the builder of world's first jet powered aircraft, the Coanda-1910. He gives his name to the Coandă effect.


Born in Bucharest, Coandă was the second child of a large family. His father was General Constantin Coandă, a mathematics professor at the National School of Bridges and Roads. Coandă studied at the Petrache Poenaru Communal School in Bucharest, then (1896) at the Saint Sava National College. After three years (1899), his father, who desired a military career for him, had him transfer to the Military Lycee in Iaşi. He graduated from that institution in 1903 with the rank of sergeant major, and he continued his studies at the School of Artillery, Military, and Naval Engineering in Bucharest. Sent with an artillery regiment to Germany (1904), he enrolled in the Technische Hochschule in Charlottenburg, Berlin.

Coandă graduated as an artillery officer, but he was more interested in the technical problems of flight. In 1905, he built a missile-aeroplane for the Romanian Army. He continued his studies (1907-1908) at the Montefiore Institute in Liège, Belgium, were he met Gianni Caproni. In 1908 Coandă returned to Romania to serve as an active officer in the Second Artillery Regiment. However, his inventor's spirit did not comport well with military discipline. He solicited and obtained permission to leave the army, after which he took advantage of his renewed freedom to take a long automobile trip to Isfahan, Teheran, and Tibet. Upon his return in 1909, he travelled to Paris, where he enrolled in the newly founded École Nationale Superieure d'Ingenieurs en Construction Aéronautique (now the École Nationale Supérieure de l'Aéronautique et de l'Espace, also known as SUPAERO). One year later (1910) he graduated at the head of the first class of aeronautical engineers.

With the support of engineer Gustave Eiffel and the mathematician, politician, and aeronautical pioneer Paul Painlevé, he began experimenting the aerodynamic techniques: one of this experiments was mounting a device on a train running at 90 km/h so he could analyse the aerodynamic behavior. Another experiment used a wind tunnel with smoke and an aerodynamical balance to profile wings to be used in designing aircraft. This later led to the discovery of the aerodynamic effect now known as the Coandă effect.

In 1910, using the workshop of Gianni Caproni, he designed, built and piloted the first 'thermojet' powered aircraft, known as the Coandă-1910, which he demonstrated publicly at the second International Aeronautic Salon in Paris. The powerplant used a 4-cylinder piston engine to power a compressor, which fed two burners for thrust, instead of using a propeller. It would be nearly 30 years until the next thermojet powered aircraft, the Caproni Campini N1. At the airport of Issy-les-Moulineaux near Paris, Coandă lost control of the jet plane, which went off of the runway and caught fire. Fortunately, he escaped with just a good scare and some minor injuries to his face and hands. Around that time, Coandă abandoned his experiments due to a lack of interest and support on the part of the public and of scientific and engineering institutions.


Between 1911 and 1914, he worked as technical director of Bristol Aeroplane Company in the United Kingdom, where he designed several aeroplanes known as Bristol-Coanda aeroplanes. In 1912 one of these planes won the first prize at the International Military Aviation Contest in the UK. In 1915, he went again to France where, working during World War I for Delaunay-Belleville in Saint-Denis, he designed and built three different models of propeller aeroplane, including the Coandă-1916, with two propellers mounted close to the tail; this design was to be reprised in the "Caravelle" transport aeroplane, for which Coandă was a technical consultant.

In the years between the wars, he continued traveling and inventing; inventions included the first jet-powered sleigh, and the first de luxe aerodynamic railroad train. In 1934 he was granted a French patent related to the Coandă Effect. In 1935, he used the same principle as the basis for a hovercraft called "Aerodina Lenticulara", which was very similar in shape to the flying saucers later developed by Avro Canada before being bought by the United States Air Force and becoming a classified project.

In 1969 he returned to spend his last days in his native Romania, where he served as director of the Institute for Scientific and Technical Creation (INCREST) and in 1971 reorganized, along with professor Elie Carafoli, the Department of Aeronautical Engineering of the Polytechnic University of Bucharest, spinning it off from the Department of Mechanical Engineering.

Bears' Cave

Bears' Cave (Romanian: Peştera Urşilor), was discovered in 1975, by "Speodava", an amateur speleologists group, and is considered to be an interesting site-seeing location. The cave is located at the outskirts of Chişcău Village, in Bihor County, Romania.


Peştera Urşilor means Bears' Cave. The cave was named so, as numerous Cave bears (Ursus spelaeus) were found in this cave. The cave was visited by these large animals more than 15.000 years ago. But one day, a rock slide closed the entrance while more than 140 bears were still in the cave. Becoming hungry, the bears killed one another until all were dead. This story is told by their remains, tons of bear bones covering the floor of large parts of the cave with the marks of bear teeth.


Bears' Cave dwells also an extraordinary range of stalagmite and stalactite formations varying in size and forms. The cave entrance - which is situated at 482 m altitude - is by the tourist pavilion. Bears' Cave is 1 km in length. It is disposed on two-overlapped levels: one which is larger, being 488 m in length and fitted out for tourist reasons, and an interior level, temporarily active, being 521 m in length, which is used for scientific reservation.


Bears' Cave is the only modern show cave in Romania, with paved paths, banisters, and electric light. This was a sort of experiment, to test if show caves are interesting for tourists. But although this experiment worked very well - the cave attracts more than 200.000 visitors every year - it is still the only well developed show cave in Romania.

Grigore Antipa

He was the first Romanian to reach the North Pole.

Grigore Antipa (27 November 1867, Botoşani – 9 March 1944 Bucharest) was a Romanian Darwinist biologist who studied the fauna of the Danube Delta and the Black Sea. Between 1892 and 1944 he was the director of the Bucharest Natural History Museum, which now bears his name.

He was the most appreciated disciple from all Ernst Haeckel’s students. In the same time, he was been the closest man of Ernst
Haeckel. Grigore Antipa gains Ernst Haeckel’s sympathy through his intelligence and communication skills, through his work abilities and abnegation. Moreover, Grigore Antipa has worked together with Ernst Haeckel during a long period of time. They were been into the same team of few expeditions around the world. After that, Grigore Antipa was been sent to work to different maritime stations from Villefranche – sur Mer, Oslo, Bergen, Stockholm, Naples and Helgoland. During this period, he worked into Haeckel’s Laboratory together with W. Kükenthal and A. Lang (the biggest zoologists from his time). Those were the times when Grigore Antipa worked and study, those were his friends and teachers. Haeckel himself described Grigore Antipa as the most brilliant from all of his students. Only three of his PhD students passed the final exams with “Summa Cum Laude”: Grigore Antipa, A. Walter and Hans Driesch.

Additionally, Antipa was a specialist in zoology, ichthyology, ecology and oceanography, one of the creators of the modern museology, initiator of the dioramas, and was a university professor. He was elected as member of the Romanian Academy in 1910 and was also a member of several foreign academies. He founded a school of hydrobiology and ichthyology in Romania.

Emil Racoviţă

Emil Racoviţă (November 15, 1868 – November 17, 1947) was a Romanian biologist, zoologist, speleologist and explorer of Antarctica. He is worldwide known as the founder of Biospeology.

Emil Racoviţă was born in Iaşi (Moldavia) to the Racoviţă family of Moldavian boyars (noblemen), whose ancestors had ascended the throne of the country during the 18th century. He started his education in Iaşi, where he had Ion Creangă as a teacher, and continued his secondary education at the "Institutele Unite" high school, taking his baccalauréat in 1886. He then studied law at the University of Paris, obtaining a law degree in 1889. But he did not pursue a law career, instead turning to the natural sciences. His mentor was zoologist and biologist Henri de Lacaze-Duthiers, a professor at the Sorbonne and at the Muséum national d'histoire naturelle. Racoviţă earned a B.S. degree in 1891, and a Ph.D. degree in 1896.


As a promising young scientist, Racoviţă was selected to be part of an international team that started out on a research expedition to Antarctica, aboard the ship Belgica. On 16 August 1897, under the aegis of the Royal Society of Geography in Brussels, Belgium, the Belgica, left the port of Antwerp, setting sail for the South. It was the ship that gave its name to the whole expedition. The 19 members of the team were of various nationalities, a rare thing for that time. The first mate of the vessel was Roald Amundsen (who was to conquer the South Pole in 1911). The team left the deck of the ship 22 times, in order to collect scientific data, to make investigations and experiments. Racoviţă was the first researcher to collect botanical and zoological samples from areas beyond the Antarctic Circle.
Belgica made the first daily meteorological recordings and measurements in Antarctica, every hour, for a whole year. The scientists also collected information on oceanic currents and terrestrial magnetism, with as many as 10 volumes of scientific conclusions being published at the end of the expedition, which was considered a success. Belgica returned to Europe in 1899.
Racoviţă’s diary, published in 1899, makes mention of the difficulties that the team-members had to endure. The results of his research were published in 1900, under the title La vie des animaux et des plantes dans l’Antarctique ("The life of animals and plants in Antarctica"). A year after his return, Racoviţă was appointed director of the Banyuls-sur-Mer resort and editor of the review Archives de zoologie expérimentale et générale.


Emil Racoviţă continued his research, contributing to speleology and exploring over 1,400 caves in France, Spain, Algeria, Italy, and Slovenia. He is considered to be, together with René Jeannel, one of the founders of biospeleology. In 1919, Racoviţă became head of the Biology Department at the Upper Dacia University (now the Babeş-Bolyai University) in Cluj. He founded the world's first Speleological Institute here. In 1920, he became a member of the Romanian Academy, and remained a major figure of scientific life in Romania until his death.

In 2006, the first Romanian Antarctic exploration station was named Law-Racoviţă.

The Scărişoara Cave

Peştera Scărişoara is one of the biggest ice caves in the Romanian part of Carpathians, more specifically in the Apuseni Mountains, and shelter a glacier (with an area of almost 5550 square meters, a volume varying between 40000 and 75000 cubic meters, and 26 meters high).


The exact date when the cave was discovered is unknown, but is mentioned in 1863 by the German Adolf Schmidl, who made some observations and the first map. Emil Racoviţă mentioned this cave and how it was born in his work Speleology, which appeared in 1927. According to the scientist Emil Pop, the ice cave was born 3500 years ago, during the glaciations, when these mountains were covered by snow and ice.

The cave is located at an altitude of 1165 metres above sea level. The cave is 105 m deep and 720 m long, the entrance shaft (50 m in diameter and 48 m in depth) giving access through metal stairs to a large chamber, (108 m long, 78 m wide) - The Big Hall. From this point three openings lead to The Church (in front, with over 100 stalagmites), Great Reservation, Coman Gallery (left) and Little Reservation (right). The part that tourists can visit includes the entrance shaft, The Big Hall and The Church, the other chambers being reserved for scientists (and can be visited only with the agreement of the Speological Institute of Cluj-Napoca. The temperature is up to +1°C in the summer and down to -7°C in the winter. In the part for tourists the average temperature is around 0°C.


Bats live in the ice cave, as do small bugs (2-3 mm long) called Pholeuon prozerpinae glaciale. In the Big Reservation a Rupicapra skeleton was discovered.

The inventor of sonicity

George "Gogu" Constantinescu (1881 - 1965)
Romanian scientist, engineer and inventor. During his career, he registered over 130 inventions. He is the creator of the Theory of Sonics, a new branch of continuum mechanics, in which he described the transmission of mechanical energy through vibrations. He discovered that these phenomena had their analogies not only with the properties of sound waves and the laws of harmony, but also with AC electrical circuits. Prototypes of rock drills working on the percussion system and polyphase rotary systems were already being demonstrated by 1913.

Born in Craiova and settled in the United Kingdom from 1912, Constantinescu was an honorary member of the Romanian Academy.

Among his inventions are a mechanical torque converter, a sonic engine and a hydraulic machine-gun synchronizer (or interrupter gear) - which allowed airplane-mounted-guns to shoot between the spinning blades of the propeller). The Constantinesco synchronization gear (or "CC" gear) was first used operationally on the D.H.4s of No. 55 squadron R.F.C. from March 1917, during World War I, and rapidly became standard equipment, replacing a variety of mechanical gears. It continued to be used by the Royal Air Force until World War II - the Gloster Gladiator being the last British fighter to be equipped with "CC" gear. After WWI Constantinesco had an idea for a low cost "peoples' car" which would travel 100 km miles on 2.5 litres of petrol at the most commonly used road speeds of 50 to 70 km per hour. He considered that this performance and low cost could be achieved by using a cheap 500 cc single cylinder two stroke air cooled engine together with his unique Torque Converter transmission which would eliminate the conventional gear box and clutch. Experience in this field could then be applied to the transmission of much higher powers in heavy vehicles such as railway locomotives. The car was displayed at London and Paris Motor shows in 1925 and attracted more than one hundred articles in world press. General Motors acquired a licence to build the car in 1926. Unfortunately development of the transmission stopped as there was no need for infinitely variable transmission while car engines were large (4-5 litres) and had plenty of torque. His torque converter was however used in self propelling railcars.


He was the designer of the Constantinesco, a French-manufactured car, and of the Constanţa Mosque (a project completed by the architect Victor Ştefănescu).