Emil Chistoforovich Lenz, whose fundamental contribution to electrodynamics and Russian geography, was born on February 24, 1804 in the town of Dorpat (which is now Estonian Tartu, and long ago the town belonged to ancient Rus’ and was called Yuriev).

In 1820 Emil Lenz graduated from the gymnasium and entered the University of Dorpat. Lenz’s independent scientific activity started in 1823, when he joined a round-the-world expedition on the “Predpriyatie” sloop as a physicist, recommended by university professors. Fast thought of young scientists resulted in development of unique equipment for deep oceanographic observations – a depth indicator hoist and water sampler. During the trip Lenz performed oceanographic, meteorological and geophysical observations in Atlantic, Indian and Pacific oceans. In 1827 the scientist summarized his data and reported them to the Academy of Sciences in 1828. This enormous work brought him a title of associate professor of Academy of Sciences. In 1829 and 1830 Emil Lenz perform geophysical research in Russian south – the scientists took part in the first ever climb of Mount Elbrus and measured its height by means of barometric method. Later Lenz used the same technique for discovering that Caspian sea level was lower than Black sea level. Same year the researcher performed gravitational and magnetic measurements and, after returning to Saint Petersburg, reported the results in 1832 and 1836.

 

 

Lenz’s wonderful talents were deep understanding of physical processes and ability to discover physical patterns. Between 1831 and 1836 Emil Lenz studied magnetism, and in 1833 his studies resulted in the Lenz law, which gives the direction of the induced electromotive force and current resulting from electromagnetic induction. The law provides a physical interpretation of the choice of sign in Faraday's law of induction, indicating that the induced electromotive force and the change in flux have opposite signs. In 1834 Lenz was elected academician in physics. In 1836 the physicist was invited to Saint Petersburg and headed the department of physics and physical geography. Lenz worked a lot – he taught, performed research, wrote books. His students later became eminent researchers.

In 1842 Lenz discovered the law, expressing the relationship between the heat generated by the current flowing through a conductor, which was independently discovered by James Joule, thus named “the Joule-Lenz law”. Lenz developed calculation technique for electric magnets and found “armature reaction” in electric machines.The scientist also studied relationship between metallic resistance and temperature. Emil Lenz did a lot for Russian geography – he was among first seven members of the Board of Russian Geographic Society, established in 1845. For the rest of his life eminent scientist worked for the society.

 

 

In 1851 his fundamental work “Physical Geography” came off the press. In this book Lenz discussed structure of the Earth’s crust, origin and movements of crust’s rocks, and showed that Earth’s crust was in permanent change, thus affecting relief of the continents. Lenz noticed three major factors, causing permanent changes of the ground: volcanic forces, water and atmosphere and organic organisms. The scientist discovered important patterns of day and annual changes of temperature and air pressure, wind activity, water evaporation, water vapour condensation and cloud formation, electric and optical effects of the atmosphere and etc. Lenz anticipated Nansen’s discovery of warm waters deep in the Arctic Ocean. Studies of water salinity led to an interesting effect – salinity showed almost no change with depth and decreased together with latitude, however, most saline waters could be found in tropical areas due to extremely high evaporation. Water density appeared to rise with latitude and depth due to temperature decrease in same directions. Lenz discovered circulation of surface waters from tropics to high latitudes and vice versa for deep waters.

It was Lenz, who showed great effect of solar radiation on all processes, taking place in atmosphere – one of central aspects of modern climatology. Lenz concluded that major part of solar radiation was absorbed by the World Ocean, and its energy went to evaporation, causing water circulation, thus being essential for world climate formation.

Great scientist died on February 10, 1865, reportedly due to a stroke.

Source: Organic Impacts

Kizilova Anna