See also: Arrhenius
Svante August Arrhenius (born with Wijk the February 19th 1859 - died with Stockholm October 2nd 1927) was a chemist Swedish which was pioneer in many fields.
- His/her son Olof Vilhelm Arrhenius was a chemist considered in Sweden.
It was married twice, during 2 years (of 1894 to 1896) in Sofia Rudbeck (one as of its former students), which gave him a son…
puis in 1905 in Maria Johansson (who gave him two girls and a boy).
En 1883, it publishes a report of 150 pages entitled " Research on the galvanic conductibility of the électrolytes" who announces his theory of the dissociation, which enables him to obtain his diploma of doctorate in 1884. Its defense of doctorate does not impress at all its professors (of which Per Teodor Cleve) which grants its doctorate to him, but with the lowest possible note (This same work will be worth the Nobel Prize of chemistry later to him).
Arrhenius sent copies of its thesis to various European scientists who worked with new approaches of physical chemistry, like Rudolf Clausius, Wilhelm Ostwald, and J.H. van 'T Hoff. The latter were impressed much more than the professors of Arrhenius and W. Ostwald even came in Uppsala to meet Arrhenius to persuade it to join its research team, invitation that Arrhenius declined, preferring to remain Sweden, probably because it had a station with Upsala, and also to deal with his/her father who was seriously sick (it will die in 1885).
En 1886, E. Edlund obtains Swedish Academy of Science that it finances a study trip to him in Europe, which enables him to spend 4 years in the laboratories of Ostwald to Riga, of Kohlrausch with Würzburg, of Boltzmann with Graz and Van' T Hoff to Amsterdam.
Il refuses a station in Germany to remain in Sweden where it will return to work with the royal Institut of technology of Stockholm , as professor, then as vice-chancellor. In 1891, it is named lecturer to the “Stockholms Högskola” (today Université of Stockholm), being promoted professor of physics (with much of opposition of its pars) in 1895, and vice-chancellor in 1896.
Arrhenius becomes then chemistry teacher with the Université of Stockholm in 1895. It is accepted with the Swedish Academy of Science in 1901. Its Nobel Prize (1903) increases the recognition of its pars, and in 1905, it is named with the direction of the “physical Nobel Institute of chemistry” , especially created for him.
Its name remained attached to the Law of Arrhenius which gives an account of the variation speed of the chemical reactions with the temperature and which he formulated in 1889 in his article entitled " One the velocity off the inversion off duck sugar by acids" .
In 1884, like development of its thery on the ions, Arrhenius proposes as a definition of the acids and bases, estimating as the acid subtances produce hydrogen ions in solution, and that the bases produce ions hydroxide in solution.
In 1889, Arrhenius also postulates that the degree of dissociation increases with the dilution of the solution, after having observed the chemical reactions gain of speed according to the temperature of the solution, and this, in a way proportional to the concentration of the activated molecules. It draws a law from it from variation of the constant speed of a chemical reaction according to the temperature.
Its theory is initially badly received by the scientific community, which regards it as false. It will be accepted however little by little for finally forming one of the angular stones of physical chemistry and electrochemistry modern.
In 1900, Knut Ångström, which published the first infra-red modern spectrum of CO2 (with two absorption bands) critical the high values of absorption calculated by Arrhenius for CO2. Arrhenius answers him highly in 1901, rejecting criticism. Two years afterwards, it briefly tackles the subject in a technical work (Lehrbuch DER kosmischen Physik, 1903). Three years later, it publishes a long text of vulgarisaton, cosmogonic formulation presenting its vision of the appearance of the ground and the life on ground “ Världarnas utveckling ” (1906) which will be translated the following year into German under the title Das Werden der Welten , 1907), then in English (Worlds in the Making, the evolution off the universe, New York, London, Harper, 1908). In this text, it suggests that the human emissions of CO2 should be sufficient to secure the world of a new glacial era. It estimates at it that a hotter ground would be necessary to nourish the human population which increases quickly. It very clearly presents a hotter world like a positive change. As from this moment, its theory on the greenhouse effect gains attention.
Néanmoins, until the years 1960, the majority of the scientists will consider this greenhouse effect as plausibly being able to influence the glacial cycles only Milutin Milankovitch modelled in a very satisfactory way on the basis of the changes of orbit of the ground. The theory of Milankovitch indeed proved to be strongly predictive with wrong way, to explain the glaciations which touched the ground since several million years. This orbital forcing is allowed nowadays like first climatic factor, CO2 nevertheless being recognized as element amplifcator (buckles positive feedback).
Arrhenius estimated - there is more than 100 years - that a reduction by half of atmospheric CO2 would decrease the temperatures average of the surface of the sphere from 4 to 5 ° C, whereas a doubling of CO2 would involve a rise in the temperature of 5 even 6 degrees Celsius (or 7 to 11 degrees Fahrenheit).
The recent estimates (2007) of the GIEC gives a value (sensitivity of the climate) ranging between 2 and 4,5 degrees. It is remarkable that Arrhenius calculated an estimate so close to that of the GIEC. Arrhenius expected so that the double CO2 rate, but the rate/rhythm of its time, i.e. in approximately 3000 years according to its calculations. With the current rhythm, that will take one century only according to calculations of the GIEC.
Starting from a botanical study of the species which pushed in its environment (fjord), Arrhenius proposed the following approximate formula, where when in a given biogeographic surface a surface grows there by owe , the number of species () that one finds there rises while becoming , according to the formula:
, being a constant to be adjusted, the constant increasing when the number of species () believes slowly, and decreasing when this number of species increases quickly.
Arrhenius proposed another formulation: . S (for species) representing the number of species, has (for Area) representing surface, and Z being constants to be adjusted.
These formulas initially were very criticized because apparently too simplifying, in particular because it do not take account length or the nature of the écotone, or of the factor of altitude or other factors related to the supposed extreme mediums very impacting for biological diversity. Beumée and Reitz strongly criticized it, but tested on plant species, it was predictive - in some limiting - for example in Sweden, Suisse and Finland, including for associations in mosaics. more recently it was predictive rate of endemism of they Malaysian (Java, Sulawesi, Sumatra, Borneo, and New Guinea); The more these islands have a large surface, the more the rate of endemism is high there and the more numerous the Taxon S (Espèce S and families) there are, on surface and equivalent biogeographic conditions (Knowing that to equivalent cartograhiée surface, a island (or a given surface) with strong relief is equivalent to a real bioproductive surface much larger than an island or zone which would be punt. In this case, the addition of data on the Pluviométrie in the models did not modify this relation. More complex calculations can be made on the écotones (Fractale S) and surfaces it developed underwater mediums for example (a coral Récif, the continental Shelf rock or sandy.), but it is admitted today that there exists a relation between real surface of a medium and diversity of the species which live it.
This relation between surface and biological diversity has taken a new importance for the 19th century, time or ecological fragmentation became important, crescent in an exponential way at the XXème century with the passing and the fragmentation of the natural environments to the profit of the development of the networks fortements with a grid of cities and transport, and with the massive use of Biocide S (Pesticide S) in Agriculture.
On did not speak at the 19th century about Biodiversité, but the ecologists speak still today about model of Arrhenius , or equation of Arrhenius (which for example was used to make a calculation estimating that to be effective, a natural reserve should in Zealand News cover a minimal surface of 10 km X 10 km
He thinks finally of a universal language and to create it a modification of the English language proposes.
At the end of its life, he writes school handbooks and books of popularization, while trying to stress the need for continuing work on the subjects which he worked.
In September 1927, he falls ill (an acute attack of catarrhe intestinal) and dies on October 2nd.
Il is buried in Uppsala.
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