Arrhenius's near-failed thesis on salty water later won a Nobel Prize
Uppsala's professors were so unimpressed by Svante Arrhenius's 1884 dissertation that they initially graded it fourth class. Its central idea, that dissolved salts split into charged ions even without electric current, earned him the 1903 Nobel Prize in Chemistry, making him the first Swede so honoured. Twelve years after the thesis, he calculated how carbon dioxide warms Earth.
Born near Uppsala in 1859, the son of a university land surveyor, he taught himself to read at three and picked up arithmetic by watching his father tally accounts. He entered cathedral school at eight and left in 1876 as its youngest and most able graduate. Dissatisfied with Uppsala's instructors, he moved in 1881 to study electrolyte conductivity in Stockholm. His 150-page dissertation contained 56 theses, most still accepted. Michael Faraday had believed ions formed only during electrolysis; Arrhenius argued salt solutions contained them anyway, so reactions in solution were reactions between ions. After Uppsala's defence the grade was lifted only to third class.
Foreign pioneers of physical chemistry reacted differently. Wilhelm Ostwald travelled to Uppsala to recruit him, and a travel grant later let him work with Ostwald, Ludwig Boltzmann and Jacobus van 't Hoff. While at Leipzig in 1889 he introduced activation energy, the barrier molecules must clear before reacting, and the equation bearing his name links that barrier to reaction speed. He also defined acids as substances releasing hydrogen ions and bases as ones releasing hydroxide ions.
In 1896, trying to explain ice ages, he used infrared observations of the Moon to estimate how much heat carbon dioxide and water vapour trap. His rule held that if carbon dioxide rises geometrically, temperature climbs almost arithmetically, and he concluded that fuel burning could warm the planet. Decades later, Charles David Keeling's measurements in the 1960s confirmed atmospheric carbon dioxide was rising.
His curiosity roamed widely: he proposed that spores might carry life between planets, an idea now called panspermia, attributed auroras and comet tails to radiation pressure, and lectured at Berkeley in 1904 on toxins and antitoxins. On Nobel committees he pushed prizes toward friends and tried to block rivals such as Mendeleev. He directed the Nobel Institute for Physical Research from 1905 until 1927, the year he died.
Source: Svante Arrhenius
