After World War I, Haber was remarkably successful in building up his institute, but in the anti-Jewish decrees of the Nazi regime made his position untenable. He retired a broken man, although at the time of his death he was on his way to investigate a possible senior research position in Rehovot in Palestine now Israel. On May 1, , Clara Immerwahr Haber sat down at her desk to write farewell letters to friends and family.
Part 3 of Our Chemical Landscape. This episode: how crop production has evolved in response to exploding global population growth. What happened before humans could produce fertilizer from the air itself, courtesy of the Haber-Bosch process? This week we look at how science has played a part in both destruction and preservation during times of war. What this suggests is that the formation of nitrogen on Earth and that of the meteorite may share a common origin — the protoplanetary disc, or the rotating disc of dense gas around a newly formed star [3].
The nitrogen in carlsbergite is mysterious in itself. Nitrogen is rarely found in crystals, and is more typically found as a gas. The energy from this occurrence raised the temperature of the gas, and melted the ice shells to form carlsbergite. A similar process may have occurred for the formation of the Earth. Harries and his team propose that the primordial ice prehistoric ice may have been dragged to the inner portions of the Solar System in the protoplanetary phase, during which ammonia was evaporated and bombarded by small bodies, forming carlsbergite-containing bodies.
As our planet is located in the inner Solar System, it is possible that the primordial ice may have accumulated on Earth during its formation [4]. While the origin of nitrogen remains a mystery, we can attempt to answer the question of why there is so much nitrogen in the atmosphere compared to other gases.
One theory is that when the Earth formed billions of years ago, gases readily mixed with other chemicals to form rocks or oceans. Additionally, nitrogen is a diatomic molecule and is unable to escape into space unlike lighter molecules such as hydrogen. Why is all of this important? That is exactly what Fritz Haber worked out how to do, driven in part by the promise of a lucrative contract from the chemical company BASF.
That company's engineer, Carl Bosch, then managed to replicate Haber's process on an industrial scale. Both men later won Nobel Prizes - controversially, in Haber's case, as many by then considered him a war criminal. You can listen online and find information about the programme's sources or subscribe to the programme podcast. The Haber-Bosch process is perhaps the most significant example of what economists call "technological substitution", where we seem to have reached some basic physical limit, then find a workaround.
For most of human history, if you wanted more food to support more people, then you needed more land. But the thing about land, as Mark Twain once joked, is that they are not making it any more. Haber and Bosch provided a substitute: instead of more land, make nitrogen fertiliser. First of all, you need natural gas as a source of hydrogen, the element to which nitrogen binds to form ammonia.
Then you need energy to generate extreme heat and pressure. Haber discovered that was necessary, with a catalyst, to break the bonds between air's nitrogen atoms and persuade them to bond with hydrogen instead. Imagine the heat of a wood-fired pizza oven, with the pressure you would experience 2km under the sea.
Compounds like nitrous oxide are powerful greenhouse gases. They also create acid rain, which makes soils more acidic, disrupting ecosystems, and threatening biodiversity. When nitrogen compounds run off into rivers, they likewise promote the growth of some organisms more than others. The results include ocean "dead zones", where blooms of algae near the surface block out sunlight and kill the fish below. The Haber-Bosch process is not the only cause of these problems, but it is a major one, and it is not going away.
Demand for fertiliser is projected to double in the coming century. In truth, scientists still do not fully understand the long-term impact on the environment of converting so much stable, inert nitrogen from the air into various other, highly reactive chemical compounds. Elizabeth Classical School, where he took an early interest in chemistry. After studying at the University of Berlin, he transferred to the University of Heidelberg in and studied under the famed German chemist Robert Bunsen.
Haber was ultimately appointed professor of physical chemistry and electrochemistry at the Karlshruhe Institute of Technology. When scientists warned that the world would not be able to produce enough food to feed its growing human population in the 20th century, he listened.
In , Haber married the brilliant chemist Clara Immerwahr, the first woman to receive a doctorate from Breslau University. Like Haber, she converted from Judaism to Christianity, and the couple settled in Karlsruhe. To keep her mind stimulated, she began collaborating with her husband on a textbook on the thermodynamics of gas, and tried to continue her own research, writing and speaking. Haber, unlike his friend Albert Einstein, was a German patriot, and he willingly became a uniformed consultant to the German War Office.
Finding an effective delivery system was challenging—one test resulted in the deaths of several German troops. Haber had a difficult time finding any German army commanders who would agree even to a test in the field. Privately, Haber said her statements amounted to treason.
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