The presentation of the confluence of factors has often included a modern perspective. Here I will touch on some consequences of Haber’s breakthrough before reviewing aspects important to the next two parts of the book.

First, the current environmental and ecological repercussions of the scientific and technological breakthrough for feeding the world’s population and the manufacturing of explosives were already appearing in the first half of the twentieth century as the possibility to mass-produce fixed nitrogen in Haber-Bosch (and other) facilities spread across the planet (Travis 2018, chapters 12–15). Although we can now produce enough food to feed the world, the nitrogen shortage has become an excess that threatens water, air, and soil quality as well as entire ecosystems and biodiversity (Ertl and Soentgen 2015; Sutton et al. 2011c). Our arable land is saturated with nitrates, which are transported through runoff into environments, especially coastal regions and oceans, not intended to receive such chemical surpluses. The resulting imbalance impacts life in these areas, often adversely through eutrophication and hypoxia. It is here, at the interface of the terrestrial and marine nitrogen cycles that the dynamic is most complex. Total synthetic fixed nitrogen production is now at the same order of magnitude as natural production either on land or in the ocean (∼ 102 Tg/year). In combination with natural conditions, it has contributed to changing quantities of biomass and species composition (Voss et al. 2011).

The effects are not only found in the natural environment, but also in our urban centers and in fundamental changes in our society. The production of food is no longer the mere collection of the annual influx of solar energy, it now consumes other sources of power as well. In achieving this change, we have used technical innovation along with energy and raw materials from fossil fuels to boost a large input mechanism into the nitrogen cycle: fertilizer. Advances underlying modern mobility have also resulted in new input mechanisms via the internal combustion engine. Driving and other forms of combustion (which we in the modern world have strategically hidden out of sight to the extent that we forget about their existence) have not only led to smog in our cities but also to noticeable growth of lichen and moss along heavily used traffic routes (Soentgen and Cyrys 2015).Footnote 1 The nitrogen cycle has not only been opened; man-made factors have bound the carbon and nitrogen cycles together in an unprecedented way. Hydrogen for the Haber-Bosch process is obtained by stripping it from hydrocarbons, and the residual nitrogen runoff effects the growth of biomass, linking it to levels of carbon, phosphorous, and other elements in biogeochemical cycles (Gruber and Galloway 2008; Sterner et al. 2008). Among other consequences, the effect of certain levels of greenhouse gases and the future of our climate have become difficult to assess, making fixed-nitrogen production one of the most critical developments of our time.

This rather dire prognosis is not meant to support the conclusion that the consequences of synthetic fixed nitrogen are inordinately or inherently negative, but rather to remind us of the risks of their extensive use. We have already changed and damaged our natural environment with the output from the power-hungry Haber-Bosch process, which consumes 1–2% of the world’s total energy production. We need to find a better way to meet our needs. Possible solutions include forms of fertilizer that release fixed nitrogen in more efficient ways, improvements in existing technologies, and new methods of synthesis (Douat et al. 2016; Erisman et al. 2008; Hawtof et al. 2019; Patil et al. 2018; Rafiqul et al. 2008; Schrock 2006; Wissemeier 2015). A provocative detail of the latter is that they include plasma, or electric arc technology, which was originally the favored production method of Fritz Haber and most of the physical chemists at the turn of twentieth century (as we will see in Part II). We may, therefore, still come full circle, but this time we will be equipped with a wider range of options than every before. Technology alone will not solve all our problems, however. An integrated approach is essential, which spans science, technology, industry, politics, and of special importance, voices from the public sphere (Bull et al. 2011; BUND 2012; Reay et al. 2011; Sutton et al. 2011a).

While the environmental impact is vast, it was certainly not one of Haber’s objectives, nor should we blame him for it. Scientists do not, without further involvement, bare responsibility for the technological repercussions of their discoveries. However, moral questions do crop up with respect to another aspect of ammonia synthesis.

The production of fertilizer and the manufacture of explosives in Europe in the first decade of the twentieth century was heavily dependent on nitrate imports. As the First World War loomed, the possibility, and eventual actuality, of blocked maritime trading routes caused many in Germany to reconsider the general security of the country and led to massive investment in science and technology to obviate possible shortfalls. Beyond a synthetic source of nitrates, much of Haber’s pre-war work investigating gas reactions also leant itself to another possibility for the war effort: the development of poison gas. This new type of weapon promised not only a solution to munitions shortages but also enabled a new strategy of warfare (Haber 1971, pp. 208–217), (Friedrich and James 2017a; Szöllösi-Janze 2017). Many scientists, some very prominent, became involved in research and deployment of chemical weapons, but it was Haber who notoriously proposed the use of chlorine gas. He was so central to the effort that one scientist even defined the product of gas concentration and exposure time before a subject’s death as the “Haber Constant.” After initial lackluster tests and attempted deployment in the beginning of 1915, chlorine gas was used at Ypres on April 22 against French and British troops; the cloud of poisonous gas spread over the battle field, killing hundreds and injuring thousands. Within months Haber, already heavily involved in the German mobilization effort, redirected research at his Kaiser Wilhelm Institute for Physical Chemistry and Electrochemistry toward gas warfare. Besides chlorine, research was conducted on mustard gas, phosgene, and other aggressive compounds as well as gas masks and respirators. Both offensive and defensive solutions were considered as the Entente Powers began to develop their own chemical weapons. Haber’s institute grew rapidly in size. Not only personnel, but also the number of buildings and research locations on-site, in Berlin, and around Germany expanded. Haber relished his role and influence as one of the earliest “intermediary experts” as the convergence of state, military, economy, and science began to transform research into something like what we recognize today as big science. This development also continued to broaden the scope of the professional chemist which had started in the early nineteenth century (Fig. 8.1).

Fig. 8.1
figure 1

Haber, second from left, inspecting gas munitions during the First World War. Source: Archive of the Max Planck Society, Berlin-Dahlem, Jaenicke Collection, Picture Number IX/9

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The use of poisonous gas (by belligerent parties on both sides) went against international law and garnered for Haber, in addition to general moral critique, accusations of war crimes. While Haber had insisted on the “humane” nature of chemical weapons to shorten the length of the war and limit the number of deaths, this moral stance apparently counted only in the case of German victory. He also saw it as a way to weed out unfit soldiers. Later, Haber admitted no new science had resulted from chemical weapons research (although technological progress was made) but never regretted his involvement in chemical warfare–blame for wrongdoing was ultimately placed at the feet of others. During the war years, Haber committed his entire scientific effort to this work and continued it into the interwar period in clandestine fashion under the guise of extermination of vermin and pests (the claim was not wholly without legitimacy). During this research, scientists determined methods for safely working with cyanides, one of which was called Zyklon A. Unforeseen by Haber, it’s successor, Zyklon B, was later used against civilian populations. Research on poison gas, much like ammonia synthesis, shows the double-edged sword embodied by scientific research, and in many ways by the person of Fritz Haber (2019).

Observing the entirety of these events, it is clear that pure science and technological breakthroughs lead to changes in systems of knowledge, means, and resources. Here, I have described one pathway leading to success (along with the corresponding consequences) that illuminates how a collection of phenomena spanning 150 years can be unified into a single framework. It was an arduous development and represents the main barrier to scientific progress: the inherently slow pace of interlinking of knowledge and processes, and the “scientification” of basic principles in a new field. While it may not have been the only possibility, I have tried to elucidate the basic pathway of advancement that, in this case, led to the final discovery.

The term “discovery” returns us to the discussion of a flow of a events, demarcated in a deliberate and informative way. Which set of events contains the knowledge that is awarded the label “discovery”? The declaration of when something was known is tied to who discovered it and which supporting evidence was used. It is also very sensitive to how the discovery itself is defined. The who has also been discussed here. Was it Haber’s discovery? What were the precise roles of others? If we consider energy science and thermodynamics, the extent of those who made contributions becomes clear only in hindsight. They themselves did not always understand what they were working towards and some could not have envisioned the final outcome. We can only understand their work in historical context and through broad engagement with their research; we now consider the advances in energy science to be the work of many men over several decades (Kuhn 1959). Similarly, Nernst, in formulating the third law of thermodynamics, at first saw only the description of a set of experimental observations that served as a mathematical tool—a first application to a concrete system. Full physical insight came later, due also to the contributions of others. Determining when these advances were made is not always straightforward.

The case of ammonia synthesis from the elements is more clear cut, though not without ambiguity. Historically, the scientific breakthrough is seen as the work of two men, Haber and Nernst. They worked simultaneously with a clear goal of the scientific results they wished to achieve and we know exactly at which point Haber was successful on a laboratory scale and when industrial upscaling took place. Interestingly, Haber’s achievement was possible without an understanding of how a catalyst functions, and without catalyst material and precursor gases whose purity would satisfy our current notion of “laboratory grade.” This success illustrates a certain facet of basic scientific research: fundamental principles need not be completely understood at the outset for important results to be obtained.Footnote 2 This reality is especially important if we consider expectations of science found in the general public. The scientific endeavor is not an infallible activity of ultimate precision, it is an art form pursued by human beings, subjected to many of the same pitfalls that beset other disciplines. Guesswork and courage are absolutely necessary.

While we can learn lessons from past successes and are now more adept at “scientification” than ever before, the following holds true: “a scientific discovery must fit the times, or the time must be ripe (Kuhn 1959).” This notion seems to be a hallmark of a scientific breakthrough. It is simply expressed, but the ability to induce the right time and correct circumstances has so far eluded us.

We are left with an important consideration. What is the best way in today’s scientific arena to move from initial identification of a phenomenon to fundamental understanding and finally to technical implementation? How do we take Hermann von Helmholtz’ advice (von Helmholtz 1950),

Whoever searches for immediate practical benefit through the study of science can be fairly certain that he will search in vain.Footnote 3

and still later arrive at a proclamation similar to Henry Perkin after his discovery of aniline purple?

…the process which is now employed for [the preparation of aniline] is a remarkable instance of the manner in which abstract scientific research becomes in the course of time of the most important practical service.

It is a transition that is constantly taking place.

In today’s environment of increasingly complex measurement facilities and material systems, our strategy is to bring the necessary conditions into close proximity to induce a reaction. The result is something I refer to as The Haze. In the case of Haber, we see how it can occur spontaneously over decades or centuries as is it thickens to a critical density out of which scientific discovery may emerge. Can we accelerate the process?

The field of chemistry, for example, can be helpful in many of the current challenges we face—either on its own or in interdisciplinary approaches with any number of other fields. These include biomedical research, climate, access to potable water, energy generation, electromobility, material recovery/separation, and recycling, or even the design of entire recycling (or other material) systems (Bender et al. 2018). Many of these will be indispensable in any kind of sustainable economy. However, the last century of research funding combined with the nature of research itself makes it difficult to know if and when research should be directed—or if it must be left completely unmanaged. This uncertainty has been exacerbated by industry’s increased focus on short term gain rather than long term ventures and stability; chemical research is now often seen as a cost rather than an investment, as economic benefits are more in focus than the advancement of social interests (Whitesides 2015).

However, some of the best examples of economic and technological success in the last twenty years are based on novel work and management models which incentivize further focus on the Haze in scientific research. What is often referred to as the “Silicon Valley Model” shows the limits of (micro-) managed, large groups tackling tasks set up as well-defined problems. In many cases, a dynamic, flexible, and decentralized approach to problem solving is more conducive to fostering effective innovation. Swift reactions to the changing realities of the tech market and a corresponding development of new products have resulted in short term planning, leading to successful long term corporate strategies (Steiber and Alnge 2016, pp. 143–155). Another example, the pharmaceutical industry, exhibited enormous growth in the 1990s due to an environment of compelled innovation provided through patents of fixed-duration and the appearance thereafter of generic drugs. However, this model has not maintained its success despite sharing many of the same approaches with Silicon Valley (Franz 2017).

When applied to basic research, the Haze offers just this kind of flexibility to find solutions to problems using independent and novel approaches. The means and personnel are brought together to develop as they may in a process that has always happened in research due to the previously mentioned difficulty of directing research efficiently (nothing can replace the creativity of the proverbial discussion at the water fountain). However, we can find ways to improve efficacy. One strategy would be to rethink the approach of problem solving and whether a well-defined problem is actually needed before a solution can be found (von Hippel and von Krogh 2017). In science there is no fixed order. For catalysis research, for example, we can roughly define that for future success we must understand the exact mode of catalytic action in performance catalysts, but unforeseen discoveries in the behavior of materials and phase transitions may do more to clarify where the solution lies than anything we currently have at our disposal. Although further modifications to scientific research may be necessary so that future technical solutions (for the energy transition, for example) may be identified and implemented, we can already point to the positive effect of flexibility and the breakdown of stringent and often arbitrary rules. Of course, we must not forget the impact of serendipity and luck. The Haze must be able to respond to any contingency.

One fundamental difference between industry and research and the implementation of, say, the Silicon Valley Model, is the assessment of a product’s value. Whereas in industry, healthy sales numbers can show a product’s market value in real time, the value of a discovery in basic research may not become evident for decades (or ever). It is one of the largest challenges in streamlining or manipulating the Haze. Fortunately, we already have a wealth of strategies to overcome it: they are as numerous and diverse as the number of scientific and technical research groups currently in existence.