1The 1918 Nobel Prize for Chemistry is probably the most important Nobel Prize ever awarded.
2It was given to German scientist Fritz Haber
3for solving one of the biggest problems humanity has ever faced.
4His invention is directly responsible for the lives of 4 billion people today.
5But when he received his prize, many of his peers refused to attend.
6Two other Nobel Prize winners rejected their awards in protest
7and the New York Times wrote a scathing article about him.
8He is simultaneously one of the most impactful and tragic scientists of all time.
9Perhaps more than any other single person, he has shaped the world we live in today.
10If you are an American citizen and you find an island with a lot of bird poop on it,
11well, then you can claim that island for the United States
12and the US will have your back.
13The president is authorized to send in the Navy and the Army to defend your newly discovered poop-covered island.
14There are currently 10 American islands that were claimed in this way.
15And even though the law that made this possible was passed in 1856,
16it is still in effect to this day.
17So, why did people want poop-covered islands so badly?
18There are a few dozen islands off the coast of Peru where millions of seabirds gather to mate
19and the waters near the island are full of fish,
20and these millions of birds eat the fish, and then they poop, a lot.
21Since the region is hot and dry, this poop solidifies and accumulates over millennia.
22There are cliffs of bird poop 30 meters or a hundred feet high.
23And technically bird poop is called guano
24and by the mid 1800s, buying and selling bird guano was big business.
25The price rose as high as $76 per pound
26meaning you could trade four pounds of guano for one pound of gold.
27So, why was there such a big market for bird poop?
28Well, to answer that we have to look inside the human body.
29By weight, most of our bodies are made up of oxygen, carbon, and hydrogen.
30But the fourth most common element is nitrogen.
31Nitrogen is part of the amino acids that form proteins.
32It's part of hemoglobin, the compound that carries oxygen in red blood cells
33and it's a central component of DNA and RNA.
34Nitrogen is essential for all life on earth.
35We get our nitrogen by eating plants or animals which have eaten plants,
36and plants get their nitrogen from the soil.
37The problem is if you farm the same soil year after year,
38you harvest the nitrogen out of it
39and eventually there isn't enough nitrogen for healthy plants to grow.
40They can't produce enough chlorophyll to photosynthesize which stunts their growth.
41Their leaves turn yellow and they are more susceptible to pests and disease.
42Crucially, for farmers, nitrogen deficiency means smaller yields.
43The way to fix this is to add nitrogen back into the soil
44which is where bird guano comes in.
45Guano is up to 20% nitrogen.
46Hundreds of years ago, Incan farmers realized that adding guano to their soil made crops grow taller.
47This is what allowed them to grow food in places that were previously unfarmable and expand their empire.
48South America's rich deposits of bird poop did not go unnoticed by the rest of the world.
49In 1865, Spain went to war against its former colonies of Peru, Chile, Ecuador, and Bolivia
50for control of their guano-laden islands.
51But such was the world's appetite for nitrogen that by 1872 guano was running out
52and Peru banned further exports.
53The world would need another way to get its nitrogen fix.
54This was a crisis.
55William Crooks, a British chemist, made a dire prophecy in 1898.
56With the world's growing population and dwindling supplies of nitrogen, he said,
57"We stand in deadly peril of not having enough to eat."
58In less than 30 years time, he argued, people all over the world will be dying of starvation,
59but he also proposed a solution.
60"It is the chemist who must come to the rescue."
61"It is through the laboratory that starvation may ultimately be turned into plenty."
62Because here's the thing, nitrogen isn't rare, it's common.
6378% of the air is nitrogen
64but it's in a form that plants and animals can't use.
65Two atoms of nitrogen triple bonded together.
66This bond is one of the strongest in nature.
67The way to measure the strength of a chemical bond is by the amount of energy that's required to break it.
68So, to break apart two chlorine atoms, for example, would take 2.5 electron volts.
69To break apart two carbons requires 3.8 eV.
70Two oxygens, 5.2 eV.
71But to break apart two atoms of nitrogen requires 9.8 electron volts,
72a tremendous amount of energy.
73There are two processes that do this naturally.
74Lightning releases so much energy, it breaks apart N2 into individual nitrogen atoms.
75They then quickly react to form nitrogen oxides
76and these molecules stay in the atmosphere until they react with water droplets in clouds
77and fall to the ground in rain.
78There are also a few types of bacteria living in soil that can break the N2 bond
79using a tremendous amount of energy to do so,
80and they make nitrogen available for plants.
81But bacteria only replenish the nitrogen slowly
82and there's not enough lightning to produce nitrogen compounds at scale.
83So, chemists tried.
84In 1811, Georg Hildebrandt mixed nitrogen and hydrogen in a sealed flask
85trying to make ammonia, one of the nitrogen-containing molecules found in guano.
86When that didn't work, he submerged the flask 300 meters underwater to increase the pressure
87and that didn't work either, but he was on the right track.
88Increasingly sophisticated versions of these experiments were carried out over the following hundred years.
89All of them failed.
90So, when Fritz Haber became interested in this problem in 1904,
91he was joining a long line of failed chemists.
92He was 36 years old, working as a low level academic at the University of Karlsruhe.
93He was also a new father with a 2 year old boy named Herman
94and a wife, Clara, who was one of the first women to get a PhD in chemistry.
95Driven by pride and competition with another scientist,
96Haber spent five years on the problem.
97His idea was to combine nitrogen and hydrogen not only at high pressure,
98but also at high temperature, and in the presence of a catalyst,
99something that lowers the amount of energy required to split diatomic nitrogen.
100To do this, new experimental apparatus had to be invented.
101Haber worked tirelessly on this project
102building equipment that could tolerate ever higher temperatures and pressures.
103He also got lucky.
104At the time he was moonlighting as a technical consultant for a light bulb manufacturer.
105So, there he had access to lots of really hard to find materials.
106Like the element osmium.
107Osmium is rare.
108In his day, there was only about 100 kilograms of the refined metal in existence
109but the company he worked for was experimenting with using it for filaments in their light bulbs.
110So, they had most of the world's supply.
111Haber suspected it might make the perfect catalyst,
112so he brought a sample back to his lab.
113And there in the third week of March 1909,
114Haber placed his sheet of osmium in the pressure chamber
115and then he pressurized and heated the nitrogen and hydrogen to 200 atmospheres and 500 degrees Celsius.
116Under these conditions, the triple bonds broke apart
117and nitrogen reacted with hydrogen.
118Of the total gas mixture, 6% turned into ammonia.
119When the gas was cooled, one milliliter of ammonia dripped out the end of a narrow tube into a beaker.
120An elated Haber rushed from one lab to another, yelling, "Come on down. There's ammonia."
121Germany's biggest chemical company, BASF, commercialized Haber's process.
122Within four years, they had opened a factory in Oppau producing five tons of ammonia per day.
123People spoke of making bread from the air.
124With the fertilizer from this industrial process
125on the same plot of land, farmers were able to grow four times as much food
126and as a result, the population of the earth quadrupled.
127There's a good chance you owe your life to Haber's invention.
128The Earth supports 4 billion more people today than it could without nitrogen fertilizer.
129In fact, around 50% of the nitrogen atoms in your body came from the Haber process.
130The invention made Fritz Haber a wealthy man.
131He got a promotion becoming the founding director of the Kaiser Wilhelm Institute for Physical Chemistry in Berlin.
132He also befriended some of the best scientists of his day including Max Planck, Max Born, and Albert Einstein.
133After Einstein separated from his first wife in 1914,
134he stayed the night at Haber's house.
135But if Haber was so well-regarded,
136why was he shunned by colleagues when he won the Nobel Prize?
137Well, it all comes down to what happened in World War I.
138When the war broke out, Haber volunteered for military duty.
139Unlike pacifist Einstein who denounced the war, Haber was a patriot.
140He wanted to use his expertise to help his country.
141Only a few months into the war, the German army was already running out of gunpowder and explosives.
142Ammonium nitrate, besides being an excellent fertilizer, is also an explosive.
143Just look at what happened in Beirut in August of 2020.
144A warehouse containing almost 3,000 tons of ammonium nitrate caught fire.
145And in the extreme heat, the fertilizer detonated.
146The blast which could be heard hundreds of kilometers away
147killed at least 217 people and injured thousands more.
148Seismometers registered an artificial earthquake measuring 3.3 on the Richter scale.
149This is just one of many fertilizer-related explosions.
150The Oppau plant where Haber's process was first put into practice would also explode in 1921.
151And the reason is nitrogen.
152We've already seen that it takes a tremendous amount of energy to break apart nitrogen's triple bond.
153But the flip side of that coin is that when two nitrogen atoms come together and form that bond,
154a huge amount of energy is released.
155The explosions of gunpowder, TNT, nitroglycerin, and ammonium nitrate
156all form diatomic nitrogen gas as a product.
157And the formation of that triple bond is where these chemicals derive much of their explosive energy.
158Haber lobbied to convert the factories using his process to make ammonia for fertilizer to create nitrate for explosives instead.
159His superiors believed such a conversion to be impossible, but Haber persisted,
160and soon his chemical process was at the heart of the German war machine.
161From bread out of the air to bombs out of the air.
162But Haber thought chemistry could make an even bigger contribution to the war.
163In December 1914, he witnessed a chemical weapons test.
164He was unimpressed.
165Haber believed that he could do better.
166He set out to make a gas that was deadly at low concentrations and heavier than air
167so it would sink into enemy trenches.
168Projectiles carrying chemical weapons were banned, at least in theory, by the Hague Convention of 1899.
169But in practice after the start of the war, Germany, France, and Britain all experimented with chemical weapons.
170Haber converted his wing of the institute into a chemical weapons laboratory
171and after only a few months of work, he zeroed in on chlorine gas.
172An employee, Otto Hahn, expressed his discomfort about the new weapon.
173Haber told him, "Innumerable human lives would be saved if the war could be ended more quickly in this way."
174At 6 p.m. On the 22nd of April, with the wind blowing toward the allied trenches,
175German troops released 168 tons of chlorine from over 5,000 gas cylinders.
176The wall of gas advanced across the battlefield.
177Since chlorine gas is 2.5 times heavier than air,
178it sank into the trenches of the Allied soldiers.
179Any soldier that inhaled a lung full of the gas suffered a terrible death.
180Chlorine irritates the mucus lining of the lungs so violently that they fill with liquid.
181The soldiers effectively drowned on dry land.
182More than 5,000 Allied soldiers died this way in the first attack.
183Haber was promoted to the rank of captain.
184Haber spent the rest of the war running his institute researching chemical weapons, gas masks, and pesticides.
185By 1917, the institute employed 1,500 people including 150 scientists.
186It was like a mini Manhattan project but for chemical weapons.
187In total, 100,000 soldiers were killed by chemical weapons in World War I.
188When Germany surrendered, Haber was crushed.
189All the money he made from his ammonia patent was lost to hyperinflation.
190In an attempt to pay off Germany's crippling war debt,
191he tried to distill gold from seawater
192but the project was futile.
193In 1933, the Nazis came to power
194and passed a law that all Jewish civil servants including scientists, were to be fired from their jobs.
195Haber was Jewish but he never practiced the religion.
196Regardless, his military service exempted him from the law
197but he resigned from his role as director in solidarity with all the Jewish scientists who worked at the institute.
198The next year in a hotel room in Basel, Switzerland, he died of heart failure.
199Immediately after World War I, Haber's Institute developed a cyanide-based insecticide.
200It had a barely detectable odor
201so, they mixed in a foul-smelling chemical to alert people to the danger.
202The resulting gas was called Zyklon B.
203A decade after Haber's death, the Nazis requested chemists remove the foul-smelling component
204and this form of Zyklon B, the chemical developed at Haber's Institute
205was then used to perpetrate the Holocaust.
206Thinking about this story, it would be easy to paint Haber as a villain
207or as a hero for inventing the process used to feed half the world.
208But another approach is to regard him as irrelevant to the larger story
209because someone else would have figured out a way to process nitrogen out of the air
210and other scientists were developing chemical weapons.
211Over the past few centuries, science and technology have improved our lives immeasurably
212but they have also given us ever increasing ways to destroy ourselves.
213I think it'd be great to believe that we could ask scientists to only work on problems that are good for humanity.
214But the reality is that every bit of information is a potential double-edged sword.
215You don't know the outcome of your research or how it might later be used.
216Ammonium nitrate is both a fertilizer and an explosive.
217So the real question is how do we keep increasing our knowledge and control of the natural world
218without destroying ourselves and everything else on this planet in the process?