[Script Info]
Title: 
[Events]
Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text
Dialogue: 0,0:00:07.24,0:00:08.05,Default,,0000,0000,0000,,What would you say
Dialogue: 0,0:00:08.05,0:00:09.58,Default,,0000,0000,0000,,is the most important discovery
Dialogue: 0,0:00:09.58,0:00:11.58,Default,,0000,0000,0000,,made in the past few centuries?
Dialogue: 0,0:00:11.58,0:00:12.61,Default,,0000,0000,0000,,Is it the computer?
Dialogue: 0,0:00:12.61,0:00:13.26,Default,,0000,0000,0000,,The car?
Dialogue: 0,0:00:13.26,0:00:14.17,Default,,0000,0000,0000,,Electricity?
Dialogue: 0,0:00:14.17,0:00:16.14,Default,,0000,0000,0000,,Or maybe the discovery of the atom?
Dialogue: 0,0:00:16.14,0:00:19.59,Default,,0000,0000,0000,,I would argue that it is this chemical reaction:
Dialogue: 0,0:00:19.59,0:00:21.21,Default,,0000,0000,0000,,a nitrogen gas molecule
Dialogue: 0,0:00:21.21,0:00:23.30,Default,,0000,0000,0000,,plus three hydrogen gas molecules
Dialogue: 0,0:00:23.30,0:00:26.74,Default,,0000,0000,0000,,gets you two ammonia gas molecules.
Dialogue: 0,0:00:26.74,0:00:28.34,Default,,0000,0000,0000,,This is the Haber process
Dialogue: 0,0:00:28.34,0:00:30.92,Default,,0000,0000,0000,,of binding nitrogen molecules in the air
Dialogue: 0,0:00:30.92,0:00:32.43,Default,,0000,0000,0000,,to hydrogen molecules,
Dialogue: 0,0:00:32.43,0:00:35.56,Default,,0000,0000,0000,,or turning air into fertilizer.
Dialogue: 0,0:00:35.56,0:00:36.81,Default,,0000,0000,0000,,Without this reaction,
Dialogue: 0,0:00:36.81,0:00:39.48,Default,,0000,0000,0000,,farmers would be capable of producing enough food
Dialogue: 0,0:00:39.48,0:00:41.35,Default,,0000,0000,0000,,for only 4 billion people;
Dialogue: 0,0:00:41.35,0:00:44.88,Default,,0000,0000,0000,,our current population is just over 7 billion people.
Dialogue: 0,0:00:44.88,0:00:46.88,Default,,0000,0000,0000,,So, without the Haber process,
Dialogue: 0,0:00:46.88,0:00:51.31,Default,,0000,0000,0000,,over 3 billion people would be without food.
Dialogue: 0,0:00:51.31,0:00:55.02,Default,,0000,0000,0000,,You see, nitrogen in the form of nitrate, NO3,
Dialogue: 0,0:00:55.02,0:00:58.20,Default,,0000,0000,0000,,is an essential nutrient for plants to survive.
Dialogue: 0,0:00:58.20,0:01:00.71,Default,,0000,0000,0000,,As crops grow, they consume the nitrogen,
Dialogue: 0,0:01:00.71,0:01:02.42,Default,,0000,0000,0000,,removing it from the soil.
Dialogue: 0,0:01:02.42,0:01:03.92,Default,,0000,0000,0000,,The nitrogen can be replenished
Dialogue: 0,0:01:03.92,0:01:06.35,Default,,0000,0000,0000,,through long, natural fertilization processes
Dialogue: 0,0:01:06.35,0:01:07.84,Default,,0000,0000,0000,,like decaying animals,
Dialogue: 0,0:01:07.84,0:01:09.68,Default,,0000,0000,0000,,but humans want to grow food
Dialogue: 0,0:01:09.68,0:01:11.68,Default,,0000,0000,0000,,much faster than that.
Dialogue: 0,0:01:11.68,0:01:13.59,Default,,0000,0000,0000,,Now, here's the frustrating part:
Dialogue: 0,0:01:13.59,0:01:16.59,Default,,0000,0000,0000,,78% of the air is composed of nitrogen,
Dialogue: 0,0:01:16.59,0:01:19.40,Default,,0000,0000,0000,,but crops can't just take nitrogen from the air
Dialogue: 0,0:01:19.40,0:01:22.51,Default,,0000,0000,0000,,because it contains very strong triple bonds,
Dialogue: 0,0:01:22.51,0:01:24.64,Default,,0000,0000,0000,,which crops cannot break.
Dialogue: 0,0:01:24.64,0:01:26.64,Default,,0000,0000,0000,,What Haber did basically
Dialogue: 0,0:01:26.64,0:01:27.76,Default,,0000,0000,0000,,was figure out a way
Dialogue: 0,0:01:27.76,0:01:29.53,Default,,0000,0000,0000,,to take this nitrogen in the air
Dialogue: 0,0:01:29.53,0:01:31.28,Default,,0000,0000,0000,,and put it into the ground.
Dialogue: 0,0:01:31.28,0:01:34.86,Default,,0000,0000,0000,,In 1908, the German chemist Fritz Haber
Dialogue: 0,0:01:34.86,0:01:36.18,Default,,0000,0000,0000,,developed a chemical method
Dialogue: 0,0:01:36.18,0:01:39.02,Default,,0000,0000,0000,,for utilizing the vast supply of nitrogen in the air.
Dialogue: 0,0:01:39.02,0:01:39.89,Default,,0000,0000,0000,,Haber found a method
Dialogue: 0,0:01:39.89,0:01:41.59,Default,,0000,0000,0000,,which took the nitrogen in the air
Dialogue: 0,0:01:41.59,0:01:43.05,Default,,0000,0000,0000,,and bonded it to hydrogen
Dialogue: 0,0:01:43.05,0:01:45.24,Default,,0000,0000,0000,,to form ammonia.
Dialogue: 0,0:01:45.24,0:01:47.80,Default,,0000,0000,0000,,Ammonia can then be injected into the soil,
Dialogue: 0,0:01:47.80,0:01:50.51,Default,,0000,0000,0000,,where it is quickly converted into nitrate.
Dialogue: 0,0:01:50.51,0:01:53.00,Default,,0000,0000,0000,,But if Haber's process was going to be used
Dialogue: 0,0:01:53.00,0:01:54.10,Default,,0000,0000,0000,,to feed the world,
Dialogue: 0,0:01:54.10,0:01:55.21,Default,,0000,0000,0000,,he would need to find a way
Dialogue: 0,0:01:55.21,0:01:58.42,Default,,0000,0000,0000,,to create a lot of this ammonia quickly and easily.
Dialogue: 0,0:01:58.42,0:01:59.38,Default,,0000,0000,0000,,In order to understand
Dialogue: 0,0:01:59.38,0:02:01.09,Default,,0000,0000,0000,,how Haber accomplished this feat,
Dialogue: 0,0:02:01.09,0:02:02.18,Default,,0000,0000,0000,,we need to know something
Dialogue: 0,0:02:02.18,0:02:04.40,Default,,0000,0000,0000,,about chemical equilibrium.
Dialogue: 0,0:02:04.40,0:02:06.35,Default,,0000,0000,0000,,Chemical equilibrium can be achieved
Dialogue: 0,0:02:06.35,0:02:09.51,Default,,0000,0000,0000,,when you have a reaction in a closed container.
Dialogue: 0,0:02:09.51,0:02:11.23,Default,,0000,0000,0000,,For example, let's say you put
Dialogue: 0,0:02:11.23,0:02:14.35,Default,,0000,0000,0000,,hydrogen and nitrogen into a closed container
Dialogue: 0,0:02:14.35,0:02:16.16,Default,,0000,0000,0000,,and allow them to react.
Dialogue: 0,0:02:16.16,0:02:17.76,Default,,0000,0000,0000,,In the beginning of the experiment,
Dialogue: 0,0:02:17.76,0:02:20.37,Default,,0000,0000,0000,,we have a lot of nitrogen and hydrogen,
Dialogue: 0,0:02:20.37,0:02:22.01,Default,,0000,0000,0000,,so the formation of ammonia
Dialogue: 0,0:02:22.01,0:02:24.10,Default,,0000,0000,0000,,proceeds at a high speed.
Dialogue: 0,0:02:24.10,0:02:26.68,Default,,0000,0000,0000,,But as the hydrogen and nitrogen react
Dialogue: 0,0:02:26.68,0:02:28.26,Default,,0000,0000,0000,,and get used up,
Dialogue: 0,0:02:28.26,0:02:29.88,Default,,0000,0000,0000,,the reaction slows down
Dialogue: 0,0:02:29.88,0:02:31.84,Default,,0000,0000,0000,,because there is less nitrogen and hydrogen
Dialogue: 0,0:02:31.84,0:02:33.62,Default,,0000,0000,0000,,in the container.
Dialogue: 0,0:02:33.62,0:02:36.35,Default,,0000,0000,0000,,Eventually, the ammonia molecules reach a point
Dialogue: 0,0:02:36.35,0:02:38.06,Default,,0000,0000,0000,,where they start to decompose
Dialogue: 0,0:02:38.06,0:02:41.34,Default,,0000,0000,0000,,back into the nitrogen and hydrogen.
Dialogue: 0,0:02:41.34,0:02:43.06,Default,,0000,0000,0000,,After a while, they two reactions,
Dialogue: 0,0:02:43.06,0:02:45.59,Default,,0000,0000,0000,,creating and breaking down ammonia,
Dialogue: 0,0:02:45.59,0:02:47.63,Default,,0000,0000,0000,,will reach the same speed.
Dialogue: 0,0:02:47.63,0:02:49.34,Default,,0000,0000,0000,,When these speeds are equal,
Dialogue: 0,0:02:49.34,0:02:52.15,Default,,0000,0000,0000,,we say the reaction has reached equilibrium.
Dialogue: 0,0:02:53.15,0:02:55.28,Default,,0000,0000,0000,,This might sound good, but it's not
Dialogue: 0,0:02:55.28,0:02:56.51,Default,,0000,0000,0000,,when what you want
Dialogue: 0,0:02:56.51,0:02:58.82,Default,,0000,0000,0000,,is to just create a ton of ammonia.
Dialogue: 0,0:02:58.82,0:03:00.34,Default,,0000,0000,0000,,Haber doesn't want the ammonia
Dialogue: 0,0:03:00.34,0:03:01.86,Default,,0000,0000,0000,,to break down at all,
Dialogue: 0,0:03:01.86,0:03:03.37,Default,,0000,0000,0000,,but if you simply leave the reaction
Dialogue: 0,0:03:03.37,0:03:04.86,Default,,0000,0000,0000,,in a closed container,
Dialogue: 0,0:03:04.86,0:03:06.49,Default,,0000,0000,0000,,that's what will happen.
Dialogue: 0,0:03:06.49,0:03:08.79,Default,,0000,0000,0000,,Here's where Henry Le Chatelier,
Dialogue: 0,0:03:08.79,0:03:09.98,Default,,0000,0000,0000,,a French chemist,
Dialogue: 0,0:03:09.98,0:03:11.27,Default,,0000,0000,0000,,can help.
Dialogue: 0,0:03:11.27,0:03:12.70,Default,,0000,0000,0000,,What he found was
Dialogue: 0,0:03:12.70,0:03:14.59,Default,,0000,0000,0000,,that if you take a system in equilibrium
Dialogue: 0,0:03:14.59,0:03:16.30,Default,,0000,0000,0000,,and you add something to it,
Dialogue: 0,0:03:16.30,0:03:17.72,Default,,0000,0000,0000,,like, say, nitrogen,
Dialogue: 0,0:03:17.72,0:03:18.72,Default,,0000,0000,0000,,the system will work
Dialogue: 0,0:03:18.72,0:03:20.92,Default,,0000,0000,0000,,to get back to equilibrium again.
Dialogue: 0,0:03:20.92,0:03:22.30,Default,,0000,0000,0000,,Le Chatelier also found
Dialogue: 0,0:03:22.30,0:03:23.47,Default,,0000,0000,0000,,that if you increase
Dialogue: 0,0:03:23.47,0:03:25.60,Default,,0000,0000,0000,,the amount of pressure on a system,
Dialogue: 0,0:03:25.60,0:03:26.76,Default,,0000,0000,0000,,the system tries to work
Dialogue: 0,0:03:26.76,0:03:28.98,Default,,0000,0000,0000,,to return to the pressure it had.
Dialogue: 0,0:03:28.98,0:03:30.68,Default,,0000,0000,0000,,It's like being in a crowded room.
Dialogue: 0,0:03:30.68,0:03:32.18,Default,,0000,0000,0000,,The more molecules there are,
Dialogue: 0,0:03:32.18,0:03:33.77,Default,,0000,0000,0000,,the more pressure there is.
Dialogue: 0,0:03:33.77,0:03:35.53,Default,,0000,0000,0000,,If we look back at our equation,
Dialogue: 0,0:03:35.53,0:03:37.53,Default,,0000,0000,0000,,we see that on the left-hand side,
Dialogue: 0,0:03:37.53,0:03:39.68,Default,,0000,0000,0000,,there are four molecules on the left
Dialogue: 0,0:03:39.68,0:03:41.78,Default,,0000,0000,0000,,and just two on the right.
Dialogue: 0,0:03:41.78,0:03:44.28,Default,,0000,0000,0000,,So, if we want the room to be less crowded,
Dialogue: 0,0:03:44.28,0:03:45.87,Default,,0000,0000,0000,,and therefore have less pressure,
Dialogue: 0,0:03:45.87,0:03:46.78,Default,,0000,0000,0000,,the system will start
Dialogue: 0,0:03:46.78,0:03:48.67,Default,,0000,0000,0000,,combining nitrogen and hydrogen
Dialogue: 0,0:03:48.67,0:03:51.80,Default,,0000,0000,0000,,to make the more compact ammonia molecules.
Dialogue: 0,0:03:51.80,0:03:53.82,Default,,0000,0000,0000,,Haber realized that in order to make
Dialogue: 0,0:03:53.82,0:03:55.10,Default,,0000,0000,0000,,large amounts of ammonia,
Dialogue: 0,0:03:55.10,0:03:56.60,Default,,0000,0000,0000,,he would have to create a machine
Dialogue: 0,0:03:56.60,0:03:59.60,Default,,0000,0000,0000,,that would continually add nitrogen and hygrogen
Dialogue: 0,0:03:59.60,0:04:01.44,Default,,0000,0000,0000,,while also increasing the pressure
Dialogue: 0,0:04:01.44,0:04:03.31,Default,,0000,0000,0000,,on the equilibrium system,
Dialogue: 0,0:04:03.31,0:04:05.48,Default,,0000,0000,0000,,which is exactly what he did.
Dialogue: 0,0:04:05.48,0:04:08.03,Default,,0000,0000,0000,,Today, ammonia is one of the most produced
Dialogue: 0,0:04:08.03,0:04:10.31,Default,,0000,0000,0000,,chemical compounds in the world.
Dialogue: 0,0:04:10.31,0:04:14.89,Default,,0000,0000,0000,,Roughly 131 million metric tons are produced a year,
Dialogue: 0,0:04:14.89,0:04:18.31,Default,,0000,0000,0000,,which is about 290 billion pounds of ammonia.
Dialogue: 0,0:04:18.31,0:04:19.36,Default,,0000,0000,0000,,That's about the mass
Dialogue: 0,0:04:19.36,0:04:21.45,Default,,0000,0000,0000,,of 30 million African elephants,
Dialogue: 0,0:04:21.45,0:04:24.31,Default,,0000,0000,0000,,weighing roughly 10,000 pounds each.
Dialogue: 0,0:04:24.31,0:04:28.09,Default,,0000,0000,0000,,80% of this ammonia is used in fertilizer production,
Dialogue: 0,0:04:28.09,0:04:29.04,Default,,0000,0000,0000,,while the rest is used
Dialogue: 0,0:04:29.04,0:04:30.94,Default,,0000,0000,0000,,in industrial and household cleaners
Dialogue: 0,0:04:30.94,0:04:33.31,Default,,0000,0000,0000,,and to produce other nitrogen compounds,
Dialogue: 0,0:04:33.31,0:04:35.26,Default,,0000,0000,0000,,such as nitric acid.
Dialogue: 0,0:04:35.26,0:04:36.34,Default,,0000,0000,0000,,Recent studies have found
Dialogue: 0,0:04:36.34,0:04:38.84,Default,,0000,0000,0000,,that half of the nitrogen from these fertilizers
Dialogue: 0,0:04:38.84,0:04:41.15,Default,,0000,0000,0000,,is not assimilated by plants.
Dialogue: 0,0:04:41.15,0:04:42.98,Default,,0000,0000,0000,,Consequently, the nitrogen is found
Dialogue: 0,0:04:42.98,0:04:44.64,Default,,0000,0000,0000,,as a volatile chemical compound
Dialogue: 0,0:04:44.64,0:04:47.70,Default,,0000,0000,0000,,in the Earth's water supplies and atmosphere,
Dialogue: 0,0:04:47.70,0:04:49.65,Default,,0000,0000,0000,,severely damaging our environment.
Dialogue: 0,0:04:49.65,0:04:51.48,Default,,0000,0000,0000,,Of course, Haber did not foresee this problem
Dialogue: 0,0:04:51.48,0:04:53.10,Default,,0000,0000,0000,,when he introduced his invention.
Dialogue: 0,0:04:53.10,0:04:54.77,Default,,0000,0000,0000,,Following his pioneering vision,
Dialogue: 0,0:04:54.77,0:04:56.39,Default,,0000,0000,0000,,scientists today are looking
Dialogue: 0,0:04:56.39,0:04:59.05,Default,,0000,0000,0000,,for a new Haber process of the 21st century,
Dialogue: 0,0:04:59.05,0:05:01.03,Default,,0000,0000,0000,,which will reach the same level of aid
Dialogue: 0,0:05:01.03,0:05:03.36,Default,,0000,0000,0000,,without the dangerous consequences.