6 Chemical Reactions That Changed History

[MUSIC] Physics might show us the universe’s basic
building blocks, and biology lets the universe understand itself, but chemistry is where
all the fun happens in between. We have thousands of chemical reactions going
on inside us every second, but it’s the ones we’ve mastered with our hands, in labs
and workshops and factories and even kitchens, that have made humans what we are today. A
few chemical technologies have made such an explosive change in how we live that they
have altered the very trajectory of humanity. Here’s 6 chemical reactions that changed
history. Fire was our first foray into chemistry, for
better and for worse. Whether it’s animal, vegetable or whatever’s
in hot pockets, cooking our food makes it easier to digest, we get more nutrition for
a lot less work, but there’s a different bit of chemistry that turns food from simple
nutrition into something fun to eat. In 1913, a French chemist named Louis Camille
Maillard described the most delicious reaction I know of. Pretty much everything we cook
contains sugars and amino acids, and when they react at high temperatures, the result
is… well, hundreds and hundreds of complex flavor compounds. It’s what browns grilled
hamburgers, puts the crispy crust on pizza, the golden edges on french fries, the… sorry,
I got a little carried away there. Anyway, sure, harnessing fire made food more
digestible, but the Maillard reaction made it more fun to eat, and drink, because really,
where would we be without roasted coffee? “Dogs and cats, living together, mass hysteria!” They say sticks and stones can break bones,
but metal does it much better. If your ancestors didn’t figure out the chemistry of bronze,
they were probably conquered by someone who did. The only pure metals that Earth has any good
amount of are copper, gold, silver, and platinum, but unfortunately they’re all either too
valuable, too heavy, or too soft to make good pokey sticks with. Beginning 5 to 6 thousand years ago, people
began alloying, or mixing copper with elements like tin, to make bronze, a step up in hardness
and durability from pure copper. It was later replaced by iron in most uses, but bronze
was the beginning of humanity’s heavy metal stage. Ya like civilization? I’m a big fan myself,
and one reaction above all others made it possible.
As the poet John Ciardi put it: “Fermentation and civilization are inseparable.”
Our ancestors eventually got tired of chasing dinner and were finally able to put their
roots down by putting some roots down. Domesticating plants led to a nice orderly system where
a few people grow enough food for everyone, giving others free time to explore things
like art, advanced government, and even science, or at least what passed for science at the
time. But eating raw grain is not our thing, and
what good is that harvest if it’ll be rotten in a couple weeks
By harnessing fermentation, and converting sugars into acids, alcohol, and gas our ancestors
let tiny creatures they had no idea even existed turn fruit, vegetables, grain, and even milk
into forms that were tastier and lasted longer. You know what’s also nice? Drinkable water.
But for most of human history, drinking from the wrong stream or well could get you the
last stomach ache you’d ever have. Fermentation and its antimicrobial alcoholic by products
were your friend. Considering water used to be an actual health
hazard, it’s no surprise that bathing often wasn’t high on priority lists of the past.
But nobody wants to sit with the smelly kid, even in ancient Sumeria. Tablets dating from
nearly 4,000 years ago there show formulas for mixing water, alkali ash, and oil or animal
fat to make soap. Plant and animal oils are triglycerides, a
glycerol molecule plus three fatty acids. Break them in with the alkali base, and you
get fatty acid salts, the key ingredient in soap, because they dissolve both ways. One
end is attracted to water, and the other attracts greasy nonpolar things, and the resulting
chemical mix is perfect for using water to pull olive oil stains out of your favorite
toga. News flash: Computers are a big deal, and
neither cell phones or smart thermostats would be possible without silicon chips. Silicon
is actually super easy to find, but to be used in chips it has to be super pure. How
pure? At least nine nines pure. But that’s not even the hard part. Pure solid silicon is a mass of billions of
separate crystals. It looks cool, but everywhere two crystals meet is a place where semiconductor
magic can’t happen. The Czochralski process makes that mess chip-worthy. The silicon is
remelted, and a single tiny crystal is lowered in and slowly drawn out. This first crystalline
seed aligns the growing solid mass in a single, perfect crystal of silicon, ready to be sliced
and diced and put to good use. Everything that’s alive needs nitrogen in
order to build the most basic bits of life like amino acids and DNA. But for most of
life’s history, converting nitrogen to biologically useful forms could only be done by bacteria
in soil, they pull gas from the air and convert it to building blocks like ammonia and nitrates. That was until 1909, when German chemist Fritz
Haber, with the help of a couple friends, figured out how to do it on our own. The Haber-Bosch
process converts nitrogen gas and hydrogen gas, two simple ingredients, to make ammonia,
which we can then turn into an N-finite list of useful stuff. So why is this #1? Fertilizer. For the first
time, farmers didn’t have to rely on crop rotation or shovel what the family cow provided
‘em to get nitrogen. Inexpensive chemical fertilizers let many people grow abundant
food for the first time ever. The world grew so much food, in fact, that the global population
has more than quadrupled since this chemical revolution. We make 450 million tons of nitrogen
fertilizer this way every year, a full 1 to 2 percent of all the energy we use goes to
this process. Of course salad bars and cereal aren’t the
only thing that we make with industrial nitrogen. Nitrates are necessary ingredients in making
explosives, and the Haber process allowed the nations involved in WWI and II to unleash
destruction on scales never seen before. But whether it was the battlefield or the
breakfast table that really motivated Haber to harness nitrogen from air, one explosion
definitely won out over the other, and it’s just one delicious bit of chemistry that feeds
our brains every day. Now if you enjoyed these Fine reactions, I
know we skipped over a lot of important historical chemical wonders, so let us know in the comments
what you think changed humanity more than any other reaction. Stay curious.

100 thoughts on “6 Chemical Reactions That Changed History”

  1. Bronze is no product of a chemical reaction.
    It's just a mix of 2 metal atoms at a very small scale.
    Imagine mixing ground up coffee and sugar. Except the particles are the size of atoms and the result is metal.
    There you go. You got an alloy.

    Alloys are more physics than chemistry

  2. Someone want to change the world???
    We know that chemical reaction speed is dependant on concentration of chemicals that react.
    So in photosynthesis CO2 and H2O is turned into sugars with the energy of light.
    Sure 1 could give more sun to the plant, but hear me out
    What if we increase the concentration of CO2 in the air so that photosynthesis happens MUCH faster. Plant will have more sugar.
    Sugar we eat.
    What if Global warming is something we shouldn't fear but accept as our savior.
    Sure waters will rise, climate will get warmer. But more food also

  3. The Maillard reaction did not change history; it has been going on for all of history before Louis Camille Maillard described it. Silicon, is an element and when it forms a crystal, that's physics, not chemistry. It's Okay to be ignorant (dreadfully careless with education).

  4. CIVILIZATION is the greatest game ever created by humans, agreed.
    Sorry just had to get that out there.
    Ummmm continue please. 😁

  5. These are the building blocks of life, they can create or destroy: Thats why we named getting along with someone on a an explosive or creative way Chemistry.

  6. Everything discussed here is undoubtedly important and influential, but your definition of "chemical reaction" is tenuous at best. Alloying and the Czochralski process, as I understand them, can't be considered chemical reactions by any stretch of the imagination, since one is essentially "dissolving" one metal in another, and the other is a process of crystal growth.

  7. To all those writing about this and that not being a chemical reaction: all chemical reactions have physical processes at their core. So in the end it is all physics hahaha

  8. Birth control pill is destroying the family,the family is the building block of society, no family=no society

  9. Gunpowder should've been on that list. As both a tool for warfare and as a propellant, it very definitely changed the course of human history…..

  10. Wait… bronze is just an alloy, so really just a solution and not a chemical reaction. Fermentation is a biological process, and the czokralsky process is a physical one. These aren't chemical reactions.

  11. Nobody thinks about the fact that our poop and pee is a very efficient and concentrated nutrient. 10 acres+ can easily be fertilized by you alone if used right

  12. hello, please review my translation for this video in Arabic. it is my native language and i translated it so i can play this video for my class. Thank you!

  13. Nuclear fission. It caused the most gruesome destruction and fear for the end of humanity.

    But, in the end, big serious nations are not waging wars among each other anymore exactly because nukes.

  14. Fischer-Trops reaction along with ammonia production are to blame or praise for the world we know today

  15. Lol the Have Bosh Process allows us to feed more people and also gives us better explosives she kill ourselfs with.

  16. I believe human beings are the only members of the animal kingdom with the ability to fix atmospheric nitrogen. Go us!

  17. A normal conversation

  18. Hands down the Haber process. First learned about it in High School. Made much of the 'roar' in the 'roaring 20s' possible. Got folks off of the farm as you didn't need as many people to work the land (the overall efficiency went through the roof) and made food a lot cheaper. So you could purchase illicit booze instead of oatmeal. The down side is that human population has and is exploding and because food is so very cheap nowadays, farmers and rancher can and do insist on governmental subsidies as the said foodstuffs are so very cheap — little or no real profit. Just smoke and mirrors.

  19. A generally nice video. But I have to take issue. Google (and therefore it must be right :0) describes a chemical reaction as: "a process that involves rearrangement of the molecular or ionic structure of a substance, as distinct from a change in physical form or a nuclear reaction." IMHO this doesn't apply to alloying, because the original metals and subsequent alloy don't have a molecular structure, just a repeating structure of atoms bound by non-local electrons in a conduction level. And certainly recrystallization of silicon doesn't fit this discription either.

  20. 3:47 Tablets dating from nearly 4.000 years ago show that, would you believe it, bathing WAS pretty high on the priority list.

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