One question has plagued the human condition since the beginning of time: how can we escape death?

Well, we certainly know who didn’t find the answer – the alchemists of ancient China. 

It’s 210 BC, and you are an alchemist standing before Emperor Qin Shi Huang in his court. You hand him an elixir supposed to grant him immortality and eternal reign. Only the serum contains what we now call “mercury” and if anything, you granted him mortality, as he drops dead before you (1).

Where does one begin in this journey to immortality? How do we combine chemicals to find the perfect serum? Keep in mind, we have not even come close to establishing the periodic table at this point (no, that will occur about 1000 years later) (2). 

Saltpetre – or potassium nitrate – had been used extensively to treat common illnesses and to maintain good health. There’s our starting point (3).

The search for this magic elixir persists for the next eleven centuries. We never give up… do we? 

The ingenuity of the alchemists spoke to them: it told them to mix in a few other ingredients to the saltpetre. With the trio of saltpetre, sulfur and charcoal, gunpowder was henceforth born into this world (4).

The alchemists must have been in for a surprise when their “potion of immortality” sparked and exploded before them. So how does gunpowder explode? Why don’t other flammable items like match tips and dry wood explode when we set them alight?

It comes down to a few key things. 

First is our perception of explosions. Chemicals don’t simply “explode” – it’s not an inherent quality of reactions – however, they can combust. Combustion is the release of energy from a fuel. Wood and matches combust, but they do so in a way that is relatively slower than gunpowder. Gunpowder combusts rapidly – so there is a large amount of energy release within a short period of time. 

Secondly, it’s about the availability of oxygen. Items that combust slowly typically have to wait for the oxygen to trickle in from the surrounding air, since oxygen is a critical component of combustion. This does not apply to gunpowder. The oxygen for its combustion is right there in the nitrate compound (of potassium nitrate – or saltpetre). So unlike burning wood or matches, the combustion does not need to wait for oxygen to arrive from the surrounding environment – it’s already in there with the rest of the powder (5)!

To go further on that point: the closer the atoms are, the faster the combustion reaction can progress, because chemical compounds don’t need to wait long for the heat to get to them. Since gunpowder is… well… a powder, it’s rather compact and all the molecules of potassium nitrate, sulfur, and carbon sit tightly next to one another. It is this physical arrangement that permits the fast transfer of heat between molecules, ensuring that a lot of energy can be released at once.

Ultimately, when all these physical and chemical phenomena occur in perfect unison, the high temperatures rapidly increase the kinetic energy of surrounding air molecules, causing them to shoot outwards at great speeds to form a “barrier” of sorts. When this barrier, also known as a shockwave, hits your eardrums, the gunpowder delivers what it does best: BOOM!

Now, let’s combust some gunpowder, build up some gaseous pressure, and launch ourselves into the modern day. It’s been about twelve centuries – what have we been doing with all the gunpowder?

As it turns out, we humans are very inventive, but also violent (Wow – who knew?). We quickly realised that the physical properties of the resulting gases can be harnessed to quickly move very heavy objects (6). Said heavy objects could then be guided in the direction of, say, a human being or a structure. 

Weaponry derived from gunpowder has existed for a very long time, albeit rather inefficient at first. The introduction of gunpowder to warfare came in the early 10th century, when soldiers applied gunpowder to arrows that would ignite and create fire arrows. Of course, whilst it might have been effective in creating a hole in humans, it was significantly less so when it came to creating holes in walls and structures. Only after 300 years did we then invent cannons and guns. However, those guns were slow – really, really slow – to the point that bows and arrows were actually preferred during warfare of that era. It would be another 600 years before we realised that there were more effective ways of reloading a gun; brandishing a new trend of military technology that would set the stage for the First and Second World Wars (7).

By that point, the most terrifying of weapons had begun to stray away from the use of gunpowder. Missiles and rockets began employing other chemicals as propellants, owing to the advantage it had over gunpowder (7). It would also be remiss of this article to omit the exploitation of atomic power – pervading the world with such destruction that gunpowder appeared like a child’s toy (8). 

The tragic irony of a supposed innovation in immortality leading to mortality by war and conflict will forever embed itself into our history. Even with the right intentions, the invention by the great minds of alchemy has sparked a chain reaction for widespread destruction and warfare. 

It only makes you wonder – what are we making now that will lead us further astray in the future?

References

1. Glancey J. The army that conquered the world. BBC. Accessed August 24, 2025. https://www.bbc.com/culture/article/20170411-the-army-that-conquered-the-world

2. Guharay DM. A brief history of the periodic table. ASBMBTODAY. Accessed August 28, 2025. https://www.asbmb.org/asbmb-today/science/020721/a-brief-history-of-the-periodic-table

3. Butler A, Moffett J. Saltpetre in Early and Medieval Chinese Medicine. Asian Medicine. 2009;5(1):173-185. doi: 10.1163/157342109X568982

4. Paradowski, R.J. Invention of Gunpowder and Guns. EBSCO Research Starters. 2022. Accessed August 24, 2025. https://www.ebsco.com/research-starters/history/invention-gunpowder-and-guns

5. Stanford University. Detonation and Combustion. Stanford University. Accessed September 4, 2025. https://cs.stanford.edu/people/eroberts/courses/ww2/projects/firebombing/detonation-and-combustion.htm

6. Britannica. Ammunition | Bullets, Shells & Cartridges. Britannica. 2025. Accessed September 25, 2025. https://www.britannica.com/technology/ammunition

7. Beyer G. How Did Gunpowder Change Warfare? TheCollector. 2025. Accessed October 4, 2025. https://www.thecollector.com/how-did-gunpowder-change-warfare/

8. ICAN. History of Nuclear Weapons. ICAN. Accessed October 4, 2025. https://www.icanw.org/nuclear_weapons_history