Would a fire-breathing animal ever exist?

George R.R. Martin has created an incredible world in Westeros, depicted through Game of Thrones and House of the Dragon, where dragons breathe fire to capture an audience through an interesting blend of myth and fantasy. At least for me, scientific curiosity runs deep. After watching House of the Dragon: Labyrinth of Flames on Netflix, my mind drifted towards what biological mechanisms and chemical reactions dragons might use if they existed; first though – let’s review basic chemistry! To sustain and ignite combustion, we require three essential ingredients. They include fuel, an oxidising agent – typically oxygen in air – and heat as a heat source to initiate and sustain it. Methane could serve as one such fuel; animals produce it through digestive processes. Images from Westeros show dragons fond of devouring sheep. However, our methane-fueled dragons would require diet and digestion similar to that of cows to produce enough gas to bring down an entire city. Furthermore, there may also be issues regarding storage. Methane tanks may be designed for 150 atmospheres of pressure; while even an overly bloated gut may only withstand about one atmosphere of pressure. There’s simply no biological basis for non-marine animals to store gasses at such high pressure; an alternative would be liquid storage mediums like Ethanol instead. Imagine our dragons having fermenting yeast stored in their gut, or possessing similar metabolic systems like those seen in Devil’s Hole pupfish found living in Nevada’s hot springs. Under low oxygen conditions, fish adapt by switching to an alternative respiration process that produces ethanol; however, storage remains an issue. Ethanol passes quickly through biological membranes, so maintaining high concentrations for use on the “dracarys” signal (which translates into dragonfire in High Valyrian) would require extraordinary biophysics. Get the world’s most fascinating discoveries delivered right to your inbox!Related: Dragons: Brief History of Mythical Fire Breathing BeastsIf we stick with explanations with at least some basis in real-world biology then my preferred option would likely involve something oil-related. Anytime an accidental fire starts in a frying pan, there can be devastating results. Fulmar gulls produce energy-rich stomach oil to feed their chicks and as an additional deterrent against accidental ignitions of their chicks’ food sources such as pans. This serves to minimize these fire risks in kitchen environments. When threatened, Fulmars release sticky, stinky oil over their predators to deter attacks – although unfortunately no mechanism exists yet for initiating their vomit production. You don’t want to come face-to-face with one fulmar. Feed the FlamesNow that we have our fuel source in place, let’s turn our attention towards an oxidizing agent – oxygen being an obvious candidate in most fires. However, oxygen alone won’t do enough to generate an intense and pressurised jet of flaming oil hot enough to melt an iron throne; additional ingredients would need to be mixed with fuel efficiently for successful ignition of this explosive process. An oxygen supply increases flame intensity. A dragon could draw inspiration from some chemistry utilized by bombardier beetles. They’ve evolved special reservoirs adapted for holding hydrogen peroxide that you might use when bleaching hair, providing enough of this substance for its use in hair bleaching treatments. Beetle bees when threatened can expel hydrogen peroxide into its vestibule to be decomposed by enzymes – this creates an exothermic reaction which transfers energy back to its surroundings while raising temperature near boiling point. As its reaction is so vigorous, it has even been used to propel rockets. As oxygen production and boiling water pressure builds rapidly, beetles with bombardier beaks produce toxic fumes through vents in their abdomens, forcing it out through vents on to prey or threats. Bombardier beetles store hydrogen peroxide within their bodies. (Image Credit: Johann Viloria via Shutterstock)A dragon may utilize this reaction, which has several advantageous characteristics. An oil jet would produce high pressure required to power an exothermic reaction that heated and prepared oily fuel for combustion; oxygen generated would further fuel this reaction; all that’s necessary now would be an equivalent biological carburetor that mixes these together into an explosive mix. As an added benefit, the mixture would likely erupt with fine mist of oil droplets that act like aerosol and ignite with ease. Finally, we need something spark-worthy to ignite it all and get that reaction going. Assuming my hypothesis holds true, the dragons may have developed something resembling electric organs found in many fish such as electric eels can generate short pulses up to 600V; enough power for creating sparks across short air gaps. Sparks from these spark generators could then travel through ducts at the rear of a dragon’s mouth and ignite high pressure jets of oil and oxygen to trigger flame-throwers in its mouth, lighting off an immense inferno of fire! We may never actually witness dragons unleashing floods of flame outside fiction but it can still be fascinating to ponder their science! So next time a Targaryen orders “dracarys”, take note and think about its biology behind that magical inferno! This edited article has been published under Creative Commons license by The Conversation; please see original article here for full version with source link to original article for full version with source link to original article here