Dom and Rachel felt like kids again. This camping trip had been almost identical to the one they’d done as teenagers. Admittedly without their accompanying families. And the need for one of their older brothers to buy alcohol for them. But the fire they were sitting around now was pretty much the same. And they were very much old flames. Just friends now.
“Rachel, what is fire?” Dom asked, pointing an accusatory finger at the campfire in front of them.
“Oh, don’t start this again.” Rachel recalled a similar conversation going nowhere back in their teenage years. She cracked open two more cans of tepid Tennent’s lager and handed one to Dom, who took a sip.
“Well, you were at school last time I asked you, about to do your Higher Chemistry. and what you said didn’t make sense to me then. Maybe now you’re an actual lecturer in Chemistry – at the University of Edinburgh, no less – you’d be able to give me a proper answer.”
“Fire is the very bright chemical reaction between fuel, in this case wood, and oxygen in the air. Next question.”
“I’m not satisfied with that answer and neither are you.”
“What about it doesn’t satisfy your delicate poetic mind, Dominic?”
“Why does it look the way it does? Why is it orange?”
“Well, it’s not always orange.”
“Why is this one orange?”
“It’s not completely orange. There’s a little blue bit at the bottom.”
Dom gave Rachel a look of loving exasperation. It took her back to their childhood days.
“Are you enjoying this?”
“Ok, so in this fire, the blue bit is the colour given out from the full reaction of hydrogen and carbons in the fuel, creating carbon dioxide and water. The orange is unreacted bits of carbon or soot being heated up and glowing.”
***
Fernando was listening intently. This was the first time he had ever heard the humans talk about him directly. Normally when he was a campfire they were talking about their feelings or telling ghost stories. He would always marvel at how the humans reacted to him differently depending on the context under which he was created. When he was in the hearth, the humans were happy. They would all gather around him, stretch out their arms and say things like “ooh, isn’t that lovely!” When he sprung into existence at the strike of a match, only to be used to light a cigarette, he definitely felt a little less special. He continued to exist for a while in the burning embers of the tobacco, but he knew this too would be fleeting. Not to mention he was suddenly implicated in the production of some pretty foul-smelling smoke. He’d never claimed to get on with the likes of hydrogen cyanide, arsenic and polonium-210. They gave smoke a bad name. Then there were the rare situations when his existence would cause outright panic. Humans running around the place, scared of him. Maybe the less said about those days the better.
But his orange glow was due to excited soot particles? Well, now he was learning. He felt like calling out to the humans to thank them for educating him. Maybe a little crackle would get their attention.
***
Dom and Rachel both jumped. That was quite a crackle.
“I think the fire likes you, Dom!”
Dom didn’t seem to quite share Rachel’s enthusiasm. “I will like the fire when I understand what it is and why it does what it does. Why does the fire crackle?”
“Well, that’s actually mostly to do with the wood, not the fire. The wood has little pockets.”
“What, like jacket pockets?”
“Sort of. But these pockets are full of water and sap.”
“Ew.”
“When the fire heats up the wood, the water and sap turn to gas. This expansion from liquid to gas causes these pockets to explode, which we hear as a crackle.”
“Crackle equals exploding sap gas. Got it. Now back to the colour. Why does the soot glow orange and not purple or green?”
“You really are on a mission today, aren’t you, Dom?”
“A fire burns inside me, Rachel, what can I say.”
Rachel rolled her eyes, although deep down she was endeared by his hopeless romantic side.
“Well to understand the colour of fire, we need to go subatomic…”
***
The past hour or so had been an absolute blur for Ellie. Life as an electron was always a bit of blur anyway, but this was next-level blur. All of the protons and neutrons in her original carbon nucleus used to joke that they could never trust any of the electrons in the atom as none of them were ever where they’d say they’d be at any given moment. She’d tried to explain several times that this was a consequence of the quantum mechanics that governed all particles of her size but, by the time she’d started to explain, she was already at the other side of the atom and the nuclear particles were too far away to hear. Protons and neutrons are so much bigger than electrons and after a while these kinds of comments did feel a little bit like bullying.
In her frenzied state of perpetual motion, of intense energy, Ellie wished she were back in the safety of that carbon atom right now. She’d always heard stories of other electrons getting excited and even leaving their atoms to join bonds with other atoms, and it certainly sounded like fun. Still, Ellie had been through over four and half billion bond making and breaking cycles in the past hour. She was ready for a rest. Some minor bullying about her quantum mechanics right now would really be quite a welcome break. The word “fire” had been thrown around quite a lot by a few of the electrons she’d shared instances with over the past hour. That was about all that could be communicated in the split second that she’d spend with another electron in a covalent bond before the heat would rip the bond apart and she’d be sent flying around again.
If she wasn’t flying in and out of covalent bonds, then the heat would be making her extremely excited within an atom to the point where she would actually emit a photon of visible light. Ellie had no comparison for this experience in her life. It really was like nothing else she had ever experienced. Perhaps the equivalent of an electron orgasm? She really couldn’t be sure. Nevertheless, she would always come out the other side in a state of deep relaxation. She managed to return to the lowest energy level of the atom for a few nanoseconds of peace and quiet before the heat and the associated excitement returned.
Ellie began to notice that the colour of photon she emitted changed depending on the amount of energy she absorbed and the corresponding climax she experienced. Most of the time the photons were orange, corresponding to the fairly mild levels of excitement from fairly mild temperatures, but when Ellie got super excited from being super hot (and bothered), sometimes she could produce blue photons or even combine forces with nearby atoms to mix red, blue and green photons together in an orgy of white light.
Ellie’s initial reservations about being thrown around unceremoniously between different carbon atoms had now been replaced by a deep satisfaction and a feeling that she really didn’t want the whole process to end. She only hoped that whatever higher purpose the fire served, it had similar gratifying conclusions. Perhaps even the creation of a bond.
***
“Are you still with us, Dom?” Rachel noticed that Dom appeared to have zoned out into a world of subatomic satisfaction. “It’s important to note that electrons aren’t actually conscious.”
“I mean, you definitely had me for a little moment there.”
“You are very easily captivated.”
“I think I’m left with even more questions though…”
“Such as…”
“Oh, I don’t know… how does an electron produce a photon? How does quantum mechanics influence the position and speed of an electron? Do you see us ever getting back together again?”
Rachel choked on her beer. “Well, that came out of nowhere.”
“All this time spent with you now has been reminding me just how well we worked together back then…”
“We were teenagers, Dom. That was a long time ago.”
“A fire burns inside me, Rachel, what can I say.”
“You really are a hopeless romantic.”
“Hopeless romantic and proud.”
“Look, this weekend has been absolutely lovely. I’d be lying if I said I hadn’t been wondering if you had something else in mind the whole time. I’d also be lying if I said it hasn’t been in my mind too…”
A large grin spread over Dom’s face. He felt a thrill.
“Oh, Rachel! My heart is fluttering at the speed of Ellie the Electron!”
There was a pause. Rachel tried to process what Dom had just said.
“Who’s Ellie the Electron?”
“Ellie the Electron! The climaxing electron in the story you just told!”
Rachel looked perplexed.
“Oh, never mind! Anyway, this whole evening has been a wonderful gift from Fernando!”
“Who’s Fernando?”
“The fire, silly! Tonight he will burn long and bright, content in the knowledge that he has rekindled something truly great.”
“Dom,” Rachel pulled him into her arms, “a fire really does burn inside you.”
She saw the fire in his eyes.
“What can I say?”
Fernando let out his biggest crackle yet.
Authors’ note: This story originated from a series of conversations we had with friends over the past few years where we’ve tried to explain what fire is in scientific terms and failed spectacularly. Hope this clears things up!
