Hello everyone and welcome to a special Rachel’s Science corner! Here you’ll find the audio for a special science expose that unfortunately didn’t make it into the final cut for our last episode, Ep. 45: Abandon All Hope Ye Who Enter Here. Towards the end of the book, (SPOILERS!) there’s a huge stand-off between our main characters and the big big bad guy regarding a recipe for explosives and detonators. Now I’m not a chemistry expert, but the explosion generated by this supposed recipe seemed a little crazy for what went into it. I would argue that BECAUSE I’m not a chemistry expert, I was very much proven wrong. I actually reached out to a chemical engineer friend of mine to get her official thoughts on the matter. She’s in the process of writing me up a beautiful, and far more in depth, commentary on the whole thing. This blog post will be updated with her comments as soon as she’s done! Stay tuned to our social media for that!
Now because I talked about the chemistry so full in the episode, and my friend will be talking about it in the future, I decided instead to discuss whether or not they would have survived such and explosion. So in the book, our two intrepid main characters jump out of a window (dramatically!) just as the cabin explodes and are miraculously okay. Sure they get stunned a bit, but for the most part their surprisingly unscathed from the whole experience. I’m not even going to go into how little they’d be able to hear after that (you get tinnitus from modern day firearms and this is the 1770s) so I guess the big question becomes: Exactly how much percussive force can the human body withstand?
Fortunately for us, the CDC has done a lot of the leg work for us when it comes to figuring this out. According to this study, the resulting shockwave from an explosion that blows out the windows of a house will create a maximum wind speed of 38 mph and will only cause minor damage to a human body. Let’s take a moment to quote page 319 of the Kindle edition of Teresa Medeiros’s Heather and Velvet:
” Prudence’s cheek nuzzled against something hard and familiar. She pulled off her shattered spectacles to discover it was Sebastian’s chest. They were sprawled in the grass in front of the crofter’s hut, thrown clear by the blast.
What had been the crofter’s hut, Prudence corrected herself. Only a smoldering shell of rubble and twisted boards remained…”
I’d say that goes a bit farther than blown out windows. In fact, I think that goes even farther than the second possibility on the CDC’s guideline: “Moderate damage to houses (windows and doors blown out and severe damage to roofs)”. (Which I might add results in “people injured by flying glass and debris”)
In my expert (read: not expert) opinion on demolitions, I’d say that qualifies as a residential structure collapsing: the third phase of destruction on our handy dandy list. The pressure wave of an explosion of this magnitude would likely produce a maximum wind speed of 102 mph. Not only that, but “serious injuries are common” and “fatalities may occur”. I don’t think our pair of lovebirds would have made it out of that without SOME amount of bodily trauma. I’m even more impressed that Grandpa survived being at ground zero.
To give credit where credit is due, this hut is probably fairly small and may even be dilapidated. It probably wouldn’t have taken quite that much force to knock it down. I think it’s safe to say, however, that they made it out of that situation in significantly more pieces than they should have.
Your Co-Host Rachel