One of the funniest moments in The Last Jedi happened on Crait, when a Resistance soldier touched the ground, licked his finger, and said, “Salt.” Most people don’t taste rocks to figure out what they are made of, but it turns out the joke’s on us, because a geoscientist has explained why it was a totally reasonable thing to do. This week on Twitter, EW‘s Dana Schwartz had what seemed like the right response to a method used for determining the difference between a rock and a fossil.
lick a fucking rock. just do it. see if it’s bones. who cares. stick the entire thing in your whole stupid mouth. pic.twitter.com/e43P2wxfwk
— Dana Schwartz (@DanaSchwartzzz)
But because sometimes the Internet is actually good, field geophysicist and disaster researcher Mika McKinnon defended the seemingly absurd practice, which she says is a quick, effective (and safe, if you know what you’re doing) tool for scientists to employ in the field, because texture and taste tell them a lot.
I’m feeling weirdly hurt by the viral tweet mocking geoscientists for licking rocks.
I get that we’re a bit weird even for scientists and get a bit more blunt with our toolset, but licking rocks is a real strategy. Taste & texture are diagnostic. pic.twitter.com/9XvrfU32JQ
— Mika McKinnon (@mikamckinnon) August 16, 2018
I don’t lick every wild rock I meet, and licking lab samples is just gross.
But if you’re out doing field rock ID, you already know enough to keep your tongue away from arsenopyrite & don’t waste your time nibbling granite.
— Mika McKinnon (@mikamckinnon) August 16, 2018
If I had a nickel for every time I said you gotta avoid those arsenopyrites…
That why she says it was actually a good idea for the Resistance soldier to lick the surface of Crait in Star Wars:Â The Last Jedi.
Epilogue:
Q: But what about that salt-licking scene in Last Jedi? Surely that was ridiculous!
A: No. That was plausible bordering on geo fan service.And it’s tactically important to know what rocks encompass you unless you’re a fan of dumb ways to die. pic.twitter.com/aaayanVa3h
— Mika McKinnon (@mikamckinnon) August 16, 2018
She also gives high marks to Doctor Who for using a proper tasting technique, but Jack Sparrow get a tongue-lashing for needless licking.
Q: What about the Doctor?!
A: Excellent tasting technique.I don’t remember which episode this is for context, but I’d guess dry former water body with sour-bitter-tangy sylvite (or salty halite, but that’s usually less pucker). pic.twitter.com/pFSLLPfUUJ
— Mika McKinnon (@mikamckinnon) August 16, 2018
Q: Please critique Jack Sparrow’s geology taste test technique?
A: Terrible.First: WAY too much tongue. It’s test, not a snack.
Second: Any rock tough enough to weather into that nice smooth shape isn’t one where taste is diagnostic. All you’ll get is the seawater coating. pic.twitter.com/PvlQZn3Y37— Mika McKinnon (@mikamckinnon) August 18, 2018
Okay, so we should all start licking rocks to expand our own scientific discovery, right? Not exactly.
Bad minerals to lick:
Anything that smells like garlic (arsenic). Even handling is sketch thanks to carcinogenic, neurotoxic powder; burning is bonus bad news.
Arsenopyrite: arsenic + sulfur
Orpiment: arsenic + sulfur
Hutchinsonite: sulfosalt of thallium, lead & arsenic pic.twitter.com/jDOZqVhrt1— Mika McKinnon (@mikamckinnon) August 18, 2018
It’s safe to say most normal people should still not lick rocks. Leave it to the scientists. And Resistance soldiers.
What other pop culture examples of characters licking rocks would you like to have fact-checked? Tell us in the comments below.
Featured Image: Lucasfilm
