Sunday, September 23, 2012

Mineral Fail in Stargate Universe

I've blogged previously about how a sign in Yellowstone Natl. Park used the term mineral incorrectly.  Minerals, for those who don't know, are simply this: crystalline phases that are naturally occurring.  That's it.  Pretty simple, really.  A sign depicting geoscience in a national park ought to be able to use the term correctly.

But a TV show about science fiction ought to be able to get this right as well, and be able to discuss minerals & other basic chemical compounds correctly.  

Enter Stargate Universe, a spin off of the Stargate series.  In the final part of the series opening, the crew needs to obtain a material from a planet to remove carbon dioxide from the atmosphere of their ship.  The offending dialog:

"Looks like gypsum."
"That would be good."
"We're looking for calcium carbonate..."
"Gypsum is calcium sulfate, which is 36% calcium carbonate."

Calcium sulfate is 36% calcium carbonate??  Yeah.... no... not to mention the confusions in the episode about lime, calcite, calcium carbonate, and how any of that might be used to remove CO2 from the atmosphere of the planet.  They had a reasonable idea, since lime (CaO) plus CO2 can react to form calcite (CaCO3), but it just wasn't executed quite correctly.  Bu, there's at least some mention of minerals and their usefulness, even with the errors; in most shows they don't even seem to exist!

More dialog: 

"For the sake of portability & efficiency, I'm hoping to find high concentration granular limestone.  We are looking for the dry lake bed or salt-water body all the sand came from."
"It's a desert...."
"Lime is formed mostly from the remains of marine organisms." 
"Are you saying there's life here?"
"Not likely."
"The water may be gone now, but this desert was formed by H2O evaporating on a playa floor causing gypsum to be deposited in a fine crystalline form called selenite."  

Some of the sand is placed in a beaker with a liquid & swirled around, and the solution turns red.

"That supposed to happen?"
"If this sand was high enough in calcite concentration, the solution would absorb the acid."
"The liquid would turn clear."

Hey, an acid-base reaction that's reasonable!  Calcite definitely neutralizes acid, while gypsum does not.  Unfortunately, the character who seems to know the most about the minerals (a geologist perhaps?), dies at the end of this episode.