Day One

After the isolation of working on my own in the last programme, it was great to hear from Kate that our next challenge would involve us working together as a team. On the face it if there were two separate challenges – first to build a refrigeration unit to make a water coolant (Mike, Kathy and me), and second to build a circulation system to pump that water round a make-shift spacesuit (Jonathan and Ellen). Actually, whether or not this was going to work would hinge on the two teams designing this together. So our morning was really about putting our heads together to see what the options were. That’s what’s nice about the Rough Science format – the instances of jeopardy and the backdrop of healthy competitiveness never take away from the fact that scientists tend to want to work collectively on problems rather than beaver away on their own. At the end of the day it’s a team sport.

Mind you, as a geologist I confess that I wasn’t much help in thinking of how our system would work – I mainly fiddled nervously with my hammer. I just couldn’t think how my geological skills were going to help here. As the new kid on the team, I’d also got the feeling that our production team had fingered me for the final test – walking in the spacesuit in the searing temperatures of Death Valley. Perhaps that’s what the geologist would be good for in this programme – bait. Ellen – bless her – put a stop to that, arguing passionately that we were all equal members of the team and that it wasn’t fair to pick on anyone (even a geologist). Rallying to support her, I pointed out that the spacesuit was too big for me anyway. Perhaps less helpfully, I pointed out that it was perfect fit for Ellen. Clothed in bright red cotton, I think she wished she’d kept quiet.

As the day wore on and hard graft started looming, I finally thought of something geological I could do. Our idea is to make a refrigeration device by creating a partial vacuum, inside of which water will condense into steam, cooling as it does so. Normally of course that happens at 100C, but if we get the pressure low enough we ought to get steam at normal air temperature. The trouble is that the steam will condense back into water, reversing the reaction and giving off heat. To solve the problem, Mike has caught onto the fact that the washing powder in our trunk contains zeolite, a mineral substance that draws water vapour into its crystal structure and holds it there. I had no idea that zeolite was in washing powder, but I did know that it occurs naturally in volcanic rocks. At last, a chance to escape the workshop and get into the wilderness. Kate, keen for more offroad driving, is a willing chauffer.

Now to most geologists zeolites are rather boring, unimportant minerals – quickly passed over in most geology lessons. But to chemists, zeolites are amazing minerals, with hundreds of different uses. For me, the worry is that their crystals come in lots of shapes and forms. Often they appear as tiny glass-like bubbles in volcanic ash (tuffs) or lava flows, but sometimes mixing of water and heat in deposits underneath lava flows can convert the whole deposit into a thick layer of whitish powdered zeolite. This is a particularly common in the desert volcanic landscapes of western USA, so that’s the form I was hoping to find. Finding volcanic ash layers and ancient lava flows is no problem around our silver mine home – much of the geology of the area is volcanic. The problem is distinguishing our zeolite layers from common old clay, since both have that fine whitish appearance. Zeolite minerals tend to have a sheen that clay particles don’t have, but the real test is to heat it up. Zeolites adsorb (take in) water vapour without chemically reacting with it, so later, when heated, they release the water back again. That’s where they get their nickname – ‘boiling stones’. Armed with a bucket and a primus stove, Kate and I hunted nearby volcanic rock outcrops for our powdered prey, and until we struck lucky. A few smacks of the hammer and a quick burst of flame and we had our frothing stew of zeolite. Almost good enough to eat!