Well I was watching an older episode of Mythbusters today where they busted the myth that you could rapidly cool a 6-pack of beer by burying it in the sand, pouring gasoline over the sand, and lgiht it afire… Somehow created some magical thermodynamic reaction and cooling the beer (I believe they said something about the fire taking the heat from the beer or something similar).
Now, this myth was obviously busted but doesn’t its fundamental principle violate the Clausius statement of the Second Law of Thermodynamics anyhow? I guess I don’t even understand how anyone could believe this myth in the first place…
Then I came across an alternative “idea” that some other people came up with: http://www21.sbs.com.au/sbsforum/viewtopic.php?t=10606 but I’m not buying that theory either. Are my thermodynamic assumptions correct here in that this myth wouldn’t even work from a theoretical standpoint?
That sounds like a pretty fucking stupid myth to me. I never heard of it, and why would it work? Maybe if you just poured an extremely volatile gas over the sand, the evaporation would cause a small amount of cooling of the beer.
It derives from the unfortunate over-simplification that is often taught to students, that hot air rises. As a result, people think that the fire would send the hot air shooting upwards, leaving a vacancy that gets filled with coldness from below, cooling the beer.
(1) Beer hole, down by the water’s edge. Beer goes in sand and is constantly being cooled by cool ocean waves. Rinse sand off the cans and serve chilled.
(2) Fire hole, back by the dune. Gasoline is a nice starter but use driftwood, hurricane wreckage, and flotsam to make a good-sized bonfire that will last. Wait until you’ve got coals to lay clams, corn, foil packets with meat, etc. on the fire. After dinner refresh the bonfire with wood.
You bring the cold beer to the hot dinner – that’s the only thermodynamics worth worrying about in this scenario. Anyone who tells you this is in danger of rising precipitously, because they’re full of hot air.
The origin might be from WWII when soldiers but beer cans in jerry cans filled with gas, then bubbled air through the gasoline to evaporate it. This is supposedly what cooled the beer.
I learned of the concept in 1983 from one of my anthropology professors, I’m not clear if he did it himself or just heard about it while in the war.
When a liquid changes form to a gas it absorbs heat, an easy experiment is how cold rubbing alcohol feels on your skin as it evaporates. If you can increase the rate of the change from a liquid to a gas you should be able to increase the amount of heat absorbed – for example The Jet Powered Beer cooler .
The ‘gas over sand’ myth was probably just a mistaken application of this information.
This idea reminds me of another one for keeping vegetables (and even beverages) cool by storing them in an earthenware pot in another earthenware pot filled with wet sand.