3
$\begingroup$

Background

A large colony lives in the Antarctic in a network of bases. They have so far evaded the dreadful worldwide plague.

enter image description here

When they venture outside their base they don their climate-proof clothing and their goggles. These goggles have liquid lenses.

Transmissive liquid lenses use two immiscible fluids, each with a different refractive index, to create variable-focus lenses... The two fluids, one an electrically conducting aqueous solution and one a nonconducting oil, are contained in a short tube with transparent end caps... The shape of the lens is adjusted by applying a dc voltage... http://www.smartalix.com/liquidlens.html

Question

The colonists use beer as one of the immiscible liquids in their goggles. Why is this?

$\endgroup$

This question asks for hard science. All answers to this question should be backed up by equations, empirical evidence, scientific papers, other citations, etc. Answers that do not satisfy this requirement might be removed. See the tag description for more information.

  • $\begingroup$ Cold weather goggles are typically used for protection, not to improve eyesight. People with 20/20 vision don't need any lenses in their goggles. Is everyone on this base nearsighted? $\endgroup$ – Nuclear Wang Feb 7 at 19:40
  • $\begingroup$ @Nuclear Wang - They drink a lot of beer but I don't know if that affects their eyesight. Some are shortsighted, some are longsighted. They don't have any other kind of corrective lenses available because there is no optometrist and no lens-grinding facility. $\endgroup$ – chasly from UK Feb 7 at 20:02
  • 1
    $\begingroup$ I was thinking that a variable focus lense could be used to create goggles that also work like binoculars, or microscopes, depending on voltage used. $\endgroup$ – AndyD273 Feb 7 at 20:07
  • 1
    $\begingroup$ ummm... would beer even be immiscible in the first place? It has alcohol and water which would cover a very large range of liquids... the article also mentions that one needs to be an electrically conducting aqueous solution and the other a nonconducting oil $\endgroup$ – Shadowzee Feb 8 at 4:48
10
$\begingroup$

Beer has a slightly lower freezing point than water, and is less corrosive to the electrical contacts than salt water with the same freezing point. Even better, beer can be made dark as part of the regular process (simply by roasting some of the malt longer/hotter). Therefore, the same liquid can be used in its varifocal role, as a filter against excessive sunlight (and changed out for a lighter brew in winter/night), and won't freeze at the lower temperature setting needed for some of the local conditions.

Ordinary beer freezes at a couple degrees below 0 C; wine a little lower. However, beer can be made as strong as wine and give a freezing point around -5 C -- or you can partially freeze the beer ("jacking", from apple jack, made by freezing cider) and pour off the liquid and obtain a liquor as strong as 50%, or even higher. By report it's horrible stuff to drink, but the freezing point of 50% alcohol in water is close to -40 C; by this method you can lower the freezing point down to whatever temperature your refrigeration (or weather) is good for (even Antarctica isn't likely to give you 95% alcohol, which freezes at about -118 C).

Freezing point graph of water/alcohol solutions -- from Quora

$\endgroup$
  • $\begingroup$ Do you have any figures for the lower freezing point? $\endgroup$ – chasly from UK Feb 7 at 18:23
  • 2
    $\begingroup$ Varies depending on alcohol content. Common beer at 5% ethanol ought to be good down to about -5 C, but you can make it stronger -- up to around 13%, or let it partially freeze and pour off the liquid, producing a beer-derived liquor at up to 50% or stronger. Ultimately, you can get down to about -45 C for the lowest possible water/alcohol eutectic. $\endgroup$ – Zeiss Ikon Feb 7 at 18:26
  • $\begingroup$ I've edited the tags to say hard-science because you have given some figures and no-one else has answered so far. Would you put those in the actual answer please? Thanks. $\endgroup$ – chasly from UK Feb 7 at 18:35
  • 1
    $\begingroup$ Edited, also added a graph from which I corrected my figures. $\endgroup$ – Zeiss Ikon Feb 7 at 19:50
  • 1
    $\begingroup$ @Alexander You'd have to ask the brewers who sell jacked beers. I called it a "beer derived liquor" in my comment that spurred the edit that added the actual figures.. $\endgroup$ – Zeiss Ikon Feb 8 at 12:07

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.