Some of you were likely wondering why the alcohol content mattered yesterday. Normally, I would write that off as something that could not be addressed, and simply left the impurity of alcohol being bad as an assertion. However, I was thinking about expanding that bit into a strip; the punchline regarding safety calculations hit me, and I made it. Teal's explanation is roughly correct. When cleaning non-water-sensitive electronics, such as some circuits and tight areas inside a case, the usual way to do it is with a Q-tip dipped in alcohol to moisten it. (As an aside: circuit boards, when made at the factory, are always cleaned sterilized; recently, some companies have begun cleaning them with lemon juice. The acid is enough to clean off the board, while the whole solution is biodegradable. Plus, it leaves the freshly printed boards with a lemony scent! No joke.) In any case, when cleaning electronics, there is an exact percentage of isopropyl (i.e. rubbing) alcohol that one should use, for the reason described in the strip: the solute and solvent evaporate at the exact same rate with the correct type of alcohol, leaving no residue (which is important when dealing with circuitry). Unfortunately, there are two things missing from this explanation. First, I was told this years ago--when I was a freshman, in fact--by a then-senior techie. I forget pretty much everything about the context, except for that little tidbit. So, I am not sure of whether this is true or not, though I would suspect it is. Secondly, and more importantly, I do not remember the exact concentration required. It might be 93%, maybe 93%, perhaps 96%. (I simply forgot, it was so long ago.) I picked 94% pretty much at random. Lastly: For those EVE players, the "safety calculation" skillbook is actually the skill Remote Armor Repair.