06:48 – When I was making up solutions for forensic kits yesterday, one of them required concentrated sulfuric acid, 160 mL of it. I always weigh sulfuric acid rather than measure it volumetrically, so instead of putting 160 mL into a graduated cylinder, I put 294.4 grams of it into a tared beaker.
As I was doing that, it struck me that my failing memory is something I need to take into account. I of course remembered that the density of the acid was 1.84 grams per mL. I’ve known that since I was about 12 years old, along with the densities, freezing points, and other key physical characteristics of hundreds of chemicals. Maybe thousands. At any rate, of any chemical I’d ever looked up even once. I should say, I “knew”, since those tens of thousands of factoids that used to reside in my memory have apparently taken the last train for the coast.
Yes, it’s easy enough to look up the density of sulfuric acid on Wikipedia, but what if Wikipedia is no longer accessible? In this case, it wouldn’t have been a problem, because I have a copy of the CRC handbook on the shelves downstairs. But what about all the stuff I used to know from memory I no longer remember? I need printed copies of that type of information. Either that, or a hypnotist who’s good at recovering lost memories.