Often times when I'm traveling I don't have internet access and cannot reliably use Wolfram Alpha for unit look-up. Additionally, Alpha can always choose to change how it interprets the units I enter, and I'd rather have a notebook that is stable to any server-side changes.
So, I was wondering if there is anywhere I can look up a complete (or near-complete) list of units, constants, etc., that could be summoned using the
Quantity function (e.g.
Quantity["SpeedOfLight"]). I did not find such a list anywhere in the documentation, aside from the now-deprecated "Units" package. Is there an easy way to extract such a list? At the moment when I don't have internet access I have to resort to trial and error.