Why is that so many people on this forum feel that the information pointed to by this link is of such great importance: https://gist.github.com/jboner/2841832
I don't know if that information is contained in a particular book, but it is certainly readily available all over the web.
Why do we care? Could Edison have had a similar interest, though focused more on his own business?
Separately, what good is knowledge of theory if you have no practical experience upon which to understand it? The candidates given this test were also supposed to be in line for the executive ranks. Having a general knowledge of geography, geopolitics and trade would seem to be fairly important.
It's also unclear from the article exactly how Mr. Edison interpreted or used the results. Frankly, it sounds like many of those quoted in the article were offended by being asked such "simple questions"... despite not being able to answer them. Perhaps Mr. Edison was interested in finding executives who didn't believe that common sense, mundane facts or important business details were beneath them and best left to others.
Those numbers are of practical importance to programmers in particular. They directly affect nearly everything we do to some degree. On the other hand, without knowing anything about you, I can pretty confidently guess that the identity of Leonidas and the process of tanning leather are not practical concerns for you at all.
Also, I would argue that memorizing those numbers themselves is unimportant and putting too much stock in them is a mistake (some are very likely a bit different on the computer you're working with than they were on the one used to compile the list — for example, hitting L2 cache is slightly faster than a branch misprediction on the i7 IIRC). The important takeaway IMO is the orders of magnitude at work.
If you were developing technical products in 1921, the process of tanning leather was probably very relevant, as were questions about the density of different kinds of wood, the sources and production of various metals, etc.
Just as a programmer should know the orders of magnitude of latencies, an industrial engineer in Edison's time should have a sense of the characteristics of materials he might be choosing between. For example, should the handle of a new tool you're inventing be made of leather-wrapped steel, or hickory (traditionally used for ax handles)?
The trick is not that the information is available but knowing where that information is, so that if needed, one could look it up.
I tend to want to remember the places (in this case, blogs, books, articles,etc.) where I could start looking to find a piece of information as more important.
A simple example of this is me wanting to learn Backbone.js. I have been following Addy Osmani's blog and know that he can be considered an authority on Javascript.
I trust that I have picked one of the top people in this area to help me learn this. If I just Google, just the sheer amount of links to blogs, training sites, videos, etc. would be overwhelming. It would be likely that I would pick a resource that is not the best.
With the information overload that we have, you now stand out by being able to find (and apply) the information in a timely manner.