Sometimes, I feel to contact some of the eminent researchers in my field for any of the following reasons:


Appreciating their research publication (recent times). They publish in top conferences, which are usually not hosted in my country or nearby.
Requesting comments on some of my research hypothesis
Sometimes just because I am a die hard fan of them. For example, probably the only reason I continued with research in Computer Science was due to Don Knuth.
Sometimes, to know what they think on some specific research area that has propagated due to there work. (Probably looks like some journalistic work)
For knowing how did they tackle the pressures or certain situation during their PhD or research. (Yes, it's vague but these questions come to mind and probably should be answered by oneself or personal interaction, but adding it for the sake of completion)


Since, most of them are located outside my country, I can't visit or phone them. So, how are such emails perceived. Is it appropriate to send such emails, given that they are expected to have very busy schedule and it would probably waste their time?

Though I have mentioned my field as Computer Science, the question should be applicable to all the fields. 


Question: Why are the Raspian repositories so out of date?
Answer: I know link updates are frowned upon, but this is an internal link to what you need. 

Half way down that answer it shows how you can select packages from Jessie repository so you can install the latest ones will be there.

http://raspberrypi.stackexchange.com/a/15061/894