Pronunciation of the symbol $\varnothing$ of the empty set The symbol $\varnothing$ for the empty set was introduced by Bourbaki, inspired by the Norwegian alphabet $\varnothing.$ It has no relation with the Greek letter $\phi.$
From my schooldays, when the concept of the empty set was introduced, I found people pronouncing this symbol of the empty set as "Phi". 
My questions are: 
If the symbol has no connection with the Greek letter "Phi", then is it legitimate to call it "Phi"? 
If not, what should we call the symbol $\varnothing$? 
How is the Norwegian letter $\varnothing$ pronounced?

Ø in Norwegian is pronounced somewhat similar to u in under or ea in early [1]. 
I think it is generally called "the empty set" and it is not acceptable to call it "phi". 
[1] http://www.omniglot.com/writing/norwegian.htm
