Hi guys, Its my first post here, Basically I am Graduate in physics with degree Title "Physics with Telecommunication" , After that I have done Masters in "Networks & Telecommunication". Now i want to get Enroll into PHD, but the problem is, which topic should be chosen. Kindly suggest it to me, i am highly interested in Em-waves, Gravity, Space Science, Astrophysics, & Network Security. further more i want to tell you that I have a professional knowledge about Linux, Computer Networks, ISP & Network Security. Kindly suggest me a topic for PHD :) Thanks.