Saw the movie (and the tesseract) last night and said "I got to get me one of those!".
I am using 18" tempered glass tiles. I think assembly should be pretty easy but I am a little concerned that all the edges won't be uniform. The thickness of the material is an issue. I am not sure how to explain this but in the diagram I marked them 1 and 2. I will use clear silicon caulk to join them.
Lighting. Have not decided on glow or electric. I have blue glow powder I might test on small clear tubing.
I saw this post but it doesn't have the "blue nucleus" in the middle.