I can still just remember valve receivers with them.
Interestingly my RCA book also mentions a dual magic eye valve, a 6AF6-G, never seen one of those.
The magic eye looking at you right now is a EM34 containing 2 systems (upper and lower half-circle). The EM80 is also a real beauty with its green fan. I once used 2 of them as VU meters (just as eye candy). It's about time that I finish my HV PSU so I can let them shine again.
While I'm sure you could have used just one, I like your design aesthetic. Maybe I'm being biped-centric, but eyes need to be in pairs.
The T-38 is another of those iconic birds like the B-52; and like the Stratofortress, 60 years later she has outlived every plane meant to replace her. She was designed in a different age; when pilots were meant to fall in love with their aircraft, and she is certainly a comely creature, even if intended as a trainer. It is entirely possible her feminine curves were deliberate; to excite the male libido and ego as one, driving enlistment.
Somehow I like your explanation better than the curves being just an application of the area rule.
I suspect there's a little of both in there. My first gig out of college was with an avionics manufacturer which later was absorbed by Raytheon; I lunched regularly with several of the old-timer resident aviation engineers just to listen to their stories. They were a strange lot; not the cold, mathematical automatons engineers are often painted to be, but rather soulful and humourous creatures with boatloads of irony in their "baggage". And the maths to back up their convictions.
Like Cassandra, they were cursed to "know too much"; and so were helpless to prevent the tragic comedies that seemed to constantly unfold as a consequence of their work. They had a preternatural understanding of the clockworks of the universe, and this both made them valuable to people of much inferior intellect, while at the same time drove them to forever seek a greater understanding, even as their own work broke that very clockwork they strove to understand. And the irony was that they knew all of this intimately, even the irony thereof, yet still were driven to carry on just the same.
I found myself bringing a notepad, just to scribble down strange terms they exchanged in passing; later library ponderings revealed whole mathematical, psychological & philosophical constructs that those terms referred to. It was my first inkling of the "larger world" that those with a more complete education and greater intellect than mine lived and existed in. I first "grokked in fullness" the very concept of "grok" as a result of trying to hold my own in one of those conversations.
mnem
*Cursed to know just enough to guess how little I actually know*