Could they make a huge fluorescent or neon light tube - maybe 6 feet diamerter & let me go inside it and turn?

Question

the light on?

Would that be totally trippy, or deadly?

Why the h**l hasn't this been tried before?

Answer 1

It would be deadly.  Even if you wore a respirator device to allow you to breathe, you would probably not survive the thousands of volts of electricity necessary to create the arc that makes a neon tube glow.  You probably wouldn't even make it to that point though, because before a neon tube can be operated, it first goes through a process called bombarding, where a high voltage is applied to the terminals while a vacuum pump removes the air and the tube is heated to high enough temperatures to burn off any impurities in the tube before the neon is put in.  Your body would likely be considered an impurity, unfortunately.

Answer 2

You probably good make one big enough, but the gasses inside the tube (that actually light up) are not breathable air.   You would suffocate.