As to what people know…it’s really hard to say, because information is not democratized at all in Astlan.
A lot of demons know a lot of stuff, scientifically speaking since many are from an “Earth” and many are from advanced space going races and universes. The Denubians being one well mentioned example.
Wizards also know a lot, based on their model of the universe. It’s not safe to assume that the Astlanian model of how the universe works is the same as the “Earth” one. And this applies to reality as well. Some things are true both places, but not all.
The actual laws of physics are different in different worlds. Yes, at some level there is a Grand Mulit-Universe Theory of how things work, a consistent supermodel of the Universe, but what is observable on various planes of man can vary greatly.
For example, when a nuclear explosion goes off, perhaps people on Earth are unable to witness all the effects because the overall mana levels are too low. Meaning maybe there are other types of radiation and reactions that occur during atomic division, but they aren’t observed on Earth because mana levels are too low, or more specifically “not all quantum states are reachable on Earth” Similarly, the same may be true for Astlan.
I.e. Tom assumes there is radiation sickness (admittedly likely) and certain things based on what you have on Earth. But everything that occurs during fission or fusion on Earth, may not happen in Astlan, and things that might happen in Astlan, may not happen on Earth.
Also, we don’t know for sure that Exador didn’t see blue glow. Tom was there at night, and yes using demon sight. The recorded periods of Exador being there were mostly during the day. Or maybe he didn’t think anything about it.
And the blue glow could also be “something else” maybe as mundane as a secondary reaction to the explosion, or tied to some other magic….
Now: Why is everyone so freaked out by my pipe? The answer is actually quite simple, when you think about it. Tom eventually figures it out. But it’s not “conjuration” as in it was someplace else and then teleports to my hand. Nope.