I think you put too strict a confinement on the meaning of physical and barrier:
The gravitational forces that hold the comets in the Kuiper Belt and the Oort Cloud, and the gravitational perturbations that allow one to occasionally escape, are allegorical or metaphorical in nature, and in no way can be considered a literal physical barrier?
Likewise the gravitational forces holding the earth in orbit around the Sun are purely allegorical in nature, and in no way can be considered a literal physical barrier?
Sound (as in the sound barrier) is purely allegorical in nature, and in no way can be considered a literal physical barrier?
Time (as in the 4 minute mile) is purely allegorical in nature, and in no way can be considered a literal physical barrier?
Light (as in the speed of light) is purely allegorical in nature, and in no way can be considered a literal physical barrier?
"That's pretty much what the Bible describes, IMO."
I know of no place in The Bible where it describes the parting of the waters by the firmament in terms of soaring domes and towering pillars. Enlighten me.
Not one that can have literal holes opened in it. I mean, come on! The comets don't escape through "windows" in the gravitation field--it's not like gravity goes away in certain places.
I know of no place in The Bible where it describes the parting of the waters by the firmament in terms of soaring domes and towering pillars.
I said "pretty much." The Bible describes the heavens spread out like a tent but at the same time as hard as a metal mirror, with God walking around in them. It's just artistic license to turn the hard metal tent into a dome held up by pillars.