The One Ring and invisibility

[Galendor]

...but the light escaping from the source becomes visible as soon as it leaves. This would explain why the Elendilmir continued to shine until Isildur covered it with his hood, and why Sting shone when drawn but not when sheathed in the presence of enemies.

That makes sense - as soon as the light (photons) leave the source, they become visible. Just like if the wearer of the Ring throws an object, it becomes visible the moment it is no longer touched.

But the notion that objects one is holding or wearing at the moment one puts on the Ring also become invisible raises silly questions. For example, if Frodo were holding a pint of ale and slipped on the Ring, the pint of ale should also become invisible. And if a pint of ale, then also what if he was holding, say, a chair? Does it have to be suspended in the air to become invisible? Does the pint? What if the pint is on the table, but Frodo is firmly grasping it?

I also like the explanation from The Might that the invisibility of the wearer is caused by transportation to an alternate "wraith" dimension, that is "alongside" the one other normal people inhabit. Perhaps entering this wraith dimension allows a knowledgable wearer (like Sauron) better access or immunity to magics, and this was the true intended power of the Ring.

In The Hobbit, Bilbo wears the Ring constantly for a period of days or weeks (longer?) while figuring out a way to free the dwarfs from the Mirkwood elves' dungeon. I know The Hobbit is pre-LOTR and not necessarily consistent with it, but if it were consistent then Bilbo would have existed in the wraith dimension for a relatively long period of time. Fortunately the Necromancer did not sense him there!