I heard that in the US someone invented years ago a special type of
paint that after painting say a room with it then when the room is
dark one gets the feeling that the painted walls as if 'vanished' and
you 'feel the outside atmosphere...'
Is there such a product and who manufactures it?

Maybe this is the feeling you get after sniffing the paint. ;-)

Seriously, how could this be possible? Within the known laws of
physics, how could a paint cause walls to literally disappear? As far
as I know, even the most sophisticated stealth technology cannot
achieve such a thing.

pinkfreud....LOL
Read what I said - "one gets the FEELING that the painted walls AS IF
'vanished'..." - not that it really happens!!!
I just spoke a few minutes ago to a friend in the US who told me that
he saw a room painted in this paint and he found it difficult to
describe the feeling and I quoted his words.
So for sure there is such a product!
:-)

This is magic paint.

It's only available from Wizards of the 49th Degree.

Perhaps your friend is referring to walls painted in a "trompe l'oeil"
fashion that fools the eye. In such a case, there is nothing special
about the paint: it's the artist's skill that does the trick.

Thanks...I'll check if it's so.
:-)

pinkfreud - no no - it's nothing of that nature.
Apparently it's as I described above.
And I know as a fact that the manufacturers HAVE A WEB SITE and I also
know that they have sold during the years Franchise for marketing this
paint  across the US States.

In order to have any impact at all after the lights are turned out,
paint would have to be phosphorescent, right? So is this some kind of
luminous paint?

No idea....I understood that it's not that kind of paint.
I also learnt that the manufacturers operate from Clifornia.
:-)

*California

California, huh?

Say no more ... All is explained ... It's SFX.

I've vague memories of hearing about something similar
- not vanishing walls but the illusion of space

Possibly it was something to do with high reflectivity paint
- perhaps a spinoff from lighting technology

http://www.archlighting.com/architecturallighting/al/details/article_display.jsp?vnu_content_id=1001958428

|Paint Modern "powder-coat" white paints, now used for most basic
lighting products, offer more than 90 percent total reflectivity.
Compared to the 80 percent total reflectivity of earlier paints and
porcelain finishes, this simple advance makes almost all current
fixtures more efficient than older ones. Some recent paints have
amazing characteristics: At least one lighting manufacturer now offers
products painted with 96 percent gloss white paint. Another new paint
produces over 96 percent totally diffuse reflectivity, without any
gloss.|

Thanks frde!
I will check it.
:-)