A force field that creates a barrier that people can pass through but air cannot - an airlock in a spacecraft. (Read
the full article)
"I always wondered if (and how) this would work in real life. The book doesn't really offer an explaination how the Curtain works, nor does the device seem to use a Langston Field. "
(Gatomon41 11/28/2012 2:06:34 PM )
"Clever Moties! As you recall from the story, they had other miraculous devices, including the galaxy's best coffeepot. As far as I know, the only successful 'curtain' technologies are the Air Curtain devices you sometimes see used in zoo exhibits that house butterflies. They are permeable for people - but not insects.
Supposedly, they can be used to separate 'Smoking' from 'Non-Smoking' sections in hotels."
(Bill Christensen 11/28/2012 2:26:26 PM )
"If you're interested in this 'curtain' idea, you should also check out this sonic barrier used in a Roger Zelazny novel."
(Bill Christensen 11/28/2012 2:37:18 PM )
A System To Defeat AI Face Recognition
'...points and patches of light... sliding all over their faces in a programmed manner that had been designed to foil facial recognition systems.'