Revelation space is a speculative fiction novel set in the far future during the golden age of space colonization. Spoilers ahead.
Throughout the novel there's alien civilizations that use different kinds of way to cloak constructs and settlements. Examples include devices like artificial moons and holographic, multi-spectral holograms that emulate gas giants to hide stuff inside.
The one I think andrewflnr may be referring to is a device that one race used to cloak entire regions of space to hide their civilization from technologically superior aggressors. Essentially they set up variable-gravity devices at strategic points around their region of space, and had the devices resonate to build 'waves' of gravity that would constructively interfere at a massive scale at the borders of their space, which would essentially tear any intruders apart using the amplified+alternating gravity waves. Several million years in the future, observers/scientists of other races on the outside would dismiss these chaotic space regions as an unexplained anomaly.
Mostly, I was thinking of that whole theme in relation to the
"incomprehensibly huge threat" thing Udo mentioned. If you're talking about Shrouders, I don't remember that method of using gravitational waves being mentioned. Did you hear that somewhere else?
