Robert Comsol wrote:
As is common with McCall works, the spectacular background often overshadows the subject. Note the interesting detail representing the warp field emitted by the engines. In McCall's vision, warp drive left a distinct, luminescent wake.
I forwarded the image to Andrew Probert and here is what he had to say about it:
"We [him and McCall] did talk, a couple of times, but this warp-interlace idea was totally being considered when Mr. McCall did this series of promotional paintings. This idea was very close to being implemented for a while."
Outstanding! Thanks for doing that. I wonder if it was Jesco von Puttkamer (science advisor to ST:TMP) who put the kibosh on that notion. I remember reading that he felt that any sound or light display would represent an inefficiency in the system. Of course, the final look of warp drive in that movie went spectacularly loud and bright anyway.
It's amusing that the latest film, Star Trek Into Darkness
returns to the concept of warp drive leaving a "wake". Although in that movie's case, it's more a kind of pixie dust that glitters in the space formerly occupied by the nacelles.