My position, certainly for my own writing, is that the technology should be pretty much part of the furniture. Not something that needs a scientific explanation for how it works.
Mood's point, which he clarified further, was that in sci-fi you can get away with rather more infodumping than in other genres.
I'd like to challenge that a bit, and open it up for debate.
The big temptation in sci-fi is to explain things, because it's a neat idea and maybe a clever spin on some scientific theory, and maybe you want to impress other geeks with how clever you are.
If you want folks to stop every few paragraphs in order to pick your explanations apart, then fill yer boots.
If, however, you want people to read and enjoy the story, then I suggest steering clear of anything that gets in the way.
I suggest that a detailed explanation for how a piece of technology works is only required, or even desirable, if the explanation is essential to the story.
Now, remember that how it works is not the same as what it does. The latter is usually important to understand, but can be usually conveyed by showing how technology interacts with the characters.
Here's an example from Ghosts:
Finn took a deep breath and nodded. "Time to pick up her trail." He handed Shayla a thin translucent strip about an inch across and a few inches long. "You know how to use a nose, don't you?"
"Yes, of course." Shayla took the strip and placed it across her eyes. It stuck to her skin and held itself in place. To outward appearances, this might have been nothing more than a fashionable sun visor. Perfectly reasonable in the harsh light up here.
Through the hard but flexible material she could just make out the outline of the path. Her vision cleared when she squeezed the topmost of a row of tiny protrusions at each end of the strip, and a luminous display hovered in her line of sight. Shayla gently fingered the bumps along the edge, tuning the device in to the chemical signature that had been planted on their quarry. This was another secret from the Firenzi materials laboratories, but one which the Insurrection had known about for decades.
"Got it." A hint of fluorescent violet hung in the air in front of Shayla. "Raven managed to plant the tracer OK."
The key point is how the technology is used in the story. There is not a word about how anything works, any more than you'd launch into an explanation of microwave transmission when you place a call on your cellphone.
And here, I suggest, sci-fi should be no more tolerant of infodumps than any other genre. If it's important to the story to understand a piece of technology, then work it in, preferably in a natural and subtle way as Moody so succinctly expressed.
To me, this puts sci-fi technical explanation on a par with, say, understanding political in-fighting in a thriller, or forensic science in a CSI-type story.
And, of course, you'll see I resist the temptation to give technology techno-geeky names. How different this passage would sound if I'd written it like this:
Finn took a deep breath and nodded. "Time to pick up her trail." He handed Shayla a thin translucent strip about an inch across and a few inches long. "You know how to use a micro-fluorescent chemical analyzer, don't you?"
"Yes, of course." Shayla took the strip and placed it across her eyes. "It emits microwave pulses and detects scattered radiation from which it can deduce chemical properties and highlight the presence of a specific compound."
Sorry if this sounds like a bit of a rant, but I think it's stuff like this that gives sci-fi a bad name, and gives the impression that it's only for sad gits in anoracks.
That is a myth I want to bust!