Here's my thoughts as far as how "hard" we ought to be with this stuff. We need to focus on two things above all else - plausibility, and practicality.
Can it be done, and
should it be done. If it has flaws which might keep it form being used by one polity, there might be others out there with better engineers/fewer scruples who'll have no problem using it.
In the case of lasers, despite the drawbacks that Blackwing pointed out, I'm sufficiently convinced that lasers can be used as an effective weapon in space combat - hell, the drawbacks just make it more interesting, I think, and is all the more reason to keep them. And I think we can all agree that lasers have several distinct advantages in space combat that any self-respecting space navy would want. So, it's plausible, and practical, and I say that's enough reason to use it. Likewise, concerning artificial gravity, if it's got some basis in scientific fact and/or logical conjecture, and someone in this universe will have a use for it, I'm OK with it. I personally probably wont use it for the polities I've got planned, most because they're very low-tech the other because they're very straightforward and economic, but I've got no problem with others having them.
We can't let suspension-of-disbelief be a monkey on our backs stifling what could be a very creative and fun universe - on the other hand, I see where the problem arises where everyone's idea of "realism" is gonna be different. With Comix! we didn't have this problem because we all agreed that realism had a great big Archwind-shaped hole punched through it. This was because we wanted a universe full of superhumans, super science, magic, drastically-altered history, and a healthy dollop of cheese. I think we need to figure out what we want from
this universe, and tailor our technological conjecture around that. Here's a list of things I'd love to see in TSW:
Cultural interaction - trans-galactic trade, multi-species polities, how does a race of people who've survived a thousand years of nuclear winter and only just united to escape into space react to a polity that makes its economy off selling nukes to the highest bidder?
So we're gonna need technology that's gonna allow this kind of thing to take place. Malchus was talking about translator technology, and I think along with just a language translator, we should also need cultural translators - this kind of tech would be a huge deal, as it's what makes diplomacy, commerce, and cross-species military endeavors possible. I think we should have a mixture of computers and people translators working on this.
Similarly, we need to examine interstellar communication. I do think we should be able to send messages through graveddies, either through lasers or plain old radio beams, or to pack messages onto a ship or probe, send it through, and have it start transmitting. However, once in-system I'm fine with communication being confined to 'mere' lightspeed. It's realistic AND a good storytelling theme.
And let's not forget political intrigue. We're gonna probably have a LOT of polities going on here - I personally am planning three different polities for my Sylphs as well as a human polity, and I'm sure you've all got lots of ideas sparking off. All these different nations interacting is, I think probably one of the main themes of this universe. I'd love to see nations defusing Cuban Missile Crisis-style events, political enemies maneuvering behind the curtains of fleet movements and graveddy fortifications to get the upper hand on one another, etc. This also requires the communications technology and techniques I was referring to earlier, but I'm also talking more "fun" technologies, things that would be involved in intelligence gathering and espionage. I'm not thinking so much James Bond as I am CIA/MI6 in THE FUTURE, but things like personal stealth suits and similar gadgets might be worth looking into.
Cybernetics and A.I. - So it seems like we can all agree that cybernetics should be present, even fairly common. It's already both plausible and practical in our own society (yeah, we don't have matrix plug-ins, but we're already headed down the right path with things like pacemakers and diabetic insulin pumps), so it should be even more so in the future. Siege was making a connection to Full Metal Contact, where the crews of ultra-high-velocity "hot ships" might be entirely post-baseline in order to survive just living on their ship, and I'm alright with that
to an extent - now, I love the idea of post-humanity, and enjoy writing about it, but it's not what I personally want this universe to really be about. I truly do think they should be present because they fit the plausible/practical rule, but let's keep them rare, specialized, and still relatively new.
Trans-baseline, on the other hand, where they have some new/enhanced capabilities but are still recognizable members of their original species, could be all over the place - I've got no problem with that at all.
Now, A.I. is a really tricky subject I think. I personally am I love with the idea, but I'll be the first to admit I'm not really well-versed in A.I. theory besides really basic concepts like the Turing Test. This is one technology that I'm totally willing to let my far-better-educated colleagues hash out. I personally would like to see A.I. with personalities, which could be characters in and of themselves, but I'm sure I'd be opening a can of worms with that one. On the other hand, referring to the fighter discussion we were having, it doesn't seem like anyone has a problem with autonomous computers capable of enough logic, memory, and problem-solving ability to perform dogfighting maneuvers, and really high-end computers are probably necessary for things like navigation, engineering, and fire control on starships. Whether these things are 'intelligent' or not is where I'm not sure we're all in agreement.
Finally, there's one thing we really need to take into account - all the people writing this have different levels of science education, have different styles of writing, and are gonna be focusing on different aspects of TSW. For example, I always get Cs in my science classes - even though I love the subject I'm just not that good at mathematics and biology - and while I think I can write fairly realistic stuff in Universal Constants, it's all in service to the themes of that universe, not necessarily because that's the way I think technology will actually be in four hundred years (in actuality, I have no idea), and I plan to focus on the cultural/political side of things rather than the technological one, though you better believe I'll be writing me some starship combat and planetary invasions. This is, I think, noticeably different than Siege, who knows a shit-ton more about science and is a lot better at writing about it than I am, and who I know for a fact has a different style of writing a space battle than I do (Marathon 723, right man?
)
We need some way so that anyone here can write about anything if they need to. The easiest way to do this is the Keep It Simple, Stupid rule, but that's not terribly respectful to either our Laser Gods or the rest of us. I suggest we have a subforum where behind-the-scenes tech discussion and explanation can take place outside of the fictional stories and articles. Guys like Mobius, Heretic and I can go to people like Siege, Blackwing and Ford to get advice about a particular technology, and we can reach some kind of consensus about how it could work, or whether it could work or not. I think we should keep something like a Master List of approved and "outlawed" technologies, which can of course be modified if we change our minds later. This would mostly just be to keep anyone (not that I'm accusing anyone here of this, just using an example) from writing about how their polity has a black hole generator that they're using to hold all the star systems in the galaxy hostage. More practically, so that when one of us is writing about one another's polities, we've got a good idea of what's there as opposed to their own polities.
P.S. I don't really think we've established a time setting for this. Considering the time necessary for the races to spread across the galaxy, for all those graveddies to have been explored and mapped, and for alliances, grudges, and international rap sheets to have been formed, we'd need a few hundred years - just look at all the shit that led up to WWI. Plus there's the question of when humanity gets into space, how quickly we established ourselves, etc. etc. I personally have been thinking of this being in the 27th or 28th century, but I'd like to hear what everyone else has got for ideas.
AND: thanks for reading, I know it was a little long-winded
"The universe's most essential beauty is its endlessness. There is room and resources enough for all of us. Whether there is room for all of our passions is the question, and the problem that we work tirelessly to find a solution to."
-Qhameio Allir Nlafahn, Commonwealth ambassador, during the signing of the Kriolon Treaty.