[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

starship-design: assorted musings

	In his message of Jan 29, Ben Franchuk stated that "just a few" computers
would suffice to design a starship. No offense, Ben, but this response does
not display an understanding of the complexities of the problem. I read the
article, and the guy who's wanting to do this is looking at, I think a
whole century just to DESIGN it. Let's see why.
	Let's say we need an actuator arm to open and close a ventilation louver.
No-brainer, right? A simple bar with some holes drilled in it. But what if
this ventilation louver is, say, about thirty feet across, as may be the
case in a ship this size? At this size, it wouldn't be unthinkable for the
mass of the louver blades to approach, say, half a ton. Now let's say that
we may want to move them very quickly (well, you never know). Regardless
how well balanced and lubricated these are, mass carries inertia with it,
and this actuator arm will have to put up with the strain.
	Back in the old days, a neanderthal engineer would have squinted at the
device and said, "Well, I think such-and-such a size will do," and they
would have just put up a hunk of iron on it, and if it broke, they'd
replace it with a bigger hunk. But we want this starship part to work right
the FIRST time, every time, for a verrrry LONG time. There are no
non-critical parts on a generation ship, and at this scale, we find
ourselves considering such esoteric design criteria as engineering
materails (metal? plastic? wood? bone?), strength of materials, safety
factor, stress fatigue, fabrication method (molded, cast, forged, stamped,
machined, extruded, welded, laminated, or some combination), and possible
special treatment (heat-treated, sress-relieved (thermal or vibratory),
plated, coated, anodized, or painted).
	Oh, and try not to go over budget.
	Just for kicks, try designing this exact part at home, on your own
computer. Use an arbitrary number of louver blades, and when you're done
with that, sit back for a moment and give some thought to the motor and
transmission that will have to move it. Now you're looking at motor power
supply (electric or fluidic), motor control, transmission designs,
lubrication, overload cutout and reset, position sensor, and control
telemetry and alarms, to name a few. Now, multiply this complexity by the
umpteen-to-the-bajillionth other details of a starship (or any project of
this size). It's enough to make you dizzy.
	Really, it amazes me sometimes, when I realize that a great deal of the
stuff we use today was designed to four significant figures, using log
tables and slide rules.
	I fully agree that people are necessary to such projects for our
problem-solving ability, and our creativity and insight, but really, this
is going to take as whole lot more than "just a few" computers (especially
considering the tweakiness of the ones we have now).

	On to the next thing . . .

	I've been thinking about the recent dialog on the nature of any ET's who
might be out there, and I have to say that I disagree that they'd be trying
to wipe us out. Looking at the anthill analogy, would you be so quick to
kick that ant-nest if you knew the ants might blow your foot off? I think
that, if they are out there watching us, they would likely say, "These
creatures are highly unstable and have nuclear weapons! Let's go somewhere
else for a while." I wouldn't be surprised if we are now under quarantine.
Besides, starships and their crews are very expensive, and I don't see a
successful star-traveling race as being rash enough to risk them at a
long-distance war, especially when they already have the means to find
other places to go. 
	I rather think that they would have a lot in common with us (Aliens are
people too!). The evolutionary forces which drive a species to supremacy
tend, I think, to narrow the choices. Yes, they will be aggressive and
inquisitive, and in search of the best resources and new discoveries, but
they'll be cautious as well. 

Keep looking up,
Curtis Manges