Sionnach Glic wrote:
Captain Seafort wrote:No, it means they could build physical structures that large. It does not mean that they could build physical structures that large that could move.
I had intended to mention that myself. The stresses you'd put on a ship that large just by shoving a sublight engine on it would be incredible. You'd need to almost completely redesign the interior to stop the entire structure just falling apart under the stress of its own engines. Let alone trying to get it to move FTL.
I'm sure Tyyr or someone else with engineering experience could explain this a bit better than I can.
( Kind of old but someone else necro'd it and I was called out without my knowledge )
It's very very simple. The forces acting on a fixed structure in zero G are so small as to be pretty much ignorable. Since it doesn't move Starbase 74's structure is really only there to give the builders a framework to hang things off of and keep it from all floating off.
Now take a Trek starship. Got one? Ok, not turn it vertical so the bow is up and aft is down. Now, put a finger directly under the impluse engine so the ship is resting on the tip of your finger with the only contact being the impulse engine. Got it? Ok, that's how forces are loaded on a starship traveling at sublight. Only it wouldn't be resting on your finger, your finger would be made of solid stainless steel and fired out of a cannon striking the ship directly on that point, constantly. You see when it's under thrust all the force being put on the ship, and we'll get to just how much that is, is being transferred to the ship's structure from the few points where the impulse engines are anchored to the frame. To keep the ship together all that force has be to transmitted through the ship's frame to every point of the ship, and hold together, so that the ship is accelerated rather than ripped to shreds.
That's why modern rockets are shaped like poles. You simplify the job of the engineer by loading all the forces on the frame in a single direction and its compression. It's very simple to design structures like that, steel is very good in compression and except around the engine mounts all the loads are perfectly vertical.
Now take a look at our starship. It's nothing like that. All kinds of angles and off axis protuberances. Look at the relationship between the secondary hull and the impulse engines, all that thrust that far off that huge mass? The stress on the interconnect of the ship must be tremendous! Forget about the nacelles. Those two huge chunks of metal hanging off the ends of those flimsy supports. Again, the forces in action on them are tremendous. The real science fiction here isn't the warp drive, it's the points where the interconnect and nacelle pylons intersect with the ship's structure, how those acute angled joints don't rip apart under these forces is mind boggling.
And it's important to remember the kind of accelerations we're dealing with. Shot from a cannon doesn't even come close to covering it. These ships accelerate from a dead stop to a 1/4 the speed of light in a matter of moments. Accelerations of hundred of kilometers per second at a bare minimum. 100,000 G's easy.
Even if we invoke things like the structural integrity field it is still far, far, FAR more complicated to make a structure mobile than to just make one stationary.