More like political costs, due to the way procurement and R&D now work in the US government (

). In the 60s government knew how to get R&D done: you take a truckload full of money, drive it over to the best scientists and engineers in the country, and say "Go to the moon."

Nowadays mission and build requirements are laid out by Congress before it ever gets into the hands of the actual engineers and scientists actually building the damn thing, and so the engineers and scientists are forced, by law, to build in shit that will never see use by anyone.
The classic (and most visually noticeable) of these costs are the space shuttle. The space shuttle was built with those giant thrusters sticking out of the back because one of the design requirements was to be able to go from an equatorial to polar orbit
in a single orbit; in other words, it was designed to be able to launch a nuclear missile/bomb at Russia without passing over Russian territory. Now, why you'd be doing this when you already have bombers with nukes on them flying in the air already as part of your decades-long MAD strategy I have no idea, but some Congress-critter wrote that into the spec sheet, so the engineers had to build it. Note that since we got rid of that requirement the new Ares crew capsule being designed for a future Mars mission doesn't look nearly so ridiculous, though these days the stranglehold Congress has on the NASA budget will likely ensure we don't get to Mars in our lifetimes.
Actually as I understand it the situation is now reversed for may things. From what I've read on "why our militaries stuff costs so much now" its the military wanting to many things and congress is starting to get pissed. Take the new super carriers, the navy wants it too have far to many bits bob and new things. It was designed to be ready for upgrading with that electroplate stuff, lasers and all kinds of fancy items, so it needs reactors that provide twice the power it needs at launch. Its also designed as massively multi-role further increasing its cost. If someone in congress was responsible for the militaries choice to build craft in this manner I'd imagined they have been hanged/burnt in effigy on some of the sites I was looking at. The Air Force (apparently) wants to drop the A-10 (one of our best planes in terms of current usefulness and cost) and use the far more expensive F-35 to run the same jobs which its even worse at (or so I read). Congress has been telling the Air Force no. The Navy was supposed to maintain more ships but the navy has been proposing and researching more and more expensive multi-role ships so they can't have as many! Hell the Navy's current hull rating system is about a rank up from what it was or so I read.
Now that could be wrong and their may be people in congress who are responsible, but most of the fingers I've seen are pointed at the elements of the military responsible for development and procurement spending to much on high tech. Though some of the issue can be allocated to the buying practices used, which I'm pretty sure is mostly congresses' fault.
Quick note: I just noticed that our "150 GW Prototype ISAR" has a better cost/GW and production/GW ratio than either the original Arc Reactor or the actual ISAR. Something needs adjustment there.
What? Hmm.. looks like a math fail, fixed. Thanks.
Well first off the Repulsor is going to have to scale at least by aperture size, not diameter, meaning a Frigate with a 500GW Arc Reactor and 4 10m Repulsors would add 401 million credits and 2406 production. On the other hand that's going to add a hell of a lot of thrust capacity to our frigate, and that's probably still a lot cheaper than a set of antimatter engines/fusion torches, plus a 3He reactor.
Indeed repulsors cost should scale by the square of radius at a minimum. Probably by volume, which is what a arc-reactor does. Thrust is by the square of radius, and power... We'll leave it at square of radius for the moment, so the old calcs can stand. Assuming that the stats for one are .3 production and 50,000 credits for a .1m diameter repulsor that draws 700MW and provides 12,500N of thrust*, estimated based on mach 2 peak performance of four. That would leave a 1m/1,250,000N repulsor at 300 production, 50 million credits and 70GW power. A 10m/125,000,000N repulsor at 300,000 production, 50 billion credits and 7 TW power. Frankly you don't need a freaking 125 MN thruster, much less four. A set of eight one meters (for bidirectional thruster setup) is more then enough for a frigate I'd guess. So 1000GW arc-reactor: 60P/10MC, 8x 1m Repulsors: 2400P/400MC and power draw of 560GW. Total: 2460P and 410MC.
I may want to up rate the power draw to scale by volume. That would mean that a single arc-reactor can power seven repulsors of the same production and credit cost at all levels. Thoughts?
*Technically its ~8,000N for four, but I tend to guesstimate the repulsor at 7.5cm across, not the 10cm of UberJJK and since 10 cm is nice to math with so I up rated and rounded up. This is also 1/2 what UberJJK tends to estimate.
Also on a side note the Tiger should cost at least 30P/5MC probably more. Using the by volume rule it should cost four times as much. Opps

, oh well fixing it would take far to much effort, so I'll ignore it if you guys will.
There's no way that a ship's hull is grown out of a single large crystal that's incapable of being bonded together; that'd make maintenance impossible and mean that you'd have to replace most of the ship's superstructure after even a minor battle. It would have to be built in sections that are welded/bonded together, like all modern ships are, except for things like the engines or power plant which would require special treatment to be completely uniform on the inside.
Yes but the end result size is more then a factory could handle, sure you could build the keel plates and crap, but you'd need a specialized factory/site to assemble the damned things. Even a Factory III tops out at around 8m individual objects.
A ship-sized gravity nullifier, like, say, a ship's eezo core?

I always envisioned a ship as sort of coalescing around its eezo core, with the core providing both gravity nullification for construction work, and the PME fields needed to build and weld together the high-density alloys of its superstructure. Note that this would mean a large ship (frigate or larger) would need to be constructed in two phases: Phase 1 is the construction of the eezo core/power plant combo, and Phase 2 is the construction of basically everything else: the superstructure, installation of weapons/shields/etc. I would be fine with this meaning IC that even frigate sized ships need 2 quarters of build time minimum, even if you can create more than one in parallel. Yes, this would mean that a gigantic scaffold would probably need to be built around the cruiser/larger ship as it was being constructed, but that's pretty much how all large constructions are made today as well, and you'd need a scaffold for space construction as well.
We'll yeah I'd be ship grade core the problem is that you'd need at least two so you can cycle them just to keep the thing from breaking and maybe more for any industrial processes. Doing it in space is far easier as you only need one core and you may not need to use it until you actually use the ship.
You can forge a lot of the parts elsewhere it'd be far more economical I imagine and you wouldn't have workers/robot in high mass fields (that also are producing a shielding effect), though their welding tools probably can project those.
You didn't notice the most important limitation, the one that's actually most important to us: Build Time. Frankly, upkeep costs are already irrelevant to us; we spend more each quarter on materials to keep our factories occupied than we do on upkeep, and the economic game is essentially already won now that we have Arc Reactors released to the Citadel market. The only real constraint we have is that we have ~10 years to prepare before the Reapers arrive, and whether or not we can manage to ramp up production and tech levels fast enough to be competitive in the industrial-scale war that's likely to commence. The question we as players will have problems answering aren't whether we can afford the upkeep on a factory that we plonked down 10 billion to a trillion credits on--the answer there will basically always be yes, as we can just build Arc Reactors and sell them for pretty much whatever we want--but whether we can afford the extra quarter or three it'll take for a more generalized factory, or whether we need the Production right now.
That is true... Hmm.. I may have to do some math for this after I choose ship numbers.... Specialization/Single product may knock of a quarter from factory build time...
Its worth noting that there are some vague market saturation caps and possible income caps eventually. Civilian arc-reactor demand in the combined citadel market is probably around 5 trillion units ever, though chances are you're not going to sell more then few billion units per quarter to civilian buyers (still a lot!). Not sure on the military or corporate saturation levels would be. The galaxy isn't quite made of money. Maybe ~2.5 quintillion credits all told? Not sure how much of that is bound up locally as opposed to available on the galactic level. It probably won't be a noticeable issue but I do plan to keep an eye on such things
If it were me making the ruling, what I'd be doing is restricting what size of factory can be used to build larger products, and/or how many Factories you can have in a single geographic location, so we can't cheat the build time constraint by laying down 10,000,000 Factory IIIs or 100,000,000 Factory IIs and start building any Dreadnought we want in 2-3 quarters without having to retool. I'd also consider some super-expensive tech options to let us build factories faster, so our endgame can feature us throwing out 10,000 m super-ultra-dreadnoughts against giant Reaper world devastators.
I though that was what I was doing? Most ships are too big for Factor IIIs barring special conditions, so that's what Space factories are for. I may rule that you need at least one shipyard of the right size for each larger ship assembled, though other factories can still help. That would be due to the need for a large enough assembly site. Planetary sites have a three factory limit with space having its own limits. And big factories have to be built in space.
Same rules would apply to other large constructions, though the only ones I can think of that big would be ships and space stations. So I'm using ships as an example as space stations are weird.
Argh! Goddamn kinetic barrier, how the f*ck do they work? I think I am back to considering black body radiation as the mechanism. I think I can make it work energy-wise. But, really, that's a bad solution. I will poke around breaking radiation, but that doesn't seem to work either, as the velocity change is quite marginal (and this mechanism requires there to be a material component in the shields, making them unusable for FTL). Are there any real-life effects I seem to be forgetting?
Well it does seem that dark energy is a carrier for kinetic energy/momentum, similar to photons. Head sized ball can deliver ~1250 newtons of force on impact in a vacuum and the impact is (sometimes only partially?) transmitted though shields. Of course the force may be transmitted via to some other effect and I don't know how much it'd help. Shield wise that'd mean the PME is sucking up KE/momentum from the incoming projectile.
Can't think of much other than the speed of light limit. But that seems messy. Also recall shields work on planet, not sure how cosmic microwave background radiation and its shifting by the shields would be effected by the atmosphere, but it is something to keep in mind.
Hey guys. I have a question. When an anti-hydrogen hits a regular lithium atom, does it annihilate and leave behind a helium atom or is the entire thing annihilated?
Technically speaking it all depends on how they hit. Positron - Electron annihilation is "clean", you get gamma rays and maybe some neutrinos that's it. Anti-Proton - Proton is mess, See protons (and anti-protons) have three parts and quite often only one or sometimes two of the three parts is annihilated. So what you'd get is 1/3-1 protons annihilated and then the system would have to stabilize itself. The Lithium atom may be torn in the process apart, it might not depending on factors. Of course first you'd have to you know hit the lithium nucleus with the anti-hydrogen's anti-proton. Which is rather difficult due to size and spacing and as I believe the lithium's electron shell would repel the anti-proton.
Edit: also thanks to
@UberJJK!