StarDestroyer.Net BBS

. . . without violating our modern understanding of the laws of physics, thermodynamics, chemistry, (and other pertinent laws)?

The question itself is pretty straightforward - though it probably will need some explanation to make sure my meaning is taken correctly. If we were to ask, "Can a Star Wars ship move faster than the speed of light without violating (blah blah)?" the answer is quickly a 'no.' That said, we accept (S.O.D.) that they can and *do* move faster, and treat the hyperdrive as a "black box". Other devices in Star Wars tech we aren't given exactly how they work, but we cobble together some idea. For example, the blast doors in the Trade Federation ship worked 'presumably' on electrical power that went to hydraulics. Bottom line being - we don't HAVE to suspend disbelief because we know that such a thing "could conceivably work."

So fast forward to the DS I and Alderaan... and turn this into a more robust prompt. After invading and colonizing the old-earth systems, the empire tasks you with organizing the construction of a historical curiosity. You are permitted the use of all "empire-modern" methods of construction and materiel procurement. However, you are restricted to the technology available to us here and now. As a bonus - you are permitted to construct devices that we can theorize and be "reasonably sure would work" in this day and age here, but are restricted from making/using on account of funding issues and the like of which. This 'historical curiosity' must be an 80000m radius 'or so' sphere which is capable of:
1.) Firing a directed blast of a net 2.2E32 J (not necessarily repeatedly as with the real DS1)
2.) Housing a crew complement of at least 20,000 (idiotically small for a planet-sized station, granted, but this is really not the tough part of the challenge.)
3.) Have *some* modicum of mobility so that it can reach Alderaan (or whichever moon it will be tested on). [[This is a 'token' condition; as even a very weak thruster in ZeroG can qualify as 'maneuvarability'.]]

It need *NOT* be capable of: 1.) Hyperspace/FTL, 2.) Fending off any sort of attack whatsoever, 3.) Repeated blasts, 4.) Mounted turrets, housing tie fighters, a tractor beam. (As none of these things contribute to its ability to destroy Alderaan).


I'd love to contribute to this discussion; but I know my limits - and the limit is not knowing much about technology. That said; I think this would be cool to know and figured it might spark an interesting discussion . . . so - yeah. Also; if this belongs on the STvSW board; sorry - please move it.

I'll simplify this for you- you are asking if we can make a giant laser that can vaporize a planet given

1) infinite resources
2) a maximum diameter of 8000 km

I'm pretty sure we can get the power with ALOT of antimatter- the problem is

1)turning into the laser beam and
2)not melting the laser

I agree with Samuel: the only problem are creating a weapon that will not melt and fueling it.

The Death Star beam has been calculated to be 1 X 10^38 joules (ref. Mike Wong's Alderaan page). By contrast, our sun's output is a "mere" 3.86 X 10^26 watts. In other words the Death Star is so absurdly powerful by itself it catapults the Star Wars Empire to a Kardashev Type III civilization (civilization capable of harnessing energy equivalent to a galaxy). Now let's do some math.

Matter-antimatter annihilation reaction is 9 X 10^16 joules/kg. In order to get the energy of the Death Star beam you will need 1 X 10^21 kg of antimatter. Approximately.

Now the Death Star I is 80 km in radius, which gives it an internal volume of 2.14 X 10^15 m^3, if I've got the volume of a sphere calculations right. So if its entire volume was filled with matter-antimatter fuel it would need a density of approximately 468 metric tons of fuel per cubic meter. That's incredibly dense, like 2-4 jet liners compressed into a cube 3 feet X 3 feet X 3 feet, but might be feasible with very advanced ultra high pressure storage techniques. How practical that kind of pressurization could ever be I don't know, but at least there's nothing in the laws of physics saying it can't be achieved as far as I know. Getting all that matter an antimatter to react efficiently is problematic, if you just store them in two big tanks you won't get a very efficient reaction at all. I suppose the best approach would be to pack the hard SF DS's interior with small canisters of antimatter and matter fuel under titanic pressure.

Now we come to the real problem. Channelling all that power into a coherent beam. That's going to be a big problem, because IIRC most of the products of an M/AM reaction aren't the sorts of energy that can be directly converted into electricity. An antimatter reactor would probably work by some sort of heat cycle, like modern nuclear reactors, and for an energy release of 1 X 10^38 joules ... forget about it! There aint no coolant in the universe that's going to let you contain even a small fraction of 1 X 10^38 joules in a heat sink that can fit into a 160 km sphere. Even if you could convert the energy of the reaction into electricity as some anuetronic fusion reactors might you're still screwed. Even a 1% inefficiency will vaporize the hard SF DSI. You need a mechanism that's damn near 100% efficient, and so realistically ludicrous.

My conclusion: the Death Star as depicted is flat out impossible under real physics. However, with an absurd amount of effort and very high technology, it might just be possible to build the thing as a giant bomb instead.

Also; if this belongs on the STvSW board; sorry - please move it.

you wouldn't happen to have a vested interest in that debate would you? because this doesn't really MENTION anything star trek related does it.