StarDestroyer.Net BBS

I've made a few calculations on Spacebattles, and I'm reposting them here because a certain little boy doesn't like them very much. I figure I may be onto something! My argument is based on an older quote about a star destroyer using more energy in a single jump to hyperspace than a planetary civilization uses in its entire lifetime.

Let us assume that a Star Destroyer is about 65 million cubic meters in volume, and that ten percent of this volume is solid mass. Let us further assume that the Star Destroyer is made of pure iron to keep things simple, giving a density of 7870 kg/m³. This gives us a mass of just over five hundred billion metric tons (511,601,155,000,000 Kg; 511,601,155,000 metric tons, 5.11e14 kg.) The mass of the earth is 5.98e24, a difference of just over ten orders of magnitude. If only 1% of that is blasted into hyperspace by the Death Star, it will still require eight orders of magnitude more power than the Star Destroyer's jump to hyperspace.

A K1 civilization generates power at about 1e17 watts, so this gives us our next figure of interest. We will use the K1 civilization because it is almost by definition planetary. Using this and multiplying out for a thousand years of this power level gives us 3.1557e27 joules. Using the original 1964 K1 figure of 4e14 gives us a still respectable 1.26e23 joules, and current energy consumption by the planet earth works out to around 5.049e23 joules.

We can do some more calculations now to work out just what our power requirements per kilogram are. Going with the most conservative estimate of energy needed, we are looking at around 2.97e8 joules for each kilogram into hyperspace, or 1.477e33 joules to shift the entire earth into hyperspace.

As it turns out, it does seem more efficient to hyperspace a planet rather than DET it up, but only by about 5 orders of magnitude, much less than the Trekkies would prefer given how often they bring this up.. And that assumes a very heavy Star Destroyer, and a rather short lived and primitive planetary civilization (1964 earth, 1000 years of energy production at those levels.)

If anyone would care to rip this apart in a (not so) friendly manner, I'd be glad to take it.

The entire thing is based on a single quote of dubious worth and a series of assumptions aboout factors affect the power requirements and how the 'delivery mechanism' changes this.

You're basically equating jumping a purpose-built computer-controlled object to doing the same thing to a rock with a big gun without understanding anything.

Why are we even discussing this? The power that is needed to shove something into hyperspace in some other fictional universe has NO BEARING WHATSOEVER on the Alderaan incident. And just for the record, a not inconsiderable amount of Alderaan DID remain in real space.

You're basically equating jumping a purpose-built computer-controlled object to doing the same thing to a rock with a big gun without understanding anything.

I think we can safely assume that doing the later is a bit more inefficent and that these figures represent some kind of lower limit. I'll freely admit this is not an exact calculation due to the lose nature of the quote I interpreted. It is however as far as I know the only quote of its kind that we can use to base any kind of hyperspace transition energy estimates off of. If you have better ones, I'd happily revise my calculations in light of them.

Batman wrote:Why are we even discussing this? The power that is needed to shove something into hyperspace in some other fictional universe has NO BEARING WHATSOEVER on the Alderaan incident. And just for the record, a not inconsiderable amount of Alderaan DID remain in real space.

"Some other fictional universe?" I'm pretty sure that's a quote from the Imperial sourcebook, a good ol' WEG source from the 80s. I don't actually have it on hand to confirm that, but I'm reasonably certain that's where it's from. Curtis Saxon reports this same quote on his website in this section although he fails to source it.

And yes, I am aware of the fact that parts of Alderaan were not moved into hyperspace.

Stark wrote:The entire thing is based on a single quote of dubious worth and a series of assumptions aboout factors affect the power requirements and how the 'delivery mechanism' changes this.

You're basically equating jumping a purpose-built computer-controlled object to doing the same thing to a rock with a big gun without understanding anything.

If I'm understanding him correctly, his underlying logic is that regardless of the method of getting into hyperspace (hyperdrive, magic beam weapon, whatever) it takes a certain amount of energy to do this (whereas most people who leap onto the DS novel seem to assume it magically transitions to hyperspace with no energy input) and then he figured out an "energy input per kg" for hyperspace which to me seems reasonable - Ender tried doing something similar too (and has posted his results somewhere on the board. Hell, Ender might have already knwon about this and workked it out before.) Hell, I've thought about this possibility myself since I know where the source came from, I just never bothered to work it out.

The fact the number is low simply reflects its highly conservative on a number of counts, which is hardly a bad thing. In all probability the actual number would be higher (and as discussed in the DS novel thread, the actual output could match or exceed the ANH calculations by a consierable margin.) The only flaw Vehrec made initially is that he conlcuded the number he derived meant the hyperspace-transition bit from the DS novel was efficient, and he seemed to recant that in his subsequent post

Seriously, is there something about this that I've missed that I am supposed to be outraged about?

Vehrec wrote:
"Some other fictional universe?" I'm pretty sure that's a quote from the Imperial sourcebook, a good ol' WEG source from the 80s. I don't actually have it on hand to confirm that, but I'm reasonably certain that's where it's from. Curtis Saxon reports this same quote on his website in this section although he fails to source it.

the place I saw it pop up in most immediately was either the EGW&T or the Star Wars Technical journal, or perhaps both. I know Mike covered it on his site (I believe)

Just checking Mike's site, ,I found it here and it was in the SWTJ. I think the one from the EGW&T that I was thinking of was the planetary turbolaser.

Yet another addition: This was the stuff I remember Ender posting in the outbound flight thread here, though his was a sustained power output for travelling in hyperspace, not a "total energy" figure. That would probably just reflect how conservative the figure derived from the SWTJ is, though, but to me, at least, it woudl all seem to work out, broadly speaking.

Now that we has the usual grade of feedback from the peanut gallery and Connor tried being more constructive, I'll do a bit of a breakdown. I actually looked at this angle before, but there are so many other, better ways to determine the power of the weapon I never bothered writing it all out.

1) Volume estimate. Not sure where you pulled that from, EvilleJedi of TFN and occasional poster here has done a lot of 3d rendering and estimates of a number of craft and found that an ISD is about 1e9 m^3.
2) Mass. Your math there is completely borked. You somehow multiplied it all by a factor of 10,000. Incidentally, that lowers the energy at the end, so it appears you basically underballed it. Using your figures it should mass 5.1155*10^10 kgs, or 51 million tons. Using a more accurate volume figure and an average density of water, a better mass figure would be 1e12 kgs, or 1 billion tons.
3) Energy figures. I calced out how much energy and power the jump to hyperspace took based of the run up, it is about 1e25 joules for an ISD. I posted the work both here and at SB with the expected results, including SBers demonstrating a refusal to grasp the idea of conservation of energy. As it is based off of film canon I would say it is a hardier standing, but if you don't wan to deal with that, there is quote you used. It is worth noting that as soon as a civilization hits the space age it is no longer a planetary civilization, as it now has (in theory anyways) access to all the resources in its system to sustain that civilization. So the average duration would basically be from the industrial revolution until the space age (IR as a starting point because prior to that energy consumption will be negligible by comparison). Thats in the low hundreds of years, so call it two orders of magnitude above the annual global consumption. For earth, that is about 1e20 joules. So for your civilization we are talking 1e22 joules. Given the mass of the ISD that's about 1e10 joules/kg to go to hyperspace.
For 1% of the earth to be put into hyperspace then requires ~1e32 joules. Enough to scatter its mass.
4) Source reliability. Again, we have the source of this quote being a gunnery master chief who by his own statements knows nothing about hypermatter, hyperspace, or how any of it works. This is pretty much useless.
5) Alternate estimates. Like I said, there are other, better ways to do it. Here's one of my faves; I've covered this before, but like Dr S details on his site, there is a shift in the placement of the planet/debris cloud in those frames.

Measurement of the apparent expansion of the Alderaan debris cloud provides further constraints on the properties of the Death Star's blast. The main debris cloud grows in a way that is slightly elongated in the direction of the incident beam. At late stages, the debris is clearly not concentric with the initial position of the planet. This suggests momentum transfer to a large part of the planetary bulk. Judging by the offset of the centre of mass before the beam strike and several seconds into the explosion, the mean recoil velocity of the ex-Alderaanian matter is on the order of 6.7 x 106 m / s in the plane of the picture, implying an impulse of 4.0 x 1031 kg m / s. A massless, light-speed beam delivering this amount of momentum would have a total energy of 1.2 x 1039 J. However this is an underestimate by some trigonometric factor, since the beam clearly was not parallel to the plane of the picture. Even so, the momentum-based estimate is in good agreement with estimates based on the apparent velocities of the expanding debris. The difference of one to two orders of mangitude is justified by the inefficiency of converting incident beam energy into kinetic energy of debris; much of the input energy is deposited as heat in the absorbing material.

so even if it does use some magic method to get around blowing it up, it still imparts enough energy to low it up, as shown by conservation of momentum.

Hope this helps.

It also occured to me that the actual quote only said that part of the planet got pushed into hyperspace, so there's still a portion of matter in realspacee that didn't disappear and it would pretty much mass-scatter as has already been calced. It might down the calc a bit for the original calc, but the energy required to push it into hyperspace would more than make up for it (at least going by the more likely results, if one wanted to stay conservative the hyperspace bit would still be lower by a few OOM, but then you'd still keep the original calc only slightly reduced, but the calc doesnt take into account for the total energy, only hte sustained energy to get into/stay into hyperspace.)

The fun part is that, like we've already discussed, there's far more ways we ca interpret the quotes t hat fit with what we already know than to interpret it like the trolls want to (IE use it to ignore conservation laws, the way things like that operate in SW, and the general canon/official statements to that effect.) Hell we even know from Traviss' writing that jumps TO hyperspace involve at least going to .5c.. that alone is going to require a tremendous bit of energy itself (and if they ignore that t hen they're just talifans lololol)

Edit: And, the interpretation can also be used to fudge oddities about the Alderaan incident as well (like perhaps why solid debris might have been there (we dont know how the "realspace to hyperspace" transitional boost might have fudged things, for example.)

Vehrec wrote:If anyone would care to rip this apart in a (not so) friendly manner, I'd be glad to take it.

Stark wrote:The entire thing is based on a single quote of dubious worth and a series of assumptions aboout factors affect the power requirements and how the 'delivery mechanism' changes this.

You're basically equating jumping a purpose-built computer-controlled object to doing the same thing to a rock with a big gun without understanding anything.

Wow well done Stark