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Borg Cube hull strength
Posted: 2003-02-02 09:21pm
by Laird
Seeing as no one at spacebattles will debate anymore in the vs debates this place is as good as any I suppose.
Here are the calcs
http://members.shaw.ca/dmz/borgcubecalcs.doc
based on this
http://members.shaw.ca/dmz/scorpion.zip
Thanks connor for alittle help on the calcs... Said above calcs I feel fall somewhere inbetween. the low end and high end.
Posted: 2003-02-02 09:33pm
by Darth Wong
Um, wouldn't a web-friendly format like HTML or PDF be more convenient?
Posted: 2003-02-02 09:37pm
by Connor MacLeod
That's the best you could come up with for those calcs? I would have thought there would be something more wrong with them (beyond the assumptions and estimates I made, that is.)
Posted: 2003-02-02 09:44pm
by Laird
Hey I do the best I can with what I have.:-p
Posted: 2003-02-03 01:27am
by Darth Wong
OK, I'm just copying and pasting from your Word file into this page:
Laird wrote:(note: Scaling work done from clip of episode "scorpion, part 1.")
stated "volume" of Borg cube - 28 cubic km (or roughly ~3 km long/wide/tall)
scaled "height" of cube (see "problems" below) - 350 pixels.
3000/350= 8.57 m/pixel ~8.6 m/pix.
only 3 pieces of debris appear large enough to scale.
First two are roughly 31 pixels in diameter. The second appears ~35 pixels in diameter.
This yields a diameter of roughly 267 meters for the first twoo pieces of debris, and ~301 for the second.
Assuming a roughly silicon composition (assuming the 2220 kg/m^3 composition Mike Wong used for BDZ figures, since we're talking something of a terrestrial enviroment)
Masses are approximately 3.2e10 kg for the 300 meter debris and 2.2e10 kg for the two smaller debris.
Velocity: There is a problem with the estimable velocity.
1.) While the "plume" ejecting from the planet appears to be moving at roughly 9000 km/s (estimate derived from Mike Wong's Voyager canon database) assuming earthlike proportions, subjectively (relative to the cube), the debris appears to be moving little more than 3 km/s.
Using both figures yields two different sets of KE figures:
Assuming 9,000 km/s velocity:
2.2e10 kg x 9,000,000 m/s = 8.91e23 joules, or ~2.13e8 megatons (213,000 gigatons)
3.2e10 kg x 9,000,000 m/s = 1.297e24 joules, or ~3.1e8 megatons (310,000 gigatons
2.) using 3 km/s figure:
2.2e10 kg x 3,000 m/s = 9.9e16 Joules, or ~24 megatons
3.2e10 kg x 3,000 m/s = 1.44e17 joules or ~34.4 megatons
Since we are dealing with kinetic impactors, the momentum also figures into physical resistance:
If traveling at 9,000 km/s:
for 2.2e10 kg masses: Momentum is ~2e17 kg*m/s
For 3.2e10 kg mass: Momentum equals ~2.9e17 kg*m/s
If traveling at 3 km/s:
for 2.2e10 kg masses: Momentum equals 6.6e13 kg*m/s
for 3.2e10 kg mass: Momentum equals 9.6e13 kg*m/s
Values are an upper limit for hull penetration of the individual pieces of debris (IE physical impacts as opposed to beam weapons), as indicated. Opinion leans towards 3 km/s velocity as probable accurate estimate, given limited knowledge of prior events.
Problems with estimate:
1.) Difficulty in acquiring exact scaling due to quality of source, so its possible figures may be skewed. Also problem in determining whether or not "height" of cube was totally visible or not (particularily because of Voyager in foreground)
2.) problem with velocity (described above)
3.) unknown composition of planet
4.) values only applicalbe to known large scale debris. Much smaller (and numerous) Debris ignored.
5.) state of debris (appeared glowing) ignored.
Author does not claim figures are totally accurate or meant to represent any "accurate" figures for Borg Cubes, only as an estimate given available evidence and assumptions. Consistency with other material is not guaranteed.
Much more convenient, no?
Posted: 2003-02-03 01:33am
by Darth Wong
All righty then:
Laird wrote:First two are roughly 31 pixels in diameter. The second appears ~35 pixels in diameter.
I have no idea where you saw these 30-pixel wide pieces of debris hitting the ship. The debris hitting the ship is all extremely small, a few pixels at most. The large flashes you see upon impact are obviously much larger, but that's different.
Velocity: There is a problem with the estimable velocity.
1.) While the "plume" ejecting from the planet appears to be moving at roughly 9000 km/s (estimate derived from Mike Wong's Voyager canon database) assuming earthlike proportions, subjectively (relative to the cube), the debris appears to be moving little more than 3 km/s.
There is no conflict. The cube must be accelerating away as quickly as it can, hence the relative velocity is low.
1.) Difficulty in acquiring exact scaling due to quality of source, so its possible figures may be skewed. Also problem in determining whether or not "height" of cube was totally visible or not (particularily because of Voyager in foreground)
Please provide screenshots showing these 30-pixel wide impactors (not 30-pixel wide flashes upon impact).
Posted: 2003-02-03 02:37am
by Connor MacLeod
Darth Wong wrote:All righty then:
Actually they're my calcs. Thats why I wanted as many holes poked in them as I can (I'm totally ignorant where it comes to Trek, so I rely on wht facts I was given - hence all the disclaimers about accuracy and such.)
So if you're going to yell at anyone, ya yell at me
I have no idea where you saw these 30-pixel wide pieces of debris hitting the ship. The debris hitting the ship is all extremely small, a few pixels at most. The large flashes you see upon impact are obviously much larger, but that's different.
I scaled the debris, but I think I was going by diagnols (I've been doing that rather alot lately than vertical or horizontal. Give me a second anmd let me re-scale them. I had trouble getting some accurate scalings given the clip, so that was the best I was able to.
There is no conflict. The cube must be accelerating away as quickly as it can, hence the relative velocity is low.
I was told it was stationary. Was this indicated in the episode, or did we have good reason to believe it? If so, then yeah, I can see what you're getting at. (still, what would that mean acceleration-wise?)
Please provide screenshots showing these 30-pixel wide impactors (not 30-pixel wide flashes upon impact).
I'll try re-scaling and getting Laird to post the images (I was the one doing the scaling work and such... so any errors there would be mine and maybe of the picture quality, which is much rougher than I ususally use - DVD or something Brian scanned for me.)
Hold on a sec.
Posted: 2003-02-03 02:55am
by Connor MacLeod
Yep. I fucked up the calculations. HEre's what I did wrong:
1.) I didn't account for the fact the debris was glowing (even when I already indicated that as a problem!) The "glow" given the quality of the image tends to make it look subjectively larger.
2.) I did fuck up the scalings - when I redid them they came out to only about 8 pixels or so, and I'm still not certain if its correct - the image quality makes it difficult to scale accurately in this instance with debris that small (particularily compared to DVD-quality scalings I've done.)
3.) I'm pretty sure I fucked up the cube scaling to begin with as well. I've been told its only a 1.5 km cube and not a 3 km one (which was what I based on some questionable calcs anyhow.) and I didnt get the scaling of the cube right either (I scaled it much shorter than it actually was, I believe)
4.) Its still an upper limit, since we see the debris penetrating. We have no way of establishing a lower limit on this incident.
So in short, I fucked up the scaling, which lead to the large debris (which I admit is my fault, and is probably why I thought there was something wrong with them.) I can't do anything with the clip as is, unless there is a much better selection of higher quality stills available.
A purely subjective guess might indicate they are maybe 20-30 meter diameter debris, tops. But even I can't be sure of that.
Posted: 2003-02-03 09:46am
by Darth Wong
Connor MacLeod wrote:I was told it was stationary. Was this indicated in the episode, or did we have good reason to believe it? If so, then yeah, I can see what you're getting at. (still, what would that mean acceleration-wise?)
We have good reason to believe it, since there's no reason why planetary debris would spontaneously decelerate from thousands of km/s to 3 km/s in space. However, it also implies, oddly enough, a maximum sublight speed (since the relative velocity did not change while we were watching).
Posted: 2003-02-03 03:34pm
by Connor MacLeod
Darth Wong wrote:Connor MacLeod wrote:I was told it was stationary. Was this indicated in the episode, or did we have good reason to believe it? If so, then yeah, I can see what you're getting at. (still, what would that mean acceleration-wise?)
We have good reason to believe it, since there's no reason why planetary debris would spontaneously decelerate from thousands of km/s to 3 km/s in space. However, it also implies, oddly enough, a maximum sublight speed (since the relative velocity did not change while we were watching).
I can buy that. I was thinking something along the lines of a force acting to steadily slow it from the point we see the plume to impact, however that didnt explain the fact the debris showed no deceleration prior to impact (And given the short observed timeframe, had the debris been slow as rapidly as implied, the debris shouldn't have impacted at all...)
Not that 3% of c isnt an impressive sublight speed for something supposedly that large. I do wonder one thing though, does the fact the cube is accelerating AWAY from the explosion affect the calcs any? I would imagine moving "Away" from an impact would do something to redu ce its effects.
Posted: 2003-02-03 03:35pm
by Connor MacLeod
also, I do believe tehre was a scene where the cube was stationary. If we know the timeframe form that point onwards, can we not estimate an acceleration value?
Posted: 2003-02-08 03:16am
by Gil Hamilton
Well, I don't see how it could have been moving away from the planet significantly. The scene went Yovager drops into orbit around the planet. The Borg cube intercepts and puts it in a tractor beam. S8472 appears, forms up and immediately pops the planet. Initial plume shoots up. Slooooow moving impactors hit the cube. There wasn't any shots of the Borg cube hauling off with Voyager until after the debris hit and the planet blew.