Captain Seafort

I just don't see how the gas cloud overrides all other data, like big chunks. The center of gas mass is a lot less relevant than the center of mass, and not equal to it.

The entire sequence shows a consistent shift of the centre of mass, as the remnants of the planet expand (outwards) and recoil (from right to left). Each image shows a progression from the previous one.

When did I switch to talking about you specifically in that paragraph?

This entire debate was initiated when I pointed out the inevitable implications of the Death Star's firepower for the quantity of fuel it must carry, and therefore its density.  Ergo your entire argument has been talking about me. 

That is an assumption -- the reality depends on how the explosion was generated.

Not at all - if the explosion was caused by an arms dump on the surface of Alderaan cooking off, or similarly variable external factors, then there would be no possible way to guarantee that such a lucky shot could be repeated.  The only way such confidence could be justified would be if the energy required was provided solely by the Death Star, and directed at the target planet by the superlaser.

Yes, it will, if you don't cut my sentence in half and thus skip the part about filling with water, which you then handled separately.

In other words, what you really meant was "It will sink despite being less dense than water so long as it's more dense than water". Gotcha.

There's no mention of them being shielded

There's no mention of TIEs being shielded either, but we accept that they are,

we don't see that when the Snowspeeders blow up the crashed one.

Probably because it crashed - faceplanting from 100ft up can't be good for it.

It's possible it was a 'flak burst', like the ones we usually see in large space battles in SW.

The only "flak bursts" I'm aware of are the shield flashes.

And I have demonstrated that the planet was in the same place when the secondary blast began, a blast which began to the left and above-center albeit still within the planet's pre-beam area

I'm not talking about the minutea of the explosion - I'm talking about the result.  Look at where the centre of mass of Alderaan is before the Death Star fired.  Then look at where the centre of mass of the debris field ends up. Your own screencaps show a clear progression leftwards.

give that yield exclusively to the superlaser

Before the superlaser struck, Alderaan was sitting happily in one piece.  After the superlaser had struck Alderaan was traveling in many different directions at high speed.  Ergo the superlaser injected the energy that caused this change.

then assign that value with a short time-average to the Death Star reactor

Wrong.  At no point have I made any claim about the period of time over which the superlaser is charged.

Well, you have at least conceptually acknowledged that the reactor (body) may not necessarily have had the energy itself via its fuel (food) to do the deed, but that instead it could have been a release of energy stored elsewhere (gunpowder).

I acknowlege no such this - I pointed out that Harry held such potential energy on his person in the form of propellent in the rounds, just as the Death Star held that energy in the form of fuel.

Now, let us also ponder an explosion that completely destroys the badguy Dirty Harry fired upon, going off like a multiton bomb. And we ponder this in the context of how we now know about muscle, fat, guns, gunpowder, and bullets, and densities thereof.

 

Most would agree that continuing to insist that Dirty Harry was storing that explosive energy on or in his person and transmitting it via the bullet seems a rather noteworthy assumption, at the very least.

Two solutions.  a) Harry is using explosive rounds.  Rather powerful ones. His opponent is carrying powerful explosives that were hit and cooked off.  However, if is the case then Harry would not consider his obliteration of the bad guy a "thorough" demonstration of his weapon's capabilities, as he could not be assured of such assistance on subsequent occassions.

As for ship densities and sinking, I hope you are aware that a section of a modern ship will sink despite having less density than water

Because the addition of the water will raise its density above the density of water.

So, I was watching ESB recently, and something caught my eye:

The screencap is taken from here at approximately 2:27, as Luke clears the second walker after strafing it.

Is it just me, or does that look remarkably like a shield flash?

The planet's still in the same place when the secondary blast occurs.

Compare the position of the planet and the center of mass of the debris field in the last frame and there's a clear offset.  Brian has demonstrated this repeatedly in his videos.

This recent claim of Alderaan being blown back is incorrect, and, I would think, physically unlikely.  What's the claim, that it was knocked back at a million g or something?   I think it seriously unlikely that a planet would hold any shape at all even if you were very careful with your million-g acceleration effort.

It's far from recent - SWTC has referenced the planet's recoil and the minimum yield required to impart that momentum for over fifteen years.  As for the planet holding together under that acceleration, I agree that its unlikely.  I trust you will likewise agree with my observation that it didn't hold together.

If I watch a Dirty Harry movie, I can calculate that, to blow a hole in the badguy of such-and-such size, a projectile of a certain energy and certain characteristics was used.  However, if I have no understanding of gunpowder or clockwork-style mechanics, I may end up making assumptions that require Dirty Harry's trigger finger to be capable of twitching at that energy level in order to throw the projectile using the trigger as a simple lever.

You would, however, draw the conclusion that Harry had the capability to impart the requistite KE to the bullet, and therefore would have to store that energy on his person until the bullet was fired.  While you would mistakenly conclude that it was stored as body fat rather than propellant in the round, the fundamental conclusion is accurate. Likewise, the Death Star must store mass-energy before projecting it at a planet, even if the precise mechanism is unknown.

Well, I prefer to confine my examinations to the canon

I'm glad to hear it, hence why I refer you to dimensions and power requirements derived directly from ANH.

 Certainly a Death Star with a steel exterior (at least in the docking port areas per the ANH novelization) could have been made of something more robust instead if the entire vessel density is about a thousand times more than steel anyway.  In biggaton-land that's just asking for trouble.

Steel's robust enough to do the job it needs to for that part of the station. It's a docking port, not the main belt, no why use something fancy when you don't need to?  Indeed, I wouldn't be surprised if DS armour protection is considerably less than a typical warship - it's designed to withstand capital ship attack, and its shields can withstand energy releases sufficient to destroy planets.  Why waste resources with high grade armour?

I don't bring that up to derail but to point out the consistency of "normal", accessible, authentic values, because I'm here to seek the hardest available counter-evidence, since none came to mind for me.  And, with apologies, a number of assumptions about the Death Star and how it works which result in extraordinary density just don't make that cut for me.  To my way of thinking, if a chain of assumptions, when reasoned out, results in severe and repetitive disagreement with the canon (which in this case it certainly seems to), then perhaps the reasoning is flawed.

Actually there are very few assumptions involved here - we saw Alderaan explode, violently, and we saw that the planet had been knocked back, hard.  The energy requirements for the event are based on hard physics.  The only area where there's a lack of hard numbers is in the size of the Death Star, and based on your figures the uncertainty there seem to tend towards a smaller, and therefore even more dense, vessel.

As for the Death Star size, my old DVD-era work comes to 120km for DS1, which corresponds nicely with some of the old popular values.  It was DS2 that came out to 160.

The relevent calculations are here if you'd like to have a look.

Well, as the ICS is no longer canon, we can't really say HOW big the Death Stars were.  The only canon information now is from SW.com, which simply says "size of a small moon".

Plus the film itself of course, which gives a diameter between 125 and 190 km - the 160km figure I used is bang in the middle of that.

And I'm not doing one of those "Higher Canon Tiers" things.  Ever since Disney implemented the new canon policy, ALL books save for adaptations of the movies and cartoons have been moved to the non-canon, or "Legends".  Even the ICS was dumped there, according to Wookieepedia.

Huh.  My understanding was that they'd simply binned everything below G-canon, which included the ICSes.

That estimate requires a set of assumptions about the operation of the Death Star that seem rather unsupportable.

The only assumption it requires is that the energy density of hypermatter is limited to 9E16J/kg.  The dimensions of the Death Star are provided in the original ICS, and the energy requirements to destroy Alderaan can be determined from the visuals, both from the rate of expansion of the debris field and the momentum recoil of the planet.

So do we have any canon evidence of massive ships that I'm missing?  

The Death Star.  Minimum average density in excess of 5000 tons/m^3, just to fuel the Alderaan shot.  However, it may be a slight outlier in this regard, given that scaling the DS power generation capabilties to capship size produces numbers one or two orders of magnitude above their actual capabilties.

I went with the planetoid being Ceres' size because Ceres JUST made the cut for being a "dwarf planet", and was trying to be conservative. And since "Dwarf Planet" and "Planetoid" pretty much mean the same thing, I just kinda went with it. If Memory Alpha was say, the size of Pluto, which is more than twice the diameter of Ceres, and therefore, has about ten times the volume, the facility would be freakin' enormous.

Or, if you wanted a lower limit, you could go with 400km, which is about the bare minimum for a sphere.

Surface Detail.

But the semipermeable idea is the most consistent with the greatest amount of evidence. I have several examples I didn't put in the video in my haste to publish it, which now requires a follow up. That consistency makes it the most likely scenario.

It's a logical inference from the CW era visuals, but it's contradicted in the Imperial era, implicitly by Dodonna and explicitly by Ackbar. We've only got three explicit statements on the subject - Anakin's briefing, which gave mobility as the key reason for it and which therefore is inapplicable to space vessels, Dodonna's briefing, which all but states that starfighter-proof defences are possible and very strongly implies that the first Death Star's weakness was unusual, and Ackbar's comment that fighters might stand a chance if the shields are first disabled.

The other Mon Calamari ships were perhaps 2/3 and half the size of an ISD respectively.

It's a nitpick, but I think there's at least a possibility that the Mon Cals are bigger than an ISD. Their proportions are roughly the same as HO, and assuming the models are on the same scale they're 1500m long. Assuming the same ISD assumptions as above, this would make them about 25 per cent bigger than an ISD by volume.

Okay, just did a back of the envelope comparing the cubes of the lengths of a Home One and an ISD. At 3.2 km they'd have about 8 times the volume of an ISD, assuming similar shape (which they don't really have but close enough for a guesstimate)

A bit too rough I think. Very roughly, HO is a 4km long, 800m wide cylinder while an ISD is a 1.6km long, 800m wide, 400m tall pyramid. This would give HO a volume of two billion cubic metres and an ISD a volume of 85 million cubic metres. Your initial estimate of HO being a couple of dozen times the volume is almost bang on.

Well, the counter is if starfighters were not effective, there would be no starfighters.

By that token either a) modern rifles are effective against tanks, or modern soldiers don't carry rifles. A more logical conclusion would be that fighters are used, ergo fighters must be able to do something useful. This might be reconnaissance, ground attack, destroying enemy reconnaissance ships, or something else.

I pointed out in the video that starfighters take out unarmored targets, giving their mother ship an advantage in the battle.

During the Clone Wars, possibly, depending on whether those fighters were able to go in before the shields went up. Against ISDs, I've repeatedly pointed out Ackbar's explicit statement that fighters might stand a chance against them if the capships knocked out their shields first. If fighters were capable of inflicting severe damage on enemy ships, as they did with the Ex, without such assistance.

I've covered the "dish is still visible" thing, 3 minutes: https://dl.dropbox.com/u/20522425/ScreenFlow1.mp4

404

I'd say keep it the same - just get rid of the subfora.

you go the intellectually dishonest route, picking and choosing the ones that suit your argument. SDN, for instance, is well known for choosing the latter option.

The numbers in the ICS seem to be able to be reconciled with the films, so I don't have a problem with the firepower and power generation figures in it.

These two statements sound remarkably similar to me, and the best way to go - pick and choose the technical bits that are reconcilable with the films (and basic maths), and treat the rest as a good read.

Since when can a modern aircraft stand up to a point-blank kiloton blast? Much less a gigaton one?

 

Oh that's right. Since never.

When have we seen an unshielded X-Wing do that?

What, does the ICS say an AT-AT have weapons ranges in the AU range? Or maybe it says that a thermal detonator can level mountains. Or that Luke can knock planets out of orbit by farting.

I'm not talking about the ICS, or AU - I'm talking about your fucked-up claim that VenStars have a weapons range of about 15km, given that AT-AT's have a range of over 17km, per ESB.

An interesting thing to note is that both the Encyclopedia and NEG mention that an X-Wing's hull is made of titanium.

 

Yes, titanium, which is used for modern aircraft hulls.

And?

It said veiwport, like the windows we see on the bridge of an ISD.

And the "windows" we see on the bridges of Trek ships.

It said that the TL bolts raced from the bow of the Anakin Solo right down to the planet.

Just like bolts raced from from the NR cruiser outside the Coruscant system right down to Coruscant in the green belt in the EL duology.

http://forums.asvs.org/showthread.php/2321-TCW-Weapons-Ranges

 

Light-hours my ass.

I see absolutely nothing in that clip as evidence that VenStars have a shorter weapons range than an AT-AT.

Guh.. Bah.. Nar... Vajook...

I'm sorry, I'm not familiar with those units. Could you rephrase that in terms of light hours please.

Close enough that the planet took up most of the viewport.

So their viewports are TV screens that can magnify what's on them. Big deal.

No, the quote from the book states that they're in orbit of the planet.

At what altitude? Mercury and Pluto both orbit the sun. They're obviously outside the system, given that they're having to use specialised long-range weapons.