Stewart at SDI wrote:
I was fasinated by the annallissis of the performance of the weapons described. Although I did not run the numbers, ( More on that later.) they appier to be correct in their computations.
The defects are that they are based on faulty assumetions.
1. That the Asteroid was "Vaporised".
How is this an "assumption?"
Turbolaser Commentaries wrote:
The vaporisation figure has been in debate for some time. Many state that the asteroids simply broke apart under the influence of the heat: part of the asteroid may heat up faster than other parts, and expansion stress would cause the asteroid to shatter. But this event is not witnessed in the film. The asteroids were vaporised in the film. The asteroids turned into red-glowing liquid, and then vanished from sight within 1/4 second. The asteroid material could not shed over 1000 degrees Celsius in a fraction of a second to eliminate the glow, as this would require an artificial mechanism as powerful as the turbolaser bolt itself. The rock must have been turned into vapor to account for the asteroids "flashing out of sight".
Mike Wong wrote:
Some Federation cultists have been claiming that these asteroids were not actually being vapourized, but they apparently lack an understanding of Occam's Razor. The visual effects in TESB were completely consistent with vapourization, therefore the simplest theory that fits the facts is the theory that these asteroids were indeed vapourized. The rapidly dispersing gas cloud would quickly become invisible, as do most gases in space (except for those which are kept in a continual state of excitation by outside sources such as enclosed stars or black holes, eg. in a nebula).
If you have evidence that suggests that this is untrue, I would appreciate you citing your sources and providing said evidence, as you have not done so.
2. That the Asteroid was similar to metiors found on Earth.
That's actually a conservative assumption. But even assuming your correct, so what? The following source tells us the composition of the asteroids (the scene takes place in the Hoth asteroid belt at the time of the escape from Hoth in TESB):
[quote="Tales of the Bounty Hunters, page 102]
Solo's last maneuver had been to strafe the Star Destroyer. Then he'd gone off the scopes. Dengar figured Solo must have gone back into the asteroid field. Perhaps Solo had shut down systems for a bit, so that his own ship seemed no more than an asteroid, but as Dengar sped into the asteroid field himself, he saw that even Solo himself wasn't crazy enough to risk such a maneuver. Rocks the size of his ship hurtled toward him, and these weren't the soft carbonaceous chrondites that his weapons might punch a hole through- these were nickel-iron rocks that could smash him to pieces.
Unless you have more substantial, higher evidence to contradict that, it stands as correct. In any case, so what? Mike's done calculations for melting and vaporization for ice, silicon/rocky, AND iron asteroids. Apparently you did not read the website.
And if you don't like any of those conclusions, ,you can look at a thorough analysis of the asteroid vaporization scene by cmdrwilkens here
3. That there was not a simpler explination.
Does your "simpler explanation" fit the facts the way vaporization does? A theory is not automatically better just because it is simpler.
Using the figures quoted, it was plainly impossable for the "Astroid" to be "Vaporised" In the text, it states that the phenominon lasted .25-.3 seconds. If the mass quoted, about 32,000 metric tons as I recall, was heated to incandessance it would have taken many minutes to dissipate not fractions of a second.
First off, cite your source. Its rather clear you're referring to the discussion in Brian Young's Turbolaser commentaries page, even though you're remarkably vague about it.
Second, what the hell are you talking about? What proof do you have it would take many minutes to dissipate? When you add energy to something, it tends to expand. In something as diffuse as vapor or gas, at the kinds of enerrgies we are talking about, this translates into very RAPID expansion.
In fact, you evidently ignored this
point on the very page you are citing:
Curtis Saxton suggests that the asteroids did not shatter because the melting/vaporization was "supersonic". This means that the asteroids were melted/vaporised before this expansion stress could take effect. This appears to be a valid theory, since the entire vaporization process took approximately 1/4 second (note from MW: this idea deserves further explanation: speed is everything. Thermal conductivity through the asteroid's mass is insufficient to account for the effects we saw, because the rock simply cannot conduct that much heat that quickly, even if it's pure iron. The effect would be more of an explosive effect, with a tiny area being superheated and a concussive shock wave moving out and shattering the asteroid. However, in order to shatter these asteroids so quickly, the fragments would have had to move through the rest of the asteroid at more than 600 m/s! This would require extremely rapid large-scale deformation of material, and the mechanics of solid material deformation happens to be an area which I've studied in depth. Deformation involves work, as defined by the stress-strain curve of the material, and that work becomes energy in the resulting deformed matter; this effect is known as work heating. The question of whether the asteroid was heated or shattered is therefore moot, because the act of shattering it at such great speed would create so much work-heating that the resulting material would be superheated anyway).[/quote]
Again, please cite evidence indicating it would take many "minutes" to dissipate rather than seconds.
I also like how you ignore the fact that on that [same] page, Brian Young notes other asteroid examples that illustrate yields of thousands or tends of thousands of terajoules.
We know this fron space weapons tests of both conventional and nuclear explosives.
Conventional explosives dissipate in tiny fractions of a second like those shown in the movie. While nuclear shots in the energy range cited that massed only 363 pounds ( about 165 kilos off the top of my head.) required many seconds (2-3 dozen depending) for the bomb residue to disperse enough that it was no longer visable to the naked eye.
1.) what the hell are "nuclear shots", and what does this have to do with the asteroid vaporizations? And even so, how does this translate into the "minutes" you are claiming?
2.) Mike already pointed this out: conventional explosives vaporize themselves in the process. This only proves the fact they were vaporized rapidly.
Therefore, the yeald must have been in the kilogram range or the incandesant halo would certanly been visable for much, thousands of times, longer.
How do you move from "dozens of seconds" to "thousands of times longer" or "minutes" exactly? You seem to have skipped that part.
Second, you seem to be making alot of vague and arbitrary assumptions in your "nuclear explosive = asteroid" claim, such as the amount and yield of explosive you are comparing too (IE how much energy is used to vaporize a given quantity of explosive), and you seem to be assumign this would not scale up.
For example, if we're talking about 1 kilo of TNT, the enerrgy release should be 4.185 Megajoules. since the asteroid is tens of millions of times more massive than a 1 kilo TNT explosion, the energy requirement to achieve the same effects should be roughly comparable (within an order of magnitude or so, although this also would assume the asteroid is of the same density as the explosive, when it is much denser.) The energy level fo vaporize a 32,000 ton asteroid in a fraction of a second is still well over in the tens or hundreds of TJ range.
We know from the many direct observations and remote spectographs that "Asteroids" are not "Rocky Iron" but more like soft lumps of talcum powder. Metiors that reach the surface of the planet to be found are inevitably (+-90%) Rocky Iron because the ones made up of other things burn up before landing. Spectrographic examination of the "Trails" left by metiors that do not reach the ground, indicate that most are not Iron at all.
Prove it. And then even assuming you're right, that does not apply here since we have direct evidence citing the composition (And the aforementioned cmdrwilken's link is even more thorough, but agrees with the conclusions made by Curtis Saxton, Mike Wong, AND Brian Young.
A far simpler explanation is that they were soft, pulverised and scattered by the shot. The effects seen can be explained by shock wave disrupting the surface to make it look like it was hot. Uniform distribution of dust and gas like the "dome" effect of nuclear shots.
Except we would be seeing debris from fragmentation, which we clearly do not see. Moreover, Mike has already explained the "shockwave" aspect in detail, as I have already noted. It doesn't change the results in the least.
We have no sensor readings of temperatue to know other wise for sure.
See slo-mo film of a very high velocity projectile hitting anything. My favorite is an apple that goes from red to white in a blink as a rifle bullet hits it. That shock wave could have come from "explosive heating" by X or Gamma-rays, that pennitraited into the core of the target. This effect is well known and understood due to experiments conducted for the SDI program.
Cite a source please. You're remarkably vague about providing evidence.
The "Tracer" effect of the shot moving at such slow reallitive speed could have been a "Follow threw" projectile that followed the beam, much like a laser guided bomb, to pennitrait into the target before detonation. If we consult Explosive Demolition Manuals, we can deduce the yeald of the charge. It would have been between 32 and 50 kilos, average 40 for a 20m diamiter Astroid. We know this from standard tables used in BDA and Military Manuals. (Bomb Damage Assessment) A 750 pound GP bomb with 169 kilos of PBX, leaves a crater 14 meters across and 2 deep in soft ground, throwing debris for hundreds of meters. That includes working against gravity. In free fall orbit, the only gravity that we must concider is that between the various particles of the astroid it self. It is overcome by very few joules of energy. A hard rock like object shatters easily requiring less charge to do the same work. An AP bomb exploding deep in rock has a much larger "shatter" zone than the above crater. The charge scatters the debris just enough to become invisable in the thin light due to the failure of the human eye to discern small objects of low contrast, without evolving so much gas that it takes to long to dissipate.
1.) There was no debris visible from the destruction of the asteroids.
2.) turbolasers aren't bombs or artillery shells. They're beam weapons.
The above scenario meets all of our "facts" as seen on the film and requires no twisting of reality or suspention of disbelife to make it work.
It is therefore the best solution to our "problem". The same mechanism can also explain how "blasters" work so devistatingly without causing large "side" effects.
Actually your theory is the more complex of the two (involving more unknowns.) You still haven't shown how "vaporization" contradicts the observed scenes except for saying "I don't think they were vaporized."
For that matter, for all we know your entire argument is composed of nothing but assumptions, since you've provided very little explanation or evidence about how or where the conclusions came from.