Stark wrote:
Did you even say anything? 'Something must have minimised it' = addressed, 'rebels and ewoks alive hours later' = addressed, 'amount of KE involved is well above the extinction-level threshold' isn't a disagreement. I'm not actually sure what you were getting at, since I'd already mentioned possible mitigating mechanisms - none of which you addressed - and it appears you agree with me anyway.
Gee, I didn't think that would be that difficult for you to figure out.
Well, ,shall we go over the details then?
The explosion of the 2nd Death Star releases a fuckload of energy. One way to look at it is via the fact the Emperor intended to destroy Endor. If we assume mass scattering, that comes out to somewhere in the e30-31 joule range minimum.
Another way to look at it is to estimate the 2nd DS's mass (at least some 3e20 kg by volume, assuming 90% empty, and iron density. This is conservative however, given Curti's comment about the DS2's escape velocity later in the Holocaust page and the fact that SW materials aren't iron.) and compute the KE based on the fireball expansion given on Curtis' Endor Holocaust page (around 80 km/s for the fireball, though some of the debris he notes moves considerably faster) - comes out to around the e30 joule range.
1e9 megatoins (around 4e24 joules) is the threshold for a global extinction event according to the Planet Killers page. This has all sorts of nasty effects accompanying it - superheated ejecta and dust loading, global firestorms, air blasts and ground quakes, etc.) We're talking about many many orders of magntiude MORE energy than this! Hell, the multi-TT chunks Curtis mentions alone would have many TT's worth of KE by themselves. Those alone will be nasty (TT range can destroy a large nation or even a continent, and will produce massive firestorms, air blasts, and groundquakes as a result. Many of these effects are at "ground level", ,which only compounds the problem o fhow the Rebels shield against it.)
On top of that, there is also the superheated particulate matter comprisiing the fireball (as well as any other smaller particulaet matter.) Once they interact with the atmosphere, they're going to heat it up (again, bringing up the issue of firestorms.) The Rebel fleet can do very little to directly affect any of this, because even if they deflect the impacts to occur on other parts of the planet, the magnitude of the energy involved guarantees a global effect, even if you were to assume only a tiny fraction of the actual energy I calced above is to strike (say, a millionth, you're still near the "billion megaton" threshhold.)
What's more, you could easily expect these effects ot occur within a minute or so of the DS2's destruction, given the Debris is moving at nearly 100 km/s and is only a few thousand km away from the moon. Yet the Rebels clearly are seen surviving until many hours AFTER the destruction (indeed they're fucking celebrating, which is the most idiotic thing one can do if the planet is literally dying around you, much less doing it hours after the fact.)
Now, does that make it any clearer for you, or do you need me to explain why the impact effects and the magnitude of the energy are such a problem even with the Rebel fleet providing "protection"?
Edit: This is precisely why I mentioned the repulsor. Using the Repulsor would clearly allow them to avert the actual threat of a massive input of energy into the Sancuary moon itself, thus preventing any immediately fatal effects (air blast, firestorms, dust loading) from immediately occuring. There would still be potential pollution, dust loading effects (climate being affected by the debris blocking out the sunlight) and the effects of the high-momentum impact (since there is no way they can block the momentum, its still going to cause nasty effects to the ground.)