Page 1 of 2

DS 2 diameter

Posted: 2003-09-20 09:44am
by PzGren
Hello!
I just took my copy of ROTJ and watched the DS 2 destruction scene.
I noticed the following:
The time between the destruction of the reactor and the escape of the Falcon was 33.72 seconds (+/-). After the Falcon emerged the fireball, it moved half its length (26.7/2) in 1 frame (00.4s), this equals a speed of 333.75 m/s (about mach 1). Assuming the Falcon accelerated instantaneously to this speed and didn't slow down (fair guess, I think).,The radius of DS 2 would be <11.5 km, diameter therefore <23 km.
Where is the error?

Posted: 2003-09-20 10:05am
by Ender
The error would be in the fact that it is were that small the Executor be almost as big as it.


DS2 is ~900 km in diameter.

Posted: 2003-09-20 10:12am
by PzGren
Guess what, I know that.
But where is the error in the measurement?
At the measured speed, it would take more than 22 minutes to cover 450km.

Posted: 2003-09-20 10:21am
by Sir Sirius
You assume that there is no time cap between scene changes and then proceed to base your conclusion on this assumption, even though your conclusion condradicts a number of other observations concerning the size of DS2. A form of mental tunnelvision.

Posted: 2003-09-20 10:24am
by Ender
PzGren wrote:Guess what, I know that.
So you know what the size is, get something drastically off from the size, then ask others to error check it as though it was correct?
But where is the error in the measurement?
At the measured speed, it would take more than 22 minutes to cover 450km.
How about he fact you assume it didn't decellerate after it was safe. :roll:

Fact: We know it took a few seconds to get out of there
Fact: We know the distance traveled
Fact: We thus know the speed
Fact: After the escape it was traveling at a lower speed then the calculated speed

Conclusion: It slowed down.

Posted: 2003-09-20 10:40am
by Mitth`raw`nuruodo
Relax guys, I think he's just trying to figure out what he did wrong. Nothing wrong with that.

Posted: 2003-09-20 11:55am
by PzGren
The Falcon barely escaped the explosion. It was engulfed by flames, shortly before exiting. And Lando sure as hell wasn't that happy about a correct calculation.
So I assume they did not decelerate, as this wouldn't make any sense.

Posted: 2003-09-20 01:23pm
by Burak Gazan
Speculation: after clearing the superstructure, divert discretionary power from engines to shields (since Lando is well aware the DS2 is about to go boom in a real big way :wink: ) cutting the Falcon's acceleration.

Or it's just in how the scene is cut :)

Posted: 2003-09-20 03:06pm
by Sharp-kun
http://www.theforce.net/swtc/ds/#summary

Most accepted seems to be 900K, +/- 60km.

Posted: 2003-09-21 07:56am
by PzGren
This still doesn't explain the discrepancy!

Posted: 2003-09-21 09:11am
by Mad
The Falcon could've accelerated to a very high velocity in a straight passage, then have to slow down for a turn near the exit, and didn't have a chance to accelerate back up to the previous velocity. Additionally, there may have been a time cut.

Posted: 2003-09-21 09:27am
by PzGren
That would imply, that the blast changed its speed as well. The explosion orginated from the reactor and was as fast as the falcon. Well, maybe a little faster, as the Falcon started his escape before the big BOOM and engulfed it afterwards. The time cut must have been ~20 min. Witzhout anything happening?

Posted: 2003-09-21 01:01pm
by Lex
anything about his sig is off topic, so go and make a new thread if its so important

yes, he is right, i did the same calculations and had the almost same outcome, but, the logical conclusion is: in the very last seconds, Lando but all energy he could spare to the shields

other conclusion: the fire bolt slowed down. maybe the speed gets down after it leaves the reactor room, because there are way more things between...

Posted: 2003-09-21 03:26pm
by SPOOFE
The fact that the tunnel that Lando followed to escape the DS2's superstructure was not a straight line is all the evidence you need to conclude that he obviously was not travelling at a uniform velocity during his escape. Clearly, if it took him 33 seconds to escape, then obviously he was not travelling at a mere 333.75 m/s during the entire trek.

Posted: 2003-09-21 03:54pm
by PzGren
So why was the blast right behind him? Did it also slow down at corners?? I don't think so. If it expanded wavelike, it wouldn't have changed its velocity at all, regardless of angles it had to take. Nevertheless, the last part of the tunnel was straight and the Falcon nearly toasted, so we can assume that they were at maximum speed.

Posted: 2003-09-21 04:46pm
by Dalton
Thread split.

PzGren, the only explanations I can offer are variable speeds and/or less distance to travel if they were coming from the unfinished side.

Posted: 2003-09-21 04:55pm
by Sea Skimmer
PzGren wrote:So why was the blast right behind him? Did it also slow down at corners?? I don't think so. If it expanded wavelike, it wouldn't have changed its velocity at all, regardless of angles it had to take.
The blast in the tunnel was advancing ahead of the main station obliterating blast. Since it was traveling through the tunnels to accomplish this it would indeed be slowed down at every turn.

Posted: 2003-09-21 05:34pm
by vakundok
If we assume that the tunnel used for escape also had sideways, it would slow down the explosion (without affecting the speed of the Falcon), wouldn't it?

Posted: 2003-09-21 06:13pm
by Mad
PzGren wrote:So why was the blast right behind him? Did it also slow down at corners??
During straight tunnels, the Falcon could outpace the explosion. During turns, the Falcon would have to slow down, and the explosion could catch up.

Did anyone time the explosion's expansion rate as the Falcon escaped? Howabout as the station actually exploded (after the Falcon's escape)?
Nevertheless, the last part of the tunnel was straight and the Falcon nearly toasted, so we can assume that they were at maximum speed.
Define "maximum speed." The only maximum speed in sublight is the speed of light.

Posted: 2003-09-21 08:37pm
by YT300000
Mad wrote:Define "maximum speed." The only maximum speed in sublight is the speed of light.
I think he means throttle, as in maximum acceleration.

Posted: 2003-09-21 10:36pm
by SPOOFE
Nevertheless, the last part of the tunnel was straight and the Falcon nearly toasted, so we can assume that they were at maximum speed.
No, we can't make that assumption.

Posted: 2003-09-22 05:20am
by PzGren
Why?

Posted: 2003-09-22 09:05am
by Lex
Pz is right again unfortunatly :/

If i was in charge there, i would have put all energy on engines too, to be out of there as fast as possible. but there is another possibility: the falcon flew slower thru the death star channels because maneuvering was difficult, but when the fire almost catched up to them, they speeded up like mad, that seems logical to me

Posted: 2003-09-22 11:07am
by PzGren
But that means that the average speed INSIDE / THROUGH the DS was even lower then the "escape speed" we measured as around 335m/s.
If this were so, DS had to be even smaller.

Posted: 2003-09-22 12:58pm
by Howedar
PzGren wrote:Why?
Because the Falcon would be at maximum acceleration, not maximum speed.