The grate scene blaster calculations - a new complication

[Tyralak 12,068]

In fact, this might throw a lot of energy weapon calculations into flux. Previously, Brian calculated (and most of us agreed, myself included) it would take at the very least, 60 megajoules of energy to cause the damage to the grate in "A New Hope", assuming it was iron. Well, while doing some research on modern laser weapons, I came across this article about world record breaking Free Electron Laser. The story had been repeated on a large number of other sites and news outlets. I started digging, because the first article I read, only mentioned the voltage, which doesn't tell us much. However, after reading several other articles, I find out that this type of laser - which does not use a solid state medium for gain amplification - would be able to blast through 20 feet (6.096 meters) of solid steel in a single second. At a power level of ONE MEGAWATT. (since we're dealing with a single second, the equivalent is of course, one megajoule.) A full SIXTY times less power than the calculations for the grate. Posted below are several more articles, but they basically say the same thing. Thoughts?

 

http://www.foxnews.com/tech/2011/02/18/navy-breaks-world-record-futuristic-laser-getting-real/

http://www.foxnews.com/tech/2011/04/08/navy-showboats-destructive-new-laser-gun/

http://www.popsci.com/technology/article/2011-02/navys-death-ray-laser-breaks-another-record-its-way-ripping-through-steel

http://www.popsci.com/technology/article/2011-01/navys-free-electron-laser-weapon-takes-big-leap-forward-powerful-new-electron-injector

[Vince 520]

This doesn't really affect the calculations on the grate because those estimates are based on the minimal energy needed to melt the grate, heating it red hot. Or 500 MJ to vaporize it. The real life laser does not melt or vaporize its way through 20 foot of material. 

It could be argued that blasters in star wars are incredibly inefficient because they insist on superheating stuff red hot over larger surface areas. While a real life laser can blast through feet of material at a fraction of the power. A star wars blaster effects a tinier quantity of material but heats it to far greater temperatures. Surface area should be taken into account to establish the volume of material blasted. 

 

This laser wouldn't penetrate SW tank armour. 

 

[Khas 12,158]

Actually, a laser cuts by vaporizing the material in the direct area of where it hits.  This laser would vaporize its way through 20 feet of steel per second.

 

Against SW armor, however, it might to better than you think.  The MythBusters, on their January 4th Star Wars special, calculated that the logs used to crush the AT-ST on Endor had an impact force of two megawatts, and while it is true that laser and kinetic damages behave differently, it's still "pretty" low.  In fact, if the Empire had invaded Earth during WWII, the tanks of that era would have been able to blow up AT-STs pretty easily.  But then again, the AT-ST is a pretty shitty machine anyway.

 

Also, I re-watched the scene in question.  The grate looked more like plastic than metal.  And I think I saw some debris flying around from when it exploded.

[Vince 520]

Actually, a laser cuts by vaporizing the material in the direct area of where it hits.  This laser would vaporize its way through 20 feet of steel per second.

Are you sure about that? I'm pretty certain I've read differently. If this were the case then the laser could only vape a hole much less than a cm wide through 20 feet of steel. Superdispersive armour would render the weapon useless because the energy / effect is spread over a much greater surface area. 

http://panoptesv.com/SciFi/LaserDeathRay/DamageFromLaser.php

 

Against SW armor, however, it might to better than you think.  The MythBusters, on their January 4th Star Wars special, calculated that the logs used to crush the AT-ST on Endor had an impact force of two megawatts, and while it is true that laser and kinetic damages behave differently, it's still "pretty" low.  In fact, if the Empire had invaded Earth during WWII, the tanks of that era would have been able to blow up AT-STs pretty easily.  But then again, the AT-ST is a pretty shitty machine anyway.

True, theres nothing to suggest star wars armour does particularly well against kinetics in space or on the ground, and the AT ST's are especially vulnerable. But their armour is orders of magnitude superior at handling directed energy weapons than they are kinetics. Blasters can inflict thousands of times more damage to rock or metal than armoured SW vehicles, so their armour is thousands of times more effective at handling energy weapons. 

http://www.galacticempirewars.com/armour

 

Also, I re-watched the scene in question.  The grate looked more like plastic than metal.  And I think I saw some debris flying around from when it exploded.

I very highly doubt the grate was plastic. Everything we tend to come across in starships is metal on screen: the doors, the walls, the floors, the computers, the ceilings etc. It looks like metal to me and there were no debris, only steam. There are other examples of blasters putting similarly sized holes into metal too such as the sandcrawler and an incident with a landspeeder in TCW. 

http://www.galacticempirewars.com/high-settings

 

[Khas 12,158]

I read up on how lasers cut through objects.  They burn or vaporize their way through whatever they're cutting.

 

As for the grate, I've seen hard plastics used in SW ships, mainly for computer screens, but also in other places, much how metals and plastics tend to be used in conjunction.

 

On another note, holy shit!  I just realized what blasters fire!  A high-energy form of the stuff they used to serve for lunch at my old high school!  Well, it's not THAT surprising, actually.

[Vince 520]

Where else have you seen plastics besides the lights and monitor screens? As far as I've seen, everything grey short of naval officer uniforms is metal in starships..

 

[Khas 12,158]

I've seen it used in droids on the Death Star, like that R3 Unit we see going across some of the Death Star's halls.

 

R3 Units are said to have transparent domes made of "plastex" (Yes, you're allowed to groan).  

 

Also, let's factor in a few things.  One - plastic is likely to be cheaper than metal.  On a project as big as the Death Star, serving a government as corrupt as the Empire, people are likely to cut costs on non-essential things.  No one would likely think a garbage chute grate would be super-essential.  Another thing is just the way the grate reflects light.  It doesn't quite look metallic to my eyes.  Course, I could just be imagining things, but it just lacks a metallic luster.

[Tyralak 12,068]

It does look kind of like a cast iron skillet. However, there are some nagging problems with this. They were exchanging fire back and forth for quite some time, with almost every shot missing its intended target. We saw nobody, including Leia change the power settings on their blasters. The ONLY thing that we saw that kind of reaction from was the grate. I watched the scene just now several times. Every time a shot impacted a wall or anything else, it only left a puff of smoke or steam. Even the Stormtroopers who were hit, didn't show a ton of damage. So, we have two options here (unless I'm missing something).

 

1. The grate is not made of iron, instead made of another cheaper material. Everything else the bolts are hitting is made of the usual materials those sort of items would be made of anywhere else.

 

2. The grate IS made of iron, and everything else including computer consoles, Stormtrooper armor, walls, activation panels on walls etc, is made of some sort of uber material that's orders of magnitude stronger than iron.

 

I don't see a third option, unless someone could point one out to me. 

[Khas 12,158]

Considering that humans who get hit with blaster bolts aren't blown apart by them, Option 1 looks like the best.

 

Oh, I'm not sure if this is canon or not, but I remember when playing Star Wars: Battlefront II, one of the Rebel taunts against Imperial Stormtroopers was to call them "plastic boy".

[Vince 520]

I don't see a third option, unless someone could point one out to me. 

 

There is a second-long delay between Leia taking the gun and shooting the grate and for almost all of that time her left hand thumb was positioned on top of a power setting slider. She could have easily ramped it up, considering the points you bring up, its likely she did. 

 

 

Also, let's factor in a few things.  One - plastic is likely to be cheaper than metal.  On a project as big as the Death Star, serving a government as corrupt as the Empire, people are likely to cut costs on non-essential things.  No one would likely think a garbage chute grate would be super-essential.  

Possibly. Iron is the most abundant metal in the universe to be fair, it (or equivalents) would be dirt cheap in Star Wars.

 

Another thing is just the way the grate reflects light.  It doesn't quite look metallic to my eyes.  Course, I could just be imagining things, but it just lacks a metallic luster.

Its subjective. It looks like metal to me and it blends seamlessly in with the surrounding metal walls. I feel a metallic composition is more consistent as almost everything else in starships short of certain parts of droids and computer screens is metal. 

[Tyralak 12,068]

There is a second-long delay between Leia taking the gun and shooting the grate and for almost all of that time her left hand thumb was positioned on top of a power setting slider. She could have easily ramped it up, considering the points you bring up, its likely she did. 

 

 

 

 

 

That's certainly a possibility, however where her thumb is sitting is a good inch and a half away from where the power slider is. Note also on the diagram, the slider is vertical. Her thumb also stays stationary. I just went through the entire scene on Blu-Ray frame by frame. Also, the shots fired from that weapon after she blew the grate out behaved no differently than any of the others. While it's conceivable that she could have turned the power back down after she blew out the grate, the next question would be why? If the blaster was that much more effective cranked up, why would she want to turn it down again when firing back at the Stormtroopers? Especially considering the predicament they were in, putting it at it's highest setting would be the best course of action. Not to mention, let's consider the mentality of the characters at the time. Highly frazzled and looking for a means of escape. It's doubtful a politician with limited weapons experience would have the forethought to crank up the power without looking at it, blast the grate then lower the power back down. Going through the entire scene frame by frame, it's interesting to notice, other than the grate, nothing was seriously damaged by the myriad of blaster bolts fired. Every time a bolt hit a surface there was a bright flash, followed by smoke/steam and a scorch mark. Even the computer consoles suffered no visual damage. I find it very difficult to believe that absolutely everything on that ship was crafted from advanced armor, except the ventilation grate, which was made of garden variety steel. This brings up a second issue.

 

Up until now, I was perfectly convinced that the grate was iron or steel. The reason I looked at the scene, was because I was working on research as to what blasters actually are. What type of energy do they fire? How exactly do they work? So, I decided to start doing a frame by frame of various scenes. I started with this one. Forgive me, I don't have a Blu-Ray capture device, so I will have to get creative about screencaps at a later time. Most sources talk about blasters producing a coherent energy beam that is combined with Tibanna gas then fired through the barrel. I observed that almost every shot resulted in some sort of gas being ejected from the barrel. I also noticed that whenever an object was hit, the same cloud was present at the point of impact, followed by a bright flash and a scorch mark on the object. I have begun to hypothesize that the way blasters and turbolasers work, is by containing a highly energetic plasma (charged Tibanna gas) in a magnetic bottle. When the bolt hits it's target, the containment field is ruptured and the plasma does massive thermal damage. This could partially explain why we don't see blaster bolt sized holes in things, and items like the grate were melted over a large surface area. Going by each frame, it looks as if something superheated "splashed" over the grate, melting it. That would be consistent. It would also be consistent with the large, spread out scorch marks on the walls. Not to mention the armor effects on ships. 

[Vince 520]

She did have time to change the switch before the blaster was brought in to view which, in my opinion, seems more fitting than plastic grates.

Another thing to consider, what kind of thermal properties would the grate have to have to allow blasters to melt / vape 8 liters of that material yet only scorch other materials on the same setting? We go from the walls being orders of magnitude more durable than conventional metal to the grate being orders of magnitude less durable than normal metal and stormtrooper armour. I have found ample evidence in TCW that the low powered settings which pock mark conventional metal also kill stormtroopers so those E-11's were on lower settings prior to the grate. The walls are therefor not uber armour. 

But it seems infeasible that the grate could be a thousand times easier to melt than stormtrooper armour is to penetrate and metal is to scorch. It seems unavoidable that the setting must have changed, whether the target was plastic or metal.

While it's conceivable that she could have turned the power back down after she blew out the grate, the next question would be why? If the blaster was that much more effective cranked up, why would she want to turn it down again when firing back at the Stormtroopers? Especially considering the predicament they were in, putting it at it's highest setting would be the best course of action. Not to mention, let's consider the mentality of the characters at the time. Highly frazzled and looking for a means of escape. It's doubtful a politician with limited weapons experience would have the forethought to crank up the power without looking at it, blast the grate then lower the power back down.

This could well be a limitation of the weapon itself. The damage caused by a blaster literally ranges four orders of magnitude so the highest energy shots would be a significant drain on the power pack. The gun also has to have some kind of technobabble recoil dissipation going on due to the way they sometimes deliver huge momentum. And they must remain cool despite heating things to thousands of degrees on the receiving end. Those features might limit the availability of the higher settings to a handful of shots or the gun melts internally rendering it useless (which is a popular concern in eu works) or gets to hot to handle, which is mentioned in the film novelizations iirc. 

 

 

 

The reason I looked at the scene, was because I was working on research as to what blasters actually are. What type of energy do they fire? How exactly do they work? So, I decided to start doing a frame by frame of various scenes. I started with this one. Forgive me, I don't have a Blu-Ray capture device, so I will have to get creative about screencaps at a later time. Most sources talk about blasters producing a coherent energy beam that is combined with Tibanna gas then fired through the barrel. I observed that almost every shot resulted in some sort of gas being ejected from the barrel. I also noticed that whenever an object was hit, the same cloud was present at the point of impact, followed by a bright flash and a scorch mark on the object. I have begun to hypothesize that the way blasters and turbolasers work, is by containing a highly energetic plasma (charged Tibanna gas) in a magnetic bottle. When the bolt hits it's target, the containment field is ruptured and the plasma does massive thermal damage. This could partially explain why we don't see blaster bolt sized holes in things, and items like the grate were melted over a large surface area. Going by each frame, it looks as if something superheated "splashed" over the grate, melting it. That would be consistent. It would also be consistent with the large, spread out scorch marks on the walls. Not to mention the armor effects on ships. 

That is consistent with a lot of examples. When hitting a large, thin object like the grate or blast door they tend to utterly annihilate the object without over-penetrating. 

[Praeothmin 532]

One explanation that never satisfied me was how no one was affected by all tht super heated air from the super powerful Blaster shot...

I seem to recall Brian mentioning the vent sucking it all in, but to suck in the amount of vaporized material in such a short time as to prevent the effects on people, we might have noticed the sucking effect on Leia's clothing or the characters. hair, which we didn't...