Power output of a lightsaber

[GStone]

I had thought it was mostly done by the shields that came up from under the platform on top of the heads of the droids that held the bucket to scoop the lava up.

There does seem to be shielding to protect the droids themselves, but it hardly seems sufficient to protect a human being standing on top of it, exposed to the heat of the entire lava river, to say nothing of the toxic gases often found in such environments (or even the heat of the atmosphere they must be breathing in).

Most of the time when Anakin is on the droids, it's moving around. Ben is on the much larger platform and we see that there's a shield glow underneath both. When they weren't on them, they were on the broken off catwalk and constantly climbing higher and higher.

Anakin runs across the catwalk after it starts to go over the cliff and heads towards the lava that's gotten onto the catwalk, but doesn't spend much time there because he force jumps off the thing and lands on the droid. You ever run and felt a breeze hit your face? Same thing here and when they fly around the stream, fighting.

They aren't exposed to heat of the entire lava. At any point, they're are exposed to the amount at any one section. Even if you assume uniform temperature over the whole thing, they rise above the lava and move around all over the river.

And check this out:

http://en.wikipedia.org/wiki/Image:Kala ... y_lava.jpg

In the picture, we see there's an orange red spot that's showing this stuff hasn't cooled yet. Going up closer to the top of the lava entry page, they show pictures of lava that's 1,000-1,100 degrees C and it's orange red and chunky. We go down in the list to higher temp ones and we see that ones that are of a similar color and consistency that's 1,100-1,200 degrees C.

Now, go back to the wiki picture I linked to. You can see that there's nothing wrapped around her face to suggest a gas mask and she's damn close to it. The orange red in the picture shows that it isn't a cooled off lava. She's not wearing any special clothes, either.

[l33telboi]

(or even the heat of the atmosphere they must be breathing in).

A very good point. Especially since we know that Jedi can't hold their breath indefinetly, as seen when they were gassed in TPM, when they swim underwater etc.

So what's the difference in this case? A simple way to filter out all the crap in the air and use only what's needed? Or something other then that?

EDIT: I realize i might not have made it clear, but i was referring to stuff like ash and the like when i said 'crap in the air'.

[Mike DiCenso]

Mike DiCenso wrote:
We saw in TPM what looked like melting, but there was no heat, at least nothing that could cook Qui-Gon or the Nemodians on the opposite side of the door to him.

Ted C wrote:

While Qui-Gonn's health is certainly an issue, there weren't any Nemoidians near the door on their side.

But they were standing close enough to feel the heat that should be radiating off of the door, particularly towards the end, right before the
Droidkas show up when the second set of doors had started to turn into nearly white-hot slag. And yet the Nemodians don't shield their faces or attempt to stand away any further than they already are.

Even assuming regular iron or battleship-quality steel, the heating required to do that in the time it did is something that would have given them some serious burn injuries, especially being so close to it.

For Qui-Gonn and possibly Obi-Wan, yes, but not the Nemoidians, who were well away from the door in their patent-pending oversized bridge.

But they weren't that far away.

There is no solid evidence that Force-users are able to shield themselves from such things, and that explanation doesn't wash for other characters like the Nemodians, or someone like Han Solo who have no midiclorian count of significance to be able to use the Force in that manner anyway, yet they suffer no injuries whatsoever.

This incident itself would suggest that Jedi are able to resist such heat, not to mention the lightsabre fight between Obi-Wan and Anakin in Ep3, in which they were at times mere inches from molten rock without sustaining any injury. I have no idea why you even mentioned Han Solo, since I can't recall any comparable situation in which he found himself.

I had assumed you had read the post in which you snipped my comments from. One of the issues is that of the lightsabre beam itself generating that heat; Han has handled and used a lightsabre on one canonical occasion: In TESB he used Luke/Anakin's lightsabre to cut open the dead Taun-taun he'd been riding. However the secondary canon of the ANH novelization has Luke marvelling over the apparent lack of heat from the weapon.

The fact is that Qui-Gonn's lightsabre melted a substantial quantity of metal either by direct heating or some kind of secondary effect, and that's more than sufficient information from which to develop a ball-park estimate of power output. What's more, you can probably use it as a high-end estimate, since Qui-Gonn would probably have used more power to get through the door faster if he could have.

Can't be direct, as the Luke ANH information and Han (a non-Force user) can attest to. Certainly what appears to be melting may not, in fact, be melting as we know it, anymore than a what a phaser does on it's highest disintigration settings is vaporization through DET.
-Mike

[Mike DiCenso]

I think the 'Han Solo' bit refers to when Solo is using the lightsaber on Hoth.

Ah. Still don't see why it would be a problem, though. It's pretty obvious that lightsabre's don't directly radiate huge amounts of heat, even though solids that they contact get hot. It's pretty obviously a secondary effect. There's no reason to think tauntaun flesh would get nearly as hot as a bulkhead door.

No, but there would be the matter of flash-vaporization, and superheated steam hitting Han in the face possibly.
-Mike

[Ted C]

Most of the time when Anakin is on the droids, it's moving around. Ben is on the much larger platform and we see that there's a shield glow underneath both. When they weren't on them, they were on the broken off catwalk and constantly climbing higher and higher.

The fact remains that they were within a meter or two of a river of red hot lava for a minute or so. That's a lot of radiative surface area.

Anakin runs across the catwalk after it starts to go over the cliff and heads towards the lava that's gotten onto the catwalk, but doesn't spend much time there because he force jumps off the thing and lands on the droid. You ever run and felt a breeze hit your face? Same thing here and when they fly around the stream, fighting.

What does this "breeze" have to do with anything? You're not suggesting that the atmosphere of Mustafar is going to do much to help cool him off, are you?

They aren't exposed to heat of the entire lava. At any point, they're are exposed to the amount at any one section. Even if you assume uniform temperature over the whole thing, they rise above the lava and move around all over the river.

They're certainly exposed to at least as much heat as the Nemoidians in the TradeFed flagship's bridge, and probably much more, since the planet's atmosphere is probably already hot.

And check this out:

http://en.wikipedia.org/wiki/Image:Kala ... y_lava.jpg

In the picture, we see there's an orange red spot that's showing this stuff hasn't cooled yet. Going up closer to the top of the lava entry page, they show pictures of lava that's 1,000-1,100 degrees C and it's orange red and chunky. We go down in the list to higher temp ones and we see that ones that are of a similar color and consistency that's 1,100-1,200 degrees C.

The only orange spot I see is where the lava is igniting the tar in the asphalt. I don't know how far this lava flow is from the actual volcanic crater, but the environment of Mustafar would be much more like the environment inside a volcanic crater than several miles down slope.

Now, go back to the wiki picture I linked to. You can see that there's nothing wrapped around her face to suggest a gas mask and she's damn close to it. The orange red in the picture shows that it isn't a cooled off lava. She's not wearing any special clothes, either.

This far from the lava source, I wouldn't expect the atmosphere to be so bad. Depending on the volcano, it might not even be bad at the crater. The problem is that her situation -- probably miles from the actual lava source in an Earthly atmosphere -- is far different from the situation of Obi-Wan and Anakin -- right on top of the flow on a planet that seems to have eruptions occuring all over the planet.

[Ted C]

A very good point. Especially since we know that Jedi can't hold their breath indefinetly, as seen when they were gassed in TPM, when they swim underwater etc.

It's patently obvious that Obi-Wan and Anakin were breathing Mustafar's atmosphere: they were talking and panting.

So what's the difference in this case? A simple way to filter out all the crap in the air and use only what's needed? Or something other then that?

EDIT: I realize i might not have made it clear, but i was referring to stuff like ash and the like when i said 'crap in the air'.

They would need to deal with the heat from the atmosphere, the heat from the lava flow, and any toxic gases and particles. The atmosphere probably isn't severely toxic (Padme could breathe it, and there were no obvious signs of atmosphere control up at the landing pad), but it probably is too hot to be helping them cool off from their exertions or radiant heat absorbed from the lava flow.

[Ted C]

But they were standing close enough to feel the heat that should be radiating off of the door, particularly towards the end, right before the Droidkas show up when the second set of doors had started to turn into nearly white-hot slag. And yet the Nemodians don't shield their faces or attempt to stand away any further than they already are.

That bridge was huge. They could easily have been ten yards from that door. They might have been able to feel the heat, but they certainly weren't at any risk from it.

But they weren't that far away.

I submit that yes... they were that far away.

I had assumed you had read the post in which you snipped my comments from. One of the issues is that of the lightsabre beam itself generating that heat; Han has handled and used a lightsabre on one canonical occasion: In TESB he used Luke/Anakin's lightsabre to cut open the dead Taun-taun he'd been riding. However the secondary canon of the ANH novelization has Luke marvelling over the apparent lack of heat from the weapon.

And I commented on that after someone drew attention to it. Lightsabre's don't seem to randomly radiate heat; they induce heat in solid materials on contact, but they don't radiate it at all times. The density and thermal properties of the material would probably have a significant affect on how much heat gets generated.

Can't be direct, as the Luke ANH information and Han (a non-Force user) can attest to. Certainly what appears to be melting may not, in fact, be melting as we know it, anymore than a what a phaser does on it's highest disintigration settings is vaporization through DET.
-Mike

And I have no problem with a secondary effect causing the metal's temperature to rise. The point is that energy in some form got transferred to the blast door, and that energy was sufficient to heat it to its melting point and melt a large mass of metal. The lightsabre is unquestionably the source of that energy, so the melting of the blast door is a valid means of estimating the power output of a lightsabre.

[GStone]

The fact remains that they were within a meter or two of a river of red hot lava for a minute or so. That's a lot of radiative surface area.

True, it is. However, an area under them that is wide enough to stand on (a circular top and a much larger platform, both with force fields) was under them and it wasn't that long.

What does this "breeze" have to do with anything? You're not suggesting that the atmosphere of Mustafar is going to do much to help cool him off, are you?

I'm speaking of the cool air absorbing more of the heat of the jedi, which keeps them cooled off more. Not ice cold, like when you stand in front of an air conditioner's vents, but you still aren't burning up as much.

They're certainly exposed to at least as much heat as the Nemoidians in the TradeFed flagship's bridge, and probably much more, since the planet's atmosphere is probably already hot.

I'm more inclined to think that the blast doors are designed to take more punishment that what might be naturally occuring to heat the lava. I would assume that the blast doors not only protect from long duration blaster effects, but also from the punishment dished out by explosives, which I'm sure would have to be pretty decent, even if we just went with what our Earth has developed, as portable explosives and not enormous bombs, like a MOAB.

The only orange spot I see is where the lava is igniting the tar in the asphalt. I don't know how far this lava flow is from the actual volcanic crater, but the environment of Mustafar would be much more like the environment inside a volcanic crater than several miles down slope.

If that were true, wouldn't we see the ignitions all along the length of the walk/road and not at the few spots there is an ignition?

This far from the lava source, I wouldn't expect the atmosphere to be so bad. Depending on the volcano, it might not even be bad at the crater.

But, when you get the idea that the lava in this pic is hotter than the lava from the river (determined from just seeing the difference), she isn't protected at all. The distance she's from this lava is approximately (though maybe a tad farther) than the distance Ben and Anakin were from their cooler lava. Just the heat should be something that is effecting her and there's no evidence that she's having trouble being near it.

The problem is that her situation -- probably miles from the actual lava source in an Earthly atmosphere -- is far different from the situation of Obi-Wan and Anakin -- right on top of the flow on a planet that seems to have eruptions occuring all over the planet.

And, at most, the temperature of the lava bursts would be around the same as the temperature she's near. The information about the picture says that it's a home that was destroyed with all the others on Kalapana. The kalapana page referenced this page:

http://hvo.wr.usgs.gov/kilauea/history/1990Kalapana/

which said that the thin layer of lava that flowed and cooled often got broken up again by more lava collecting underneath and breaking through, creating some areas with a thickness of over 10 meters, but most of the lava flow was around 10-20 cm thick. So, that photo could easily be anywhere, but according to the 4 map pictures that show the progression of lava over the years in that spot, the widest distance between the 2 highways where the volcano sat was around a thousands meters or so and the lava flow moved far up the coast, past Kaimu Bay, and even redrew the coastal boundry of the bay, making it no longer existing, as a bay and turned it into just part of the general path of the coast.

[Mr. Oragahn]

Side effects or not, the point is that if a Jedi want his weapon to do that, it will.

X joules of energy managed to melt that door over a given period of time, and that should be enough to know where to start from.

Working on a couple of screenshots will help to gauge the size of the door, each layer's thickness, and the volume of molten metal.

Here's a page about the various series of steel and their physical properties, including density and melting point:

http://www.ssina.com/composition/chemical.html

I have no idea which one would be the most appropriate for an estimation.

[Praeothmin]

But, when you get the idea that the lava in this pic is hotter than the lava from the river (determined from just seeing the difference), she isn't protected at all.

I couldn't find that information anywhere.
Where exactly did you find info saying that free flowing lava, in a complete liquid form, is cooler than lava that has begun to cool off?

I'm speaking of the cool air absorbing more of the heat of the jedi, which keeps them cooled off more.

Mustafar is a giant, natural foundry.
Where would the cool breeze come from? All we see are rivers of lava, of which the heat would only be going up, towards Anakin and Obi-Wan.

In fact, once the shields protecting the big "antennas" failed, the metal started melting, and it fell. But the shield never seemed to protect the two Jedi, it was structure-hugging all along.

In fact, in the picture you provided with the woman:

The pahoehoe flow fronts were typically only 10-20 cm thick as they moved through the area. However, the thin leading edges of the flows quickly crusted over and stagnated. As lava continued to push beneath the crust, the cooled surface was lifted up until eventually lava again broke out of the sides and front of the inflated flows.

So the black crust was cooled off lava. The hot lava was underneath it, so I really don't know how that could result in greater heat then flowing lava.

They would need to deal with the heat from the atmosphere, the heat from the lava flow, and any toxic gases and particles. The atmosphere probably isn't severely toxic (Padme could breathe it, and there were no obvious signs of atmosphere control up at the landing pad), but it probably is too hot to be helping them cool off from their exertions or radiant heat absorbed from the lava flow.

Agreed.

And if the Nemoidians were supposed to feel the heat of parts of a metal door melting from 10 feet away, imagine how much heat Anakin and Obi-Wan were exposed to on Mustafar, just with the super-heated air.

[GStone]

I couldn't find that information anywhere.
Where exactly did you find info saying that free flowing lava, in a complete liquid form, is cooler than lava that has begun to cool off?

At the top of the page, it says "Lava, when first exuded from a volcanic vent, is a liquid at temperatures from 700 °C to 1,200 °C (1,300 °F to 2,200 °F)." Further down, we see a picture of flowing lava that's kinda chunky, but is still orange red and that is about 1,000-1,100 degrees C. The slightly hotter lava (1,100-1,200 degrees C) is the silver looking one that kinda looks like liquid mercury.

Mustafar is a giant, natural foundry.
Where would the cool breeze come from? All we see are rivers of lava, of which the heat would only be going up, towards Anakin and Obi-Wan.

From the wind that's hitting their face that's caused by their running. It is a little cooler.

In fact, once the shields protecting the big "antennas" failed, the metal started melting, and it fell. But the shield never seemed to protect the two Jedi, it was structure-hugging all along.

The shields I'm talking about that portected them in part was from the platform Ben was on and the droid Anakin was on.

In fact, in the picture you provided with the woman:

The pahoehoe flow fronts were typically only 10-20 cm thick as they moved through the area. However, the thin leading edges of the flows quickly crusted over and stagnated. As lava continued to push beneath the crust, the cooled surface was lifted up until eventually lava again broke out of the sides and front of the inflated flows.

So the black crust was cooled off lava. The hot lava was underneath it, so I really don't know how that could result in greater heat then flowing lava.

In the image of the silver colored lava, it's indicated that it is a higher temp lava than the red orange and chunky looking version. In the image I provided, all that is the liquid mercury looking colored lava.

[Mike DiCenso]

Mike DiCenso wrote:
But they were standing close enough to feel the heat that should be radiating off of the door, particularly towards the end, right before the Droidkas show up when the second set of doors had started to turn into nearly white-hot slag. And yet the Nemodians don't shield their faces or attempt to stand away any further than they already are.

Ted C wrote:
That bridge was huge. They could easily have been ten yards from that door. They might have been able to feel the heat, but they certainly weren't at any risk from it.

Even if they (Nute Gunray and Rune) were far enough not to catch fire, they could have been close enough that they would have to be shielding their faces, or reacting in some way other than fear of the Jedi coming through. There is also the matter of how much closer to the door the other Nemoidian bridge crew members were.

Mike DiCenso wrote:

But they weren't that far away.

I submit that yes... they were that far away.

I think some screencaps are in order here. The bridge of the ship was big to be sure, but it's not like the crew, along with Nute and Rune were plastered up against the far side of it opposite the blastdoors, either.

And I commented on that after someone drew attention to it. Lightsabre's don't seem to randomly radiate heat; they induce heat in solid materials on contact, but they don't radiate it at all times. The density and thermal properties of the material would probably have a significant affect on how much heat gets generated.

Speaking of which, besides taun-taun flesh, we also see that when Anakin/Vader kills the Seperatist leaders on Mustafa, their clothing glows in a very peculiar way (no flames, no smoke), and there is no evidence of severe burning of, or steam from the flesh underneath.

And I have no problem with a secondary effect causing the metal's temperature to rise. The point is that energy in some form got transferred to the blast door, and that energy was sufficient to heat it to its melting point and melt a large mass of metal. The lightsabre is unquestionably the source of that energy, so the melting of the blast door is a valid means of estimating the power output of a lightsabre.

A lightsabre certainly does something that in some cases looks like melting, but it may, in fact, not be. However, it would seem that we can estimate an equivalent from that.
-Mike

[Praeothmin]

At the top of the page, it says "Lava, when first exuded from a volcanic vent, is a liquid at temperatures from 700 °C to 1,200 °C (1,300 °F to 2,200 °F)." Further down, we see a picture of flowing lava that's kinda chunky, but is still orange red and that is about 1,000-1,100 degrees C. The slightly hotter lava (1,100-1,200 degrees C) is the silver looking one that kinda looks like liquid mercury.

Ok, I found on the lava page at Wikipedia, here:
http://en.wikipedia.org/wiki/Lava

The silver "crust" is the cooling off lava. The lava underneath that crust is the one that is hotter than the free-flowing one.
The crust itself will not be 1,200 °C.
And in any case, whether the lava is at 1,000 °C or at 1,200 °C, the air above it, most off all on a planet like Mustafar, will only be a little cooler, which will still make it as hot as hell.
For example, if you were to come out of a steam room, and into a room with a temperature of aroud 30 °C, even though to you it will seem cooler, the air will still be hot.
Go to a foundry, walk near the liquid metal containers, and tell me that the ambient air isn't hot.

From the wind that's hitting their face that's caused by their running. It is a little cooler.

Even if you run, creating a breeze, when you're running in a hot environment, the breeze will also be hot.
I used to drive a truck in one of my previous jobs, a truck that had no air conditioning.
I can guarantee that when the outside temp rose around 30 °C, even with my windows opened and the fan blasting air into my face ( hot air, by the way), I wasn't coling off at all.
And I wasn't running (read: exerting myself, read: augmenting my body heat) on a bridge above immense lava rivers.

The shields I'm talking about that portected them in part was from the platform Ben was on and the droid Anakin was on.

But the air around them will still be hot...

[GStone]

Go to a foundry, walk near the liquid metal containers, and tell me that the ambient air isn't hot.

I've felt it.

Even if you run, creating a breeze, when you're running in a hot environment, the breeze will also be hot.
I used to drive a truck in one of my previous jobs, a truck that had no air conditioning.
I can guarantee that when the outside temp rose around 30 °C, even with my windows opened and the fan blasting air into my face ( hot air, by the way), I wasn't coling off at all.
And I wasn't running (read: exerting myself, read: augmenting my body heat) on a bridge above immense lava rivers.

When you're running, you are also not staying in the same spot that you're giving off your own heat. That also cools you down.

But the air around them will still be hot...

And the shields themselves are preventing much of the heat from what's coming up from the lava from rising up around the area of the jedi's respective platforms, creating a cooler zone of air.

[Praeothmin]

I've felt it.

Good, so you know it isn't cool at all...

When you're running, you are also not staying in the same spot that you're giving off your own heat. That also cools you down.

Well, the funny thing is I do some jogging as part of my training routine during the summer, in the outside heat.
And as much as I run, I don't cool off, because the more I run, the more I heat up my body, and the more I heat up my body, the more I feel hot.
If there are no cool air currents (i.e. northern winds), then I won't cool off while running, and I always end up soaking wet from sweating, which wouldn't happen if I cooled off because off the very small breeze I create while running.

And the shields themselves are preventing much of the heat from what's coming up from the lava from rising up around the area of the jedi's respective platforms, creating a cooler zone of air.

If they were standing in an environment in which the air was still, perhaps.
But they aren't, they are in an environment where even only a tiny pocket of air that has a few degrees less of heat ill create air movement, which will create very warm breezes, since they are standing in a foundry like environment.