What is Skimming, really?

[IvoryRoad]

Okay, now that Alloy of Law is out, I am extremely confused about the nature of weight feruchemy. The question I have is: What, exactly, is being stored in or tapped from an ironmind?

The way I see it, there are really only two possibilities:

- Mass: I was inclined to think that this was the answer, since I definitely remember specific wording from WoA's Sazed-Marsh fight specifying that he grew more dense. Yet, we see that in Alloy of Law, this is directly contradicted. Waxillium notes, rather specifically, that the opposite is true: that he does not grow more dense, because bullets can still pierce his body. Either Harmony changed this between the books or one of them is just wrong.

- Gravitational susceptibility: this was the only other thing I could come up with, since I seem to remember from basic physics that an object's weight is determined by gravity, not by mass. But this is actually contrary to both books, since increased gravity also increases the speed at which an object falls, and both Sazed and Waxillium exploit this fact.

So what is going on? Wax says his strength increases proportionally to his weight so he doesn't crush himself, but I don't even want to think about the complications that arise from that.

Any ideas? o_O

[Kurkistan]

Okay, now that Alloy of Law is out, I am extremely confused about the nature of weight feruchemy. The question I have is: What, exactly, is being stored in or tapped from an ironmind?

The way I see it, there are really only two possibilities:

- Mass: I was inclined to think that this was the answer, since I definitely remember specific wording from WoA's Sazed-Marsh fight specifying that he grew more dense. Yet, we see that in Alloy of Law, this is directly contradicted. Waxillium notes, rather specifically, that the opposite is true: that he does not grow more dense, because bullets can still pierce his body. Either Harmony changed this between the books or one of them is just wrong.

- Gravitational susceptibility: this was the only other thing I could come up with, since I seem to remember from basic physics that an object's weight is determined by gravity, not by mass. But this is actually contrary to both books, since increased gravity also increases the speed at which an object falls, and both Sazed and Waxillium exploit this fact.

So what is going on? Wax says his strength increases proportionally to his weight so he doesn't crush himself, but I don't even want to think about the complications that arise from that.

Any ideas? o_O

There's a rather extensive thread on this where the conclusion was that mass was essentially what was stored. As to not growing more dense, I think Wax might just not be thinking in the right terms about what "density" means for how much energy is required for a bullet to pierce his body.

Density is mass per unit volume, but what we're concerned about with bullets puncturing Wax's skin is Bulk Density. Consider Wax's body as constantly at "poured density" no matter what the mass of his component particles are. His density will go up as the mass of his component elements go up, but they will not "settle" more closely together, leaving the lattice that is Wax just about as vulnerable as ever. If we get up to ridiculous proportions of mass, then the individual molecules might have enough inertia to significantly affect the energy of a bullet trying to pass through this lattice, but on the practical level we won't see much of a difference.

Consider an example: A cubic meter of loosely packed sand and a cubic meter of loosely packed lead particles of the same gauge as that sand. The metal-cube is by far more dense, with more mass per unit of volume, but not significantly harder to puncture or dent than the sand. If every component of a Skimmer's body grows intrinsically more massive, he would be "denser" in the strictly mathematical sense, but might not necessarily see the kinds of resistance to puncturing one normally attributes to "dense" compounds, such as tightly packed sand or lead particles.

Where this comparison fails is that heavier particles are more likely to "pack in" into a tighter lattice. But the effects of Iron Feruchemy appear to be such that the elements of a Skimmer's body are forced to stay in the same relative position to each other, instead of "sifting together." Otherwise, we would have some very squishy Skimmers on our hands.

Most of the "science" here is off of half-read Wikipedia articles and quarter-remembered science classes, so feel free to call me out if I'm just rambling like a lunatic.

Edited November 30, 2011 by Kurkistan

[IvoryRoad]

There's a rather extensive thread on this where the conclusion was that mass was essentially what was stored. As to not growing more dense, I think Wax might just not be thinking in the right terms about what "density" means for how much energy is required for a bullet to pierce his body.

Density is mass per unit volume, but what we're concerned about with bullets puncturing Wax's skin is Bulk Density. Consider Wax's body as constantly at "poured density" no matter what the mass of his component particles are. His density will go up as the mass of his component elements go up, but they will not "settle" more closely together, leaving the lattice that is Wax just about as vulnerable as ever. If we get up to ridiculous proportions of mass, then the individual molecules might have enough inertia to significantly affect the energy of a bullet trying to pass through this lattice, but on the practical level we won't see much of a difference.

Consider an example: A cubic meter of loosely packed sand and a cubic meter of loosely packed lead particles of the same gauge as that sand. The metal-cube is by far more dense, with more mass per unit of volume, but not significantly harder to puncture or dent than the sand. If every component of a Skimmer's body grows intrinsically more massive, he would be "denser" in the strictly mathematical sense, but might not necessarily see the kinds of resistance to puncturing one normally attributes to "dense" compounds, such as tightly packed sand or lead particles.

Where this comparison fails is that heavier particles are more likely to "pack in" into a tighter lattice. But the effects of Iron Feruchemy appear to be such that the elements of a Skimmer's body are forced to stay in the same relative position to each other, instead of "sifting together." Otherwise, we would have some very squishy Skimmers on our hands.

Most of the "science" here is off of half-read Wikipedia articles and quarter-remembered science classes, so feel free to call me out if I'm just rambling like a lunatic.

Eh... just looked at the thread. Too much jargon for my english artsy brain.

I do like your explanation, though. Much more visually-oriented. Thanks. lol

/thread, everybody!

[Kurkistan]

Eh... just looked at the thread. Too much jargon for my english artsy brain.

I do like your explanation, though. Much more visually-oriented. Thanks. lol

/thread, everybody!

Nooooo! Not "/thread!"

Pay no heed to to the man behind the curtain! I still have no idea whether or not my explanation holds water, so we might want to wait until somebody else can weigh (ha) in on this.

Edited November 30, 2011 by Kurkistan

[Deus Ex Biotica]

I always assumed it involved making more/less of your mass be Dark Matter.

[Pechvarry]

There's a rather extensive thread on this where the conclusion was that mass was essentially what was stored. As to not growing more dense, I think Wax might just not be thinking in the right terms about what "density" means for how much energy is required for a bullet to pierce his body.

Density is mass per unit volume, but what we're concerned about with bullets puncturing Wax's skin is Bulk Density. Consider Wax's body as constantly at "poured density" no matter what the mass of his component particles are. His density will go up as the mass of his component elements go up, but they will not "settle" more closely together, leaving the lattice that is Wax just about as vulnerable as ever. If we get up to ridiculous proportions of mass, then the individual molecules might have enough inertia to significantly affect the energy of a bullet trying to pass through this lattice, but on the practical level we won't see much of a difference.

Consider an example: A cubic meter of loosely packed sand and a cubic meter of loosely packed lead particles of the same gauge as that sand. The metal-cube is by far more dense, with more mass per unit of volume, but not significantly harder to puncture or dent than the sand. If every component of a Skimmer's body grows intrinsically more massive, he would be "denser" in the strictly mathematical sense, but might not necessarily see the kinds of resistance to puncturing one normally attributes to "dense" compounds, such as tightly packed sand or lead particles.

Where this comparison fails is that heavier particles are more likely to "pack in" into a tighter lattice. But the effects of Iron Feruchemy appear to be such that the elements of a Skimmer's body are forced to stay in the same relative position to each other, instead of "sifting together." Otherwise, we would have some very squishy Skimmers on our hands.

Most of the "science" here is off of half-read Wikipedia articles and quarter-remembered science classes, so feel free to call me out if I'm just rambling like a lunatic.

I'd love it if Brandon saw this post. Could help him immensely at signings instead of always having to say "ehh I had to break some physics..." and tapering off without a good explanation.

Unless, I suppose, it's completely not what he had in mind for the science of it.

[fyodor]

To dumb down what the other posters said, you're more dense in that you weigh more and occupy the same space, but not in your ability to stop bullets.

Okay, now that Alloy of Law is out, I am extremely confused about the nature of weight feruchemy. The question I have is: What, exactly, is being stored in or tapped from an ironmind?

The way I see it, there are really only two possibilities:

- Mass: I was inclined to think that this was the answer, since I definitely remember specific wording from WoA's Sazed-Marsh fight specifying that he grew more dense. Yet, we see that in Alloy of Law, this is directly contradicted. Waxillium notes, rather specifically, that the opposite is true: that he does not grow more dense, because bullets can still pierce his body. Either Harmony changed this between the books or one of them is just wrong.

- Gravitational susceptibility: this was the only other thing I could come up with, since I seem to remember from basic physics that an object's weight is determined by gravity, not by mass. But this is actually contrary to both books, since increased gravity also increases the speed at which an object falls, and both Sazed and Waxillium exploit this fact.

So what is going on? Wax says his strength increases proportionally to his weight so he doesn't crush himself, but I don't even want to think about the complications that arise from that.

Any ideas? o_O

[Aradel]

I always assumed it involved making more/less of your mass be Dark Matter.

I don't think dark matter would be the answer, Nobody's really sure what that stuff is made of anyway.

What I do remember about the physics of mass and and gravity (density not included, sorry) is called General Relativity In laymen's terms it works like this. Mass (determined by both physical mass and energy) bends space-time like a bowling ball on a sheet of cloth. More massive objects make bigger bends and smaller objects fall into their "dip" like a baseball on the same sheet as the bowling ball.

(It's not a perfect analogy. I'd hate to see what would happen if gravity pulled us towards things only a few times our size. Ouch.)

My theory is that storing and tapping an Ironmind increases and decreases your "mass shadow" (the dip in the cloth of space-time) . That means that gravity treats you like an object of smaller or greater mass than you really are. It would actually be a simpler explanation because all that's changing is how much energy your mass exerts on space-time.

[Kurkistan]

I don't think dark matter would be the answer, Nobody's really sure what that stuff is made of anyway.

What I do remember about the physics of mass and and gravity (density not included, sorry) is called General Relativity In laymen's terms it works like this. Mass (determined by both physical mass and energy) bends space-time like a bowling ball on a sheet of cloth. More massive objects make bigger bends and smaller objects fall into their "dip" like a baseball on the same sheet as the bowling ball.

(It's not a perfect analogy. I'd hate to see what would happen if gravity pulled us towards things only a few times our size. Ouch.)

My theory is that storing and tapping an Ironmind increases and decreases your "mass shadow" (the dip in the cloth of space-time) . That means that gravity treats you like an object of smaller or greater mass than you really are. It would actually be a simpler explanation because all that's changing is how much energy your mass exerts on space-time.

That one doesn't work because acceleration towards the ground (as well as horizontal velocity) remain constant no matter what degree of storing/tapping a Skimmer is at. This means that the effects of gravity are unchanged by a Skimmer's Feruchemy.

Edited December 1, 2011 by Kurkistan

[Aradel]

That one doesn't work because acceleration towards the ground (as well as horizontal velocity) remain constant no matter what degree of storing/tapping a Skimmer is at. This means that the effects of gravity are unchanged by a Skimmer's Feruchemy.

True. The books mention several times that changing "weight" doesn't change how fast you fall. But General Relativity doesn't change that either. At least I don't think it does. A building falls faster than a baseball by such an impossibly minuscule amount that it's not even worth trying to measure. You have to have planet-sized mass differences to get notable differences the way I think you're thinking.

[Kurkistan]

True. The books mention several times that changing "weight" doesn't change how fast you fall. But General Relativity doesn't change that either. At least I don't think it does. A building falls faster than a baseball by such an impossibly minuscule amount that it's not even worth trying to measure. You have to have planet-sized mass differences to get notable differences the way I think you're thinking.

My point is that gravity isn't an issue. Your "mass shadow" has absolutely no effect upon inertia, while your mass does. Skimmers quite clearly possess more inertia when tapping and less when storing. Therefore mass is stored. This might very well affect the size of your mass shadow, but we don't particularly care about this, for exactly the reasons you've outlined. Mass determines both, and is thus what we concern ourselves with.

[Deus Ex Biotica]

Right, but that's the whole point. If you could store, say, 25% of your "being effected by gravity," you really would fall 25% slower.

That's why I use Dark Matter. It's not well understood, but from what we do know, it might be able to explain changing mass without changing either volume or density.

-- Deus Ex Biotica

P.S. Though, at this point, I suppose I am just trading Brandon Sanderson's magical handwave for an equally little-explained physics one. Theoretical science can be pretty light on full explanations...

[Aradel]

My point is that gravity isn't an issue. Your "mass shadow" has absolutely no effect upon inertia, while your mass does. Skimmers quite clearly possess more inertia when tapping and less when storing. Therefore mass is stored. This might very well affect the size of your mass shadow, but we don't particularly care about this, for exactly the reasons you've outlined. Mass determines both, and is thus what we concern ourselves with.

Okay, I don't think you were thinking what I thought you were thinking after all.

Also, I dub thee *Shooter of Goradel's Ego*, I'm glad you're around to correct my faulty logic. I didn't think that mass shadows wouldn't tweak inertia, thanks.

[Kurkistan]

Okay, I don't think you were thinking what I thought you were thinking after all.

Also, I dub thee *Shooter of Goradel's Ego*, I'm glad you're around to correct my faulty logic. I didn't think that mass shadows wouldn't tweak inertia, thanks.

Sorry for the shooting. I guess the thought that you thought that you thought that you knew what you thought I was thinking made me react a bit strongly.

*Changes title*

Tangent:

As for conceiving of space-time as a stretched cloth, I prefer to think of concentrations of mass as points of consistent low-pressure suspended in some constant-pressure substance in three dimensional space.

The more massive the object, the lower-pressure it's center of mass. The low-pressure zones this causes would create "flows" of whatever substance occupied this space, which would impel massive objects towards each other at varying speeds based upon how significant the relative amount of low-pressure is for each in any given direction. A massive object alone in space would have constant pressure on all sides, and thus would not be affected by gravity.

Throw in inertia, and you just modeled the physical interactions of massive objects. Oh joy.

Edited December 3, 2011 by Ookla the Conformist

[Ari]

Right, but that's the whole point. If you could store, say, 25% of your "being effected by gravity," you really would fall 25% slower.

That's why I use Dark Matter. It's not well understood, but from what we do know, it might be able to explain changing mass without changing either volume or density.

-- Deus Ex Biotica

P.S. Though, at this point, I suppose I am just trading Brandon Sanderson's magical handwave for an equally little-explained physics one. Theoretical science can be pretty light on full explanations...

Well, you'd accelerate downwards 25% slower. Falling isn't a matter of constant velocity until you reach terminal velocity, at which point your weight doesn't matter until you hit the ground.

[fyodor]

I also want to note that the initial explanation that Sazed offers about reduced graviational pull doesn't seem consistent.

It seems that even within WoA Sazed demonstrates greater inertial mass (resistance to acceleration) when Marsh tries to Pull/Push him. Now I know that additional greater gravitational mass will create some additional resistance to movement (greater lateral frictional force between your feet and ground) but the descriptions are much more consistent with a more massive object than some sort of extra foot drag.

[Deus Ex Biotica]

Well, you'd accelerate downwards 25% slower. Falling isn't a matter of constant velocity until you reach terminal velocity, at which point your weight doesn't matter until you hit the ground.

Touché. But they would accelerate 25% more slowly, and their terminal velocity would be 25% slower as well.

And, yes, Skimming clearly changes your inertia and momentum (but not your velocity) when you use it. Otherwise, almost none of the tricks Wax uses as a Crasher would work, nor would Sazed's responses to Pushes and Pulls. Heck, when Wax fights Miles on the train, he taps weight while shouldering Miles in the stomach, and this hits harder than a normal blow.

-- Deus Ex Biotica

[fyodor]

Since this is already a nerdy discussion, I'll point out that the terminal velocity would be like twelve percent lower not twenty five.

Terminal velocity is reached when the downward force (gravity) is equal to the upward force (drag). Drag is a function of velocity-squared, not velocity. So if the gravitational force is 75 percent of what it was, you'd need a velocity at about eighty eight percent to generate enough drag for acceleration to stop.

Touché. But they would accelerate 25% more slowly, and their terminal velocity would be 25% slower as well.

And, yes, Skimming clearly changes your inertia and momentum (but not your velocity) when you use it. Otherwise, almost none of the tricks Wax uses as a Crasher would work, nor would Sazed's responses to Pushes and Pulls. Heck, when Wax fights Miles on the train, he taps weight while shouldering Miles in the stomach, and this hits harder than a normal blow.

-- Deus Ex Biotica