Iron Ferrings

[Red Star]

I registered with this forum to start this topic so I might discuss a few questions that have been nagging me throughout my reading of Alloy of Law. I do not know if they have been expressed before but here goes:

1.) My understanding of AoL tells me that it is velocity, not momentum, that is conserved when an Iron Ferring fills or taps mass from his Ironminds. I infer this because if momentum were conserved, then the Ferring could use his increased strength when moving or Pushing/Pulling to change his velocity, then fill his Ironmind and take advantage of the conservation of momentum to increase his velocity to ridiculous levels. For example, this would allow the Ferring to jump while heavy, then decrease his mass to gain incredible velocity, or fall while light and increase his mass to stop in midair. Conversely, if velocity is conserved rather than momentum, why don't Iron Ferrings flare their mass in mid-swing to punch people out with the force of a freight train, knocking their opponents across rooms like ragdolls? Though that could easily be handwaved by saying the mass change only applies to yourself.

2.) My other question has to do with the required secondary powers of Iron Ferrings, namely increasing the force of their Pushes/Pulls and the strength of their own bodies proportionally with their current mass. In AoL, we see Wax commenting on how his body's strength must be greater to cope with his increased mass; we also witness how this applies to his Steelpushing at several times, most notably in the explosion sequence where a brief period of mass-enhanced Steelpushing flattens the nails in his house and in the ending sequence where he greatly increases his mass and uses the increased strength of his Steelpushing to crush a building by ripping all the metals down. My question is why doesn't this apply the other way around? I think I remember seeing Wax decrease his mass and Push behind him for high velocity jumps, but this shouldn't be possible if Push force scales with mass. The narration also mentions that Wax constantly keeps himself at 3/4 mass to make himself nimbler. Considering Sanderson's love for logically limited magic systems, why don't we ever see Wax's lower mass proportionally decreasing his strength? For that matter, if strength only scales up with mass, why don't Iron Ferrings ever think to achieve true flight with crafted wings?

It seems to me that in a more physically plausible 'verse where momentum is conserved between mass changes, many more tricks would have been possible with Iron Ferrings than are shown. Even velocity conservation could have been exploited in ways that weren't shown even in a book featuring a Crasher. I love the magic system Sanderson has created in the Mistborn novels, it presents so many opportunities for interesting storytelling that I don't understand how it's not more popular with fanfiction writers. I also don't think Sanderson misses many opportunities to squeeze some more plot out of his magic systems, which is why I am perplexed to find potentially unexplored aspects of a power combo he has dedicated an entire protagonist to.

Edited January 23, 2012 by Red Star

[Eric]

I registered with this forum to start this topic so I might discuss a few questions that have been nagging me throughout my reading of Alloy of Law. I do not know if they have been expressed before but here goes:

Welcome aboard!

1.) My understanding of AoL tells me that it is velocity, not momentum, that is conserved when an Iron Ferring fills or taps mass from his Ironminds. I infer this because if momentum were conserved, then the Ferring could use his increased strength when moving or Pushing/Pulling to change his velocity, then fill his Ironmind and take advantage of the conservation of momentum to increase his velocity to ridiculous levels. For example, this would allow the Ferring to jump while heavy, then decrease his mass to gain incredible velocity, or fall while light and increase his mass to stop in midair. Conversely, if velocity is conserved rather than momentum, why don't Iron Ferrings flare their mass in mid-swing to punch people out with the force of a freight train, knocking their opponents across rooms like ragdolls? Though that could easily be handwaved by saying the mass change only applies to yourself.

I'm not sure I'm following all of your examples here. Increased strength from what? Tapping weight to stop falling? Since gravity still applies, that shouldn't work, regardless of what is conserved.

2.) My other question has to do with the required secondary powers of Iron Ferrings, namely increasing the force of their Pushes/Pulls and the strength of their own bodies proportionally with their current mass. In AoL, we see Wax commenting on how his body's strength must be greater to cope with his increased mass; we also witness how this applies to his Steelpushing at several times, most notably in the explosion sequence where a brief period of mass-enhanced Steelpushing flattens the nails in his house and in the ending sequence where he greatly increases his mass and uses the increased strength of his Steelpushing to crush a building by ripping all the metals down. My question is why doesn't this apply the other way around? I think I remember seeing Wax decrease his mass and Push behind him for high velocity jumps, but this shouldn't be possible if Push force scales with mass. The narration also mentions that Wax constantly keeps himself at 3/4 mass to make himself nimbler. Considering Sanderson's love for logically limited magic systems, why don't we ever see Wax's lower mass proportionally decreasing his strength? For that matter, if strength only scales up with mass, why don't Iron Ferrings ever think to achieve true flight with crafted wings?

High mass does not increase the actual force with which you Push or Pull. It alters the amount of that force that is imparted to the other object because you take more or less energy to move.

It seems to me that in a more physically plausible 'verse where momentum is conserved between mass changes, many more tricks would have been possible with Iron Ferrings than are shown. Even velocity conservation could have been exploited in ways that weren't shown even in a book featuring a Crasher. I love the magic system Sanderson has created in the Mistborn novels, it presents so many opportunities for interesting storytelling that I don't understand how it's not more popular with fanfiction writers. I also don't think Sanderson misses many opportunities to squeeze some more plot out of his magic systems, which is why I am perplexed to find potentially unexplored aspects of a power combo he has dedicated an entire protagonist to.

An entire protagonist who is going to appear in more books, and numerous RAFOs by Brandon on what is possible with each metal, leads me to believe that this will probably be answered at some point.

[Red Star]

I'm not sure I'm following all of your examples here. Increased strength from what? Tapping weight to stop falling? Since gravity still applies, that shouldn't work, regardless of what is conserved.

Anyone increasing their mass via Irontapping would need to be proportionally stronger in order to support their own weight. And even though it doesn't look very intuitive, conserving momentum while increasing mass would decrease your velocity. Gravity doesn't enter into it, since gravity is a constant acceleration. You would be under the influence of gravity before and after the mass shift, but the shift itself would change your velocity were momentum conserved.

High mass does not increase the actual force with which you Push or Pull. It alters the amount of that force that is imparted to the other object because you take more or less energy to move.

The amount of force imparted to both you and the other object IS the force with which you Push or Pull. The resulting accelerations for both you and the other object depend on your respective masses. My point is that I see Wax deploying much stronger Pushes when he is tapping from his Ironmind. Either Push force scales with mass, or Wax should *always* be strong enough to crush buildings, something Vin needed to ingest the Mists before doing.

As for Wax appearing in future novels, I think I remember Sanderson stating somewhere that he planned to do a modern-era trilogy and that Alloy of Law was just an in-between idea that ended up being so awesome it got its own book. Which I can understand, really. What kind of author could possibly resist using his magic setting in an Western when given the chance?

[ulyssessword]

There is a fairly comprehensive thread buried here regarding iron Feruchemy. Basically the conclusions were as follows:

1. Velocity is conserved, as you understood. This breaks physics a whole lot more than conserving momentum, but it is much easier to grasp logically. As to why people don't increase their mass when travelling at high speeds, I don't think they have thought of it yet. The same thing goes for flight.

2. My understanding of the force of steelpushes is that it doesn't scale linearly with mass. For example, being at 50% mass would reduce the force that you can exert to 75% of normal, but this still allows you to accelerate yourself 1.5x as quickly. The same goes for increasing your mass, 100x the mass would give 50x the steel pushing power. Something similar would happen with physical strength as well.

[name_here]

I think they do exploit momentum nonconservation sometimes, but it's a good way to break your arm unless you are a Keeper.

[Red Star]

There is a fairly comprehensive thread buried here regarding iron Feruchemy. Basically the conclusions were as follows:

1. Velocity is conserved, as you understood. This breaks physics a whole lot more than conserving momentum, but it is much easier to grasp logically. As to why people don't increase their mass when travelling at high speeds, I don't think they have thought of it yet. The same thing goes for flight.

2. My understanding of the force of steelpushes is that it doesn't scale linearly with mass. For example, being at 50% mass would reduce the force that you can exert to 75% of normal, but this still allows you to accelerate yourself 1.5x as quickly. The same goes for increasing your mass, 100x the mass would give 50x the steel pushing power. Something similar would happen with physical strength as well.

Thanks for your feedback, your thread link was certainly enlightening and it seems that we came to many of the same conclusions. Indeed, conservation of velocity and nonlinear power scaling explains most of what we see in canon. It makes me wonder why Wax doesn't make a habit out of exploiting mass-boosted Steelpushing as if it were free Duralumin.

[Thor]

Thanks for your feedback, your thread link was certainly enlightening and it seems that we came to many of the same conclusions. Indeed, conservation of velocity and nonlinear power scaling explains most of what we see in canon. It makes me wonder why Wax doesn't make a habit out of exploiting mass-boosted Steelpushing as if it were free Duralumin.

To your last sentence: he does use mass-boosted Steelpushing pretty often, but not to a Duralumin-level as that would take up waaaaaaay to much stored weight to use frequently. Sadly, Wax doesn't have a NI (nigh-infinite) amount of a Feruchemical attribute to throw around like Miles does...

Edited January 24, 2012 by Thor

[Eric]

Anyone increasing their mass via Irontapping would need to be proportionally stronger in order to support their own weight.

Right, but as noted by Wax, Sazed, and the other thread, it's not perfectly proportional, nor is it really useable muscular strength.

And even though it doesn't look very intuitive, conserving momentum while increasing mass would decrease your velocity. Gravity doesn't enter into it, since gravity is a constant acceleration. You would be under the influence of gravity before and after the mass shift, but the shift itself would change your velocity were momentum conserved.

I get this, but you were talking about stopping yourself mid-fall. Your velocity would approach 0, but shouldn't hit it, since gravity is constant acceleration. (Speaking of which, if this did work by conservation of momentum, wouldn't that sudden jolt be roughly as lethal as hitting the ground? Not sure it would be a good plan.)

The amount of force imparted to both you and the other object IS the force with which you Push or Pull. The resulting accelerations for both you and the other object depend on your respective masses. My point is that I see Wax deploying much stronger Pushes when he is tapping from his Ironmind. Either Push force scales with mass, or Wax should *always* be strong enough to crush buildings, something Vin needed to ingest the Mists before doing.

My understanding is that Wax is always strong enough to crush buildings. However, he's not always massive enough to not crush himself if he tries it. Much like how Vin and Kelsier can put out enough force to flatten and deform a coin between without Duralumin or Compounding, just burning pewter to keep from getting hurt in the process.

As for Wax appearing in future novels, I think I remember Sanderson stating somewhere that he planned to do a modern-era trilogy and that Alloy of Law was just an in-between idea that ended up being so awesome it got its own book. Which I can understand, really. What kind of author could possibly resist using his magic setting in an Western when given the chance?

I'd have sworn someone pointed out somewhere that Brandon decided to do some more Alloy books since he ended up liking the characters or setting particularly well. I can find references to it, but not the original statement...

[fyodor]

I registered with this forum to start this topic so I might discuss a few questions that have been nagging me throughout my reading of Alloy of Law. I do not know if they have been expressed before but here goes:

This bears some further discussion. I would look up the other thread for a more detailed explanation, but Skimmers don't become "stronger" in the sense of muscular strength. The tensile/supporting strength of Wax's body increases so that he doesn't fall apart but he can't lift heavier objects or otherwise perform acts of strength. If you look at Sazed's descriptions, he has a lot of trouble moving when heavy. Similarly, Wax is lighter on his feet when at 3/4 weight. This lightness comes from having the same physical strength but moving a lighter body.

[Zas678]

Here's what Brandon had to say about it:

QUESTION

Does Iron store mass or weight?

BRANDON SANDERSON

Excellent question. The thing is it really does involve mass, but I’m breaking some physics rules, basically. I have to break a number of physics rules in order to make Magic work in the first place. Those whole laws of Thermodynamics, I’m like “You are my bane!” (laughter) But I try to work within the framework, and I have reasonings built up for myself, and some of them have to be kind of arbitrary. But the thing is, it does store mass if you look at how it interacts, but when a Feruchemist punches someone, you’re not having a mass transference of a 1000 pounds transferring the mass into someone else.

So there are a few little tweaks. You can go talk to Peter, because Peter has the actual math.

....

So anyway, you can talk with him, he’s got more of the math of it. I explained the concept to Peter and he’s better with the actual math, so he said “We’ll figure it out.”