Feruchemy: Iron

[Ferumancer]

Hi, all! I've been thinking about feruchemy a lot recently, and I've decided to try to do a couple of theories on them. This is the first one, so feedback would be really great. 

IRON

People seem to either really like this, or not pay any attention to it at all. I am definitely on the side of really liking it. I have two theories on this one. Brandon Sanderson has stated that iron allows you to store your mass into the metalmind, allowing you to become lighter or heavier. This also means that iron effects density, since density is mass/volume, and the volume of the item(in this case, a human) doesn't change.

With that in mind, you could(with enough skill) make yourself as dense as the air around you(1.225 kg/m^3) and effectively fly. Admittedly, would have to store 99.875% of your weight, and you wouldn't have much control, but you would be able to change your altitude by making yourself denser or less dense than air, and then as dense as air. this would allow you to store into pewter, steel, zinc, a little bit of bronze, and several of the other hard to store metals. 

My next theory is that of durability. As an object gets denser, it also gets more durable, as fewer things are able to pass through it and break it. Now, if you were to tap iron enough, would you be able to make your skin dense enough to stop a bullet? This gets cooler as you make yourself the bullet. Now, in the books(don't have a copy by me, so I don't know exactly where) Wax says something about his velocity not changing when he taps or stores in the air. In order for that to happen, his energy needs to go WAY up. E=MC^2, right? So now you have a super high energy bullet proof person.

Are my theories correct, or is there something I'm missing?

 

[BeskarKomrk he/him]

Here's an annotation for The Alloy of Law that has some relevant information: http://brandonsanderson.com/annotation-the-alloy-of-law-chapter-six/

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At the same time, I acknowledge that the weight manipulation aspect of Feruchemy is one of its more baffling powers, scientifically. Is he changing his mass? If so, he should become more dense, which I don’t actually make the case when it plays out in fights. (Otherwise, increasing his weight enough would make him impervious to bullets.)

 

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Beyond that, Wax can’t make himself so light that he has no weight at all.

So he can't be bulletproof and he can't store all of his weight. Where exactly the cutoff is with how much weight he can store, we don't really know. But it seems likely he couldn't make himself float just with Feruchemical Iron.

I also don't have the book with me at the moment, but I'm pretty sure Wax makes a comment at some point that his velocity does change when he changes his weight mid-flight. His momentum is the thing that stays constant. Not sure what this means for energy conservation off the top of my head, I'll have to get back to you on that.

Edit: I haven't done any consideration of air resistance, but I don't think it's possible for energy to be conserved along with momentum.

Edited September 26, 2016 by BeskarKomrk

[The One Who Connects he/him]

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I asked Brandon about Iron Feruchemy at the release party, though. I have had a pet theory about Feruchemical iron for a while - that it messes with the person's connection to the Higgs field. Brandon confirmed it in the signing line. Exact words will, I'm sure, be on the transcript, but I asked specifically if it involved Higgs field stuff, and he said yes.

For those who don't know - the Higgs field is a quantum field that interacts with various particles and gives them their mass. The force carrier of the field is the Higgs boson, recently discovered by the LHC.

So, by decreasing your interaction with the Higgs field, you could decrease your mass without messing with the amount of matter in you. How it interacts with density would be more subtle, but I think that it works out most of the kinks with Feruchemical iron and density.

Credit goes to Seonid in this thread.

[PantsForSquares he/him]

12 hours ago, Ferumancer said:

Now, in the books(don't have a copy by me, so I don't know exactly where) Wax says something about his velocity not changing when he taps or stores in the air. In order for that to happen, his energy needs to go WAY up. E=MC^2, right? So now you have a super high energy bullet proof person.

E=mc^2 is the relation between mass and energy. It's better to understand it as E/m=c^2. The energy expression that's of importance here is KE=(mv^2)/2, where KE is your kinetic energy.

The really important thing about this is that you're going to be able to use your ability to store/tap Feruchemical Iron to change your velocity. If your energy is constant (ie, moving forward in a vacuum), tapping F-Iron is going to decrease your velocity, whereas storing it is going to increase it. I suspect that this, along with a bendalloy time bubble (both for deflection and time-skipping), are the keys to actually achieving "FTL" travel (FTL from the perspectives of others, at least).

As far as conservation of energy vs. momentum, you can conserve both energy and angular momentum. Linear momentum won't be conserved, though.

[Oversleep]

Density does not change, momentum is conserved (it's repeatedly stated in the books, for example the final chase after Bleeder or Khriss asking Wax about changing his weight mid-air), you can make yourself float:

You're welcome.

Edited September 28, 2016 by Oversleep

[cometaryorbit]

Well the "density doesn't change" thing is a bit weird. Technically density does change if mass does, since density is just mass divided by volume.

When the characters in the books (and that annotation) talk about density not changing, they mean that the body doesn't become more resilient or resistant to being punctured as you'd expect a more dense object to.

Which I think would have its own weird physics implications because of "Newton's impact depth approximation" [ https://en.wikipedia.org/wiki/Impact_depth ] - density itself, not just structural strength, affects how deep a high-speed projectile goes into a target, since there is more mass to be pushed out of the way (transfer momentum to).

EDIT: Flight would be hard (astronauts in the space station can't really fly/swim through air well), and artificial wings or some such would be too heavy. (Assuming Wax's volume is about 0.1 cubic meters, which is likely high, to be neutrally buoyant in air he would have to weigh about 120 grams. Even clothes would weigh him down.)

Edited September 28, 2016 by cometaryorbit
add comment about floating

[Jondesu he/him]

12 hours ago, cometaryorbit said:

Well the "density doesn't change" thing is a bit weird. Technically density does change if mass does, since density is just mass divided by volume.

I'm pretty sure their mass doesn't change, so density wouldn't either.  It's the interaction of their mass with the planet that changes; i.e. their weight.  It's done in a more scientific and technical way in some ways, with some admitted hand-waving by Brandon to smooth over some of the resulting problems that could occur.

jW

[Eki]

4 hours ago, Jondesu said:

I'm pretty sure their mass doesn't change, so density wouldn't either.  It's the interaction of their mass with the planet that changes; i.e. their weight.  It's done in a more scientific and technical way in some ways, with some admitted hand-waving by Brandon to smooth over some of the resulting problems that could occur.

jW

Nope, it's mass, with some oddities:

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Interview: Nov 8th, 2011

Alloy of Law Midnight Release (Verbatim)

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. Oh Peter’s back there. Peter is dressed up as Allomancer Jak from the broadsheet. In fact we’re giving some out broadsheets, aren’t we Peter. So when you come through the line, we’re giving out Broadsheets. Please don’t take fifty—I think we might have enough for everybody. The broadsheets are the newspaper from the Alloy of Law time. It’s an inworld newspaper. It’s actually reproduced in the book in four different pages, and we put it together in one big broadsheet.

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.”

Which would mean that the density does change.

Also, I'm pretty sure what Wax says is that when he stores mass, he does speed up.

[Spoolofwhool]

49 minutes ago, Eki said:

Nope, it's mass, with some oddities:

Which would mean that the density does change.

Also, I'm pretty sure what Wax says is that when he stores mass, he does speed up.

Density would change, except magic makes it so that it doesn't. So tapping and storing mass keeps your density constant. 

[Turbonator]

@Eki, I believe you are referring to when he is using a Steelpush. The speeding up is theorized to be his "effect" from being Twinborn. Also, in BoM, while at the Set's hideout, it is stated that he is slightly weakened by storing weight, or something to that effect.

[Eki]

7 minutes ago, Turbonator said:

@Eki, I believe you are referring to when he is using a Steelpush. The speeding up is theorized to be his "effect" from being Twinborn.

No, momentum (which is mass times velocity) is conserved:

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Interview: Feb 25th, 2016

Calamity-Austin

Question

When Wax changes his weight, is that weight or mass?

Brandon Sanderson

He is...he is changing...so he is actually changing his mass, in a weird...It's kind of halfway in between, is really what it is. But it follows the laws of conservation of momentum, so it's not just weight. It's timidly half-stepping in between.

So when his mass decreases, his velocity goes up. Of course, he loses a lot of the momentum to the air, which slows him down. This would be true for any Iron Ferring, but they don't move as quickly, so they probably never really notice it.

@Oversleep, did you mean to write "density doesn't change"? Because the post you linked to says that you would float like a balloon, which implies that your density is in fact changed.

[Oversleep]

I think I need to reinstate some things:

Density does not change. Tapping iron would not make you more dense but it will make you heavier/more massive. It's weird and it's handwaved to bosons and we need to repeat "density doesn't change while mass does" every day and maybe we will finally stop breaking our heads over that massive () weirdness.

And floating up is not about density per se (although it's easier to use it) but by weighing less than the volume of air that would take your place. So if you weigh less, you'll float up... even if your density doesn't change and it's the point that brains start to ache.

The thread I linked earlier contains some discussion over those things, I think it would be helpful to go and read it, it's only two pages long.

[Eki]

But the thing is, density is literally mass divided by volume. By definition. It's a derived value, not a fundamental property. And we know that it's mass that is stored (with a few quirks), not just the interaction with gravity.

Of course, there is handwaving, but regardless of how the magic works, density will be the mass of an object divided by the volume it occupies. That's what the word means.

Some of the effects that higher density (and mass) would normally have seem to be different when storing or tapping iron, and that's where the handwaving is.

[cometaryorbit]

2 hours ago, Eki said:

But the thing is, density is literally mass divided by volume. By definition. It's a derived value, not a fundamental property. And we know that it's mass that is stored (with a few quirks), not just the interaction with gravity.

Yeah, exactly. Saying that mass changes but density doesn't (when we know volume stays the same) is incoherent. It's not an "impossible in our world but works in the Cosmere because magic" thing like storing muscle mass or Soulcasting, it's an inherently self-contradictory statement.

I know there's an annotation, and IIRC a comment by Wax, about density not changing -  but those are in the context of "bullets would still hurt you at 100x weight" so it seems to really mean that you behave in regards to other objects (impacts) as if you were your normal density.

[Voidus]

1 hour ago, Eki said:

But the thing is, density is literally mass divided by volume. By definition. It's a derived value, not a fundamental property. And we know that it's mass that is stored (with a few quirks), not just the interaction with gravity.

Of course, there is handwaving, but regardless of how the magic works, density will be the mass of an object divided by the volume it occupies. That's what the word means.

Some of the effects that higher density (and mass) would normally have seem to be different when storing or tapping iron, and that's where the handwaving is.

Sort of, magic is involved here so we need to do slightly weirder maths than you usually would. For example we have to take the higgs field into account, and the mass we're talking about increasing isn't mass in the ordinary sense, there's no more actual stuff there, Protons and Neutrons aren't getting bigger, extra atoms aren't popping into existence and creating a higher concentration of person in the space it's ordinarily in.

So the density of a feruchemist + their tapped iron is larger than that of the feruchemist by themselves but the mass concentration of all constituent parts of the feruchemist remain constant.

[PantsForSquares he/him]

21 hours ago, Eki said:

No, momentum (which is mass times velocity) is conserved:

You actually can't conserve linear momentum in physics. Energy can neither be created nor destroyed, which results in kinetic energy being conserved (minus changes in air resistance). Linear momentum being conserved is only true of perfectly elastic collisions, and isn't as strict of a restriction as conservation of energy.

Let's say that a Iron Ferring of initial mass M is moving at some velocity V. He then stores mass to reach M/2.

To solve for his new velocity, you can't use momentum. You have to use energy to figure out that his initial kinetic energy is going to be (MV^2)/2. If we neglect air resistance, that has to equal his kinetic energy at the moment of his change in mass. When you solve for it, you find his new velocity to be equal to V√2, or approximately 140% of his original velocity. For a 50% decrease in mass, he gets a 40% increase in velocity. At low velocities, and without precise measurements, it looks to be a fairly linear relationship, but it isn't.

Now, if you compare his momenta, you end up with MV vs. (√2)/2*MV. There's about a 30% decrease in overall momentum here, which isn't going to be super observable at relatively low velocities. In general, an Iron Ferring will lose momentum when he stores mass, and gains momentum when he taps mass.

The fun part, though, comes from conservation of angular momentum. If an Iron Ferring is spinning, and he stores mass, he should start spinning faster.

I'm not sure why Brandon wrote that momentum is conserved, so if someone could clarify that with him, it would be great.

Edited September 29, 2016 by PantsForSquares

[Eki]

@PantsForSquares In our universe, in a closed system, momentum is conserved. In a non-elastic collision, momentum is just transferred to other particles in the system (and so is energy, by the way. That's why a bouncing ball heats up). Energy is also conserved, of course. I think the expansion of space messes things up, but on a local scale, both of those things are true.

When you start introducing magic though, none of those things have to be true any more. In this case, we have a WoB that says that momentum is conserved, but the laws of magic are under no obligation to conserve kinetic energy.

13 hours ago, Voidus said:

Sort of, magic is involved here so we need to do slightly weirder maths than you usually would. For example we have to take the higgs field into account, and the mass we're talking about increasing isn't mass in the ordinary sense, there's no more actual stuff there, Protons and Neutrons aren't getting bigger, extra atoms aren't popping into existence and creating a higher concentration of person in the space it's ordinarily in.

So the density of a feruchemist + their tapped iron is larger than that of the feruchemist by themselves but the mass concentration of all constituent parts of the feruchemist remain constant.

So the extra mass kind of works on the whole cognitive image of you? In the same way that an object is either inside or outside a speedbubble? You just add mass uniformly to yourself, and that mass only "kicks in" in certain situations.

[Oversleep]

The way to think about it is that the mass doesn't change, but the object behaves as if it were more massive. Like in the near-light speeds things behave more massive without increase in mass.

Edited October 12, 2016 by Oversleep

[BeskarKomrk he/him]

@PantsForSquares @Eki It's been a little while since I took Classical Mechanics (about 4-5 years), but from what I remember, I agree with Eki. Momentum is strictly conserved in any kind of collision (given a certain reference frame) if you take into account all the particles involved in the collision. Energy is always conserved overall, but kinetic energy is only conserved in perfectly elastic collisions. In all other types of collisions, the "lost" kinetic energy is transformed into heat/sound.

The problem I'm having thinking about this now is that this isn't really even a "collision", per se. Wax is doing this all by himself. Even thinking about this a few days ago, I set up the momentum conservation equation as m1*v1 = m2*v2. But where does the mass go? Where do things stored in metalminds live? I would assume that the attributes stored in a metalmind have to have some representation in either the Cognitive or the Spiritual Realm (since it's obviously not in the Physical Realm; Wax's metalmind doesn't get heavier when he stores weight in it). So could there be some sort of cross-Realm conservation law that governs these interactions?

[Ferumancer]

This Higgs Boson particle is interesting. Can anybody explain it a bit more simply? I don't quite understand.

[Eki]

5 hours ago, Ferumancer said:

This Higgs Boson particle is interesting. Can anybody explain it a bit more simply? I don't quite understand.

I'm far from an expert in this, but pretty much, there is something called the Higgs field, which is what gives fundamental particles (like quarks and electrons) their mass. The Higgs boson is an oscillation (a wave, or a shaking, pretty much) in that field, kind of like how a photon (a light particle) is an oscillation in the electromagnetic field. The boson itself doesn't do much, but finding it would give more evidence for the existence of the Higgs field, since the theory predicted it would be there. Since scientists are now pretty sure they really have found a Higgs boson, the theory seems very likely to be correct.

However, most of the mass in for example a proton doesn't come from the Higgs mechanism. The Higgs only gives mass to the quarks within the proton (which is very important, because anything without mass travels at the speed of light. If the quarks wouldn't slow down, protons would never form in the first place), but most of the mass comes from the actual energy it takes to bind the quarks together.

10 hours ago, Oversleep said:

The way to think about it is that the mass doesn't change, but the object behaves as if it were more massive. Like in the near-light speeds things behave more massive without increase in mass.

In the case of relativistic mass, the object behaves like it has a higher mass in every way. The particles really do have more mass when travelling in relation to an observer. In the case of Feruchemical iron though, the person acts like they have more mass in some ways, and their normal mass in others.

Edited September 30, 2016 by Eki

[Stark he/him]

The way I look at this is that magic breaks real world physics rules, while creating loopholes for the Laws of Physics to work with..  But, it has it's own Laws that it follows.  With Feruchemy, we all have our base statistics, our mass, health, mental acuity, physical speed and physical strength that function at a given level over the time that is our lives.  Strength, speed, acuity, and even eyesight tend to have a lot of variability over the course of our lives, and do not make for fantastic examples.  So I'm going to ignore compounding for the moment, and looking at Atium feruchemy to start.

 

You can store youth and look older, or tap it and look older.  But on the whole, the amount of youth and age you have is set.  You have from birth to death in a linear progression.  Feruchemy allows you to mess with the r2 of that line, by placing outliers on either side of the curve of age vs time.  A 20 yr old can spend 4 days at 40 to get 1 day at 5, or four days at 10, etc, etc.  But while this screws up the r2, the best fit line that goes through these points still should be identical to the line that would have been without Feruchemy.

 

If I apply this chart view to Iron Feruchemy, and assume an individual of 100kg +/- day to day fluctuations, you can account for density.  Wax spends a lot of time at a lower mass (50-75kg) storing that mass.  He tends to use up that mass in explosive bursts of extreme mass to make incredible pushes, or break through floors.  But overall, his average mass, that fits the curve is the linear line that would have been without Feruchemy, is still 100kg. I don't thinkI'm explaining it very well, but my theory is that real world Physics does not interact with his current mass for the purpose of density and other mass based calculations.  It interacts with his best fit line.  For your standard, non-iron ferring, the best fit line and data points line up perfectly with an r2=1.  For Wax, with his r2=0.25, or some such, his density, force, kinetic energy, momentum, etc are all based off the best fit line that remains at his average, while his actual mass fluctuates wildly all over the place.

 

Or, over 21 arbitrary time units, he keeps his mass at 50kg for 15au, and 75kg for 6au.  Then, he needs increased to increase his mass drastically, drains the entire metalmind, and spends 1au at 1000kg.  His average mass over those 22au is still his standard 100kg.  Feruchemy spoofs the physics, so that it always applies to that base 100kg, while the actual varies.  This can be pseudo-scienced to working because a Feruchemist is limited to what they are born with, so they must always respect their baseline average.  Which is why a naturally blind Feruchemist cannot make themselves see by storing sight.  No matter how much nothing you store, you will never get something.

 

Compounding, and those lovely little medallions from the south, ruin all of this, of course.  But that is how I apply the magic to the physics in my head, in any case.  I have no idea if this actually makes sense, my math and physics are a good 15 years rusty with disuse.  

Edited September 30, 2016 by Stark

[Stark he/him]

Another interesting couple of questions (to me, at least) I have regarding Feruchemical iron is: At what point is a mass considered part of the Feruchemist's mass for the purpose of reduction?  There was a WoB quoted earlier in this thread, that indicated that no matter how low Wax reduced his Mass, his bracers mass remained unchanged.  I would assume that extends to his gear and clothing as well - his guns don't lose mass when he is storing, and running around in full plate mail would negate many of the benefits to mass reduction.  So elements outside of his person are unaffected.  But what about what he has consumed?

 

From a biological perspective, anything in your Gastro-Intestinal tract is considered to be outside your system.  It is only once the nutrients have been absorbed by your small intestine that they are considered to be inside your system.  Would the food and drink he has consumed, and is in the process of digesting, be affected by an alteration to his mass, as it can be perceived as being outside of his biological system?  Or, for that matter, the bits of steel he has consumed for pushing?  Or, if we want to get into six-year old humour, biological waste that has not yet been eliminated?  If those (admittedly small) chunks of mass are not included in his iron mass reductions, that could provide non-negligible, unalterable masses anchoring him down. (And ludicrous dialogue options for Wayne regarding the importance of pooping regularly for Wax... ugh.)

 

As a counter point, however, we have seen that metal inside a person, whether via piercing, implantation, hemalurgic spike, or in a stomach, cannot be easily manipulated by Allomantic pushes/or pulls.  One of the best recent examples of this is Miles stabbing his knife into his arm on the train top battle in Alloy of Law to prevent Wax from disarming him.  Which would imply that once a material has entered the Gastro-Intestinal tract, it is considered as part of you for the purposes of Allomancy, and I assume Feruchemy. (So no poop dialogue from Wayne. Yay).  So it is conceivable that metal in your stomach, or elsewhere, would have it's mass would be reduced by the same percentage as the rest of you if Feruchemical iron was being used.  

 

That, if true,  of course leads to another couple of questions:  At what point is an item considered to be inside/part of you? (IE: something in your mouth vs. in your stomach) And, if Wax's Iron Bracers were piercing him or implanted somehow, would they be affected by his mass reductions as well?

 

My final question before I stop for now, after some preface:  Both Saze and Wax referred to their mass reductions by fractions.  They would reduce there mass by half, or a quarter, or they would triple their mass for a few seconds.  They never (that I can remember) refer to the amount of mass they reduced or added by absolute values.  Do Feruchemical iron mass adjustments work by fraction/pecentage, or by absolutes?  To clarify, here is a hypothetical situation: I had a non-altered mass of 200kg, and stored my mass at 50% for a month, essentially leaving me at 100kg for that time period.  I then realize that even with the Feruchemy, it is not healthy for me to be that massively overweight, and undergo a strict weightloss regimine, reducing my mass to a healthier 100kg.  Once my weight loss is complete, the i find the need to tap my iron reserves.  Do I have one month's worth of 100kg extra I can add (iron stores absolutes), or do I have one month's worth of 50kg extra I can add (iron stores percentages)?  This can apply to any storage of a physical/mental attribute - strength, sight, health, speed, acuity.  It is far more interesting to me if Feruchemy stores absolute values rather than percentages.  That could allow a blind Feruchemist to see using sight they had stored before they lost their sight, or someone experiencing dementia to think clearly again.  Or, as we have seen, a Feruchemist in poor health to recapture health from an earlier time when they were much healthier, but has little use for health stored while already sick/injured (which leads me to believe that absolute values are stored).  Feruchemy storing absolute values also fits with it being an end neutral art - no waste.

 

Quick summary of my questions to discuss:

Does iron affect the mass of items withing a feruchemist's/ferring's GI tract?

If yes, When is something considered as being inside the ferruchemist/ferring?

Would this affect metalmind's piercing the feruchemist/ferring, or are they still as resistant to magic as other invested items?

Does Feruchemy store absolute values of traits, or percentages?

[Eki]

I think everything that is part of the cognitive image of yourself is considered part of you - basically what you said, really. So this would be the same mechanic as what decides what's inside a speed bubble, or what gets Lashed in the Stormlight Archive. The rules for these things are pretty fuzzy, but we know some things that affect them. I think this is one of the points in Brandon's magic systems where you have to start waving your hands and just go with it. Still interesting to think about though.

I would guess it stores absolute values, but that it's more intuitive for both the Feruchemist and the reader to tap and store fractions of their current mass.

[Stark he/him]

Very succinct answers to my almost endless ramblings. You get an upvote!

 

For the most part, I have no issue suspending my disbelief and just rolling with the magic, when it is well crafted.  And Brandon's magic is usually extremely well crafted.  I just also enjoy thinking of the "what if"s and "how"s.  But your point about the Cognitive image of your being affecting what is considered you is a fantastic answer that covers many possibilities.