Iron Feruchemy

[Stormtide_Leviathan]

How is storing weight affected by local gravity? If I were to store half my weight for one hour on earth, and then I went to the moon and stored half my weight for another hour in a new metalmind, are those two metalminds more or less identical? Or does the one created on earth have more stored because of the stronger local gravity?

[Trusk'our he/him]

4 hours ago, Stormtide_Leviathan said:

How is storing weight affected by local gravity? If I were to store half my weight for one hour on earth, and then I went to the moon and stored half my weight for another hour in a new metalmind, are those two metalminds more or less identical? Or does the one created on earth have more stored because of the stronger local gravity?

As far as I understand, the Investiture in both Metalminds should be identical, since iron Feruchemy actually stores mass instead of gravitational pull.

Spoiler

https://wob.coppermind.net/events/239-alloy-of-law-release-party/#e10010

Questioner

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.

<snipped for relevance>

In other words, if you travel to a place with less gravity and tap your Ironmind you will still be less heavy than on a planet with more gravity where you tapped the same amount. 

[Stormtide_Leviathan]

4 hours ago, Trusk&#x27;our said:

As far as I understand, the Investiture in both Metalminds should be identical, since iron Feruchemy actually stores mass instead of gravitational pull.

Hmm. So even in zero gravity you can store in an ironmind? Interesting

[Trusk'our he/him]

1 hour ago, Stormtide_Leviathan said:

Hmm. So even in zero gravity you can store in an ironmind? Interesting

Should be able to, yeah.

And Ironpulling/Steelpushing should be effected similarly in space. More mass from an Ironmind could let you get more proportional control over a large object, like spacewalking to rearrange your ship. 

Might be weird and dangerous though, since when you reduce your weight you speed up as the conservation of momentum applies and even more drastically with no air resistance to slow you down. 

[DoctaDajman]

18 hours ago, Trusk'our said:

Should be able to, yeah.

And Ironpulling/Steelpushing should be effected similarly in space. More mass from an Ironmind could let you get more proportional control over a large object, like spacewalking to rearrange your ship. 

Might be weird and dangerous though, since when you reduce your weight you speed up as the conservation of momentum applies and even more drastically with no air resistance to slow you down. 

I think it will be a key component to FTL travel as well. In space I dont know how much thruster it would take to move a massively heavy craft but if that craft could start moving and then start storing all of that weight they would speed up and continue speeding up until acted upon by something else no?  You get a speed bubble or two to surround the ship as well and suddenly you are absolutely cooking through space.  Slowing down?  

I imagine that tapping a ton of weight and putting on the opposite speed bubble would be able to really really aid in slowing one down to a near standstill. 

But truly I know nothing of physics outside of what I need to know for my job. And my job certainly doesn't require me to even begin thinking of how conservation of momentum might work in the vaccum of space.  I reserve that for thinking about the cosmere and how dope a full feruchemist would be as an astronaut... add in the ability to make a space suit out of roseite or some other aetherbound ability and you are set. (Well some way to generate a bit of thrust would be welcome as well but the vision still stands) 

Edited May 4, 2025 by DoctaDajman