Metalmind FTL

[BigBadBagsworth He/him/his]

It seems that when a metalmind is filled, the power instantly diffuses through the metal. So theoretically, you could have a thousand kilometer long breath mind to transport air 1000 km instantly from one person’s lungs to another. More interestingly, imagine a spaceship has a thousand km long nicrosil pole, turns itself into investiture (possibly by having something like Nightblood poke the ship, then store the investiture it turned the ship into in the nicrosil pole) and an awakened metalmind on the other end takes the investiture out. It’d just be investiture at the other end, but it may be possible to have a bunch of the ship’s identity stored at the far end of the pole and recode the identity of the investiture you take out. So, Nightblood takes the ship and turns it into identityless investiture, which instantly travels through the metalmind, and then a metalmind full of the ship’s identity returns the ship’s identity to the un coded investiture, and a ship has traveled one thousand kilometers in no time at all. You could also, instead of using a gigantic, expensive pole, Connect two separate pieces of nicrosil a thousand miles apart, and have them share their investiture the same way someone’s investiture infuses a piece of worn or ingested metal. The problem here is that you’d need to have gone to the place you’re teleporting to in order to have identity at that end and to connect the pieces of nicrosil. But you could use something like Aon Tia to place a 10 pound metalmind where you want to teleport instead of transporting another ship. Or you could use a small ship that only carries the necessary metalminds to transport a ship of almost any size. It would also be possible to use cognitive FTL to place a metalmind in the place you’re trying to teleport to, then teleport. Either way, almost no energy is used.

 

 

[#1 Taln Fan he/him]

Just a heads up, since your post contains info from other Cosmere books other than Mistborn, I've moved this to Cosmere Discussion

[PanLin they/he]

Mayyyybe? I suppose if it is possible, the main issue would be having a single piece of cadmium or nicrosil 1,000km long that still considers itself to be a single piece. That's also the main issue with your 'connect two pieces' theory—either you'd need a feruchemist at each joint manually transferring from one piece to the next, or you'd need to convince the three different nicrosil pieces to consider themselves as one entity.

I think it would also be super difficult to re-separate that investiture on the other end into the right distribution of identities, physical forms, cognitive forms, spiritual forms, investiture, etc. Maybe it could work if you converted each element into a different pole to transfer them so they're easier to decode at the other end? Nicrosil, aluminum, duralamin, all the good stuff.

All of this sounds like it would be super difficult to do to a single person, let alone a whole ship, and it doesn't account for any damage to everyone's spirit webs this would do. Outside of aether propulsion and steel pushing, I think it'd be interesting to see the use of Connection to pop into the spiritual realm, connect to the destination, and pop out of the spiritual realm without technically having 'moved' at all.

Also, outside of the mechanics of all that, trusting Nightblood to convert and not consume anything seems wildly inadvisable.

[listerfeend]

So, if I'm understanding this correctly, it seems we are trying to achieve FTL travel using Feruchemy alone? Or are you specifically attempting to create Teleportation without the use of the Surge of Transportation? 

I am fairly certain you could use Feruchemy to achieve FTL travel in a "warp drive" kind of sense, but I doubt that you could manipulate it in such a way as to teleport something across any kind of distance. There are just too many things that make up an object or person to transport, and no real way to combine them again at the end. Remember, Identity is really only one aspect of a thing in the Cosmere. 

I think a much more realistic use of Feruchemy to achieve FTL travel would be to essentially create an Alcubierre adjacent drive of some kind, by storing weight (mass, hopefully, Brandon has been super cagey about whether mass==weight in the context of Feruchemy) and tapping it on either end of a ship, thereby contracting spacetime at the front, and expanding it in the rear, to achieve FTL. This would PROBABLY require compounding, in some way, so you'd need a Misting and Ferring of iron and steel.  

[PanLin they/he]

57 minutes ago, listerfeend said:

I think a much more realistic use of Feruchemy to achieve FTL travel would be to essentially create an Alcubierre adjacent drive of some kind, by storing weight (mass, hopefully, Brandon has been super cagey about whether mass==weight in the context of Feruchemy) and tapping it on either end of a ship, thereby contracting spacetime at the front, and expanding it in the rear, to achieve FTL. This would PROBABLY require compounding, in some way, so you'd need a Misting and Ferring of iron and steel.

I wonder if this would also need a careful application of Allomantic time bubbles and physical pushing/pulling? Or at least to do something similar that wouldn't be possible in the real world: time and the speed of light are inseparably linked, so theoretically could Feruchemists store weight/mass while Allomancers speed time up inside the vessel, both to counteract the time dilation that naturally happens as matter reaches the speed of light?

[listerfeend]

7 minutes ago, PanLin said:

I wonder if this would also need a careful application of Allomantic time bubbles and physical pushing/pulling? Or at least to do something similar that wouldn't be possible in the real world: time and the speed of light are inseparably linked, so theoretically could Feruchemists store weight/mass while Allomancers speed time up inside the vessel, both to counteract the time dilation that naturally happens as matter reaches the speed of light?

This is actually I viable secondary option for FTL, rather than something that would be needed for the Feruchemical version I hastily thought up above. I think. See, the beauty of something like an Alcubierre Drive is that the vessel itself is not traveling faster than light, therefor there would be no time dilation to deal with. You see, by contracting space in front of, and expanding it behind, the vessel, space itself is doing the traveling. The vessel, for all intents and purposes, is actually just sitting still while spacetime flows around it. 

[PanLin they/he]

1 minute ago, listerfeend said:

The vessel, for all intents and purposes, is actually just sitting still while spacetime flows around it. 

 You're so right, my bad. I started thinking of the drive as maintaining a bubble of unmodified spacetime and my brain went "oh hey bubbles, like temporal allomancy"

[listerfeend]

4 minutes ago, PanLin said:

 You're so right, my bad. I started thinking of the drive as maintaining a bubble of unmodified spacetime and my brain went "oh hey bubbles, like temporal allomancy"

Honestly I suspect that time bubbles would absolutely be another way to achieve FTL travel though... Maybe even a better way, though the metals for it are extremely expensive and rare...that may end up not being the case later on though. I'm willing to bet that Soulcasting doesn't stay a Roshar restricted thing for too much longer (someone will figure out a way to make more Soulcasters of the 'fabrial' variety soon enough), and that would make obtaining Cadmium and Bendalloy trivial for Scadrians of means...

[PanLin they/he]

33 minutes ago, listerfeend said:

(someone will figure out a way to make more Soulcasters of the 'fabrial' variety soon enough)

Oh, fully agree. This is pure speculation, but between things like Soulcasting, Soulstamping, Hemalurgy and all the other increasingly weird ways people in the Cosmere have of messing with Identity and Connection, I wonder if Scadrians will find a way to rewire the rules of Allomancy and be able to use different metals for different powers.

Plus, I'm pretty sure we know that Allomancers can use unkeyed Investiture to fuel any Allomantic power their Spiritweb allows for.

[listerfeend]

16 hours ago, PanLin said:

I wonder if Scadrians will find a way to rewire the rules of Allomancy and be able to use different metals for different powers

I'm sure it's possible, I wonder if Brando will go there though. With the right spirit web modifications, and a bit of inspiration, I'm sure that there is a way to 'build' a Mistborn that could use metals to power Radiant Surges or something along those lines. Possibly, anyway.

 

16 hours ago, PanLin said:

Plus, I'm pretty sure we know that Allomancers can use unkeyed Investiture to fuel any Allomantic power their Spiritweb allows for.

This is 100% accurate and is told to us in Mistborn Era 2. Shai basically directly tells Marasi that the unkeyed Dor they are using would power her, but it wouldn't be super duper useful because Marasi can only use Cadmium.

[PanLin they/he]

1 hour ago, listerfeend said:

I'm sure that there is a way to 'build' a Mistborn that could use metals to power Radiant Surges or something along those lines.

Yeah, interesting. So Allomancy kind of goes like:

Burn a specific metal allowed by your Spiritweb -> that opens that metal's door to Preservation's power -> you get that specific power for a bit

So I guess there's a few potential ways to hack it, right? Either:

• Change your Spiritweb to allow burning of different metals (we've seen this one happen)
• Mess with that metal's Identity or Connection (?) to make it open a different door, maybe even to a different Shard (would that even work?)
• Interrupt the Investiture you get back from Preservation so it does something else

Obviously the stuff you get back would be keyed to Preservation, so that would need addressing.

Which raises another question: If you, an allomancer and feruchemist, burned any metal while storing all the Identity you could, could you unkey the Investiture you get back and channel it into a jar or something, rather than have it fuel the ability it's supposed to?

[listerfeend]

7 minutes ago, PanLin said:

So I guess there's a few potential ways to hack it, right? Either:

• Change your Spiritweb to allow burning of different metals (we've seen this one happen)
• Mess with that metal's Identity or Connection (?) to make it open a different door, maybe even to a different Shard (would that even work?)
• Interrupt the Investiture you get back from Preservation so it does something else

I suspect that messing with the Identity AND Connection would be required, and you'd have to have some pretty Shard level amounts of Investiture to make that happen (I would think). You're basically forcing a Connection to another Shard at that point, and that could have some pretty disastrous consequences, especially if you are trying to Connect to one of the more hostile Shards (Odium and Ruin come to mind).

I think you're second theory is much more interesting though.

 

9 minutes ago, PanLin said:

f you, an allomancer and feruchemist, burned any metal while storing all the Identity you could, could you unkey the Investiture you get back and channel it into a jar or something, rather than have it fuel the ability it's supposed to

I'm not sure if this would work, at least not exactly as described, but I highly suspect there is something here, and it's probably what Ghostbloods are using to "unkey" the Dor. So, the reason I think there is another step: Storing your Identity doesn't change the Identity of the Investiture you are getting back. It just blanks the "This Investiture can be used only by this Identity" safeguard. So, storing Investiture this way is essentially how we have the Allomantic grenades and the Medallions. 

However, finding some way to blank the Identity of the Investiture itself, then storing that in a nicrosil mind, while also storing your own Identity, would definitely provide a completely unkeyed source of Investiture.

[Espella]

Do we have any reason to believe that investiture diffuses through a metalmind instantly and not at speed of light? There's a WoB saying that most uses of investiture do follow speed of light, and implies that you need specific tricks to get around it:

Quote

Brandon Sanderson

The weird thing about Investiture is… Like how light sometimes acts as a particle or a wave, right? There is a third state for Investiture. It is sometimes being a particle; it is sometimes being a wave. There are third states. And when we get into the scientific age, we’ll talk about this.

Most uses of Investiture do follow the speed of light. For instance, spanreeds are bound by the speed of light. But some don’t. For instance, seons are not bound by the speed of light for communication, ansible-style. Right now, for instance, Elsecalling is bound by the speed of light. When you see the portal in Wind and Truth, you’ll notice there was a border to the portal, so there was a little bit of a tunnel. That would have gotten longer and longer, depending on how far they were going, to the point that it could last years, if you’re traveling lightyears. Now, there are ways around this, but you have to be doing it in specific ways with specific states of Investiture, and things like that.

You should assume that Investiture is often acting like a matter (when you’re seeing it) that is radiating a certain type of energy that is acting like light. So it’s state number three, which is an actual physical thing that generally looks like a liquid, radiating particles that are acting like photons, which could be either particle or wave depending on… yeah.

Dragonsteel Nexus 2025 (Dec. 5, 2025)

My assumption would be that any methods that bypass speed of light involve spiritual realm shenanigans in some way since we know time works different there, and feruchemy doesn't strike me as a method very likely to have avenues to do those sorts of shenanigans since it's very reliant on a physical user touching a physical object and transferring things between them. 

[DrPhysics he/him]

On 2/16/2026 at 11:44 AM, listerfeend said:

Brandon has been super cagey about whether mass==weight in the context of Feruchemy)

Since Wax speeds up when storing "weight" in the air, he is most definitely storing mass. If he was sitting how gravity attracted him, you wouldn't see the speed up. 

On 2/17/2026 at 1:11 PM, Espella said:

My assumption would be that any methods that bypass speed of light involve spiritual realm shenanigans in some way since we know time works different there.

You're right. So far, everything suggests that information/investiture/etc is bound by the speed of light within the realm it travels in.

Span reads share a connection that is separated by the physical realm. Aons connect through the spiritual realm, so the effective distance between them is zero. 

I imagine one of the ways around the Elsecalling portal that he talks about would be to cross the much shorter distance in the cognitive realm at the speed of light, popping out faster than light would have traveled in the physical realm. Another would be to enter the spiritual realm and pop out somewhere else.