Lightspine

Nobody on Roshar seems to know this is possible, but I'll just leave this WoB here: Perhaps they'll figure it out eventually. Not exactly Kaladin's style though...

Ah, you're saying my theory should allow for stormlight drainage from a distance? The way Arnist method does say that the larger gemstones merely need to be "brought close" to the smaller one, which I think implies they don't need physical contact. If it can be done from a distance, the distance isn't that large though. However, that still doesn't explain the spear. I completely see why you feel like the aluminum is needed as a "conductor" of investure. My theory has plenty of holes in it. It did a good job of explaining stormlight transfer between gemstones, but some processes that we see—like when Radiants breath light in from gems, or when they infuse other objects—don't quite follow it. That said, maybe it's because these are "active" processes which somehow need "energy input" to happen.

A very good point that I didn't think about. I don't think we even know for sure if the weapon needs to cut the Radiant or just make contact with them. Maybe it's because the Radiant will be able to recharge immediately once contact with the fabrial is lost, so it's better to use it in a close-up fight where you can actually press your advantage. If you hit them from afar, they might be recharged by the time you reach them.

Something's definitely strange about that fabrial. Most fabrials are powered by stormlight and need it to operate—even the ones that mimic surges (healing and soulcasting). I think that the epigraphs to these chapters are supposed to be a big hint: (Heads up: some time in the middle of writing this post I went from planning to brush a bit with physics to full on way too much thermodynamics talk. This was not what I expected to be writing today. Have fun. Also, I've learned physics but am far from an expert so please, PLEASE correct me if I get anything wrong) Chapter 4 epigraph: Chapter 5 epigraph: Both of these epigraphs tell us something that we haven't known before: that gemstones "want" investure. However, I think speaking in those terms is similar to how we describe chemical/physical processes "wanting" to happen in thermodynamics. One of the core laws of thermodynamics is seeking a a lower energy (or more stable) state, and I feel like something similar is happening here. From here on, I'm going to talk as if investure has "low energy" and "high energy" states, but I'm doing so for sake of analogy. Investure is energy in the cosmere, and we don't quite know the Laws of Investure Thermodynamics or anything. I'm just conjecturing that those laws provide states which the investure tends to move towards ("low energy") and states which the investure tends to avoid ("high energy"). Stormlight held within a small gemstone has an analogous behavior to being in a higher energy state compared to when it is held in a large gemstone. This would explain the Arnist method, where stormlight is drawn from smaller gems into larger ones. In turn, being infused in a gem is more stable than being infused in another object (such as through a lashing) or a human, since these things lose stormlight more quickly than gems. Since stormlight likes to "evaporate" on its own, even from a gemstone, being free seems to be the absolute minimum of energy in this system. All stormlight will eventually reach this state. (Note: I'm only speaking about stormlight here, since not all investure behaves the same. Breaths held by a human seem to be in an energy minima, for example. And some of my recent theories involve voidlight behaving differently/not escaping like stormlight does) One last thing I want to include in my description is "activation energy" of sorts. This is needed to explain why stormlight escapes more quickly in a "higher energy state." Stormlight doesn't immediately leave gemstones the same way that a pot of water brought to 100ºC doesn't immediately become steam. Some of the water is energetic enough to evaporate, and some isn't, so this process takes time. (Extra note: if you're confused now by why I'm talking about water spontaneously undergoing a process that requires more energy, this is because I haven't talked about entropy. Basically, behavior towards "lower energy" is actually behavior towards a uniformity of energy distribution. Hot stuff cools down until everything in the system is the same temperature. The colder stuff around it accepted that heat because the universe as a whole now has a more even energy distribution, or higher entropy. Fundamentally, this happens because of mathematical probability. Thank you for coming to today's surprise physics mini-lesson. Assume from now on that some of the stuff I call "lower energy" includes processes which increase "energy" in some ways, but still happen on their own because of how it changes the wider system.) Anyway, here's my breakdown of the "thermodynamics" of stormlight: Contained within Honor's perpendicularity: very, very high energy. Literally bursting to get out of there and invest anything it can. Contained within an object that isn't a gemstone: the second-highest energy state. A large amount of the stormlight has enough "energy" to escape, so the objects leaks quickly. Contained within a Radiant: lower energy than inanimate objects. Of course, there is a variance here depending on how many oaths the Radiant has sworn. Contained in a gemstone: pretty low energy. Stormlight escapes slowly. Larger gemstones --> lower energy. Here is where we also need to talk activation energy again: the "activation energy" needed for stormlight to escape a gemstone is higher than that needed to move to a larger gemstone. The speed at which something occurs is dependent on how high activation energy is, while the long-term result is more dependent than how "low energy" a state is. Thus, stormlight can transfer to a larger gemstone more quickly than it evaporates. In the end, it will evaporate anyway, but for the meantime it moves to a larger gemstone. A large gemstone serves as a local minimum of energy, where activation energy is high enough to prevent rapid leakage. But how do spren get trapped? My proposal is that, while stormlight is leaving a gemstone, the "activation energy" for the spren enter that gem is lowered. Being in a gemstone is lower energy state for these spren than being free, so once the "activation energy" to enter the gemstone is lowered, this happens spontaneously. Extra extra note: here I describe spren as having a different behavior than stormlight. Common spren might not be made of the same investure as stormlight, since some have been around since before the Shattering of Adonalsium. Maybe the reason why surge fabrials like Soulcasters don't contain trapped Radiant spren is because these spren, having Honor's investure, behave like stormlight and can't be trapped in the same manner You're probably wondering now why I wrote all this, so let me get back to the point: aluminum. In the model I just wrote out, investure held in aluminum would be at the absolute top of the list. It behaves as if it's already immensely invested, even more so than Nightblood, to the point where you can't cram investure in. And also, now we can think about how that fabrial works. I've already said that an infused gemstone is a lower energy state than an infused Radiant. According to this model, all you need to do is lower the "activation energy" and provide a means for the stormlight to move (a catalyst!). Maybe the gemstone is constantly having stormlight removed from it? Or maybe voidlight, which seems to "draw in light" rather than escaping, can somehow lower this "activation energy." Alternatively, the aluminum is somehow essential to all this. Or maybe I've overthought this whole situation and should throw this post in the garbage bin. There's plenty here which could be totally wrong.

I see you're agreeing with most of my theory! I like your thoughts on how the gemhearts contribute. I didn't mention it in the original post, but my thoughts on why the Heavenly Ones have a "speed limit" is just because they don't have enough voidlight with them for "multiple lashings" (or the voidbinding equivalent), but I'd never considered gemheart strain. The only times we've seen gems broken is by excessive Soulcasting, and I'm not quite sure how that works. Your thoughts on external lashings are exactly the same as mine. Not exactly sure how this lines up with the teleporting Fused. I had a post about it last week (sort of looks like I'm a bit Fused-obsessed doesn't it? :P) but I'm not especially confident about the theory I proposed there. However, I agree with you that the healing and Transportation should both require immediate voidlight expenditure (as part of the first class of powers I wrote in the post).

@Gilphon is completely correct here. I extended my theory in this post, you should check out the edit at the bottom. There's a WoB there about how stormlight can't be perfectly contained.

I think we pretty much agree on everything except this one point. In my interpretation, Lashings don't fade away because the stormlight is being consumed to power the acceleration, but purely because the object is leaking the stormlight. Unless I'm misinterpreting you, you believe that the object loses stormlight for both of these reasons. I admit your idea is a lot more intuitive, but for me it lacked explanatory power. I spent a while hunting for a WoB about this but found nothing pointing either way. You might find my interpretation of how the Fused work similar to how Breaths work, since motion is being powered without investure loss, and I did manage to find a WoB adjacent to that: I don't think this has much to say about the point we're arguing over. However, it does modify my theory about the Fused a little since my reference to their holding stormlight perfectly turns out to be untrue. That said, it doesn't kill my idea because it also suggests that different types of investure stick differently. It's completely possible for voidlight to not leak at all from the Fused, even if stormlight would. Maybe this is one of the "fundamental differences" between Voidbinding and Surgebinding. Wow, was writing this before the last few comments, but looks like this WoB might help answer the question about Venli.

I don't know why it's necessary to say that lashing other things is harder when it could simply be that they're not retrieving that voidlight. However, I think I actually agree that their surge of gravitation could be structured a bit differently. I was considering suggesting that the Heavenly Ones don't actually need to recall their voidlight in order to change their lashings. Basically, they get to skip the step I mentioned of cancelling their lashing and instead can directly change the direction of their existing lashing. This allows them to change direction with minimal lag time. I decided not to propose it because 1). it wasn't strictly necessary to the theory and 2). I'm trying to make as few assumptions as possible and follow rules we already know. I'm not against the idea that Voidbringer surges aren't the exact same as Radiant surges, but I do think that they should have some fundamental similarities. Even if you disagree with the mechanics I described, I hope you can agree with me that the two classes of surges I described seem to also divide the efficiency with which the Fused can use them.

I've seen some considerable confusion surrounding the new information we have about the Heavenly ones: that they don't consume Voidlight during flight, but do use it to heal. Here's a couple of the comments about it in the Chapter 4&5 Discussion board: However, I think there's a much less convoluted explanation that draws on mechanics we've already seen. I already posted a short comment about this on the Chapters thread, but there's some more to break down so I'm deciding to make this a whole post. Basically, we know that Kaladin has the ability to retrieve stormlight from his lashings, but he doesn't seem to have tried this on lashings on himself. We've also heard that Voidbringers can hold stormlight perfectly (see edit note). This provides a very simple explanation: that when the Fused lash themselves, the lashing doesn't "leak" voidlight. When they change direction in flight, they can retrieve this voidlight and lash themselves in a different direction. They lose voidlight if they lash others unless they retrieve that voidlight, and also because other objects tend to leak. This might also explain how Leshwi outmaneuvers Kaladin, despite having a lower top speed. Kaladin just keeps stacking his lashings, which means that he doesn't stop accelerating in a direction he's lashed himself until that lashing runs out, even if he applies another lashing in a new direction. He's like a charging bull. Leshwi is removing her prior lashing with each change in direction, allowing her to make sharper turns. In the second comment I linked, @vegvisr brings up the fact that there must be a difference between the investure use of different surges. I agree. I'm dividing Surgebinding into two classes of powers: those which consume stormlight/voidlight immediately with immediate effects, and those which infuse light to apply a lasting effect. Healing/Progression, Elsecalling, and Soulcasting consume light while being used. This is why the teleporting Fused runs out of voidlight, and why the Heavenly Ones lose voidlight when they heal themselves. Illumination, Gravitation, Adhesion, and (probably) Abrasion infuse objects with investure and and the duration of the effect depends on how long the object can remain infused. Most objects leak stormlight, limiting the duration of the second type of surge, with the only exceptions being perfect gemstones and the Fused. Fused which use the first kind of surge are limited by their voidlight, since they lose some every time they use their power. Those of the second are not, since they don't leak voidlight and their lashings/illusions/slipperiness remain indefinitely, and they can recall this voidlight to be used differently. I think the reason why nobody suggested this explanation earlier is because Gravitation lashings feel like something which should be draining investure. Isn't investure consumed in order to continuously accelerate an object? It feels a bit unintuitive, but I'm pretty sure that the textual evidence points towards Gravitation being in the second class of surges. In short, I think this class of surges doesn't work by "powering" anything, but rather by changing the properties of an object. As long as the object is imbued with investure, its behavior is altered or "tricked." When something is lashed sideways, it only fall sideways—but no longer down toward the planet. The stormlight or voidlight isn't providing the acceleration here, but rather somehow tricking the object into thinking that a different direction is "down" and, in the case of multiple/partial lashings, changing the strength of the gravitational force. As for Adhesion, the object is being tricked so that it behaves as if a perfect vacuum is formed when it touches another object. Or something like that. It's a little unclear. Abrasion is tricking the object into behaving as if it is smooth. Illumination might be a bit different; it's not exactly applied to an object. Shallan describes it as if her illusions are made out of the stormlight. We also know that a perfectly cut gem will glow forever, as we see with the King's Drop. Providing light doesn't consume stormlight at all. Shallan might be merely shaping the stormlight into different colors and shapes, and also altering its brightness somehow. Anyway, even though I'm more confident in this explanation than I have been about any other theory I've ever made, I know there's still plenty of room for controversy. Please roast me to Braize if you think I'm getting stuff wrong. Edit: due to a WoB I found, just wanted to say Szeth's belief that voidbringers can hold stormlight perfectly is actually incorrect. They merely hold it longer than a human can. However, the same WoB states that different sources of investure will stick to objects differently (like Breaths v.s. stormlight), so it doesn't rule out the possibility that the Fused can hold voidlight perfectly. WoB spoilered for length:

I think the Fused have perfect retrieval of voidlight and lashings. When Kaladin lashes something, he can retrieve some of the stormlight from it and cancel the lashing. Shallan does the same with her illusions. But we've never seen Kaladin try retrieve stormlight from a lashing on himself, have we? That's probably the trick here. I think that the Fused can fly forever because they can reuse the same amount of voidlight over and over, cancelling their lashings and retrieving all of the voidlight to be lashed in a different direction each time they change course during flight. Probably because they have gemhearts.

I don't think that it's nearly to the same degree as on Sel, but any increase in investure should bring Realms closer together. Also, now that I actually hunted down the WoB about this, it doesn't need to be in the Cognitive Realm: Honor's splintering brought investure from the Spiritual Realm to the Physical and Cognitive Realms, so it should have pulled Realms together at least a little bit. It's spread out through all of Roshar, so it's possible the effect isn't too pronounced but it almost certainly exists. I really like that interpretation of Nale!

Most of those theories are based around this quote from Nale: I'm having some trouble finding posts discussing this—maybe I'm pretty bad at searching this website—but I don't remember any going much more in depth than speculating that Honor's regulation was restricting the number of oaths, or something along those lines. The main reason I referenced this was because it's the first quote that comes to mind when surrounding how Honor's death may have changed surgebinding. That said, we also have reason to believe that Nale is wrong about this, both because he doesn't actually prevent the Desolation and because this WoB throws serious doubt on his credibility: (I think the last line of this WoB is talking about Ishar and not Nale btw, I think it's pretty heavily implied here by "Nale trusts Ishar too much" and "Do not trust anything any Herald says. Ever" that the Nale quote from above could be totally off the mark. That said, it might contain nuggets of truth. It's possible that he's right about something changing without Honor's regulation, just totally wrong that it could lead to a Desolation) I guess it's possible that the splintering mostly manifested into the increase in intelligent spren, I just think it's also very probable that other spren have also become more widespread. I'm not trying to say that spren were rare before his death. An increase in the amount of investure in the Cognitive Realm does make the boundary between Realms thinner, so it's very possible that accidentally slipping into it has become somewhat easier! Nice catch, I wish I'd thought of that. So, increase in amount of angerspren or no, I think it's safe to say that it's easier than ever to get stuck in Shadesmar.

I'm pretty sure they can't be Rushu, or any of the ardents who work with Navani, since she's too deeply involved with all the fabrial stuff. The SoH were very interested in Shallan's offer of fabrial schematics, which means it's something their current spy isn't providing them with. So whoever is feeding them info isn't privy to (or is choosing not to give) the fabrial tech.

It's definitely probable that Honor's death has had an effect on the Nahel bond. Some stuff that Nale mentions points to this, and I've seen it discussed that perhaps five oaths is no longer a limit. However, I think there might be a different explanation for how Soulcasting has changed; Shadesmar has become more dangerous. The spren are splinters of Honor and Cultivation, so this WoB makes it very likely Honor's death lead to an explosion in their numbers. Syl mentions that intelligent spren are much more common now than they were before the Recreance, so we at least know for sure that their members have increased. And we also know that some spren, such as angerspren, are extremely dangerous in the Cognitive Realm. In addition, the Oathgates no longer facilitate travel between Realms, so it's easier to get trapped in the Cognitive Realm—with Cultivation's perpendicularity being the only escape (although this is more of a danger for Elsecallers than it is for Lightweavers, who can't fully enter the Cognitive on their own). Since Transformation involves partially entering Shadesmar, as we see Shallan do at the end of WoK, the more dangerous nature of the Cognitive Realm could very likely be the reason behind Jasnah's quote.

Possible, but it would be immensely disappointing for an important character whose literally been built up since the prologue of WoK.

I don't think the traitor feeding Dalinar's info to the SoH is among the upper ranks. They're able to inform them about his plans, but obviously Shallan's offer of fabrial diagrams was outside of their reach. This means they're almost definitely not one of the scholars/ardents who works with Navani, so we can rule out that contingent of people. Taravangian is an option, but he's such a higher-up in the coalition that I'm pretty sure he could have provided the fabrial technology the SoH. Could be one of the Highprinces, though. Restares is suspiciously missing, but I think it would be an interesting twist if Ialai was Restares all along. (Cue astronaut meme?) One last thing I have on my mind is that Honorspren which hasn't bonded anyone. I saw somebody else here suggesting it's Phendorana trying to claim Kaladin because she's more "senior" than Syl. I like that idea, but there's another possibility on my mind: Somebody had to have experienced being stabbed by one of those spears the first time, right? As the number of Windrunners grows, the chances of one of them dying increases as well. I think it's possible that a Bridge 4 Windrunner died and left behind the unbonded spren Kaladin mentions, and that's one of the things weighing heavily on Kaladin. As for the theory that they're after Rock, I don't think that's the case. His beliefs might keep him from combat, but he obviously has no problem with surgebinding, so I'm more inclined to the idea that he belongs to another order. He would fit the Edgedancers (interaction with Rlain during Oathbringer POV) or Stonewards (can't think of someone more dependable) quite well.

Ah, perhaps they need the investure in order to make up the loss of leaving behind a body, instead of perfectly converting that body's investure to spren form? Building off what you said, maybe being a Cognitive Shadow stapled to a body is what impedes the full "phase change" of investure.

I was heavily considering this description when I crafted the original post, but I wasn't sure how it could lead to the corpse left behind each time. I'm wondering if you have any insight on this. How Radiant spren --> shardblades works (or at least my interpretation, this could be more up to debate than I realize) is that the investure that makes up the spren is of Honor and it can make a "phase change" from their spren form to solid Tanavastium metal. This process is completely reversible (much like phase changes of matter in real life). For the Fused, this should mean that their physical body is built by some "phase change" converting the investure that makes up their soul from the red-light-spren-thing form into flesh and blood. I don't have a problem with this part since investure, energy, and all matter are the same in the cosmere. However, this should allow for the reverse "phase change" of investure from physical body to spren-ish form without leaving anything behind, right?

Thanks for the praise! I'm just a little confused by what you mean here. We haven't seen spren needing investure to remain in the Physical Realm once they're already there, have we?

That's a really cool idea, and I think it's totally possible that the crumbling body is being soulcasted. However, I don't think they're soulcasting the new body. First of all, that would allow for clothes (although not invested spheres, I guess). More importantly though, I think soulcasting a biologically functional body is kind of impossibly difficult. It's just too intricate, and far beyond the abilities of any soulcasters we've ever seen. So, even if they're soulcasting, the new body is probably being formed by their coginitive or spiritual aspects being reflected into the Physical.

I guess that could make sense, even it's not my intuitive interpretation of what's going on. That's essentially what my theory is saying, although I'm claiming Transportation is needed to get their "spren form"/cognitive shadow into the Physical Realm. My explanation for the body crumbling is that this process separates the cognitive shadow, which is the Fused's cognitive aspect, from their physical body. Sorry if that wasn't clear!

I see, that makes a lot more sense than how I originally interpreted you. However, I do still think the process you describe would make distance irrelevant: moving a hundred meters shouldn't take any longer than moving ten. This is not the impression I got from the description: In addition, I don't see why your explanation would involve the "red-violet light" zipping around at all. Especially since it doesn't seem to be simply moving in a straight line between locations:

That makes sense when it comes to the body-forming bit, but I'm a bit confused by what it means to "move" the spiritual self. As you said, all places (and times too) are one in the Spiritual realm, and I don't think we've actually ever seen an instance of such movement. Also, shouldn't this allow for more instantaneous movement? If the Fused is moving spiritually, distances shouldn't matter and I don't see why Kaladin would outspeed him with Lashings. If anything, I think this might better explain Oathgates than the Fused.

In the most recent chapters, we just saw that "teleporting" Fused doing some extremely weird stuff. His method of movement is clearly different from the instances of Transportation we have already seen. Just a short summary of differences: No rotating column of light (seen with Oathgates and WoR epilogue) Leaves a crumbling body behind The Fused can't take its clothing or possessions with it. It's clear that it isn't just popping back and forth from the Cognitive Realm. When people enter the Cognitive, they are able to take their body with them as well as their possessions. (WoB spoilered for length): Rather, the fact that the Fused forms a new body with every appearance is more reminiscent of the principle behind stormlight/feruchemical gold healing; using investure to change your body to match your perception of self. It could also be related to what @Scriptorian points out here. First of all, however, I think I actually have an explanation for what's going on with that crumbling body. It would be one thing if the body left behind were flesh and blood, but this one turns to soft stone (crem?) and then disintegrates away. We see that stuff like bodies can change the material they are composed of through Soulcasting, which alters the cognitive aspect of objects and has repercussions in the Physical Realm. But what would happen if an object (or body) somehow had its cognitive Identity ripped away? All matter in the Cosmere must have a cognitive aspect born from how it is perceived by sentient beings, so I believe that an object that loses its identity would fade away. But first, its appearance in the Physical Realm would be influenced by perception. And on Roshar, I think that the general consensus is that crem is the most bland, boring, nothing stuff in existence. Thus, when something on Roshar has a cognitive aspect of "nothing," perception leads to it manifesting as crem. Thus, the Fused is operating by moving its cognitive self independently from its physical self, thus robbing its physical body of a cognitive aspect. I think whatever surge it's using—most likely Transportation, but maybe we're getting tricked—is critical to this. Here is my proposal on the sequence of events: First, the Fused uses Transportation to create a "mini perpendicularity" and moves its cognitive shadow into the Physical Realm. It moves as a spren can, since spren and cognitive shadows are pretty much the same thing realmatically speaking, and then creates another "mini perpendicularity" to re-enter the Cognitive Realm. (Note: in case you're confused, spren like Syl and windspren are completely in the Physical Realm and can fly around anyway) Since it does not perceive itself as "dead," the physical reflection of its cognitive aspect manifests, forming a body. Basically, the opposite of Jasnah transferring her physical self into the Cognitive Realm and back. I hope my theory doesn't seem too ridiculous or overly complicated. Maybe there's a simpler explanation for what's going on here!

Nice catch! Fixed?! (sorry for poor editing skills)