Steven posted his promised discussion about the physics of Touma’s Imagine Breaker power over at Chizumatic. It’s very spoiler-filled, as is my response below. It started as a comment, but just kept going. I don’t know how to characterize it; it’s not exactly an agreement, nor is it a rebuttal. I’m just killing a few more catgirls by pointing out some implications in the worldview. Below the fold, since there’s spoilers.
Ok, if you take the name of Touma’s power, and assume that magic is “externally powered reality alteration” as opposed to a psionic’s “internally powered reality alteration” then it makes sense that Touma can cancel magic as well as psioncis. It doesn’t require a 3rd power type, which is what I was postulating (from lack of a better alternative). I felt that was a “messy” explanation, but didn’t have any other that could explain how his power worked.
Unfortunately, based on this explanation, it’s theoretically possible for someone to generate an “altered reality” (that is, use a power) that is greater than Touma’s ability to cancel it. Logically, such a someone would probably be the source of the external powers; that is, an angel or other such magical source. After all, we see an angel’s power cause changes all across the world (President Kuroko, lol!). What level is that power? Yet Touma wasn’t affected? In brief, would such beings be subject to the same limits as human beings? Probably not. It just may be that Touma’s not met a magic user strong enough to channel that much power from an external source. If he meets the source directly and depends on his power, he might be in for a nasty surprise.
A possible inconsistency: We twice see ability users devastate areas measured in hundreds of square feet, but Touma not only shields himself, he protects a cone shaped area immediately behind and to either side. Also, he negates Mikoto’s iron sand-swords all the way back to her hands. In other words, the power has to touch him, but once it does, he has an amorphous area of effect that extends beyond skin contact.
What are the implications for magically or psionically accelerated objects tossed at him? If there had been a glass counter between him and the Graviton Bomber, would he have been cut by the flying glass?
As Steven pointed out,Touma is not immune to swords; nor was he immune to having a subway collapsed on top of him (a fate he narrowly avoided). Yet he was immune to having a summoned car dropped on him? Does that mean the substance of the car was inherently magical?
I still believe he is not immune to a railgun shot — but only assuming he is beyond the end of the field Mikoto generates to fire the coin. If she generates her field all the way through the target (him) to guide the coin (likely, given her accuracy with such an aerodynamically unstable object), it would fail the instant the field touched Touma, before the coin began to move forward.
I thought I might need to deal with the question of why Touma didn’t prevent the explosion entirely. I think there are two ways to retcon that.
The one I like better is this: Touma can’t run time backwards. When the edge of the explosion reaches him and he touches it, what’s already happened is permanent as far as he’s concerned. He can’t retroactively nullify it. But he can prevent it from continuing to spread past him and into the area behind him, and that’s what he does do.
As to the railgun attack, the entire path of the coin is the same as the explosion. Whether Mikoto is using electric fields on the coin or not, she is using her power to move it, in the sense that what it does after she thinks she’s ceasing to use electric fields is still the result of her imagination rendered physical by her power. So the coin would stop once it struck Touma’s right hand, and fall on the floor.
However, as I think I’ve mentioned elsewhere, I don’t think that Mikoto is really firing a projectile. What she’s doing is to vaporize the metal and use it to create a plasma channel for an electricity attack. So the channel would stop at the point where it touched his hand, and any electric arc passing down it wouldn’t connect to him and zorch him.
I don’t remember the specific event of a summoned car failing to drop on him. Where/when was that?
Also note that when Touma cancelled Mikoto’s iron-sand whip, he wasn’t doing so retroactively. He cancelled its existence going forward, and that works in terms of his power and his conception of what it can do. Cancelling an entire explosion, however, would require time paradoxes, so he doesn’t do that.
Oops, I didn’t use any spoiler tags. I apologize.
ONE MORE THING… [spoiler]Yes, you are right that if Touma were to meet a magic user who could channel more power than Touma can (including whatever effective power boost he gets because reality inherently resists change) then he could be affected by magic. The same is true when it comes to psionics. (Why didn’t I think to use that word?)
But the other thing that’s distinctive about Touma is his power level, which I think really is level 6. However, he has twice encountered people even stronger than he is. One was the alchemist. The other was that angel. And he didn’t defeat them with his hand. The good guys won other ways.[/spoiler]
Well, I’m not concerned about either preventing the explosion entirely, or the iron-sand whip, because I assumed both of those work as you described; the point I was making was that his power is not strictly limited to touch range; it’s contact range — as long as he contacts any part of the power manifestation, he’s able to nullify the entire power.
Most of the time, that is.We still have the contradictory arm-severing, which we kicked around before. Except, upon re-viewing it, Touma didn’t even try to stop it with his hand — at the time he was still working his way through the implications of Stile’s deductions. Immediately after losing his arm, he freaked the mage out by, as you said, convincing him that Touma himself was a monster and that the mage had lost his powers. Freakishly, after Touma lost his right arm, not one attack by the mage could touch him.
Why? I could see the third, fourth, and subsequent attacks being ineffective, because the mage had begun to doubt his power after the second one missed. But why did that happen? And how the hell did Touma remain standing after having his arm severed? The only solution I can see that works is that Touma made the fundamental leap to realize that not only did the mage’s power work based on what he imagined to be real, but so did his own — and he instinctively refused to believe in his own collapse, or the other guy’s power working. So the second attack missed, which messed with the mage’s mind, and at that point, his Ars Magica essentially turned on him, causing all his attacks to fail.
This implies that, while he still “leans” on his right hand as a mental crutch, Touma subconsciously realizes how his power works and can manifest it without using his hand.
And finally, on the railgun, I still think the coin never leaves the vicinity of Mikoto’s hand. If she’s not turning it into plasma, the field collapses as soon as it touches Touma (and as I state above, not necessarily his right hand), thus the coin might go no more than a few feet. If she is doing the plasma/lightning trick, then the same problem still occurs. The plasma has to be controlled by a magnetic field in order to travel in a straight line. As soon as that magnetic field touches Touma, it collapses. So at worst, there’s a ball of expanding plasma right in front of Mikoto’s hand.
There’s also still the incidentwhen Kuroko tries to teleport Touma and fails. He doesn’t have the right hand in contact with her; he’s holding the cat. The last time we discussed this, someone postulated in the comments that teleporting him, involved teleporting his right hand, so it canceled the entire effect. It just confuses me that his arm can be severed, which certainly also affects the hand…. does that work because it’s an indirect effect? Or did it not matter because Touma’s reality was that he could remain standing and functional after losing his arm, and that the doctor could reattach it with no difficulty? He should have had months or years of rehabilitation, yet he’s good as new (not even a scar!) with a few days. Almost the entire Index series takes place over one summer.
And most importantly, does the author actually think about this stuff, or are we killing catgirls for no reason?