Allomantic Fireballs

[Red Star]

Ever since the introduction of Duralumin in Well of Ascension (And Vin's daring ballistic launch in her rescue of Breeze early in WoA) I have waited for some Mistborn to use this to launch projectiles at ludicrous speed. Until this was attempted against Zane using coins (he countered with his own Duralumin Push) I hypothesized that the projectiles would travel far too fast for any Mistborn or Coinshot to counter. When I finally saw it performed with a single light projectile (earring) in the Vin/Marsh fight in Fadrex (Hero of Ages), I was disappointed in its execution. The narration describes Vin being thrown back into a wall with the force of the Push, and the result of the push was not only an intact earring, but Marsh escaping with nothing more than a hole through his head!

If I remember correctly Vin was launched into a wall, implying that she was accelerated to about 13.9 m/s (50km/h). Assuming Vin weighs about 50 kg, transferring the 695 kg-m/s impetus to a 2g earring results in the earring traveling at 347500 m/s.

This is about 7 times faster than a falling star, and the atmosphere up there is much thinner; just the friction the earring causes by moving that fast would create a huge fireball, and the earring in question would have quickly turned to plasma. Marsh's head should have been vaporized, along with most of his upper torso and a big chunk of the wall behind him.

Was anyone else bothered by the fact that both Marsh and the earring survived this intact? Sure, it would kill the plot if someone figured out they could turn anyone into chunky salsa just by Duralumin Pushing small objects, but the resulting visuals would be pretty cool.

[dyring]

Ever since the introduction of Duralumin in Well of Ascension (And Vin's daring ballistic launch in her rescue of Breeze early in WoA) I have waited for some Mistborn to use this to launch projectiles at ludicrous speed. Until this was attempted against Zane using coins (he countered with his own Duralumin Push) I hypothesized that the projectiles would travel far too fast for any Mistborn or Coinshot to counter. When I finally saw it performed with a single light projectile (earring) in the Vin/Marsh fight in Fadrex (Hero of Ages), I was disappointed in its execution. The narration describes Vin being thrown back into a wall with the force of the Push, and the result of the push was not only an intact earring, but Marsh escaping with nothing more than a hole through his head!

If I remember correctly Vin was launched into a wall, implying that she was accelerated to about 13.9 m/s (50km/h). Assuming Vin weighs about 50 kg, transferring the 695 kg-m/s impetus to a 2g earring results in the earring traveling at 347500 m/s.

This is about 7 times faster than a falling star, and the atmosphere up there is much thinner; just the friction the earring causes by moving that fast would create a huge fireball, and the earring in question would have quickly turned to plasma. Marsh's head should have been vaporized, along with most of his upper torso and a big chunk of the wall behind him.

Was anyone else bothered by the fact that both Marsh and the earring survived this intact? Sure, it would kill the plot if someone figured out they could turn anyone into chunky salsa just by Duralumin Pushing small objects, but the resulting visuals would be pretty cool.

It was most likely not the Earing that caused Vin to be launched into the wall, it was when said earing connected with March´s head, wich weigh quite abit more;)

Not sure how much "weight" there would need to be to push something(even something small) through someone´s head, but alot more then just the weight of an earring, wich throws your math off by, well alot.

[Red Star]

It was most likely not the Earing that caused Vin to be launched into the wall, it was when said earing connected with March´s head, wich weigh quite abit more;)

Not sure how much "weight" there would need to be to push something(even something small) through someone´s head, but alot more then just the weight of an earring, wich throws your math off by, well alot.

When trying to imagine the effect of accelerating a projectile to great speeds, it helps to remember guns. Many movies show victims of bullets being thrown bodily by the force of the impact, but this is inaccurate. The force of the bullet's impact is less than the recoil of the gun that fired it (due to loss). Action and reaction, as the Mistborn novels are so fond of illustrating, tells us that the force that hurled Vin into a wall must have its opposite counterpart. Since she was targeting the earring, that must be where it ended up. And yet, most of the impetus seems to simply disappear.

Your objection smells like another slight problem I had with Mistborn's physics, which was that (at least early in the books) a Steelpusher would not be able to support his weight using a coin until AFTER it hit the ground. Which is ridiculous; trying to accelerate a coin in midair would push you back just as readily as a coin supported by the ground. Though this problem is remembered, not researched, so I may have just been reading it wrong at the time. Furthermore, accelerating a coin in midair enough to support your weight might be undesirable for the large, unstealthy impact it would create (though transferring more than your weight to an object massing not more than a gram probably raises other issues I haven't mentioned).

Anyway, I would still like to know why projectiles in Mistborn don't blow people apart with the mere wind of their passing, create sonic booms and light the atmosphere on fire with friction alone. Surely this would be both awesome and more physically accurate than not doing so?

[Eric]

The narration describes Vin being thrown back into a wall with the force of the Push, and the result of the push was not only an intact earring, but Marsh escaping with nothing more than a hole through his head!

You have this backwards. The narration describes Vin Duralumin-pushing the earring through his head, seeing it pop out the other side, and then being thrown back, presumably because it hit something solid (like the walls of the stone keep she was in) before the Push ended. All of your math that follows is based on an erroneous assumption.

[Zas678 he/him]

Here's the quote.

Pewter flared in her stomach, restoring her to life. Marsh moved to complete his slap, but she pulled out of the way, then yanked him off balance by pulling her other arm—which he still held—to the side. He hung on, barely, but when he turned to face Vin, he found her holding her earring in one hand.And she duralumin-Pushed it directly into his forehead. It was a tiny bit of metal, but it threw up a drop of blood as it hit, ripping through his head and passing out the other side.

Marsh dropped, and Vin was thrown backward by her own Push. She crashed into the wall, causing soldiers to scatter and yell, raising weapons. Yomen turned toward her, surprised.

I guess that the quote could work either way, but Eric's explanation makes more sense.

[Red Star]

You have this backwards. The narration describes Vin Duralumin-pushing the earring through his head, seeing it pop out the other side, and then being thrown back, presumably because it hit something solid (like the walls of the stone keep she was in) before the Push ended. All of your math that follows is based on an erroneous assumption.

The main reason I express this doubt is so that I may better understand how Sanderson was driven to ignore the obvious advantage his protagonists could have easily gained by accelerating small bits of metal to incredibly fatal velocities by way of (duralumin-assisted) Steelpushing. Yes, you can handwave the impetus away as having been transferred to the earring as it was supported by the wall behind Marsh, but that does not change the fact that she should have blown a hole in the goddamn keep.

Rationalize canon all you want, I know of no explanation for the characters not using their capacity to accelerate bits of metal to incredible velocities to kill each other in spectacular ways, except that it would defeat the plot; sort of like bringing a high-caliber howitzer to a knife fight. Sure, there's a keep wall tenuously protecting canon in this particular situation, but is there anything except the needs of the plot stopping Mistborn from Duralumin-Pushing their metal until friction turns it into molten slag?

What do you guys even think would happen if someone were to Duralumin Push a coin?

[Aiken Frost he/him]

Sure, there's a keep wall tenuously protecting canon in this particular situation, but is there anything except the needs of the plot stopping Mistborn from Duralumin-Pushing their metal until friction turns it into molten slag?

Yes: there is a upper-limit of how much power, and thus, how much speed, a mistborn can apply to a push. Even with duralumin.

[Eric]

Yes, you can handwave the impetus away as having been transferred to the earring as it was supported by the wall behind Marsh, but that does not change the fact that she should have blown a hole in the goddamn keep.

I don't think you're getting what I mean about the assumptions being off.

A good example is a punch. A boxer's punch has more energy than a 9mm bullet. A 9mm bullet (519 joules, per Wikipedia) can go straight through a man's head, while a boxer's punch (Rocky Marciano topped out at 1028 joules) can launch a much lighter person into a wall. That's pretty much exactly what happened in the scene where you argue that Vin should have blown a hole in the wall. I don't think your equations hold up because you're making assumptions of much higher velocity than the visible results indicate.

Edited January 27, 2012 by Eric

[Satsuoni he/him]

Also, I am not sure if you understand the difference between a gun and Mistborn push. (Sorry if I am wrong). In the gun, the force is applied to the bullet only inside the barrel, afterwards it decelerates due to air resistance. The mistborn push applies a (probably weaker) force continuously until either the Allomancer stops pushing, or metal goes out of range. The effect is similar to poking the enemy with an extending stick. You won't get much recoil when you are poking air, but try poking a wall, and you will be pushed back, the force of the push distributed more or less equally along your mass.

[the95th]

Also is it not also affected by the size of the metal, a small piece of metal was harder to connect to then a bigger bit. Therefore The small earing, less then 0.25cm squared if the earring in my ear ( I have vins earring) is to scale is probably difficult to put the entire force of a push behind.

Bullets travel at like 700mph, but they dont explode peoples heads much and they are bigger and heavier then an earring, and aerodynamicly designed.

From the design of the earring i have, it would be impossible for vin to achieve a good push as it is in a C shape.

For instance the Lord ruler was all powerful because he could push and pull on Glass.

[Aminar]

Also is it not also affected by the size of the metal, a small piece of metal was harder to connect to then a bigger bit. Therefore The small earing, less then 0.25cm squared if the earring in my ear ( I have vins earring) is to scale is probably difficult to put the entire force of a push behind.

Bullets travel at like 700mph, but they dont explode peoples heads much and they are bigger and heavier then an earring, and aerodynamicly designed.

From the design of the earring i have, it would be impossible for vin to achieve a good push as it is in a C shape.

For instance the Lord ruler was all powerful because he could push and pull on Glass.

Her earing is a simple round stud. That makes it as aerodynamic as a BB or shotgun pellet(read, very).

[Eric]

Actually, it's slightly better, as a stud is a bulb with a pin. So it's like a BB with a stabilizing tail. However, a bullet still wins out due to the tapered front end (and spin from rifled barrels). Ball ammunition isn't generally as accurate as the tapered style.