Let's make a speedster!

[Quantus he/him]

On 5/23/2023 at 3:39 PM, alder24 said:

As far as I know, there are two effects here that works together - heat and air compression. It's like a spaceship entering the atmosphere with enormous speeds - it compresses the air in front of it, heating it up and friction carries that heat into the spaceship. If you get rid of heat, by for example storing it in a Brassmind, you still have air compressed in front of you, resisting you harder and harder the faster you go. At some point every step would just feel like running into a concrete wall. But friction would eliminate that issue as well, as you can basically get rid of air drag fully. 

This last part isnt true, there is still a terminal velocity even without friction.  Friction is relevant to the surface drag force, but even if you reduce it to zero there is still a force required to shove the mass of the air out of the way as you pass through the space, and a vacuum forming behind you pulling you back.  At lower speeds surface effects can pull the airflow around more to reduce that vacuum drag (ie dimples on golf-balls), but it has to be slow enough that air is able to move and respond for those effects to work.  As you approach the Speed of Sounds you start outrunning the wave propagation of the gas entirely and the air can no longer respond fast enough to move out of the way. 

So in Surge terms, I think you'd be better off using Adhesion, and/or Transformation, to entirely remove the air in front of you and create a moving vacuum bubble.  Or convince Nightblood that the Atmosphere is Evil.  But No Air means both No Air Friction and also No Terminal Velocity.

EDIT:  Or think really far outside the box and see if Lightweaving can Change the Speed of Sound of a medium. It could fall into the category of Wave Manipulation, and we've seen how Physics can and will bend over backwards to adjust for magic effects (like driving chemical changes by draining color with awakening).  

Edited May 26, 2023 by Quantus

[alder24]

17 minutes ago, Quantus said:

This last part isnt true, there is still a terminal velocity even without friction.  Friction is relevant to the surface drag force, but even if you reduce it to zero there is still a force required to shove the mass of the air out of the way as you pass through the space, and a vacuum forming behind you pulling you back.  At lower speeds surface effects can pull the airflow around more to reduce that vacuum drag (ie dimples on golf-balls), but it has to be slow enough that air is able to move and respond for those effects to work.  As you approach the Speed of Sounds you start outrunning the wave propagation of the gas entirely and the air can no longer respond fast enough to move out of the way. 

So in Surge terms, I think you'd be better off using Adhesion, and/or Transformation, to entirely remove the air in front of you and create a moving vacuum bubble.  Or convince Nightblood that the Atmosphere is Evil.  But No Air means both No Air Friction and also No Terminal Velocity.

Isn't the air drag a frictional force? Without air drag, there is no terminal velocity. Per WoB it will work, but per other WoB there are still some restrictions, so I guess you're right and those are the reasons why you can't run with steel and Abrasion as fast as possible.

Spoiler

Questioner

I had a question about [steel] Ferrings. So, I saw that you had mentioned in a previous talk that you could only move so fast with air resistance, like eventually you'd start burning up. If you were to become an Edgedancer as well?

Brandon Sanderson

If you can combine those two powers, Edgedancing and [steel] Ferring, then you are able to do things that would circumvent that restriction. Yes, indeed.

Skyward San Francisco signing (Nov. 8, 2018)

 

Spoiler

Steeldancer

So if a steel compounder became an Edgedancer... 

Brandon Sanderson

Oh, here we go. [Audience laughs]

Steeldancer

If a steel compounder became an Edgedancer, how fast could they go?

Brandon Sanderson

[Dramatic sigh] They could go quite fast. They are not going to ever reach superhero levels of bending reality for speed. So, I will say quick, but not that quick. We aren't outracing an atom bomb, as the Flash periodically does. 

Legion Release Party (Sept. 19, 2018)

 

In case of Adhesion I do wonder how it will work, as a vacuum bubble is right next to normal air and that bubble would still need to push the air in front of it to the side. It can cause some drag. Mabe creating some gradient will help, but I personally doubt a Windrunner will be able to achieve speeds close to the speed of light in the atmosphere.

[Quantus he/him]

4 minutes ago, alder24 said:

Isn't the air drag a frictional force? Without air drag, there is no terminal velocity. Per WoB it will work, but per other WoB there are still some restrictions, so I guess you're right and those are the reasons why you can't run with steel and Abrasion as fast as possible.

  Hide contents

Questioner

I had a question about [steel] Ferrings. So, I saw that you had mentioned in a previous talk that you could only move so fast with air resistance, like eventually you'd start burning up. If you were to become an Edgedancer as well?

Brandon Sanderson

If you can combine those two powers, Edgedancing and [steel] Ferring, then you are able to do things that would circumvent that restriction. Yes, indeed.

Skyward San Francisco signing (Nov. 8, 2018)

 

  Hide contents

Steeldancer

So if a steel compounder became an Edgedancer... 

Brandon Sanderson

Oh, here we go. [Audience laughs]

Steeldancer

If a steel compounder became an Edgedancer, how fast could they go?

Brandon Sanderson

[Dramatic sigh] They could go quite fast. They are not going to ever reach superhero levels of bending reality for speed. So, I will say quick, but not that quick. We aren't outracing an atom bomb, as the Flash periodically does. 

Legion Release Party (Sept. 19, 2018)

 

In case of Adhesion I do wonder how it will work, as a vacuum bubble is right next to normal air and that bubble would still need to push the air in front of it to the side. It can cause some drag. Mabe creating some gradient will help, but I personally doubt a Windrunner will be able to achieve speeds close to the speed of light in the atmosphere.

SO, in this case there's Friction drag (surface interaction with heat conversion) and then there's the vacuum drag; both could be "air drag" but they come from different sources.  Think of it this way, even if you coated an object in an idealized Perfect Grease that eliminated all shear forces at the surface, there's is still a person sized (by volume) mass of air that is being shoved a shoulder-width sideways at a high acceleration (causing all kinds of compression, vacuum, and usually phase change effects on the air).  That's a force that has done work on a Mass, and it bleeds energy out of the system relative to the velocity it's slamming into the air. Because of that, the object will eventually reach an equilibrium point and stop accelerating.   The larger or the fast the object, the more the balance shifts from surface effect to the inertial effects.  And that happens even if both you and the fluid itself has no friction (ie zero viscocity) still has mass to be moved.  

 

Here's a far more detailed breakdown than I can pull together off the top of my head. It's a kinda long lecture but the relevant bit is:

Quote

3: Terminal velocity in falling bodies. The rate at which the fluid can move out of the way of the falling body is dependent on the viscosity of the fluid. Under a constant strain (the weight of the falling body) the fluid reaches a constant velocity, the value of which is governed by the viscosity η. This is actually a bit more complicated. Even motion through a fluid without friction will exhibit terminal velocity. Just accelerating the fluid to get it out of the way requires that a falling object exert a force on the fluid, implying a reciprocal force on the falling object. For ‘large’ objects falling at ‘large’ velocities, like you or I falling through air, this inertial effect is the most important. For small objects falling at low velocities, the frictional effects associated with viscosity are more important. You can see that in the two fluid friction laws we discussed so much earlier in the class:

• Ff fluid = 12πηDv (small/slow)
• Ff fluid = 1/2CρAv2 (large/fast)

https://www2.gwu.edu/~phy21bio/Reading/McKayRealFluids.pdf

 

https://www2.gwu.edu/~phy21bio/Reading/McKayRealFluids.pdf

[cometaryorbit]

I think combining both Windrunners' Adhesion (and Shardplate-related? windspren tricks with air pressure) and Abrasion would do better than either Surge alone.

On 5/26/2023 at 3:20 AM, Walter The Moral said:

Bendalloy savants are able to move with their speed bubbles, which could make that work.

Good point!

So probably for in-atmosphere speed, Steel Compounder Twinborn Windrunner with Abrasion Honorblade and spikes for A-Pewter and A-Bendalloy, and savant of the latter [ideally].

 If you can't get a honorspren to accept Hemalurgy, then either:

- Steel Compounder Twinborn with spikes for A-Pewter and A-Bendalloy, and savant of the latter, 

or

- A-Pewter/F-Steel Twinborn Windrunner with Abrasion Honorblade.

[Argenti he/him]

On 5/28/2023 at 11:05 PM, cometaryorbit said:

- Steel Compounder Twinborn with spikes for A-Pewter and A-Bendalloy, and savant of the latter, 

 

Honor blades don't have issues with spikes, so slap the Windrunner Honorblade and an Abrasion Honorblade on top.

[cometaryorbit]

On 5/30/2023 at 1:24 PM, Argenti said:

Honor blades don't have issues with spikes, so slap the Windrunner Honorblade and an Abrasion Honorblade on top.

Good point! I somehow got so focused on the Windrunner stuff (at least Kaladin's storm-shield trick) involving windspren and thus likely not being available with a Honorblade (since the Windspren are Plate-related) that I somehow dropped the Honorblade(s) completely from the Hemalurgy option. At least the Abrasion from Edgedancer/Dustbringer Honorblade would help. I'm not sure if the "basic" Adhesion effects from the Windrunner Honorblade - without the windspren-related tricks - would give you anything or if that's just Full Lashing 'magic glue'.

Edited June 2, 2023 by cometaryorbit