Abrasion

[QuaN7umVo1D]

Would abrasion be useful for traversing underwater, like could it be used to swim faster?

[Landis963 he/him]

On 2/9/2018 at 11:15 AM, Dunkum said:

but we know specific body parts can be included or excluded when increasing or decreasing friction.  I am not 100% sure about the mechanics of swimming, but it seems like the torso and head could be slicked while the arms and legs remain untouched and you would provide some benefit.

Actually, with the butterfly stroke you could have your arms oscillating back and forth between sticky (pushing water behind you) and normal (returning to starting position) and everything else slick.  This setup also appears to work for any stroke where the arms leave the water, if of course the Radiant in question could keep the rhythm going.  And keep from thinking about it. 

[Shqueeves he/him]

We see someone use it to walk through water easier, so I'd assume so

[Yata he/him]

23 hours ago, Dunkum said:

for that matter in Lift's chapters she mentions that it lets her slide through the air faster, so it stands to reason it would affect water too.

The problem is using Abrasion to lower the friction while you are swimming will mostly stop you from moving and mostly will drive you down.
Sure you could reach the bottom and walk underwater but I believe it's not what the OP meant

[Dunkum he/him]

10 minutes ago, Shqueeves said:

We see someone use it to walk through water easier, so I'd assume so

for that matter in Lift's chapters she mentions that it lets her slide through the air faster, so it stands to reason it would affect water too.

[Landis963 he/him]

1 hour ago, Yata said:

The problem is using Abrasion to lower the friction while you are swimming will mostly stop you from moving and mostly will drive you down.
Sure you could reach the bottom and walk underwater but I believe it's not what the OP meant

Of course, you could go the opposite way - increase the friction so that you have more traction in the water.  

[Dunkum he/him]

but we know specific body parts can be included or excluded when increasing or decreasing friction.  I am not 100% sure about the mechanics of swimming, but it seems like the torso and head could be slicked while the arms and legs remain untouched and you would provide some benefit.

[Calderis he/him]

10 minutes ago, QuaN7umVo1D said:

When did this happen? I've read all three of the main series plus Edgedancer, yet I can't seem to recall this.

The Purelake vision. The color of the armor implies they were a Dustbringer, and Dalinar comments on how the Radiant moved through the water as if it had no purchase on her. 

[Landis963 he/him]

8 minutes ago, QuaN7umVo1D said:

Wouldn't that make it harder to gain speed?

True, but you wouldn't need to gain speed if there was no time pressure or if all you needed to do at the moment was tread water.  Or you could do the oscillating maneuver I mentioned above - swapping between slick and sticky to get the most out of every stroke.  

[The One Who Connects he/him]

14 hours ago, QuaN7umVo1D said:

When did this happen? I've read all three of the main series plus Edgedancer, yet I can't seem to recall this.

It's also in Edgedancer. IIRC, there was even a faint mention of feeling like air and light had no grip on her.

14 hours ago, QuaN7umVo1D said:

Wouldn't that make it harder to gain speed?

From my perspective, no actually. I see it as a game of trade-offs.
More friction would allow you to push off the water with more force, allowing you to speed up faster, while limiting your top-speed.
Less friction would increase your top speed by quite a bit, but if the water can't grip you, you can't push yourself forward.

Consider Yata's point about sinking. If you have no friction with the water, you aren't gonna be able to swim upwards, because you can't push off the water below you. Change up to forwards, and the example still holds.

---

Also, please try not to double(or triple) post. It's better to just respond to everything in one post than to clutter a page with multiple. If you need to add more/respond to someone else, you can edit your existing post to do so.

Edited March 12, 2018 by The One Who Connects

[Dunkum he/him]

A few of these comments seem to suggest that you'd sink without friction, but is that actually true?  it seems like bouyancy is completely independent from friction or hydrodyanmics.  so friction should be able to modify some of the force needed to move through water, but not the force needed to adjust your height specifically.  moving up or down involves both forces, but only one of them is changing because of the abrasion surge.

[Shallan's Ward he/him]

Sorry to butt in like this, wind to theoretically be able to walk in to point the water with Abrasion?

Edited February 17, 2018 by Shallan's Ward
Typo correction

[QuaN7umVo1D]

On 9.02.2018 г. at 3:33 PM, Yata said:

The problem is using Abrasion to lower the friction while you are swimming will mostly stop you from moving and mostly will drive you down.
Sure you could reach the bottom and walk underwater but I believe it's not what the OP meant

The way I was thinking about it is getting enough momentum with a jump and slicking yourself to make the momentum last longer. Its the regaining of momentum that keeps bugging me, because, as you said, you gonna sink hella fast.

[QuaN7umVo1D]

On 8.02.2018 г. at 4:18 PM, Shqueeves said:

We see someone use it to walk through water easier, so I'd assume so

When did this happen? I've read all three of the main series plus Edgedancer, yet I can't seem to recall this.

 

[QuaN7umVo1D]

On 9.02.2018 г. at 5:20 PM, Landis963 said:

Of course, you could go the opposite way - increase the friction so that you have more traction in the water.  

Wouldn't that make it harder to gain speed?

[QuaN7umVo1D]

3 minutes ago, Calderis said:

The Purelake vision. The color of the armor implies they were a Dustbringer, and Dalinar comments on how the Radiant moved through the water as if it had no purchase on her. 

Huh, always thought she was a Lightweaver because of the red colour, but I don't remember the water part, I guess it's a dead giveaway. Thanks mate!

[Calderis he/him]

13 hours ago, The One Who Connects said:

game of trade-offs.
More friction would allow you to push off the water with more force, allowing you to speed up faster, while limiting your top-speed.
Less friction would increase your top speed by quite a bit, but if the water can't grip you, you can't push yourself forward.

I think for a skilled user, it wouldn't be one or the other.

I mean, I picture it no different than moving on land like skating. You increase friction on the points you want to grip and move, and decrease friction elsewhere. 

With the skating example, I see a skilled user lowering the friction on the foot they're "skating" on will having normal friction with the foot that pushes. 

With swimming, I think you'd want to maintain some friction on the torso that avoid sinking like a rock, but fully slick the limbs, save whatever portion is currently "pushing." 

It would be insanely complicated to keep up, but with practice you could probably swim pretty damned fast. 

[Calderis he/him]

8 hours ago, Dunkum said:

A few of these comments seem to suggest that you'd sink without friction, but is that actually true?  it seems like bouyancy is completely independent from friction or hydrodyanmics.  so friction should be able to modify some of the force needed to move through water, but not the force needed to adjust your height specifically.  moving up or down involves both forces, but only one of them is changing because of the abrasion surge.

The issue here, at least in the way I understand the surge working, is that when something is made "slick" with abrasion, things don't actually touch it. It basically makes a pocket of repulsion between the molecules on the surface of whatever is effected that nothing fully penetrates. 

So in water, you would be pressing the molecules of water outward around you. You'd be forcefully displacing the water around your body, and giving it no purchase with which to effect you. So the water has to be able to touch your body in order to allow buoyancy to take effect. 

[Dunkum he/him]

18 hours ago, Calderis said:

The issue here, at least in the way I understand the surge working, is that when something is made "slick" with abrasion, things don't actually touch it. It basically makes a pocket of repulsion between the molecules on the surface of whatever is effected that nothing fully penetrates. 

So in water, you would be pressing the molecules of water outward around you. You'd be forcefully displacing the water around your body, and giving it no purchase with which to effect you. So the water has to be able to touch your body in order to allow buoyancy to take effect. 

but newton's third law says that while you push out on teh water it pushes back in on you, I don't see any reason why that would be suspended here, so the bouyancy effects should still hold

[Yata he/him]

8 hours ago, Dunkum said:

but newton's third law says that while you push out on teh water it pushes back in on you, I don't see any reason why that would be suspended here, so the bouyancy effects should still hold

And a frictionless object would not be pushed back.

It's exactly the same case of Frictionless Lift to be unable to be slowed by the air while she moves around. She pushes on the air but the air is unable to push back on her.

[Dunkum he/him]

12 hours ago, Yata said:

And a frictionless object would not be pushed back.

It's exactly the same case of Frictionless Lift to be unable to be slowed by the air while she moves around. She pushes on the air but the air is unable to push back on her.

I understand the basic concept, but I'm saying that it is not clear that it applies to bouyancy specifically.  the bouyancy equations I have seen only conseder 3 factors: the density of the fluid involved, the accelleration due to gravity, and the volume of fluid displaced.  they don't take into account things like shape or surface area or roughness.  this suggests that  changes to reduce drag from the water would not affect bouyancy.  I'll also note that my brief stint looking into this suggests that bouyancy is caused by pressure differentials.  so the claim that bouyancy wouldn't affect someone coated to become frictionless suggests that fluid pressure in general wouldn't affect them, but that would mean that, for example, lift's ears should pop if she made her whole body frictionless, because she'd be experiencing no air pressure; or that she could safely sink to the bottom of the ocean, because teh pressure would have no effect.  so yes, she can reduce drag and move through air or water more quickly, but it doesn't seem like that should extend to her automatically sinking.