Speculation: Derethil was an Edgedancer

[ecohansen]

The Wandersail was nearly destroyed in the crash, but Derethil and most of his sailors survived.  They found themselves on a ring of small islands surrounding an enormous whirlpool where, it is said, the ocean drains.

....

 

Derethil and his men set sail, and though the winds were still, they rode the Wandersail around the whirlpool, using the momentum to spin them out and away from the islands.

 

As always, apologies if similar ideas have been posted before--I couldn't find any priors.

 

When I read about the Wandersail's escape maneuver, the first thing I thought about was a gravitational assist ( https://en.wikipedia.org/wiki/Gravity_assist) But that wouldn't work, because gravitational assists simply add to your velocity in the direction of the assisting planet's orbit.  Since the whirlpool seems to be a stable, non-moving geological feature of Roshar, no gravitational assist is possible: it will just suck the Wandersail in, or (if the Wandersail was already moving at the whirlpool's escape veocity) alter its direction.

 

But what if there was an Edgedancer or Dustbringer aboard? Someone who could alter the Surge of Abrasion?  Then, the ship could enter the whirlpool, and build up angular velocity around the center equal to that of the water.  Then, the Surgebinder could make the ship frictionless.  The ship would now be decoupled from the water, and would experience no force pulling it towards the center.  It would continue in a straight line, like twirling an Olympic hammer around your head and letting go.

 

Thoughts?

Edited February 13, 2016 by ecohansen

[Oversleep]

Use rowing to counteract force sucking it in, ride the whirlpool until eascepe velocity is reached.

As I read it, there was no way to skip the whirlpool. They had to defeat it to get away from the islands.

[Brightshade the Cunning]

I'm not sure that the surge of abrasion works that way. We only see it used to affect an individual (i.e. lift). And while it might be possible for the surge of abrasion to help them to escape the whirlpool, the amount of investiture necessary to affect the entire ship is probably well beyond the capability of anyone to use, even with a spren to stabilize them.

Edited February 14, 2016 by cljehja

[ecohansen]

Cljehja--Welcome!  Have an upvote!

 

I agree that what I suggest is a stronger use of Abrasion than we've seen yet, but Lift isn't a full Radiant, and we've mostly only seen her push the limits of her Abrasion when she's low on food, and therefore power.  When Lift is climbing, it makes sense that she would alter the Abrasion between her shoes and the wall--so it seems likely that she can alter the friction of things other than her skin.  Let's say she can easily make her whole body Slick.  For the sake of argument, say that each oath offers a 10X-power upgrade.  Three Oaths would then allow you to alter the Abrasion on an item 1000 times the surface area of a human body.  That seems about right for the portion of a sailing ship below the waterline.

 

Oversleep, since the water itself is not escaping the whirlpool, it is obviously moving at a speed below the whirlpool's escape velocity.  So how could the water accelerate the ship to a speed greater than its own? You *COULD* use rowing to accelerate the ship in the same direction as the water--if you rowed fast enough, you would move in progressively-wider orbits and eventually escape. But wouldn't that just be counteracting the whirlpool, rather than "using its momentum?"  And how would you achieve such superpowered rowing?  Kaladin seems to get some Pewter-like strength and speed upgrades, so would you suggest that the Wandersail is manned with Windrunner galley-slaves?

Edited February 14, 2016 by ecohansen

[Oversleep]

Oversleep, since the water itself is not escaping the whirlpool, it is obviously moving at a speed below the whirlpool's escape velocity.  So how could the water accelerate the ship to a speed greater than its own? You *COULD* use rowing to accelerate the ship in the same direction as the water--if you rowed fast enough, you would move in progressively-wider orbits and eventually escape. But wouldn't that just be counteracting the whirlpool, rather than "using its momentum?"  And how would you achieve such superpowered rowing?  Kaladin seems to get some Pewter-like strength and speed upgrades, so would you suggest that the Wandersail is manned with Windrunner galley-slaves?

I feel we need to get some physicist educated in the fluid mechanics here (or some seasoned sailor, but these are even harder to come by). I am not sure about the speed water has in different layers, but it seems that the lower you go the faster the whirlpool rotates (extrapolating from rotating rigid body) [as in the faster you are moving when your ship is there]. So when you're lower you move faster than the water above you; you use rowing to move up the whirlpool and given that you do it fast enough, you can maintain some of the speed you attained while being lower.

Actually, to achieve such rowing, you don't need superpowers, just lots and lots of men. Given they change often, you could fight the whirlpool for some time.

Rowing is the key here, as you're right that water won't accelerate you beyond its own speed, but to escape the whirlpool that big the key is the centrifugal force.

I'm not really qualified to speak about these things as half of that is guessing based on the knowledge from similar branch of physics, but I actually don't know much about fluids.

 

Sometimes I wish I could just mail my problems to some physicists like Brandon does to have them figured out Like, "can a hot enough fire become invisible?". That fire mages stuff I have to put up with

Edited February 14, 2016 by Oversleep

[Brightshade the Cunning]

I agree that what I suggest is a stronger use of Abrasion than we've seen yet, but Lift isn't a full Radiant, and we've mostly only seen her push the limits of her Abrasion when she's low on food, and therefore power. When Lift is climbing, it makes sense that she would alter the Abrasion between her shoes and the wall--so it seems likely that she can alter the friction of things other than her skin. Let's say she can easily make her whole body Slick. For the sake of argument, say that each oath offers a 10X-power upgrade. Three Oaths would then allow you to alter the Abrasion on an item 1000 times the surface area of a human body. That seems about right for the portion of a sailing ship below the waterline.

While you argument for the increase in power is logical, there are a couple of flaws. First, part of gaining access to certain powers is part of an oath, such as lift being able to use regrowth. While this obviously doesn't affect abrasion as she could use that before the oath, the oath doesn't actually seem to increase the power of a surge, just add new abilities. Second, it appears that oaths increase your ability to use surges (makes it easier) rather than increasing their strength, suchh as with Kaladin speaking the second oath the lashings were the same as before, he just seemed to find it more natural.

Also, thanks for the upvote.

Edited February 15, 2016 by cljehja

[ecohansen]

Cljehja, yeah you could easily be right, but I still think I could be right too. Aside from glimpses in Dalinar's visions, we haven't seen a full all-oaths Radiant in action yet, so we can only speculate about how their interaction with a surge differs from a surgebinder's interaction wit it.

Oversleep, I don't understand your comparison to a "rigid body". On a rigid body, for instance a music record, exactly the opposite is true. Think about a spot 2 inches from the center of a record. With each revolution, it needs to move 2*pi*r=2*3.14*2=12.96 inches. A spot 4 inches out needs to move 2*pi*r=2*3.14*4=25.92 inches in the same timespan. If you're twice as far from the center, you need to move twice as fast.

However, you're right about vortices and conical flow. ( http://maxwell.ucdavis.edu/~cole/phy9b/notes/fluids_ch3.pdf). There, total speed varies with the inverse of the radius: an item twice as far from the center is only moving half as fast. However, that increased speed needs to be decomposed into three vectors: one pulling you horizontally towards the center, one moving circularly tangent to the center, and one pulling you down. You can only harvest the speed of the tangent vector; you need to counteract (row against) both the inward and downward vectors. The downward vector's share of the total speed will increase as you move towards the center, and the tangent vector's share of the total speed will decrease.

This is where the math gets too confusing for me. I think that the ratio of the different velocity vectors at any point is dependent on the shape of the whirlpool, so we would need to know the depth of the basin and the radius of the drain-hole. I've gone back and forth on whether or not I can imagine points where you can harvest more energy from the tangent vector than you lose to the other two. Maybe. I'll keep working on the math. But it just doesn't seem likely to me at the moment.

.....

Another way to decouple the ship from the inward pull of the water would be to just pull it out of the water by Lashing it up into the sky, but if the Wandersail could fly than it wouldn't have gotten into the predicament in the first place.

Edited February 15, 2016 by ecohansen

[natc]

While you argument for the increase in power is logical, there are a couple of flaws. First, part of gaining access to certain powers is part of an oath, such as lift being able to use regrowth. While this obviously doesn't affect abrasion as she could use that before the oath, the oath doesn't actually seem to increase the power of a surge, just add new abilities. Second, it appears that oaths increase your ability to use surges (makes it easier) rather than increasing their strength, suchh as with Kaladin speaking the second oath the lashings were the same as before, he just seemed to find it more natural.

Also, thanks for the upvote.

Syl implies Kaladin was always able to shift gravity (I mean he could reverse lash well enough) so we've never really seen someone gain abilities from oaths before. Only thing that ever seems to change is how long their stormlight lasts/how glowy they are.

Besides, you could just put more stormlight into it and get a stronger effect. This isn't stat-bounded RPG magic, it needs more juice to run on the more it is exerted.