Cosmere Physics "lite" AMA

[Sythrin]

19 hours ago, DrPhysics said:

I actually answered that one in another, longer post.

So its air tight? Hmm interesting. So it can be used to create airsealing during a spaceship breach?
But than my question comes up, if they are air tight, than how do explosions work physcily? In "alloy of law" I believe, that Wayne opens a speedbubble to win them time from a suicide bomber. But they new the fire/pressure/energy would still come to them. Would it be just be able to enter but not leave?
If the later is true, what would happen if we create an allomantic grenade and pump it full with a speedbubble, for lets say to make it run for at least in an hour internally.
And than we put a bomb inside it. What would happen? Or open a gas tank that fills it with gas. Would on the edge the gas condense and than leave the bubble again?

Another thing with timebubbles but I am not sure if it is a physicy question is about the movements of bubbles when the allomancer has a significant movement, than the bubbles get that as well. If you are to slow but still are in a vehicle, it could damage it.
If a mistborn opens a smaller slowbubble and a bigger speedbubble and right at the edge, if there is a fast moving object, be it a bullet or something else. Would that object be cut in half or at least stretched or if you do it the other way, smushed together?

19 hours ago, DrPhysics said:

Helium 3 would be useful for power generation, but since you could generate electricity with a simple heat fabrial connected to a Sterling engine, there really wouldn't be a need

Well not sure. Helium-3 could maybe be easier to handle? The heating fabrial would still need to be reguraly stormlight infused and the gem could crack. Would not one time usage to make a 1m^3 block of glay into the massi equivalent of helium 3, not be much better energy production? Bare in my mind, I dont know a lot about helium 3 and how stable it is or how easy it would be to transport or if it has some hazardous dangers.

[DrPhysics he/him]

1 hour ago, Sythrin said:

But they new the fire/pressure/energy would still come to them. Would it be just be able to enter but not leave?

Pressure waves can go through (sound does) without any air crossing the boundary. And maybe explosions have enough energy to break through. We just don't have enough information at this point.

 

1 hour ago, Sythrin said:

Helium-3 could maybe be easier to handle? The heating fabrial would still need to be reguraly stormlight infused and the gem could crack.

Helium 3 is not easier to handle. Regularly infusing with stormlight is much much much easier than containing helium-3 in an environment where fusion can occur. 

 

Using fusion where stormlight is available because we might crack a gemstone would be comparable to saying we should give everyone jetpacks (incredibly complex, expensive, and prone to error) because a car might get a flat tire.

[Through the Living Heir he/him]

One day while I was rather tired (I think I’d done a hard swim work out) I came up with an “ingenious” method of propulsion for Rosharian aircraft. If you had two soulcasters (probably Radiant ones) on your ship, one in the front could soulcast air into osmium, creating a vacuum and reducing friction, while the one at the back could take that osmium and soulcast it back into air, causing a pressure differential that could be used for propulsion. I felt very clever for a few minutes, then realize I was being stupid and a single Windrunner could do so much better. To salvage my proposal, I considered that this method could potentially act as maneuvering thrusters that provide faster acceleration than a single Lashing would. How well does this work, do you think? Is there a better way to use the soulcasting pressure effects? 

[DrPhysics he/him]

55 minutes ago, Ookla the Inquisitive said:

I considered that this method could potentially act as maneuvering thrusters

The active converting isn't probably very useful (the large forward suction would be hard to control), but I can imagine a soulcast-powered rocket. You fill a tank with chuncks of a material that's connected to a nozzle. Soulcaster converts a chunk at a time and the extra pressure is pushed out the nozzle. (This would be particularly useful for a rocket ship).

 

But it might be more efficient (for an airship) to create a fabrial jet engine: an attractor fabrial to pull air in, a heating fabrial to rapidly heat it, then let it expand out the back. Give it a shape that takes advantage of the venturi effect.

Edited November 29, 2024 by DrPhysics

[alder24]

22 hours ago, DrPhysics said:

Pressure waves can go through (sound does) without any air crossing the boundary.

This is wrong because the air is moving in and out of speed bubbles, it crosses the boundary. However, just like a bullet is redirected, air particles are as well.

Spoiler

Kurkistan

What's it like inside a time bubble on a windy day?

Brandon Sanderson

So, I've had to play around a little bit with the air. Air moves in and out, you would still feel it windy, but as I have it you will not feel it from the direction the wind is coming, it will be deflected a little bit. So you might be a little bit in a wind tunnel or something, probably a swirl.

Skyward Chicago signing (Nov. 16, 2018)

 

[DrPhysics he/him]

9 minutes ago, alder24 said:

This is wrong because the air is moving in and out of speed bubbles, it crosses the boundary

I talk about that in the other thread. The only way that would work is if the boundary was actively creating and destroying air molecules, which doesn't match the behavior of anything else crossing the boundary.  Hopefully a space age story will supercede that particular WOB.

[Dofurion]

On 11/28/2024 at 1:46 PM, DrPhysics said:

Where it could be useful would be materials science and/or the semiconductor industry. There are specific alloys and crystal structures that simulations tell us would be more useful that what we have, but the technology to build and test them is very cost prohibitive. So, if a souldcaster could grow something by imagining the exact crystal structure (potentially including gemstones) that could be very useful. (Think commercially available spider silk for bridge construction, or a steel that lets us run plane engines a few degrees hotter, increasing their efficiency).

I was just thinking that the Rosharians have the perfect tools to do the relevant tests on high entropy materials.
My opinion is that the Rosharians could start with fantastic technology (Fabrials) but in the long run they would end up developing the technology that is theoretically possible in real life.

While the Scadrians would start with recognizable technologies, they would eventually develop totally fantastic technology.

SoD2

Spoiler

Composite metal is something that will not exist in reality, and will most likely be alloys of some Godmetal or Feruchemically charged metals.

But I understand that Sanderson's plan is the opposite of what I think.

 

On 11/28/2024 at 1:46 PM, DrPhysics said:

he only other one would be nuclear materials for weapons, but it would be very difficult to soulcast those without killing the soul caster. (You don't want to just stand next to a big chunk of plutonium). Could make for some very scary suicide bombers.

I imagine that fans of [Hafnium 178m2] would be delighted

Edited December 1, 2024 by Dofurion

[Wanguu He/Him]

On 12/1/2024 at 9:05 AM, Dofurion said:

I was just thinking that the Rosharians have the perfect tools to do the relevant tests on high entropy materials.

Haha, this is possible if they can manage to soulcast inidividual atoms at a time! High entropy metals are so hard to pull off because you need to have a homogenous while amorphous mix of metals. If they're somehow capable of soulcasting individual atoms at a time like that, then they would likely be better off at soulcasting nanomaterial structures. It's unclear if radiants using transformation can transform anything into any other element, or just the 16 allomantic metals.

If anything, Soulcasting would be most useful to convert one material to another - you could 3d print something out of plastic (which is faster and cheaper than metal 3d printing) and then convert that to metal.

This, however, leads to a question that will likely never be answered. How does soulcasting transfer the microstructure? We know that soulcast wood still retains the external texture of wood, but if you look under a microscope would it be solid metal? Would there be cells? If not 1:1, would there be grains in the metal, or single crystal?

Sorry for the rant - I am a materials engineer and have long wondered about how soulcasting works at the microscopic scale.

[DrPhysics he/him]

22 hours ago, Wanguu said:

Haha, this is possible if they can manage to soulcast inidividual atoms at a time!

I could see them getting there (either with soulcasting or cohesion) purely because of how useful perfect gemstones are. I can see it starting with someone using cohesion to remove imperfections and/or rejoin cracked gemstones, then building on that knowledge. 

Space age Roshar could have some amazing materials science.