The Science of Worldbuilding

[Eagle of the Forest Path he/him]

11 hours ago, StrikerEZ said:

It's about 304 square miles, and about 10,000-15,000 feet tall. They're not sheer cliffs, but it is a very steep angle.

Wow! That's like, half as tall as Mount Everest. (Discounting that Everest is on a plateau, so it's not actually 30,000 feet from foot to top)

11 hours ago, StrikerEZ said:

I actually hadn't thought about what rock they'd be made of. It doesn't really matter what type of rock they are, except I guess to determine how sturdy it is. What do you recommend would be the best type of rock to use?

That depends on what you want. Granite or basalt are sturdiest, so you can dig out more without compromising the structure and house a larger population. But if you use weaker rocks like sandstone or even limestone, you can add more risk of cave-ins, which is something you might like in the story.
I suggest that you first figure out what you need from the stone for the story, then find a geologist or engineer to work out what materials work best for that.
The alternative is that you decide on the material(s) first, then find the geologist or engineer to work out what that means for the story.

11 hours ago, StrikerEZ said:

Yeah, I have a plan for that. The magic on that world really helps with ventilation, lighting, food, etc.

Okay, then! But what happens if the magic fails?

[StrikerEZ he/him]

5 minutes ago, Eagle of the Forest Path said:

Wow! That's like, half as tall as Mount Everest. (Discounting that Everest is on a plateau, so it's not actually 30,000 feet from foot to top)

Yeah, they’re meant to be pretty tall. They’re a product of both natural and magical creation.

10 minutes ago, Eagle of the Forest Path said:

That depends on what you want. Granite or basalt are sturdiest, so you can dig out more without compromising the structure and house a larger population. But if you use weaker rocks like sandstone or even limestone, you can add more risk of cave-ins, which is something you might like in the story.
I suggest that you first figure out what you need from the stone for the story, then find a geologist or engineer to work out what materials work best for that.
The alternative is that you decide on the material(s) first, then find the geologist or engineer to work out what that means for the story.

My current inclination towards granite and basalt right now, because I don’t really like the idea of cave-ins lol. It’d be interesting to add them, but I’ll probably go for safety and higher population. 

5 minutes ago, Eagle of the Forest Path said:

Okay, then! But what happens if the magic fails?

(There’s probably a SA joke there)

Well, the way the magic system works, it’d be hard to crash an entire ventilation or plumbing system. 

[Eagle of the Forest Path he/him]

2 minutes ago, StrikerEZ said:

(There’s probably a SA joke there)

Elantris, actually.

[StrikerEZ he/him]

3 minutes ago, Eagle of the Forest Path said:

Elantris, actually.

Ah, okay. I get that one.

Yeah, magic is kind of hard to make fail in my universe. People can fail at using it, but that’s their fault, not the magic’s fault. 

[StrikerEZ he/him]

Okay, I need your help again guys @Silverblade5 @Glamdring804 @Eagle of the Forest Path @The One Who Connects

I'm coming up with an alien species, and I know that I want them to see in either UV light or infrared light. What type of star would be needed for each scenario, and how would that affect life on each version of the planet?

[Glamdring804]

9 hours ago, StrikerEZ said:

Okay, I need your help again guys @Silverblade5 @Glamdring804 @Eagle of the Forest Path @The One Who Connects

I'm coming up with an alien species, and I know that I want them to see in either UV light or infrared light. What type of star would be needed for each scenario, and how would that affect life on each version of the planet?

So if a species evolved in the starlight of a particular star, then their visible spectrum will naturally be centered on the most intense wavelengths produced by that star. Those wavelengths would be the most useful on their planet, since they would be the brightest, and contain the most visual information. Our sun emits light mostly in the visible spectrum, obviously. The brightest colors are yellow and green.

The color of a star's light is a function of its temperature, which is in turn a function of its size. Smaller, dimmer stars have a strong reddish hue, and bigger, brighter stars have a strong blue hue. So if you want aliens to see in infrared light, then they probably come from a planet orbiting a red dwarf. If you want aliens that see in ultraviolet, they probably come from a planet orbiting a blue or blue-white supergiant.

There is, however, an issue with the second scenario. A star's lifetime is inversely proportional to its size. Meaning, the larger the star is, the higher the internal pressure, and the exponentially faster it burns through its fuel source. Extremely large stars have lifespans of only a few million years (as opposed to our sun's lifespan of roughly 10 billion years). This isn't nearly enough time for life to evolve from scratch on the star's planets. Any life that arises there would have to have been seeded from somewhere else shortly after the planet was formed, in order to evolve eyesight before the star's death.

[StrikerEZ he/him]

On 6/3/2018 at 9:40 AM, Glamdring804 said:

So if a species evolved in the starlight of a particular star, then their visible spectrum will naturally be centered on the most intense wavelengths produced by that star. Those wavelengths would be the most useful on their planet, since they would be the brightest, and contain the most visual information. Our sun emits light mostly in the visible spectrum, obviously. The brightest colors are yellow and green.

The color of a star's light is a function of its temperature, which is in turn a function of its size. Smaller, dimmer stars have a strong reddish hue, and bigger, brighter stars have a strong blue hue. So if you want aliens to see in infrared light, then they probably come from a planet orbiting a red dwarf. If you want aliens that see in ultraviolet, they probably come from a planet orbiting a blue or blue-white supergiant.

There is, however, an issue with the second scenario. A star's lifetime is inversely proportional to its size. Meaning, the larger the star is, the higher the internal pressure, and the exponentially faster it burns through its fuel source. Extremely large stars have lifespans of only a few million years (as opposed to our sun's lifespan of roughly 10 billion years). This isn't nearly enough time for life to evolve from scratch on the star's planets. Any life that arises there would have to have been seeded from somewhere else shortly after the planet was formed, in order to evolve eyesight before the star's death.

Okay, so what you're saying is that better scenario is for the aliens to see in infrared, I need them to evolve on a planet that revolves a dwarf star?

What other qualities would need the planet need to have in order to develop life? What qualities would the life there tend to have?

[Glamdring804]

4 hours ago, StrikerEZ said:

Okay, so what you're saying is that better scenario is for the aliens to see in infrared, I need them to evolve on a planet that revolves a dwarf star?

What other qualities would need the planet need to have in order to develop life? What qualities would the life there tend to have?

I'm saying it would be far easier for an infrared seeing civilization to evolve around a red dwarf without external intervention. The other direction would be difficult without some sort of head start.

Well for starters, any plant life would likely be very dark in coloration. It also might be red in hue, as it would have adapted to the redder sunlight. Also, the habitable zone around red dwarfs is small enough that any planet  in the habitable zone would likely be tidal locked (kinda like Taldain). So it wouldn't have days and nights. Instead, one side would be a scorching desert, the other would be a frozen wasteland, and in the twilight region in between would be a strip of habitable land. Such a planet also wouldn't have a moon, unless there was external intervention, as is the case with Taldain.

Other than that, I'm not really sure how life would evolve. Other traits would depend on other factors, like how large the planet is, etc.

[StrikerEZ he/him]

19 hours ago, Glamdring804 said:

I'm saying it would be far easier for an infrared seeing civilization to evolve around a red dwarf without external intervention. The other direction would be difficult without some sort of head start.

Well for starters, any plant life would likely be very dark in coloration. It also might be red in hue, as it would have adapted to the redder sunlight. Also, the habitable zone around red dwarfs is small enough that any planet  in the habitable zone would likely be tidal locked (kinda like Taldain). So it wouldn't have days and nights. Instead, one side would be a scorching desert, the other would be a frozen wasteland, and in the twilight region in between would be a strip of habitable land. Such a planet also wouldn't have a moon, unless there was external intervention, as is the case with Taldain.

Other than that, I'm not really sure how life would evolve. Other traits would depend on other factors, like how large the planet is, etc.

Okay, that makes more sense. There is a bit of external influence on the evolution of the sapient species, but I want to keep it as realistic as possible. I want it that, without the intervention, the species could've evolved there naturally.

Hmm...could you describe a bit more how that whole tidally locked thing works? How much of a planet that is roughly earth-sized would be habitable? How many people could possibly live in this habitable zone?

Thank you so much for your help!

Edited June 5, 2018 by StrikerEZ

[Glamdring804]

5 hours ago, StrikerEZ said:

Okay, that makes more sense. There is a bit of external influence on the evolution of the sapient species, but I want to keep it as realistic as possible. I want it that, without the intervention, the species could've evolved there naturally.

Hmm...could you describe a bit more how that whole tidally locked thing works? How much of a planet that is roughly earth-sized would be habitable? How many people could possibly live in this habitable zone?

Thank you so much for your help!

Well, the basic concept is that one face always receives sunlight, and the other never does. Regarding specific numbers, I actually don't know exactly how large the habitable band would be. It would depend on a lot of things, like how much water the planet has, how thick the atmosphere is, where the mountains are, etc. For an earth-sized planet, it would probably contain at least a continent's worth of land, since the band goes all the way around the circumference of the planet.

[StrikerEZ he/him]

7 hours ago, Glamdring804 said:

Well, the basic concept is that one face always receives sunlight, and the other never does. Regarding specific numbers, I actually don't know exactly how large the habitable band would be. It would depend on a lot of things, like how much water the planet has, how thick the atmosphere is, where the mountains are, etc. For an earth-sized planet, it would probably contain at least a continent's worth of land, since the band goes all the way around the circumference of the planet.

Okay, thank you so much! 

[Lunarhade]

Hi, very new, not sure at all if I'm doing this right, but reading through some of the questions and responses on here I realized these are the kind of conversations I've been craving but lack science people in my life.

So  @Glamdring804 I have a question I would love to get a physics perspective on if it's not too much trouble.

In one of my stories, there is a kind of magical nanotechnology capable of synthesizing any one kind of energy from light and also the inverse (produce light by siphoning any one kind of energy). This material is so efficient that for all intents and purposes it breaks the laws of thermodynamics (very slow entropy).

One of the chief aims of this magitech is to allow for suspension. On cursory inspection, it makes sense to me that potential gravitational energy being converted almost instantly into light before it can become kinetic energy could create suspension. I want to know, does that make enough sense that it wouldn't nag at you? Does your brain do what my brain did and realize that potential gravitational energy is not as tangible let's say heat, which as I understand it is a result of particles bumping into one another. The problem arises when I see potential gravitational energy, in essense, as no different than the earth creating kinetic energy through gravity. And I want to have ships capable of flight with this magitech, which raises the question: if the kinetic energy (from the planet's gravity) of the system is being turned into light, then it would stand to reason that any other source of kinetic energy (engines, wind) would also be absorbed by the material before it can result in movement. A flying ship that can't move forward is a problem. 

Is there a loophole in physics? A different way to think of energy that could allow me to justify a suspended object's gravitational potential being canceled out but still being able to be propelled around?

[Glamdring804]

9 hours ago, Lunarhade said:

Hi, very new, not sure at all if I'm doing this right, but reading through some of the questions and responses on here I realized these are the kind of conversations I've been craving but lack science people in my life.

So  @Glamdring804 I have a question I would love to get a physics perspective on if it's not too much trouble.

In one of my stories, there is a kind of magical nanotechnology capable of synthesizing any one kind of energy from light and also the inverse (produce light by siphoning any one kind of energy). This material is so efficient that for all intents and purposes it breaks the laws of thermodynamics (very slow entropy).

One of the chief aims of this magitech is to allow for suspension. On cursory inspection, it makes sense to me that potential gravitational energy being converted almost instantly into light before it can become kinetic energy could create suspension. I want to know, does that make enough sense that it wouldn't nag at you? Does your brain do what my brain did and realize that potential gravitational energy is not as tangible let's say heat, which as I understand it is a result of particles bumping into one another. The problem arises when I see potential gravitational energy, in essense, as no different than the earth creating kinetic energy through gravity. And I want to have ships capable of flight with this magitech, which raises the question: if the kinetic energy (from the planet's gravity) of the system is being turned into light, then it would stand to reason that any other source of kinetic energy (engines, wind) would also be absorbed by the material before it can result in movement. A flying ship that can't move forward is a problem. 

Is there a loophole in physics? A different way to think of energy that could allow me to justify a suspended object's gravitational potential being canceled out but still being able to be propelled around?

Okay, so let me take a crack at this.

First off, I need to explain a fairly common physics misconception that you seem to have fallen into. Energy is not "stuff." There is no tangible quantity called energy that can be taken and isolated on its own. Rather, energy is a quality of matter. It's an intrinsic property that all objects have in some form or another, like color or mass. Things can have energy, but without that matter, the energy just isn't there. You can store energy by arranging matter into specific configurations, like chemicals in a battery, or raising the counterweight of a trebuchet.

In order to keep something levitated, you couldn't just suck the kinetic energy out of an object and convert it into light. Energy doesn't work that way. To hold the object up, you need to somehow push against it. However, if your magic system works by pushing energy around and such, there is another way you could cause something to levitate via energy alone. The concept is similar to how the surge of Gravitation works in Stormlight Archive: You would use energy to manipulate the curvature of spacetime. Objects, in general, tend to go from places of high potential energy to low potential energy. Something in far Earth orbit has way more potential energy via it's position, than something on Earth's surface. So, the Earth's gravity tends to pull it towards the planet. With advanced enough technology, you might be able to manipulate the fundamental constants of the universe, so that you create a barrier of extremely high potential between the object and the Earth, essentially making it so gravity no longer points down on the object. Doing so, however, would require you to somehow manipulate the constants that dictate the gravitational force for whatever is powering the levitation. And a civilization that's advanced enough to do that would basically be God.

Does this make any sense to you? This is some pretty difficult concepts here, including some stuff that's way above my current level. Energy is one of the most misunderstood physics concepts. It's difficult to learn eve with an entire semester of physics classes.

[Lunarhade]

First of all, thank you very much for taking the time to respond,

This is kind of what I was worried about, energy is too intangible to treat the way I want to treat it with the magitech. I wanted to stray away from manipulating forces as not to stride too close to Stormlight, but I recognize Brandon chose them for a reason. I imagine things would be easier if I changed the scope of the nanotech to manipulate forces directly, but perhaps not. As I understand it you are saying it is not the combination of potential and kinetic that makes things fall, those are just the properties we label things being acted upon forces that do make things fall. For the thought experiment (assuming we ignore the weirdness of a force being transformed into light) could I justifiable say the force of gravity on the system is being siphoned away, thus weightlessness? 

What you said about matter requiring energy. With this system, I imagined also that I could transform light into kinetic energy. For example, a gun which works by transferring absorbed light from a ring on the outside of the gun into the base of the bullet made of the same magical material, thus allowing for it to be propelled? If true, then this could potentially be the solution to levitation, as the thing that counters gravity like drag does on planes.

PS
For context magitech's source stems from an interdimensional species who for all intents and purposes are gods. The people of this universe stole and then forgot much of what that species could do. So basically a lot of the time they are hijacking technology they don't understand and that's how I balance the fact it is God-like.

PSS

Thank you again, I have been starved for people willing to have conversations like these, its why I finally took the plunge and joined on here.

[Glamdring804]

18 hours ago, Lunarhade said:

First of all, thank you very much for taking the time to respond,

This is kind of what I was worried about, energy is too intangible to treat the way I want to treat it with the magitech. I wanted to stray away from manipulating forces as not to stride too close to Stormlight, but I recognize Brandon chose them for a reason. I imagine things would be easier if I changed the scope of the nanotech to manipulate forces directly, but perhaps not. As I understand it you are saying it is not the combination of potential and kinetic that makes things fall, those are just the properties we label things being acted upon forces that do make things fall. For the thought experiment (assuming we ignore the weirdness of a force being transformed into light) could I justifiable say the force of gravity on the system is being siphoned away, thus weightlessness? 

What you said about matter requiring energy. With this system, I imagined also that I could transform light into kinetic energy. For example, a gun which works by transferring absorbed light from a ring on the outside of the gun into the base of the bullet made of the same magical material, thus allowing for it to be propelled? If true, then this could potentially be the solution to levitation, as the thing that counters gravity like drag does on planes.

PS
For context magitech's source stems from an interdimensional species who for all intents and purposes are gods. The people of this universe stole and then forgot much of what that species could do. So basically a lot of the time they are hijacking technology they don't understand and that's how I balance the fact it is God-like.

PSS

Thank you again, I have been starved for people willing to have conversations like these, its why I finally took the plunge and joined on here.

The way I would do it is say that the magitech manipulates the properties of space-time in the region the object occupies, and fiddles with the fundamental constants, causing the force of gravity to go away. You're mostly correct in your interpretation of forces and potential energy. The best way I've had it described to me, is that energy is an object's capacity to do damage. There are a lot of different ways something can do damage. An object can have the capacity to deal damage based on its position, like a boulder at the top of a cliff, or two magnets with their north poles held close together. We call this "potential energy" because the object doesn't directly manifest its energy, but it has the potential to do so, given the proper nudge. Things can also directly have energy, most commonly because of their movement. i.e. a bullet has the capacity to do damage via moving really fast, and a hot poker has the capacity to do damage because its individual atoms are moving really fast.

The light-into-kinetic energy thing is actually really easy. We already see a similar effect in the real world. Photons have momentum, which means they can push on objects and impart their energy into them, a process that usually involves the absorption and/or re-emission of the photon. Solar sails are a proposed interplanetary propulsion method. This could also very much be used to levitate objects. Your proposed method doesn't immediately break anything in the way your other idea did.

In fact, by sourcing the magic from a place that's outside our universe, you have leave to do pretty much anything you want with it. If it's outside our universe, then it's not constrained by our conventional laws of physics. So yeah, that totally works.

Glad I could help.