Taldain is Screwed!

[Channelknight Fadran]

Taldain is screwed!

I say this before I do any research because I tend to be wrong about these kinds of things. The original idea for it all came when I was watching Game Theory on Youtube because I was bored. I recalled a certain episode from the very channel about gravity’s relationship with centripetal force. Put simply, your weight here on Earth isn’t actually your mass multiplied by gravity. Your weight here on Earth is slightly more than your mass multiplied by gravity because another force—centripetal force—is preventing gravity from taking complete hold of you. I hope you feel better the next time you weigh yourself because you’re actually slightly fatter than the scale says you are.

Now, I was considering this relationship, and then I suddenly remembered something from the Cosmere. An anomaly, to say the least: A planet trapped in one spot between two stars. According to Arcanum Unbounded, “Taldain is a tidally locked planet trapped between the gravitational forces of two stars in a binary system.” As a concept, this is pretty cool, and the fact that the planet is held in place by equal gravitational pull from two masses makes sense, at least in a pinch.

However, most planets in the universe tend to orbit and star and spin about an axis. Ours (Earth) is one of these. Our gravity is 9.8 meters per second. However, this gravity is fighting alongside this factor.

Factor: Earth is spinning about an axis at 465 meters per second at the equator.

What does this mean?

Well, what this means is that there’s a lot in play that gives us that sensation of being pulled down. In the diagram above that I heartlessly stole from the internet, we get a pretty good idea of what centripetal force does. If that blue dot were you and the axis the Earth’s axis, then by spinning around, your body will attempt to launch off the planet at thousands of miles an hour and be instantly cremated by the buckets of radiation lying around in space. However, your hundred-pound-worth of human flesh is kept firmly on the ground by another force: gravity. These two forces keep each other in check to make sure we aren’t glued to the ground by gravity or launched into space by centripetal force.

So what does this mean for Taldain?

Well… not much.

While centripetal force does keep gravity in check, nothing’s that much different without it. Assuming Taldain has the same gravity as Earth (which is plausible, as Sanderson’s gravity system is incredibly similar to ours), then 135 Kg at the equator with centripetal force amounts to about 134 without. If Taldain happened to have been spinning about an axis but suddenly stopped—which it didn’t—then there would’ve been some chaos (people at the equator being hurled due east faster than the speed of sound, either dying from hitting a mountain or getting severe whiplash followed by enormous tidal waves promptly eliminating everything), but seeing as how that never happened, then it can be assumed that Taldain is safe, right?

Wrong!

Taldain’s two stars are completely different from one another. The “Dayside” star is a huge supergiant star that provides constant noonday sun to the inhabitants. The “Darkside” star is hidden behind a mess of rings which prevents most of its heat from reaching the Darkside. What does this mean? Well, on the Dayside, everything’s regularly hot and dry, as shown by the abundance of white sands. On Darkside, however, everything’s cold and wet. And what happens if you put something super cold next to something super hot?

You get wind!

See, cold air is more dense than warm air. When something dense has the opportunity to disperse, it’ll take it. So the cold side of Taldain is going to constantly rush over to the warm side of Taldain, causing massive planetary winds that’ll blow through any barrier cities. Oceans? Forget about sailing. Those waves are going to be massive.

However… I’m going to give Taldain the benefit of the doubt here. Thousands of massive storms on the border between Dayside and Darkside isn’t actually very realistic. There would be high winds, yes, but there’s never any drastic temperature changes due to the fact that either side has a consistent heat source. It’s quite plausible that equilibrium had been achieved and maybe winds barely even show themselves. It’s possible that Taldain is fine as it is.

However, I have one more trick up my sleeve to hopefully destroy Taldain as we know it. And that has to do with nothing more than the planet itself; how it was created.

Creating a planet that just so happens to be in the perfect habitable zone for not one but two stars is a very strange anomaly. There aren’t a ton of ways to explain this but there are a couple methods.

Method 1: There were once actually three stars in the Taldain system. The one in the middle was of significant less mass than either of the other two. In fact, its mass in comparison to those of the dwarf star and the supergiant was so miniscule that its outer layers were actually sucked away by the other stars. The supergiant simply ate these outer layers, chomping them down like a bag of cheetos. The dwarf star, on the other hand, created a ring out of the collective stardust that it consumed. Once the outer layers were consumed, the star cooled, and what remained became a planet. I find this option intriguing and actually quite plausible—not like the next method, which is unrealistic but also really destructively cool.

Method 2: There were also once three stars in the Taldain system. One, however, had a lot more mass than the other two. This star did the opposite of the Method 1, and instead of getting its surface stripped away, chowed down on the stars nearby. Eventually, something (I dunno what) happened, and a ton of its mass was stripped away to form its moon. Over the process of time (a lot of time), this star cooled into a planet, but it continues to strip away at either star, as is the process of receiving Investiture from the shard Autonomy. This option is incredibly unrealistic because if anything Taldain should have the other two stars orbiting it, not the other way around. However, that could actually be a possibility, in retrospect—instead of being trapped between two stars, two stars are trapped by Taldain, who orbit it at such a perfect rate that they appear to be in the same place 24/7

Either way, though, I haven’t spelled doom for the Taldain people. At the end of the day, my clickbait title wasn’t true. Taldain is perfectly fine.

Unless I’m wrong, which I usually am about these things! Feel free to inform me about other forces caused by a lack of centripetal force or the consequences of being nearby a supergiant star! Until then, I’m going to continue teaching my seminar on High Imperial.

Sincerely,

Channelknight

[18th Shard he/him]

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Necarion

Is Taldain orbiting at a Lagrangian point? *Brandon laughs* It would make the orbits work.

Brandon Sanderson

*long pause* I'm not sure the implications, I have to think through implications before answering questions.

Necarion

The situation I'm thinking of, it would orbit the big star but at the same period as the smaller star.

Brandon Sanderson

Yeah, well, I'll just say "yes", but I want to make sure I'm not saying "yes", without...well, yes that's how it has to work.

Necarion

Right.

Brandon Sanderson

Because [Taldain] I want to be not like Roshar where we have unstable orbits and things. Uh, but I… I'm saying yes, but I hope that doesn't get me into trouble scientifically.

Arcanum Unbounded San Francisco signing (Nov. 30, 2016)

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Questioner

Will we ever get an explanation about the cosmological feasibility of the world [Taldain]?

Brandon Sanderson

Oh, the cosmological feasibility of a tidally locked planet between two stars?

Questioner

We have one of those in our solar system, and it's not very habitable.

Brandon Sanderson

Yeah, *crowd laughs* the nice thing about the cosmere is I can do planets that would not work in a large scale way because I can hang something and say, "This orbit will degrade in two million years, but it was created and placed there," right? Which allows me to create planets that on a geologic timescale are not stable, but are stable on a rise and fall of human civilizations scale. And that's one of the advantages of being in fantasy, is I can go back to that. Like I try to be rule based when I can, but I also have magic and things that can interfere. So the answer is that. *crowd laughs* We know it's-- I mean, I don't think Roshar's moons are stable on a geologic timescale either. I think they're too close. There's a bunch of stuff in the cosmere that is not stable if you look at tens of millions of years, but it's just fine for a million or two years.

White Sand vol.1 release party (June 28, 2016)

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Paleo

The placement of Taldain, the solar system, was it done by someone?

Brandon Sanderson

So...Taldain, yes.

Paleo

Has it to do with the travel in the Cognitive Realm?

Brandon Sanderson

Not 100%. That's a side effect

Leipzig Book Fair (March 24, 2017)

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BlackYeti

How did you get the temperature differential between the two halves of the planet such that life could survive on both sides and travel between them?

Brandon Sanderson

Right, yeah. We've got a couple things going on here that are helping with it. The thing about Darkside is-- And I've had to run this through my physicists, and they're all kind of "Ehhh", so we're still working on the physics-- But the idea is there is a light source over there, but it works like a black light. And so, there's warmth, and there's radiation, and that's why people over there are dark-skinned. They've actually adapted to this radiation, there's a lot of UV and things like that. But there is-- It works like a black light. So for a Daysider going over, it's all-- it feels dark and dim, but it's more twilight-ish than it is completely dark, if that makes sense. And with that and with... jet-streams and stuff we were able to kind of justify it mostly. I mean, it's still going to be colder on the other side and things. But I didn't want it to be like snowing and things like that, all the time over there. And so we kind of had to do some jumping through hoops astrologically to make it work.

Manchester signing (Aug. 6, 2014)

 

[Karger he/him]

20 hours ago, Channelknight Fadran said:

There aren’t a ton of ways to explain this but there are a couple methods.

You missed one method and I am afraid that it is the method used in this case.  God literally decided that a planet there would be cool so they put it there(as above WoBs demonstrate). 

[Weltall]

Yeah, Taldain is basically an example of 'God Did It' and results in a system that isn't stable across geological or astronomical timeframes but is stable enough for the relatively short span of time that Brandon is working with. Unfortunately, Adonalsium is dead so nobody can ask why they set things up that way. Ditto Roshar with its slowly eroding continent and unstable moons. At least in that case, we know there was a reason the Rosharan System was set up that way, we just don't know what it was yet.

[Koloss17 She/They]

On 5/29/2020 at 7:33 PM, Weltall said:

Yeah, Taldain is basically an example of 'God Did It' and results in a system that isn't stable across geological or astronomical timeframes but is stable enough for the relatively short span of time that Brandon is working with. Unfortunately, Adonalsium is dead so nobody can ask why they set things up that way. Ditto Roshar with its slowly eroding continent and unstable moons. At least in that case, we know there was a reason the Rosharan System was set up that way, we just don't know what it was yet.

Ah yes, the almighty “a wizard did it” but from a celestial level (I hope this contributes, and is not just upping my post count, cuz I don’t want to be that kind of person).

[Weltall]

1 hour ago, Koloss17 said:

Ah yes, the almighty “a wizard did it” but from a celestial level (I hope this contributes, and is not just upping my post count, cuz I don’t want to be that kind of person).

Ehhhh, I'm not sure it does but I approve of your Ambition all the same.

[Spren of Kindness she/her]

I don't really know much about planetary science, but I think you're right.  I'm rather fond of the idea that Taldain will one day get pulled into one of it's suns, but again I don't know physics.

So one day Roshar's moons are going to do something?  And where did the stuff about Roshar degrading come from?  Can anyone point me towards that?

[Honorless he/him]

What types of stars are those two anyway?

I was thinking that the Darkside star might be a white dwarf but would a white dwarf be able to sustain a binary system like this and if so for how long? (Looks unhappily at WoP regarding Rosharan moons). Because why would a star be so dim, is it all because it's obscured by the particulate ring? What is that supposed to be? A protoplanetary disk?

I was thinking maybe the other star is like a supergiant or a red giant (which it probably isn't, since it's blue), but that would make it a variable star and people on Dayside would notice that.

These two stars shouldn't be in such a close to perfectly circular orbit much less have a planet dead centre between them, tidally locked.

Edited August 21, 2020 by Honorless

[Weltall]

12 hours ago, Spren of Kindness said:

ISo one day Roshar's moons are going to do something?  And where did the stuff about Roshar degrading come from?  Can anyone point me towards that?

Word of Brandon that Roshar's moons are unstable and the continent might eventually vanish, and a more specific one here. And a more detailed Word of Peter on the moons.

So yeah, the system as we know it is not stable on an astronomical timeframe but on the timeframe that Brandon's working with from whenever Adonalsium created the system to the end of the saga, it's stable enough. The same is true for Taldain.

2 hours ago, Honorless said:

What types of stars are those two anyway?

Per Khriss in Arcanum Unbounded, blue-white supergiant (O-type?) and a dim white dwarf.

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I was thinking that the Darkside star might be a white dwarf but would a white dwarf be able to sustain a binary system like this and if so for how long?

Literally Goddidit and it's not supposed to be sustainable. Asking too many questions will probably make your head explode. Or get you a visit from one of Autonomy's avatars.

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These two stars shouldn't be in such a close to perfectly circular orbit much less have a planet dead centre between them, tidally locked.

See previous answer. Also, per Isaac the charts are not meant to be perfectly accurate. I'd give that one a read, it's quite interesting how he came up with them.