Do Rosharans have it harder on other planets because of the higher gravity and less oxygen?

[Sythrin]

Just started the series „the expanse“. People that live in space, have problems living on planets. And asked myself if Rosharans have the same problems?

[KaladinsSenseOfHumourSpren He/Him]

It would be interesting if they did, and I certainly think they should, but we don't see it anywhere. Sigzil was fine on other planets, though that was probably the Dawnshard. I don't think we've seen any other Rosharan worldhoppers.

[Ookla the Newt she/her]

If Rosharans were to have the same problem, would Connection shenanigans fix it?

I'm pretty sure if the problem were to be present, it would happen the other way around, but there are several Nalthian or Scadrian worldhoppers who don't seem to struggle with the lower oxygen / higher gravity. Might be bc of acclimization though, so not sure.

[Myst He/Him]

I’m pretty sure that it’s the other way around, Roshar has less gravity, and more oxygen

arcanum unbounded 

Spoiler

In the silverlight summary of the system it says that roshar is 0.6 cosmere standard in size, so smaller planet, smaller gravity. It also mentions that they have higher oxygen levels, and so fire behaves weirdly, making them use spheres for light instead 

Edit: wait, I misunderstood the comment, you’re asking if they have it harder on other planets because of the lower oxygen and high gravity there. My bad

In answer to that though, I don’t think it would matter, as most worldhoppers are invested in some way, and so would be able to ignore any problems they would otherwise have

Edited October 24, 2025 by IHadAThought
Mistakes

[Nitpicking]

5 hours ago, KaladinsSenseOfHumorSpren said:

It would be interesting if they did, and I certainly think they should, but we don't see it anywhere. Sigzil was fine on other planets, though that was probably the Dawnshard. I don't think we've seen any other Rosharan worldhoppers.

It is widely (or maybe narrowly?) believed that we see some Skybreakers on Scadrial at the end of The Lost Metal. The "coinshots" Steris meets at the end of the book during the Sanderlanche, who specifically ask about whether it would be legal to act and use a power that Skybreakers have, flinging themselves through the air. Brandon sort of half-denied it.

https://wob.coppermind.net/adv_search/?query=skybreakers+"the+lost+metal"&date_from=&date_to=2025-10-25&speaker=&ordering=-date#15986

[KaladinsSenseOfHumourSpren He/Him]

5 hours ago, Nitpicking said:

It is widely (or maybe narrowly?) believed that we see some Skybreakers on Scadrial at the end of The Lost Metal. The "coinshots" Steris meets at the end of the book during the Sanderlanche, who specifically ask about whether it would be legal to act and use a power that Skybreakers have, flinging themselves through the air. Brandon sort of half-denied it.

https://wob.coppermind.net/adv_search/?query=skybreakers+"the+lost+metal"&date_from=&date_to=2025-10-25&speaker=&ordering=-date#15986

Interesting

But I guess any difference could be nullified by stormlight

Of course, a Scadrian pewterarm could probably beat a Radiant not using their Surges, because some stormlight strength is being used to resist gravity.

I'd be cool to see that battle

[Nitpicking]

13 hours ago, KaladinsSenseOfHumorSpren said:

Interesting

But I guess any difference could be nullified by stormlight

Well, except there is no more Stormlight.

[KaladinsSenseOfHumourSpren He/Him]

4 minutes ago, Nitpicking said:

Well, except there is no more Stormlight.

Oh right.

Towerlight then, if that's still working.

Lifelight for Lift, if that's also still working with Cultivation gone.

[Nitpicking]

3 minutes ago, KaladinsSenseOfHumorSpren said:

Lifelight for Lift, if that's also still working with Cultivation gone.

It'll be interesting when Lift realizes she can give Lifelight to other Radiants, and everyone starts piling food up around her and asking her to please, please fill gemstones so they can do stuff.

[Trusk'our he/him]

52 minutes ago, Nitpicking said:

It'll be interesting when Lift realizes she can give Lifelight to other Radiants, and everyone starts piling food up around her and asking her to please, please fill gemstones so they can do stuff.

Can the typical Radiant use Lifelight? Lift herself cannot substitute Stormlight for her Lifelight, so it's possible the reverse is true for others.

Spoiler

https://wob.coppermind.net/events/32-arcanum-unbounded-fort-collins-signing/#e8073

Laryyl (paraphrased)

[Can Lift] get Stormlight from spheres like normal or if it's just from food for her.

Brandon Sanderson (paraphrased)

She can only get it from food.

Laryyl (paraphrased)

Which [is it] related to her boon or her curse?

Brandon Sanderson (paraphrased)

RAFO.

 

[DoctaDajman]

On 10/24/2025 at 2:24 PM, Sythrin said:

Just started the series „the expanse“. People that live in space, have problems living on planets. And asked myself if Rosharans have the same problems?

I would say they would have to adjust to it. A world hopper who gets into Scadrial will probably have a little while feeling like total garbage and have to acclimate. Even with stormlight keeping them alive I think they would still find themselves weaker than the average Scadrian. Stormlight doesnt give strength so much as it heals your body so quickly that it can push itself to 100% capacity where the average person uses like 70% of it thanks to the Body preserving itself.  Being able to instantly heal through tears and rips really allows an increase of strength but it isn't more than just perfecting what that person can do if their mind would allow it. 

But I think it would be a little like the issues I see with people building portals from sea level to the top of everest. They should technically throw massive air emboli. 

[NeverTrustAesSedai He/Him]

2 hours ago, Trusk'our said:

Can the typical Radiant use Lifelight? Lift herself cannot substitute Stormlight for her Lifelight, so it's possible the reverse is true for others.

  Reveal hidden contents

https://wob.coppermind.net/events/32-arcanum-unbounded-fort-collins-signing/#e8073

Laryyl (paraphrased)

[Can Lift] get Stormlight from spheres like normal or if it's just from food for her.

Brandon Sanderson (paraphrased)

She can only get it from food.

Laryyl (paraphrased)

Which [is it] related to her boon or her curse?

Brandon Sanderson (paraphrased)

RAFO.

 

WoB

Spoiler

Questioner

Has there ever been a Radiant besides a Bondsmith that has used Lifelight before Lift?

Brandon Sanderson

RAFO.

JordanCon 2021 (July 17, 2021)

Given that he didn't give this an outright No, it's not ruled out as a possibility, I guess? However, I don't find it likely. Presumably it wouldn't be built into the Surgebinding system, as they would never have seen a need for it. There may be a workaround, but again, I find that unlikely.

[Nitpicking]

14 hours ago, NeverTrustAesSedai said:

Given that he didn't give this an outright No, it's not ruled out as a possibility, I guess? However, I don't find it likely. Presumably it wouldn't be built into the Surgebinding system, as they would never have seen a need for it. There may be a workaround, but again, I find that unlikely.

Navani is a Bondsmith and a fabrial engineer.  She could hack the magic system.

But I was kidding.

[Qianweilian He/him]

On 10/24/2025 at 4:53 PM, IHadAThought said:

arcanum unbounded 

  Hide contents

In the silverlight summary of the system it says that roshar is 0.6 cosmere standard in size, so smaller planet, smaller gravity. It also mentions that they have higher oxygen levels, and so fire behaves weirdly, making them use spheres for light instead 

Actually, it doesn't say that, the numbers are a bit different: (pg 535 on kindle)

Quote

At 0.7 cosmere standard in gravitation and 0.9 in size—and possessing a high-oxygen environment—Roshar

La Paz, Bolivia is at about 12,000 meters about sea level. According to a study Google found, high-altitude pulmonary oedema develops in about 15.5% of the population when ascending 5,500 m by airlift. Untreated HAPE has approximately a 50% fatality fate. Fortunately, none of the Rosharans are going to be going to Scadrial instantly, (except Hoid in WaT), but even elevation changes in our world have a dramatic effect. Roshar has a lot of oxygen, fire is mentioned as being dangerous and unpredictable for worldhoppers (who at the time of Arcanum Unbounded are sure to have seen some stuff), something it's not even close to being at sea level. Luckily for Rosharans everywhere, Shadesmar travel between planets is not short, and (IoTE spoilers)...

Spoiler

even with the Dynamic, it takes the crew 10 days to get back to Silverlight from...wherever they were.

Hypothetical travelers are going to have enough time to acclimate. If instant teleportation is ever developed across planets for relatively non-invested individuals (before healing minds/fabrials become commonplace), Rosharans could be in lethal trouble.

Edited October 27, 2025 by Qianweilian
wrote "trailers" instead of "travelers" for some reason...

[DoctaDajman]

2 hours ago, Qianweilian said:

Actually, it doesn't say that, the numbers are a bit different: (pg 535 on kindle)

La Paz, Bolivia is at about 12,000 meters about sea level. According to a study Google found, high-altitude pulmonary oedema develops in about 15.5% of the population when ascending 5,500 m by airlift. Untreated HAPE has approximately a 50% fatality fate. Fortunately, none of the Rosharans are going to be going to Scadrial instantly, (except Hoid in WaT), but even elevation changes in our world have a dramatic effect. Roshar has a lot of oxygen, fire is mentioned as being dangerous and unpredictable for worldhoppers (who at the time of Arcanum Unbounded are sure to have seen some stuff), something it's not even close to being at sea level. Luckily for Rosharans everywhere, Shadesmar travel between planets is not short, and (IoTE spoilers)...

  Hide contents

even with the Dynamic, it takes the crew 10 days to get back to Silverlight from...wherever they were.

Hypothetical travelers are going to have enough time to acclimate. If instant teleportation is ever developed across planets for relatively non-invested individuals (before healing minds/fabrials become commonplace), Rosharans could be in lethal trouble.

Does the cognitive realm then acclimated the traveler through it?  Is there a gradual increase in the cognitive vs physical? 

Honestly if this isn't hit on in some way I will be disappointed. Brandon does amazing world building and magic building. But if investiture and cognitive realm travel make the differences negligible then the fact that they exist at all is a waste of world building efforts. It would be like saying parshendi have carapace in WOBs but never mentioning it in the books as a challenge humans have to overcome. 

[Qianweilian He/him]

12 hours ago, DoctaDajman said:

Does the cognitive realm then acclimated the traveler through it?  Is there a gradual increase in the cognitive vs physical? 

We know that planetary subastrals grow similar to the host planet as you travel through them. I'm assuming that as you get closer to another planet, the air concentration grows more and more similar to the planet. Note: (This could be interesting on Roshar if sailing from the Horneater peaks to someone else changed air concentration despite unchanged elevation in Shadesmar)