7 ms·

Cool so it's an "eyeball" planet? http://nautil.us/blog/forget-earth_likewell-first-find-aliens-on-eyeball-planets http://nautil.us/blog/forget-earth_likewell-f

Cool so it's an "eyeball" planet? http://nautil.us/blog/forget-earth_likewell-first-find-aliens-on-eyeball-planets http://nautil.us/blog/forget-earth_likewell-first-find-alien...

rezashirazian 10y ago
This is the first time I'm reading about this concept and I find it fascinating. If there was to be intelligent life on an eye ball like planet the cultural, mythological and theological aspects of having a thin habitable strip of land sandwiched between ice and fire would be captivating.
- valarauca1 10y ago
  I'm imaging an age of discovery-esque expeditions to the center of the Solar Plane. They'd likely have radically different definitions of poles. One hot enough to melt lead, one cold enough to freeze C02.
  - thaumasiotes 10y ago
    > They'd likely have radically different definitions of poles. One hot enough to melt lead, one cold enough to freeze C02. Well, in a certain sense the West Pole and East Pole would exist in the manner you describe, but the behavior is not similar to that of the north and south poles. The stars will still rotate around the north-south axis, and east-west still won't affect that. It's not obvious that both phenomena should be called "poles".
    - dragonwriter 10y ago
      > The stars will still rotate around the north-south axis, and east-west still won't affect that. It's not obvious that both phenomena should be called "poles". Note that "north - south" poles already refers to two distinct phenomena, the axis of rotation and the axis of the magnetic field (these happen to be closely-enough aligned on Earth that the latter has historically been used as a proxy for the former, though this is by no means a universal feature of all planets.) The axis of orientation to the sun, for a tidelocked planet, seems no less plausibly described as "poles".
      - thaumasiotes 10y ago
        North and south magnetic poles are named after the north and south celestial poles because they seem to coincide. That doesn't apply to the solar poles. People always make use of local geographic features when describing directions; river communities use "upstream" and "downstream" and island communities use "inland" (away from the sea). Those aren't termed poles (even though "inland" is defined by reference to a line perpendicular to the ground!), and while I agree that the axis of orientation to the sun is more pole-like than they are, it's still different enough that I don't see that it would necessarily be referred to in the same terms.
        dragonwriter 10y ago
        > North and south magnetic poles are named after the north and south celestial poles because they seem to coincide. Sure, and that's why the axis-to-the-star probably wouldn't define "north" and "south" poles, but not a reason it doesn't make sense to call that the points where the surface intersects that axis through the planet "poles".
        thaumasiotes 10y ago
        That all depends on how some not-particularly-advanced people feel about it when the terms are determined. Having thought a bit more, I tend to think it's unlikely that both axes would be significant to the same people (and therefore that they are particularly unlikely to share terminology): - One important aspect of east-west historically is that east is sunrise and west is sunset. This wouldn't matter to anyone on Tidelocked World, but it corresponds pretty well to the idea of having a Day Pole and a Night Pole. The Day Pole would be apparent to anyone who lived in an area where the sun was visible, and the Night Pole would be totally unapparent to everyone else; it is significant only in that the Day Pole is on the opposite side of the world. - Historically, north is cold and south is hot. This would apply, I believe, only to the day side of Tidelocked World. It reinforces the idea of a Day Pole while doing nothing for the Night Pole (everything beyond the terminator should (?) be equally cold). - North and south are also defined by reference to the stars, which rotate around the polar axis (this is the origin of the word "pole", and would definitively rule out a Sun Pole if "poles" had to be defined that way, which they don't). This would be apparent to everyone living in the night, but probably not to anyone in the day. If you believe all that, then we have the sun as a navigational aid that guides us toward the hottest part of the world, and the stars as a navigational aid to indicate the North and South Poles, but no concept of a Night Pole, because that concept is useless on the night side and there are no local indicators for where it is. Day people would be likely to refer to "sunward" and "darkward" in the manner of islanders, and night people would likely refer to "north" and "south", but day people would be unlikely to recognize "north" and "south", and night people would be unlikely to recognize "lightward".
  - room271 10y ago
    Check out Proxima by Stephen Baxter: https://www.amazon.com/Proxima-Stephen-Baxter/dp/045146771X https://www.amazon.com/Proxima-Stephen-Baxter/dp/045146771X It's a Sci-fi book about life on Proxima Centauri and includes the idea you mentioned. (Also a really good read!)
    - TeMPOraL 10y ago
      God damn it! I have this annoying habit of impulsively buying books recommended on HN. Never been disappointed by one though. So thanks! :).
  - AdamN 10y ago
    Until the 20th century, no human had been on either pole of Earth either.
    - raverbashing 10y ago
      But differences of temperature between Earth poles temperatures and those temperature differences in tidal-locked planets is much smaller
  - aaron695 10y ago
    We haven't explored the bottoms of the oceans very well yet. So that'd be more advanced than us I think.
  - TeMPOraL 10y ago
    > They'd likely have radically different definitions of poles. One hot enough to melt lead, one cold enough to freeze C02. Think of the industrial applications! You'd have early metalworks near the hot pole, and when they'd finally figure out thermodynamics, I could imagine a planetary thermal engine created by bridging the hot and cold areas...
    - xg15 10y ago
      You could pretty easily imagine a planetary thermal engine on earth as well though - between the poles and the equator. In fact, we do have one. It's called "weather".
  - wlievens 10y ago
    Who says they have poles? Maybe they only have austrians and hungarians.
    - bitwize 10y ago
      A Polandball planet would definitely have poles.
- VikingCoder 10y ago
  Also check out https://en.wikipedia.org/wiki/Rocheworld https://en.wikipedia.org/wiki/Rocheworld
- mrfusion 10y ago
  A song of fire and ice perhaps? That might explain their strange seasons.
  - astrosi 10y ago
    There is an alternative explanation for their off seasons proposed in this April fools arxiv paper http://arxiv.org/abs/1304.0445 http://arxiv.org/abs/1304.0445
    - mirimir 10y ago
      The Three-Body Problem by Liu Cixin features a more extreme version. https://www.goodreads.com/book/show/20518872-the-three-body-problem https://www.goodreads.com/book/show/20518872-the-three-body-...
- mark-r 10y ago
  Hard to imagine it being habitable when simple weather patterns would expose the thin strip to both extremes.
- mangeletti 10y ago
  He was told that when approached the light would swiftly ascend to scorch him. Like the others, he was told to stay in the narrows, where both the light and the cold darkness were at a safe distance, but he set out on foot anyway. When he first encountered the Anteriorkies, Perimetus knew his defiance had paid off, and the Anteriorky leader gave Perimetus shelter from the angry light above...
  - sciguy77 10y ago
    What are you quoting?
    - deleted 10y ago
      [deleted]
    - scroy 10y ago
      It's Mangeletti.
  - sdoering 10y ago
    This would pull me into the rest of the book. You just feed me images and a whole story to imagine. Thanks a lot.
    - joshvm 10y ago
      I don't know any published books that use this as a trope, but it's a popular writing prompt on reddit: https://www.reddit.com/r/WritingPrompts/search?q=tidally&restrict_sr=on&sort=relevance&t=all https://www.reddit.com/r/WritingPrompts/search?q=tidally&res... This was a good one: https://www.reddit.com/r/WritingPrompts/comments/35mgnn/wp_a_planet_rotates_once_every_1000_years_so_that/ https://www.reddit.com/r/WritingPrompts/comments/35mgnn/wp_a...
      - orp 10y ago
        A similar concept was used in Jack of Shadows by Roger Zelazny, but with fantasy elements. https://www.amazon.com/Shadows-Rediscovered-Classics-Roger-Zelazny-ebook/dp/B01F7T7R5O/ref=sr_1_1?s=books&ie=UTF8&qid=1472118117&sr=1-1&keywords=jack+of+shadows https://www.amazon.com/Shadows-Rediscovered-Classics-Roger-Z...
Dragonai 10y ago
What a fascinating article! Thanks so much for sharing!
1812Overture 10y ago
I imagine convection would give one of these planets crazy weather.
hawski 10y ago
How such planet can protect its water from solar wind? There are probably different possibilities to get magnetosphere than Earth-Moon dynamo, but I don't know much about it.
- apparissus 10y ago
  The Moon isn't responsible for Earth's magnetosphere, rather our liquid iron core is.
  - ergothus 10y ago
    Isn't it not that we have such a core, but that the core MOVES that creates it? If so, I can imagine the Moon playing a role in that. That said "I can imagine" isn't terribly good science. Articles like https://en.wikipedia.org/wiki/Dynamo_theory https://en.wikipedia.org/wiki/Dynamo_theory don't make mention any role of the Moon, and googling around drowned out the actual question by talking about how the Moon might have once had a magnetosphere, along with articles about how smaller planets might be able to.
    - throwaway5752 10y ago
      If so, I can imagine the Moon playing a role in that It doesn't. The planet was spinning when it coalesced from a planetary nebula and conservation of angular momentum means it sped up as it coalesced. As the moon moves further away it _slows down_ the rotation of the planet.
      - hawski 10y ago
        I stay corrected on accepted theories. I tried to find some discussion on this subject. I found this [1] quite recent paper (2016-03-31) that states that influence of Moon is necessary to maintain Earth's magnetosphere. Just food for thought. There are articles that quote this paper on the Web, but they have this suspicious date of 1st April (but paper was published day before) :) [1] http://www.sciencedirect.com/science/article/pii/S0012821X16301078 http://www.sciencedirect.com/science/article/pii/S0012821X16...
deleted 10y ago
[deleted]
chocolatebunny 10y ago
reminds me of the movie White Dwarf: http://www.imdb.com/title/tt0114926/ http://www.imdb.com/title/tt0114926/
euroclydon 10y ago
They say the star's gravity fixes one side of the planet toward the star, and that ice builds up on the other side. I suppose if the atmosphere had enough mass, and the balance was precarious enough, the far side could accumulate enough ice to flip toward the star and become the near side. So there might be a season change every so often
- Spellman 10y ago
  Winter is Coming!
- FreeFull 10y ago
  I feel like adding mass on one side would only made the tidal locking stronger. Either way, you'd need some sort of massive energy input to make the planet spin up again.
  - vanattab 10y ago
    It would be interesting to study given a specific level of ice build up how big of an asteroid would have to hit it at the perfect angle to make it flip?
- nbevans 10y ago
  That's an awesome plausible theory. Must be happening somewhere in the universe for sure!
- andrewflnr 10y ago
  You mean a cataclysmic planetary flood every so often. All that ice suddenly exposed to continual bright sunlight is going to melt fast.
dmichulke 10y ago
Is there any ballpark figure as to how broad (in degrees or km for an earth-sized planet) the habitable zone would be?
dmichulke 10y ago
Is there any ballpark figure as to how broad (in degrees or km for an earth-sized planet) the habitable zone would be?

Cool so it's an "eyeball" planet? http://nautil.us/blog/forget-earth_likewell-first-find-aliens-on-eyeball-planets http://nautil.us/blog/forget-earth_likewell-first-find-alien...

rezashirazian 10y ago

This is the first time I'm reading about this concept and I find it fascinating. If there was to be intelligent life on an eye ball like planet the cultural, mythological and theological aspects of having a thin habitable strip of land sandwiched between ice and fire would be captivating.

valarauca1 10y ago
I'm imaging an age of discovery-esque expeditions to the center of the Solar Plane. They'd likely have radically different definitions of poles. One hot enough to melt lead, one cold enough to freeze C02.
- thaumasiotes 10y ago
  > They'd likely have radically different definitions of poles. One hot enough to melt lead, one cold enough to freeze C02. Well, in a certain sense the West Pole and East Pole would exist in the manner you describe, but the behavior is not similar to that of the north and south poles. The stars will still rotate around the north-south axis, and east-west still won't affect that. It's not obvious that both phenomena should be called "poles".
  - dragonwriter 10y ago
    > The stars will still rotate around the north-south axis, and east-west still won't affect that. It's not obvious that both phenomena should be called "poles". Note that "north - south" poles already refers to two distinct phenomena, the axis of rotation and the axis of the magnetic field (these happen to be closely-enough aligned on Earth that the latter has historically been used as a proxy for the former, though this is by no means a universal feature of all planets.) The axis of orientation to the sun, for a tidelocked planet, seems no less plausibly described as "poles".
    - thaumasiotes 10y ago
      North and south magnetic poles are named after the north and south celestial poles because they seem to coincide. That doesn't apply to the solar poles. People always make use of local geographic features when describing directions; river communities use "upstream" and "downstream" and island communities use "inland" (away from the sea). Those aren't termed poles (even though "inland" is defined by reference to a line perpendicular to the ground!), and while I agree that the axis of orientation to the sun is more pole-like than they are, it's still different enough that I don't see that it would necessarily be referred to in the same terms.
      - dragonwriter 10y ago
        > North and south magnetic poles are named after the north and south celestial poles because they seem to coincide. Sure, and that's why the axis-to-the-star probably wouldn't define "north" and "south" poles, but not a reason it doesn't make sense to call that the points where the surface intersects that axis through the planet "poles".
        thaumasiotes 10y ago
        That all depends on how some not-particularly-advanced people feel about it when the terms are determined. Having thought a bit more, I tend to think it's unlikely that both axes would be significant to the same people (and therefore that they are particularly unlikely to share terminology): - One important aspect of east-west historically is that east is sunrise and west is sunset. This wouldn't matter to anyone on Tidelocked World, but it corresponds pretty well to the idea of having a Day Pole and a Night Pole. The Day Pole would be apparent to anyone who lived in an area where the sun was visible, and the Night Pole would be totally unapparent to everyone else; it is significant only in that the Day Pole is on the opposite side of the world. - Historically, north is cold and south is hot. This would apply, I believe, only to the day side of Tidelocked World. It reinforces the idea of a Day Pole while doing nothing for the Night Pole (everything beyond the terminator should (?) be equally cold). - North and south are also defined by reference to the stars, which rotate around the polar axis (this is the origin of the word "pole", and would definitively rule out a Sun Pole if "poles" had to be defined that way, which they don't). This would be apparent to everyone living in the night, but probably not to anyone in the day. If you believe all that, then we have the sun as a navigational aid that guides us toward the hottest part of the world, and the stars as a navigational aid to indicate the North and South Poles, but no concept of a Night Pole, because that concept is useless on the night side and there are no local indicators for where it is. Day people would be likely to refer to "sunward" and "darkward" in the manner of islanders, and night people would likely refer to "north" and "south", but day people would be unlikely to recognize "north" and "south", and night people would be unlikely to recognize "lightward".
- room271 10y ago
  Check out Proxima by Stephen Baxter: https://www.amazon.com/Proxima-Stephen-Baxter/dp/045146771X https://www.amazon.com/Proxima-Stephen-Baxter/dp/045146771X It's a Sci-fi book about life on Proxima Centauri and includes the idea you mentioned. (Also a really good read!)
  - TeMPOraL 10y ago
    God damn it! I have this annoying habit of impulsively buying books recommended on HN. Never been disappointed by one though. So thanks! :).
- AdamN 10y ago
  Until the 20th century, no human had been on either pole of Earth either.
  - raverbashing 10y ago
    But differences of temperature between Earth poles temperatures and those temperature differences in tidal-locked planets is much smaller
- aaron695 10y ago
  We haven't explored the bottoms of the oceans very well yet. So that'd be more advanced than us I think.
- TeMPOraL 10y ago
  > They'd likely have radically different definitions of poles. One hot enough to melt lead, one cold enough to freeze C02. Think of the industrial applications! You'd have early metalworks near the hot pole, and when they'd finally figure out thermodynamics, I could imagine a planetary thermal engine created by bridging the hot and cold areas...
  - xg15 10y ago
    You could pretty easily imagine a planetary thermal engine on earth as well though - between the poles and the equator. In fact, we do have one. It's called "weather".
- wlievens 10y ago
  Who says they have poles? Maybe they only have austrians and hungarians.
  - bitwize 10y ago
    A Polandball planet would definitely have poles.
VikingCoder 10y ago
Also check out https://en.wikipedia.org/wiki/Rocheworld https://en.wikipedia.org/wiki/Rocheworld
mrfusion 10y ago
A song of fire and ice perhaps? That might explain their strange seasons.
- astrosi 10y ago
  There is an alternative explanation for their off seasons proposed in this April fools arxiv paper http://arxiv.org/abs/1304.0445 http://arxiv.org/abs/1304.0445
  - mirimir 10y ago
    The Three-Body Problem by Liu Cixin features a more extreme version. https://www.goodreads.com/book/show/20518872-the-three-body-problem https://www.goodreads.com/book/show/20518872-the-three-body-...
mark-r 10y ago
Hard to imagine it being habitable when simple weather patterns would expose the thin strip to both extremes.
mangeletti 10y ago
He was told that when approached the light would swiftly ascend to scorch him. Like the others, he was told to stay in the narrows, where both the light and the cold darkness were at a safe distance, but he set out on foot anyway. When he first encountered the Anteriorkies, Perimetus knew his defiance had paid off, and the Anteriorky leader gave Perimetus shelter from the angry light above...
- sciguy77 10y ago
  What are you quoting?
  - deleted 10y ago
    [deleted]
  - scroy 10y ago
    It's Mangeletti.
- sdoering 10y ago
  This would pull me into the rest of the book. You just feed me images and a whole story to imagine. Thanks a lot.
  - joshvm 10y ago
    I don't know any published books that use this as a trope, but it's a popular writing prompt on reddit: https://www.reddit.com/r/WritingPrompts/search?q=tidally&restrict_sr=on&sort=relevance&t=all https://www.reddit.com/r/WritingPrompts/search?q=tidally&res... This was a good one: https://www.reddit.com/r/WritingPrompts/comments/35mgnn/wp_a_planet_rotates_once_every_1000_years_so_that/ https://www.reddit.com/r/WritingPrompts/comments/35mgnn/wp_a...
    - orp 10y ago
      A similar concept was used in Jack of Shadows by Roger Zelazny, but with fantasy elements. https://www.amazon.com/Shadows-Rediscovered-Classics-Roger-Zelazny-ebook/dp/B01F7T7R5O/ref=sr_1_1?s=books&ie=UTF8&qid=1472118117&sr=1-1&keywords=jack+of+shadows https://www.amazon.com/Shadows-Rediscovered-Classics-Roger-Z...

Dragonai 10y ago

What a fascinating article! Thanks so much for sharing!

1812Overture 10y ago

I imagine convection would give one of these planets crazy weather.

hawski 10y ago

How such planet can protect its water from solar wind? There are probably different possibilities to get magnetosphere than Earth-Moon dynamo, but I don't know much about it.

apparissus 10y ago
The Moon isn't responsible for Earth's magnetosphere, rather our liquid iron core is.
- ergothus 10y ago
  Isn't it not that we have such a core, but that the core MOVES that creates it? If so, I can imagine the Moon playing a role in that. That said "I can imagine" isn't terribly good science. Articles like https://en.wikipedia.org/wiki/Dynamo_theory https://en.wikipedia.org/wiki/Dynamo_theory don't make mention any role of the Moon, and googling around drowned out the actual question by talking about how the Moon might have once had a magnetosphere, along with articles about how smaller planets might be able to.
  - throwaway5752 10y ago
    If so, I can imagine the Moon playing a role in that It doesn't. The planet was spinning when it coalesced from a planetary nebula and conservation of angular momentum means it sped up as it coalesced. As the moon moves further away it _slows down_ the rotation of the planet.
    - hawski 10y ago
      I stay corrected on accepted theories. I tried to find some discussion on this subject. I found this [1] quite recent paper (2016-03-31) that states that influence of Moon is necessary to maintain Earth's magnetosphere. Just food for thought. There are articles that quote this paper on the Web, but they have this suspicious date of 1st April (but paper was published day before) :) [1] http://www.sciencedirect.com/science/article/pii/S0012821X16301078 http://www.sciencedirect.com/science/article/pii/S0012821X16...

deleted 10y ago

[deleted]

chocolatebunny 10y ago

reminds me of the movie White Dwarf: http://www.imdb.com/title/tt0114926/ http://www.imdb.com/title/tt0114926/

euroclydon 10y ago

They say the star's gravity fixes one side of the planet toward the star, and that ice builds up on the other side. I suppose if the atmosphere had enough mass, and the balance was precarious enough, the far side could accumulate enough ice to flip toward the star and become the near side. So there might be a season change every so often

Spellman 10y ago
Winter is Coming!
FreeFull 10y ago
I feel like adding mass on one side would only made the tidal locking stronger. Either way, you'd need some sort of massive energy input to make the planet spin up again.
- vanattab 10y ago
  It would be interesting to study given a specific level of ice build up how big of an asteroid would have to hit it at the perfect angle to make it flip?
nbevans 10y ago
That's an awesome plausible theory. Must be happening somewhere in the universe for sure!
andrewflnr 10y ago
You mean a cataclysmic planetary flood every so often. All that ice suddenly exposed to continual bright sunlight is going to melt fast.

dmichulke 10y ago

Is there any ballpark figure as to how broad (in degrees or km for an earth-sized planet) the habitable zone would be?

dmichulke 10y ago

Is there any ballpark figure as to how broad (in degrees or km for an earth-sized planet) the habitable zone would be?