[NO SPOILERS] How do they tell years?

[razorpowell]

Hey,

Just started reading the books after I saw the show- big fan of both, I've almost finished the book in about 4 days. But I have a major problem with the entire concept of seasons.

Summers can last decades and winters can last a lifetime. This summer lasted nine years. That all sounds totally cool.

Except how do they tell years without seasons? That is, after all, how years were initially measured- by how many winters had passed. So how do the people of Westeros come up with the concept of a year, if a winter can last 10 of them?

Thanks

[Xray the Enforcer]

Just did a rudimentary search and found this post by Happy Ent. I haven't checked the entire thread for spoilers, There are definitely spoilers in that thread, so you might want to proceed slowly in that thread if you decide to read avoid it for now.

http://asoiaf.westeros.org/index.php/topic/48177-question-about-seasons/ (don't click if you don't want future events spoiled)

We've discussed this for a decade, here's a brief summary.

1. Nobody has ever found an explanation of how the seasons work that is compatible with celestial mechanics (i.e., the idea that Martinworld is a planet orbiting a sun, just like our world.) It is thinkable (indeed, I find it plausible) that GRRM himself has no idea, nor cares much about it. The main obstacles to finding such an explanation are the existence of a North Star (which means the rotational axis is fixed) and the fact that Winter makes the sun set earlier (which means Winter cannot be reduced to things like atmospheric effects or sun spots).

2. It is easy to base a concept of "year" around solar or other astronomical observations. Seasons are not necessary for this. Just watch the stars. Our civilisations have done this for millennia. It is also extremely useful to have a concept of year, independent of seasons, for logistical reasons, taxation, leases, etc., but even farming (though our world, where seasons coincide with the solar cycle, makes years even more useful). Clearly, GRRM has given very little thought to questions of agriculture in a world with no seasonal cycles, so it is plausible that this is an aspect of the world-building that is not very well developed. Trying to rationalise these things beyond what the author invested is probably futile (but can be entertaining nontheless).

3. Yes, we know that the lunar cycle is pretty much what ours is, because the female menstrual cycles is aligned with it ("Moon's Blood"). From details such as Joffrey's birthdays and Daenarys's pregnancy we can also infer that years are pretty much as long as on Earth. (You can make these arguments go away by postulating that women on Martinworld menstruate every 60 days, or are 18 months pregnant, or a well-fed girl like Sansa reaches puberty at a different "age" than on Earth.)

Just going to remind people that the OP has NOT finished the books, so please do not put any book spoilers in this thread.

[zmflavius]

Years are, in fact, not decided through seasons, but rather through solar or lunar movement, such as when Earth finishes a circuit around the Sun, or the Moon orbits Earth 12 times. These are roughly analogous to growing periods of crops, hence why they are used. As such, the year is likely decided through the amount of time it takes for a full harvest to be collected.

[Ser Warpechowski]

By fortnights, since everytime some time has passed it has been a fortnight.

GRRM use the word fortnight more than boiled leather in the books.

[Greylander]

I have read that GRRM has said the explanation of seasons (and by extension, years) will explicitly *not* be a science-fiction kind of explanation.

But in as much as the aSoIaF world does for the most part work like the real world, we can expect that years are measured by the apparent movement of the sun against the background of stars (or, equivalently, as the year cycles, there will be different constellation directly above you at midnight [or any other time of day/night]).

Because it is mentioned that days get shorter/longer in winter/summer, it strongly suggest that the seasons depend, at least in part upon axis tilt relative to the sun just as seasons do on earth, but for seasons to last years would then require that the planet's axis stay tipped toward/away from the sun rather than staying fixed as it does here on earth. Our fixed axis (north pole) is tipped toward the sun in summer (for the north hemisphere) and away from the sun when we have moved round to the opposite side of the sun, hence our seasons are tied to years. We could imagine in the magical world with somewhat different physical laws, that the planet's axis precesses in such a way that it can continue to tilt toward (or away from) the sun as it moves around the sun.

Someone above mentioned a "north star". Is a north star mentioned in the books? I do not recall. If there is a "north star", it must not be a normal star if it can stay fixed above the north pole while the north pole precesses and points in different directions. But perhaps the "north star" in GRRM's world is some kind of atmospheric phenomenon, and not a star at all -- a phenomenon that is tied to the rotational (and/or magnetic) axis? For all we know it could be a magical, extremely bright glowing gem (a Silmaril, perhaps? lol!!) hovering a few hundred miles above the north pole. It is also possible that while there is a star recognized as the "north star" it does not actually stay fixed, but simply stays close to being directly above the north pole of the rotation axis.

As an alternative to a wobbly axis of rotation, it could be that the axis, the north pole, stays fixed ("straight up" so to speak) but some weird physics means that the planet does noth exactly revolve aroun the sun all the time -- in summer (for northern hemisphere) it could revolve in a plane slightly "below" the the sun, while in winter it revolves in a plan slightly "above" the sun. This would create seasons without the need for axial tilt, the stars remain fixed (just like the north star), and aside from their somewhat random and lengthy duration, much of the way that seasons work would look the same from the point of view of people on the planet (days longer/shorter, etc.).

As to animals, plants, harvests, and surving the winter, we can suppose that while animals and plants are quite similar to the real world, they are adapted to the long and unpredictable seasons -- bears able to hybernate for years, and so forth. And when summer lasts all year, you get 3-4 times as many harvests as in the real world, so it is much more feasible to store enough food for very long winters. We can also suppose that there are some kinds of animals and plants which somehow thrive in winter, so that there is some possibility of gathering limited amounts of food.

[Hyper]

As an alternative to a wobbly axis of rotation, it could be that the axis, the north pole, stays fixed ("straight up" so to speak) but some weird physics means that the planet does noth exactly revolve aroun the sun all the time -- in summer (for northern hemisphere) it could revolve in a plane slightly "below" the the sun, while in winter it revolves in a plan slightly "above" the sun. This would create seasons without the need for axial tilt, the stars remain fixed (just like the north star), and aside from their somewhat random and lengthy duration, much of the way that seasons work would look the same from the point of view of people on the planet (days longer/shorter, etc.).

It wouldn't have to be that extreme of an explanation... My personal 'pseudo-scientific' theory of the season is that the world of the story has an axial tilt like Earth, but only a subtle one. The orbit around its sun takes a year.

The primary cause of the long seasons is not the axial tilt (although it may have a small effect), but instead an accelerated climactic changes of the entire world weather - Think of the winters as mini ice-ages. Something (magical?) seems to be causing macro weather patterns that take several hundreds or thousands of years on our planet to compress into decades on the ASOIAF world.

That's my preferred theory, anyway. B) :D

[Greylander]

It wouldn't have to be that extreme of an explanation... My personal 'pseudo-scientific' theory of the season is that the world of the story has an axial tilt like Earth, but only a subtle one. The orbit around its sun takes a year.

The primary cause of the long seasons is not the axial tilt (although it may have a small effect), but instead an accelerated climactic changes of the entire world weather - Think of the winters as mini ice-ages. Something (magical?) seems to be causing macro weather patterns that take several hundreds or thousands of years on our planet to compress into decades on the ASOIAF world.

That's my preferred theory, anyway. B) :D

Hyper, the assumption of climatic shifts would work -- except that the lengthening/shortening of days is mentioned in the books as corresponding with the seasons. Winters are associated with darkness ("the long night", etc.). Although any ol' magical explanation can be made up, the explanation closest to the "real" world needs to involve axial tilt relative to the sun.

There are basically 4 "facts" from the books that need to be reconciled:

1. seasons that last longer than a year, sometimes decades
2. seasons of variable, unpredictable length
3. changing length of night/day that correlates with the seasons (just like real Earth)
4. existence of a "North Star" (anyone know where this appears in the books??), which may or may not be "fixed".
5. the voyages of Euron Crow's Eye seem to imply a spherical world

Of these #4 depends largely on the explanation of the others, while #2 could be anything.

#1, #3, and #5 make sense with least deviation from real world by playing around with axial tilt, or otherwise with position of sun relative to world.

For all we know, in GRRM's world, the sun is really a fiery chariot driven by a god, so that the sun goes round the planet, not the other way round, and the course of the sun is determined by whim of the god not by gravity.

[Spring Bass]

There's no mention of change in the polar star from Summer to Winter, so I highly doubt that it's a matter of axial tilt. Martin has also directly said that the world is round, and somewhat bigger than Earth.

My speculation is that it's some type of magic manipulating the amount of light that gets through the atmosphere to the planet's surface, but the actual days (meaning sunrise-to-sunset) seem to get shorter in Winter. I have no idea how you'd fit that into it, unless the magic is also changing the image of the planet's sunrises and sunsets while it's at it.

EDIT: This is one area where commentary from the World of Ice and Fire book (written from the perspective of a Maester) would be interesting. What do they make of the strange combination of unchanging polar star, changing day length, and the connection to the Winters and Summers?

[Xenophon]

There's no mention of change in the polar star from Summer to Winter, so I highly doubt that it's a matter of axial tilt. Martin has also directly said that the world is round, and somewhat bigger than Earth.

That's not a problem if the motions of the sun and the stars are decoupled.

Here's my favorite (and entirely speculative) cosmology:

The world is geostationary (like the Ptolemaic model, in RL). At the center is the earth (or whatever GRRM calls it), and it doesn't move. The stars are points of light on a big sphere that spins around the earth. The moon, the sun, and everything else (planets, comets, etc) are in between.

The seasons are caused by changes in the orbit of the sun. When the others grow stronger/whatever magic causes winter happens, the orbit of the sun is pushed to the south. (The moon could move as well, if you want things to get really dark.) Likewise, during summer, the sun orbits further to the north. That way, the days grow longer and shorter, but the stars don't change.

The main drawback of this system is that it means somewhere on the other side of the world will always have the opposite weather from Westeros. Where exactly this would be depends on whether the center of the sun's orbit moves, or just the angle of its plane of rotation changes. Either way, somewhere is getting a long winter whenever Westeros has a long summer.

A geostationary cosmos also can account for how the comet at the end of AGoT was visible to everyone both day and night--the comet didn't appear to move because it really wasn't moving, it was just sitting up there in the sky while everything else in the heavens was moving around the earth.

[Spring Bass]

The main drawback of this system is that it means somewhere on the other side of the world will always have the opposite weather from Westeros. Where exactly this would be depends on whether the center of the sun's orbit moves, or just the angle of its plane of rotation changes. Either way, somewhere is getting a long winter whenever Westeros has a long summer.

That's the other reason why I'm skeptical of it. It'd be rather anti-climactic if the Others can only ever conquer half-a-planet, because the people in the Southern Hemisphere are enjoying the Long Summer while the people in the Northern Hemisphere are getting wiped out. :D

[Xenophon]

That's the other reason why I'm skeptical of it. It'd be rather anti-climactic if the Others can only ever conquer half-a-planet, because the people in the Southern Hemisphere are enjoying the Long Summer while the people in the Northern Hemisphere are getting wiped out. :D

In the war between R'hollor and the Great Other, there can be no winners. A Game of Thrones. The only winning move is not to play. How about a nice game of chess?

[Talan Snow]

Hey,

Just started reading the books after I saw the show- big fan of both, I've almost finished the book in about 4 days. But I have a major problem with the entire concept of seasons.

Summers can last decades and winters can last a lifetime. This summer lasted nine years. That all sounds totally cool.

Except how do they tell years without seasons? That is, after all, how years were initially measured- by how many winters had passed. So how do the people of Westeros come up with the concept of a year, if a winter can last 10 of them?

Thanks

I was at a book signing for A Feast For Crows in Madison WI where Martin specifically said that the coming of Winter is due to magic, pure and simple. He said that a woman had shown him a diagram of a possible planet that might have seasons similar to how he describes them in the books, but that he said "It's nothing like that. It's just due to magic."

I personally like thinking that this is all taking place on a world which experiences periodic "little ice ages" (hence the coming of Winter). I think that's cool, so that's my interpretation of it. And for me, what it means is that during "Summer" there are still seasons but that it's more like "rainy season" (i.e. a "California winter") during "Summer" but that when "Winter" arrives its the opposite and it's very cold and dark for very long parts of the year.

[DaenerysFaithful]

I don't know about the tilt of the axis and all that, but there are mentions of breaks in these seasons with what they call "false spring" and shorter time periods where a season doesn't last as long nor is as harsh as others were in the past. We also have to account for the differences in climate during these seasons. Why the Southern Kingdoms and Free Cities feel Summer temperatures when it is Summer the North is merely less cold than it would be during a winter.