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I'm fascinated by The Dark Tower series of books by Stephen King. One of the aspects that I love most is the distortion of space and time:

Roland's world is said to have "moved on", and it appears to be coming apart at the seams. Mighty nations have been torn apart by war, entire cities and regions vanish without a trace and time does not flow in an orderly fashion. Sometimes, even the sun rises in the north and sets in the east.

I'm trying to think of a way for this to happen without magic and spacetime distortion, though. Would it be possible for a planet to orbit a start in such a way that, for a certain period of time, the sun would rise on the north instead of east (even if it still sets on the west)?

Moreover, would this be possible in an inhabitable world - while keeping the world inhabitable - and in such a timespan that a human being might be able to experience this transition?

This question is different from World with a different sun every day, and random days with no sun as that one is about many different daily variations of the sun.

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  • $\begingroup$ Simply adjust the planet's rotational axis further from being orthogonal to the planet's orbital ecliptic plane and you'll get different apparent sun movement directions throughout the year, similar to Uranus $\endgroup$
    – Dragongeek
    Commented Oct 30, 2020 at 18:37
  • $\begingroup$ What is the definition of "north" and "east" in the language spoken in that world? Because with our Earthling definitions what you ask is a logical impossibility. (By definition, "north" is the pole around which the planet rotates counterclockwise; the rest of the cardinal points follow.) If the sun rises and sets daily, then by necessity it must do so at points almost symmetrical with respect to the meridian. So it is indeed possible (and nothing special) for the sun to rise NNE and set NNW; or for it to rise SSE and set SSW; or to rise west of north and set east of north. $\endgroup$
    – AlexP
    Commented Oct 30, 2020 at 18:44
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    $\begingroup$ @Dragongeek On Uranus, depending on where it is in its orbit, the sun would either rise and fall E/W, or it would just hang over one pole. The Sun would never appear to rise and fall N/S. To get a N/S sunrise/set we need the axial to tilt to change so fast that it competes with the speed of rotation. The planet basically has to be rotating on more than one axis (while the inhabitants still somehow see one of those axis as the proper one to use when defining "North"). $\endgroup$
    – Harabeck
    Commented Oct 30, 2020 at 19:02
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    $\begingroup$ @Harabeck First, approximate a planets' axis to 90° and assume that the axis currently points towards the sun. If I am at the sunwards pole, the sun stays stationary at my zenith during the day. As the year progresses, from my viewpoint, the sun appears to spiral around my zenith in an ever increasing radius, descending towards the horizon until it eventually traces along the horizon and then dips below, leaving me in the dark for the next half-year. By moving my location from the pole and decreasing year duration, I imagine some strange sections of spiral could be "cut" from the sun's path. $\endgroup$
    – Dragongeek
    Commented Oct 30, 2020 at 19:49
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    $\begingroup$ Discworld, when A'Tuin is changing course, would give you this level of silliness from the Sun. $\endgroup$
    – user79911
    Commented Oct 30, 2020 at 20:04

4 Answers 4

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Picture a world orbiting a sun much hotter than our own -- perhaps Sirius, or an even hotter star (never mind the short lifetimes of type O and B stars). Its habitable zone is far larger than Sol's -- and the year of a habitable zone planet is correspondingly longer. Just as small M dwarves have planets in their tiny habitable zone with a year amounting to a week or less in Earth days, a start larger and hotter than Sirius would have a year in its habitable zone of decades, perhaps even centuries.

Now, tilt the planet's axis roughly 90 degrees, as is the case with Neptune. You could have the sun barely clearing the northern horizon each day (like you'd see at Point Barrow, Alaska in late December) when a man is born, and by the time he's grown, the sun rises somewhere near due East and crosses the sky to the West. When he's old, if he live near enough to the equator, he might see the sun flirting with the southern horizon, and his children or grandchildren will again see it rising in the east.

No magic needed, no distortion of space or time, just the ability to terraform a world quickly enough. An O star only remains on the main sequence for a million or a few million years -- not long enough for a terrestrial planet to have a stable, solid crust, never mind evolve life -- but a mid-range B or one of the larger/hotter A stars should last long enough to find in mid-life with continents and oceans, and some kind of atmosphere on a planet with an orbit of a century or longer.

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For a short periode of time, maybe

In theory, every orbit is possible. If you change the Rotation of the Planet and its orbit around long enough, you can create something like this.

For example, the Planet might have a Moon that is not on the same Orbital Plane as the Planet itself. Sure the two Worlds would become Tidally locked to each other but there is a time where the two Follow each other but are not locked yet. With a very Strange axial Tilt and a strange Moon, you might get Time window in which the Sun rises in the North and sets in the East. But of course, this would change over the year.

But again, this would only work for a very short amount of time. If at all. The Tilt and so on would have to be perfect and the Planet would basically wobel around.

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    $\begingroup$ Can you please show the kinematics so that the sun does not trace a daily path (almost) symmetrical with respect to the meridian? $\endgroup$
    – AlexP
    Commented Oct 30, 2020 at 18:45
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    $\begingroup$ I am working on an Animation and man.... It aint easy. Ill give you an Update $\endgroup$
    – Erik Hall
    Commented Oct 30, 2020 at 18:46
  • $\begingroup$ @AlexP, ok so if you want i can upload what i got but in the end, the best i could come up with for now is that the Planet rotates 360* around 2 Axis at the same time in one day. This creates sort of a Wobel motion in the sky. If we then also add like +90* of extra Rotation around the Z Axis, we KIND of get what OP is looking for. $\endgroup$
    – Erik Hall
    Commented Oct 30, 2020 at 19:10
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    $\begingroup$ A solid rotating body rotates around exactly one axis; that's pure geometry, and we cannot argue with geometry. (Euler's rotarion theorem: the compositin of two rotations is a rotation.) (And then what is the meaning of the word "north"?) $\endgroup$
    – AlexP
    Commented Oct 30, 2020 at 19:14
  • $\begingroup$ Hold up. I said that wrong. As you said, the two Rotations are just a single one. Let me show you. imgur.com/gallery/AHPIDF0 $\endgroup$
    – Erik Hall
    Commented Oct 30, 2020 at 19:25
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actually this happens in our world, the thing is it is quite gradient, and caused by seasons, if you get this rotation and exagerate it, you get the sun actually looks like it comes from the east and others from the north, but this would also give you a much more harsh winter and summer, both being cold, as the north and south poles of your planet would move, placing you at the full top and full bottom here, you would also have a hot in between, you could have the planet in an orbit wich makes it look like there are 2 summers 2 springs, 2 automns, 2 winters making it look like one month only, and also the days would greatly vary in length, so would the nights there would also be nightless weeks, and dayless ones

edit, combine it with the other aswer second edit, you can watch this happen at the north and south poles, the sun is never at the top, and it looks like it moves in a pattern which is admittedly cool

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    $\begingroup$ It does not happen on Earth. The sun's path is more or less symmetrical around local noon. Where I live, this time of year, the sun rises and sets in the south (as in, face south and you'll see sunrise followed a while later by sunset). A few months from now it will set and rise in the north. At no time will you see it work as written. $\endgroup$
    – Keith Morrison
    Commented Jan 18, 2021 at 19:46
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Have a planet with an axial tilt that varies greater than that of Earth's. Maybe it tilts by approximately 10 degrees each Earth year, and completes a full circle every 36 or so years. That will also put the climates of different regions in periodic changes.

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