20

Let me start with the additional problems that arise: The trajectory of the suns is not stable. If they are slightly off-center, gravity will pull them towards the side of the cylinder that they're closer to, analogous to the ringworld stability issue. You could work around this by using stellar engines of some sort to keep the stars centered, or making the ...


5

The inhabitants can calculate the height of the “star” by using simple trigonometry with people positioned at different points in its path and synchronized watches. Knowing its height the size of the star can then be calculated by measuring its angular diameter and again using trigonometry or even simpler similar triangles. It is impossible to say how ...


4

First pass: the geometry is simple In the first pass, we disregard the cylindrical shape of the world, and we assume that the light sources are in free space, moving against a black backdrop. Let's assume that: Each of the light sources moving through the tube produces the same amount of light as our own Sun; and At midnight we want to have the same ...


4

The apparent magnitude of the sun as seen from Earth is -26.75; when a celestial body with this brightness shines we consider it to be 'daytime'. Conversely when the full moon (magnitude -12.74) shines, we still consider it to be 'night time'; the sun is 400,000 times brighter than the full moon. Since apparent magnitude follows an inverse square law ...


4

Since Newtonian/Einsteinian physics clearly don't apply here, I see no reason these "stars" and "suns" couldn't be actual hydrogen-fusing stars, just flying across the (infinite?) flat world at a (handwaved) speed and (handwaved) density such that they provide the day and night cycles. If they stars have the same population distribution as those in our ...


4

An infinite flat surface would not work from a gravitational perspective as the surface would disintegrate under gravity into lots of small planets or if there was no rotational movement a single ever expanding black hole. So best to use a planet or Dyson ring. The habitability of the tunnels would depend on a lot of factors: the depth of the ocean, the ...


3

Air Pressure Follows the Same Rules there as on Earth Atmospheric pressure is largely the effect of the amount and composition of gasses, and the effect of gravity on the gasses. Due to how fluid pressure works, the use of tunnels is largely irrelevant and can be safely ignored. Assuming your world is not infinite horizontally, but is rather arbitrarily ...


3

Blocking sunlight does not cause scattering or change the observed colors in the way that a sunset does; it only makes the sky darker or lighter, depending on how much sunlight was blocked. With all of the sunlight blocked (the umbra), we have night or near-night. With none of the sunlight blocked (the antumbra), we have sky blue (not including sunsets). And ...


2

If the tube rotated to produce "gravity", that gravity would pull down to the outside of the tube. So people would look up at the suns passing by. If the suns have the mass of Sol, the Sun, they will eventually swell into red giants and greatly increase their luminosity after about ten billion years. That will cook the inside of the cylinder and maybe ...


2

The sky would range from reds nearest the sun’s periphery to blues as you look further from the sun then farthest edges of the sky should look violet. As you stated it will be because of Rayleigh scattering.


1

I can talk about the math in the abstract but since we have no figures here, it will be rather abstract. The two factors will be: 1. Absolute magnitude of the suns 2. Distance from the sun to the surface when the sun is directly overhead. The suns' light falls off by the square of the distance. This will determine its relative magnitude, which will ...


1

I don't mean to be obvious but there are flat earth theorists who have theories on this in the real world. The way I understand it is that basically the sun is a spotlight and points at different parts of the earth at different times, the moon and stars are points on a black background that move in odd ways and I am not sure how they explain seasons. I ...


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