Thoughts about sphere worlds

Kamog · #1 November 25th, 2003, 07:53 AM

To get around the problem with artificial gravity not being uniform inside a sphere world, maybe we could build the world so that it is not a solid one-piece sphere, but a combination of ring worlds stacked one on top of each other. So at the equator, you have a large diameter ring world, rotating to produce 1G of artificial gravity. Above and below this ring world, you have two more ring worlds of slightly smaller diameter, rotating at a different speed as to also produce 1G. Then, above and below those, have slightly smaller-diameter ring worlds rotating at its own speed to produce 1G, and so on. So the sphere world will consist of hundreds of ring worlds arranged in the shape of a sphere, with the largest ring at the equator and the smallest rings at the poles. The smallest rings will have to rotate the fastest to produce the same gravity. All the ring worlds could be enclosed in a larger, solid sphere so that it looks like a solid sphere world from the outside, but would consist of separate ring segments with independent rotations inside. Hmm, I guess this really isn't a sphere world...

narf poit chez BOOM · #2 November 25th, 2003, 08:02 AM

but it is a Dyson's sphere. a Dyson's sphere just has to cover the entire sun.

Kamog · #3 November 25th, 2003, 09:28 AM

I was thinking about ring worlds, and it occured to me that artificial gravity created by rotation would not work the same way as natural gravity generated from mass. If you have a spinning cylinder, the centrifugal force causes objects sitting on the inside walls to experience an outward force, causing them to stay against the walls, right? But imagine the spinning cylinder, and placing a ball inside the cylinder, close to the wall, but not touching. It's not clear to me that the ball would be attracted to the wall. It seems to me that the ball would not experience any force towards the wall at all; it would just sit there.

Imagine standing in a circular room, with curved walls in the shape of a cylinder, and the walls were turning but the floor is stationary. It doesn't matter if the walls are turning really fast, you'll just stand there and you won't be pulled towards the walls. Now, if you were leaning against the wall, suddenly you'll be pulled against the wall.

So what would happen if you lived on a ring world, and you jumped up? Would you fall back down?
...
...thinking...
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OK, yes, you would fall down, because before jumping, you were rotating with the same velocity as the rest of the ring world. When you jumped up, you still retain that instantaneous velocity (speed and direction) that you started with, plus a small vertical component added from the jump. Now, whereas the ring is constantly changing velocity (even if it's rotating at a constant speed, the angular direction of the movement is constantly changing), while you are in the air, you still retain the same instantaneous velocity you started out with as your feet left the ground, the velocity at the same speed in a straight line. Because the ground is curved and rotating, and you're moving in a straight line tangent to the point where you jumped from, you will hit the ground - a straight line intersecting an arc - so it's just as if you've fallen back down.

narf poit chez BOOM · #4 November 25th, 2003, 09:37 AM

you know, someone once wrote an interesting story about people using dolphin suits to fly in a spherical orbital habitat.

Omnicron1 · #5 November 26th, 2003, 05:34 AM

ecosystems are directly dependent on the one way flow of energy into them from the sun to support life...there are a few instances of life without sun near heat vents and such but still a one way flow of energy and the earths core would cool if it were too much farther from the sun....sooo i assumed that even the farthest planets in the game werent beyond jupiter and not beyond saturn at the most by this it would not be an accurate graphic but if the solar systems in the game, despite the fact that even the farthest planets can support life, can in fact encompass pluto's orbit im sorry about my rant about the inaccuracies of the graphic but i now have to rant about the inaccuracies of the star graphic which is now faaaaaaaaaarrrrrrr too large (1000s of times our suns own mass and volume and too large to support itself making it a blackhole or very near to it)so some graphic is wrong....

narf poit made good point about centriFugal force (someone said Centripetal and thats the opposite) not being a good artificial gravity...but he said that jumping would bring you back to the outside but Narf you were right to begin with because the rule about matter continuing in the same speed and direction would be negated by the jump if you had enough strength to jump from the centrifugal force then you turned the speed and direction around and you would float away from the "ground" which points out that this type of artificial gravity would not support a thick enough atmosphere because air is not dense enough to be significantly affected by centrifugal force..try spinning a balloon around really fast and see if it follows the same course as say a balloon of water...soo if this were the method of gravity it would be more than 1G if you wanted to breathe...

nother importante questione!! if you can move all the matter in many solar systems to cover a star why not sift out all those resources on the way... i can see getting lots of radiactives(energy from sun) or organics (grow real well if they can handle the constant sun) but minerals c'mon you built the place for god's sake!!!!

narf poit chez BOOM · #6 November 26th, 2003, 05:59 AM

no, that was Kamog.

Fyron · #7 November 26th, 2003, 08:05 AM

Omnicron, it is highly unrealistic to expect all graphics to be to scale. If the star was displayed as a single pixel, you would still need millions of pixels to display the solar system to scale! Of course, then the star and planets would be the same "size". So lets make the sun take up a few 1000 pixels, so we can get more accurate scales for the planets. Now we need billions of pixels for the width of the system map! Give me abstract scaling any day!

(note that numbers are made up, and are likely to be overly generous, with real values probably being many times larger)

Also, please note that SE4 is a game, not a simulation. Some level of unreality is not only expected, but required!

Who cares if it is practically impossible to build a sphereworld (or even a ringworld) in the real world! It is practically impossible to colonize a planet in a different star system too. Should we remove that because it is unrealistic?

[ November 26, 2003, 06:08: Message edited by: Imperator Fyron ]