What would a "flat" world be like?

[jhwegener]

What would living on a "flat" world be like? Or what if the bodies of the sky (not the clouds - stars, planets, sun and moon) were "small" bodies perhaps at a distance of a few kilometres (or at least not more than some dosens or hundreds of kilometres)?
Forget for a moment the finer details of "natural laws" - gratity etcetera, and accept it for a moment. If eart was formed as a flat "disk" there should be no horizons other than the real edge of its edge, which should be visible at least from high places. If we climbed up mountains - or perhaps just high man made structures like pyramids an towers, we should feel the sun more, or in the night stars should be brighter and the moon appear bigger. If we travelled to the west the evening sun should be a very hot brigth experience, and appear very big, the dawn very cold. The opposite should be true if You went eastwards.
What is the point with all this (perhaps You find it is all nonsense)?
Well, we know that people from different parts of the world for centuries - even millenia - travelled long distances, and had experiences from sea level and highlands. Some of those peoples must have observed their world (not only the greeks, that tell us what they thought and in some cases had an advanced understanding). Some must have realised that a "naive" understanding of the world did not fit. Polynesians must have had exellent skills in navigation, like greeks, phoenicians, arabs, malayans and chinese. Observations of the sky must have been important for them. Perhaps some of them changed their world view in the proces?

[mr obvious]

If you are looking for a 2D world, the story "Flatland" may be what you are looking for.

However, from your description you appear to be asking what if the Earth itself were a pancake and we had 3-dimensional aspects to our existence. However, many of the examples you give can be applied to a round Earth as well. For example, being on top of a mountain at noon makes you closer to the sun than if you were at the base of the same mountain at noon (of the same day). I don't know if that qualifies as 'feeling the sun more.' Similarly with the east/west concepts - the sun is so far away that traveling from one 'edge' to another adds a puny distance to proximity.

I am also unsure what you mean be a "naive" understanding of the world. If you are referring to the concept that the world is flat; that is likely an oversimplification. In a few hundred BC Eratosthenes measured the circumference of the Earth; that measurement would not be possible without the a priori assumption that the Earth was a sphere. Sailors probably were keenly aware of ships dipping below the horizon; astronomers could probably see the shadow of the Earth on the Moon during an eclipse. So I'm not sure what you're getting at. Sorry for the rambling reply.

[jhwegener]

If you are looking for a 2D world, the story "Flatland" may be what you are looking for.

What interest me most is how our world view became what it is, and the question if it perhaps happened more than once? (or at least it could be).

However, from your description you appear to be asking what if the Earth itself were a pancake and we had 3-dimensional aspects to our existence. However, many of the examples you give can be applied to a round Earth as well. For example, being on top of a mountain at noon makes you closer to the sun than if you were at the base of the same mountain at noon (of the same day).

Of course You are right, but the relative difference is extremely small.

I don't know if that qualifies as 'feeling the sun more.' Similarly with the east/west concepts - the sun is so far away that traveling from one 'edge' to another adds a puny distance to proximity.

Ancient peoples(pre telescope) would have found such distances unbelievable.For many of them probably, the sky played an important role in religion and mythology, and in their world view in general.

I am also unsure what you mean be a "naive" understanding of the world. If you are referring to the concept that the world is flat; that is likely an oversimplification. In a few hundred BC Eratosthenes measured the circumference of the Earth; that measurement would not be possible without the a priori assumption that the Earth was a sphere. Sailors probably were keenly aware of ships dipping below the horizon; astronomers could probably see the shadow of the Earth on the Moon during an eclipse. So I'm not sure what you're getting at. Sorry for the rambling reply.

I have do definitive conclusion or any "theory" strictly speaking, but make some questions.
One is how mankind realised the world another who coud do it. I imagine people who made frequent and long voyages to be in a better position to know.
And one more thing about the greeks and other people: We may know the greek ways of thinking extremely well compared to other peoples, because there is left much in greek compared to other peoples (may did not write much or anything). Perhaps some of them had more advanced world view than we know? (especially perhaps people like polynesians and malayan peoples, since they were ocean going peoples).

[mr obvious]

I'm not quite sure what you are asking and I'd guess that my meager background in astronomical history is inadequate to address your questions anyway.

All I remember vaguely is that most societies did have fairly good observations (e.g., Mayans having spectacular calendars, and possibly having predicted the path of Mars and the fact that it has 2 moons, although I may be confusing science fiction with interesting facts by now). I wouldn't be surprised to hear that many (most?) societies knew a lot more about the 'structure and timing' of the local solar system but cannot give you fruitful guidance. Sorry.

[Swift]

Kansas?

[ravens_cry]

What, a bunch of geeks get together to discuss a non flat world (but not a Flatland apparently) and no mention of the Discworld?
In all seriousness, I don't see how this would form naturally, life has so far shown us that lumping planet sized amounts of matter together tends to make planet like shapes, but I can imagine it being relatively normal gravity wise if you had a lot of material underneath the surface. Think it being like a hockey puck with frosting. However, what kind of day night cycle would you have? Would it be stable if it spun on its edge?

[mike alexander]

Wouldn't gravitational force drop off as the inverse, not the inverse square? At least near the center and not too high up.

[HypothesisTesting]

Wouldn't gravitational force drop off as the inverse, not the inverse square? At least near the center and not too high up.

Yes, that is correct. After you get too high up it will revert back to inverse square because when you are very far away, the earth will look like a point object.

[orionjim]

What would living on a "flat" world be like? Or what if the bodies of the sky ...

I agree with mr obvious, Edwin A. Abbott’s Flatland is a great story. And mike alexander has brought up a good point.

Something to think about is if you give people height or a dimension for height things get different. If you look at the 1st attachment you will find three figures. In Fig 1 you have two people “-“ and “+” starting to walk off in opposite directions. In Fig 2 they have walked ~10 miles. If they keep walking for years and years and then light years and light years and eons and eons, someday they will reach infinity; whatever infinity is. And when they look ahead they begin to see each other.

The question is what will happen when they reach out to shake hands?

It wouldn’t be a pretty sight. As their hands crossed the point of infinity they would instantly be yanked to the opposite infinity.

The mechanism that shows that it is possible to reach infinity is in the 2nd attachment. Turning the knob clockwise will move the “+” an increasing amount in the +x direction.

To see this in action see this site and drag the red dot around the circle.


Jim

[jokergirl]

The Discworld series has also come up with a few very interesting explanations on that matter.
Of course, the light on Discworld is slowed down to about the speed of sound in places because of the Discworld's extremely dense magical field, so the findings might not apply to everything else...

[Nicolas]

Discworld not only comes up with interesting explanations, they also look at the practical side. For example, even though Discworld is flat, you can't fall off, thanks to the circumfence.

But let's keep it real here. The earth is not flat, it is round. Round as a pancake.
(c) Herman Finkers

[neilzero]

Long time scientists, of the generalist type, likely always had problems with some of the theories related to the flat Earth hypothesis. There have been times in the past when it was dangerous to express such doubts. When reasonably safe, they likely discussed ATM theories such as the Earth being spherical.
With advanced technology, it will likely be possible to build poker chip shaped habitats with diameters of thousands of kilometers in solar or earth orbit. Because of their great mass, they will have (varying with location) gravity of about one percent that of earth's surface. As you move from the center of either side, you will perceive that you are climbing a hill which will become quite steep at the edge. Almost a vertical cliff. You will need mountain climbing equipment to traverse from the flat to the edge, but down will be perpendicular at the center of the edge of the this giant poker chip. Neil

[HenrikOlsen]

From Niven's Larger than Worlds:

The Disc

What's bigger than a Dyson sphere? Dan Alderson, designer of the Alderson Double Dyson Sphere, now brings you the Alderson Disc. The shape is that of a phonograph record, with a sun situated in the little hole. The radius is about that of the orbit of Mars or Jupiter. Thickness: a few thousand miles.
Gravity is uniformly vertical to the surface (freshman physics again) except for edge effects.. Engineers do have to worry about edge effects; so we'll build a thousand-mile wall around the inner well to keep the atmosphere from drifting into the sun. The outer edge will take care of itself.
This thing is massive. It weighs far more than the sun. We ignore problems of structural strength. Please note that we can inhabit both sides of the structure.
The sun will always be on the horizon, unless we bob it, which we do. (This time it is the sun that does the bobbing.) Now it is always dawn, or dusk, or night.
The Disc would be a wonderful place to stage a Gothic or a swords-and-sorcery novel. The atmosphere is right, and there are real monsters. Consider: we can occupy only a part of the Disc the right distance from the sun. We might as well share the Disc and the cost of its construction with aliens from hotter or colder climes. Mercurians and Venusians nearer the sun, Martians out toward the rim, aliens from other stars living wherever it suits them best. Over the tens of thousands of years, mutations and adaptations would migrate across the sparsely settled borders. If civilization should fall, things could get eerie and interesting.

[Nicolas]

Is this statement Gravity is uniformly vertical to the surface (except for edge effect) correct? My feeling tells me that there will be an offset towards the centre.

And if you build a giant wall around your sun, how much heat does it still give to your disc?

[HenrikOlsen]

A wall a couple of thousand miles high isn't giant compared to the size of the sun. Which will be wobbling anyway.