forum I need some help from someone who understands physics.

Started January 08, 2018 by @Krista Williams

tune

My world is very unique. I basically took a bunch of junk the ancient astronomers used to believe and made it true for my world. It’s flat, it’s surrounded by an orb of stars and the sun rotates around it. I also took some threads from mythology, such as the sun and moon being actual intelligent beings instead of inanimate objects.

What I need to know is how these changes will affect the laws of physics as we know them, thus equipping myself with a general knowledge of what I can do and what I can’t.

Any comments will be helpful. Thanks in advance!

Well, the problem is, that you can't realy ask the question of actual physics, when your world in it self can't work.

Its basically like this:
Because our "reality" works with gravitiy all planets have to be some kind of round shape.
This is because all matter attracts to other matter, which means that huge junks of matter (like planets) always draw on its center point.
To put it simple, gravitation is the "glue" that holds plants together and stops the molecules from just flying off into space on their own.
Paired with the rotation of planets it is the reasons for stuff like sattelites being able to orbit earth, "feeling" lighter when going higher into space and the other way around etc. etc.
I'm sure you know all this, but it is important for my next point.

There are several (scientific) reasons, why this "old world picture" is impossible (given our physical laws).
First of all, when there is still gravitation, the edges of your circular world would just be pulled to the center of the world.
If there is no gravitation, the question is, what is holding your world together.
Of course you could say "It's to gods or some other mythical force" which, of course, is fine for a fictional world, but when the explanation is basically "magic" you can't realy ask physics to explain it without giving some ground rules.
There has to be some explanation, why the "planet" is not just collapsing. If it is a "logical" (and not "magical") explanation, you can think about the application of physics again.

Second there is the problem with the water.
If your world is like the old believes I remember from history class, the water flows down the sides, the where does it go?
You could say that it is "caught" by some force that brings it back to the planet, for example just appearing from under the ocean (which would not be a big problem for the application of physics, because its basically like in the game portal, which also had correct physics, but with portals ;-) But back on topic)
But this could still create a problem with the topic of gravitation.
Given you found a physical explanation why the world can exist (for example by just inventing new laws), how can the water flow over the sides and "down" (which is, what was believed back in the day) without there being any graviation? (This also extends to the people on the planet and everything else)

Your third big problem is with the sun (and moon):
You said that it is rotating around the world.
As we said before, rotation works (in our cosmos) by combining two opposing energies:
First being the gravitation, that pulls everything together and the second being the movement of objects and thir inertia.
when these two energies work against each other, they can create an orbit of the lighter object to the heavier object.
But how can this be possible when, you got rid of gravitation so your world won't collapse.
And even if there is still gravitation, the smaller (in terms of mass) object always rotates around the smaler (like its with our earth and sun).
But in your world, the sun is rotating around the earth, which is just not explainable with our physical laws.

To summerize:
I like the idea to bring that old world picture to live, but there is a reason why it was disproved and is not possible.
That said, all ficional worlds always only have to abide to their OWN rules (if that question is even asked, what you did ;-P ).
This means that having the rule of "The sun rotates around the earth because it does and it also doesn't affect the earth with its gravitation" is fine and completely solves my third point.
But also it means that you have come a with a change in the laws of physics, which means you can't apply the anymore in a "universal" manner, only with "but"s.

There are also two ways to do this:

1. Find logical (in context of our physics) explanations why your world can exist and make them as clear as possible, so our "law"s can still be applied to them.
   Taking from the example before: Portals are not possible in the way you would need them, but you can just state that those exist (e.g. through divine power), and then we can apply our other physics on them, which is fine.
2. Come up with completely new physical laws
   This is WAY harder, because you have to think about universal laws that can explain, why a planet is not drawn to a sphere, but the people on that planet still don't fly off into space (just to take an example)
   As I said before, you can always pull the joker of "divine power" here, but at some point the question of physics is not really relevant anymore (just do the "normal" applications and explain everything else with the "joker" and you wouldn't have asked the question =) )

Sorry for the WOT, but I just kept writing down, what came into my mind XD
I'm happy to discuss all this of course, If you have notes or questions or whatever =D

TL;DR World is not explainable with physical laws and thus the question of explaining "some" things doesn't work. Ignore physics or "rebuild" them for this

very very interesting idea op, and very very interesting and insightful comment wild!
this sort of topic intrigues me very much, and so i very gladly will try to join this discussion with my limited knowledge (due to my bad memory problems making me forget things even though i might be very interested in them).

I was thinking about the sun (and moon i would suppose?) problem - of how it would work to actually have it gravitate around the earth, in this scenario with all points up ahead given. and although this might be going in from a wrong end, it is a way to perhaps start thinking about the path to a solution, perhaps.
(note:) Not perhaps the greatest idea, but thought i might share it to keep the discussion going (and - i love talking about and exploring these ideas and would love to assist).

so considering if the sun (and moon) are actual intelligent beings; perhaps that also means that they are not purely made out of the same matter as stars, or what have you.
like, there are tons of variation on what The Ancient Ones believed or mused what the sun might be, or might be symbolized as. and even, current ideas spread around romanticizing the idea; a gargantuan sapphic goddess made out of pure warmth, floating around the earth, lovingly spreading life and health to all the creatures of this earth?
or is perhaps the sun still a floating orb of fire, that connects fueling burning hatred inside one ascended mortal who now controls the sun at their whim? ruling with an 100000 degree iron fist by threat of impending blight to scorch previously thriving forests and farms into deserted wastelands?

i don't know. but - my point being this: depending on what the sun is and what it is made of - physics will act accordingly. or rather, according to whatever rules you will make.
but. physics is a hard thing to really have stapled down in "Yes, this would work" since - well - if it is talking about things that just, wouldn't work with our, the current understanding of physics, things can get rather confusing and convoluted, to say the least.
but there's so much things we also don't know. for example, might go on of a bit of a stretch here, but things even the most educated don't know much about: magnetic fields. how do they work. "how do they play in to this?" you might ask a physics professor. they might just say "i have no idea, no one does." and laugh. and cry.

another example that might be more to the point:
dark matter. what, the fuck, how.. so how do we - yes.
what i mean with bringing this up - there are a lot of things that can change up a situation Grandly. change it up into a way that we, in our current state of things, can not really grasp.
there are a lot of things we have no idea about. science, is a lot and lot of speculation.
few things are set, as things change the more and more we learn!

so basically: if you want to make a world that is flat, the sun gravitates around it, and there is an orb of stars around it (and gosh knows what is beyond that) - that makes for another playing field.
if you wanna rationalize it - going in from the "how does our physics even work?" when they might not ever apply - it might be going from the wrong foot, or feet?

it's a great idea to learn about physics in general, and all things world-building, of course, to build a whole new universe, or whatever one might call it.
but remember: this is a whole new thing you're creating. a new world unlike our world. and it is wonderful, and you have a LOT of planning, and writing down, and thinking, and pondering, and tearing your hair out of your skull to do - if you want to do it like you're thinking. and your thinking is great. and it will be amazing.

maybe an idea would be to look at it from another point of view than the "this is the general 'how-it-works' of our world." maybe look into the stranger things we don't quite understand or have an explanation for?
search around information for really, what did those old ancient astronomers think? and what do you want to make out of what they think? and what you want to make? think about that - and go from that - perhaps?

again - great great discussion and idea. sorry for this mess above, i am not sure whether it was useful or interesting even, at all, to be honest haha.
but anyway, good luck on everything, am looking forward to seeing more.

@norbinary very interesting ideas and thoughts. And yes I think it was helpful ;-)

The easiest way would indeed be to just take mystic forces (to which I count physical concepts we don't understand, as you elaborated) and make up reasons, why it all works with those.
But the OP wouldn't have started the discussion, if that was what he wanted to do.

I think it basically comes down to this:
With our current understanding of physics it is not possible, BUT I easiest way to do it is this:
First, decide which physical concepts still apply (for example gravitation). This should then not be altered, because they can be your "this is the logical reason this works".
Second, take force, that are "new" (like divine power) or we don't understand and let them work for you, still applying the concepts you wanted to keep.

Then you can to something like this:
The dark matter in my world just happened to have formed in a way that it made a disk. On that disk the ancient sun and moon created the earth and the oceans.
The dark matter also formed in a way that it applies gravitation to the upper side of the disk (because I say it does ;-) )
Because of that people do feel like they would on our earth.
Also the sun and moon are not mere planets but beings of a matter that bares all imagination and they don't rotate around the earth, because of some physical concept, but because they want to (yes, they are that powerful.
The thing with the water is just portals as explained before.

Now I have bend some rules, so others can still apply and you can still explain stuff with at least some physical concepts.

Of course that is just one way you can do it, there are infinite possibilities.
Another idea would be having influence from Greek mythology and have an ancient being carry the world on its shoulders.
You can always have things that act in contrary to normal physics, but then apply the same on the rest of the cosmos.

I think my answer to the original question would be:
Because the world can't exist with our understand of physics, you have to bend the rules.
After you did that (in whatever way), decide which "rules" we know still apply and then think/ask about their implications.

I'm happy to continue the discussion as it is very exciting and interesting =D

I am wayyyy too into all this nerdiness lol. OP, the great thing about fiction is that you can make up your own laws of physics. I agree with the other commenters completely.
Very interesting world by the way!

This is exactly the kind of input I was looking for! Thank you so much, all of you!

As I stated before, the way I created this world was by taking old beliefs of our world that have been proven impossible and adding it to my new world. I knew that taking away the spheric shape of the planet and the orbit around the sun would affect the gravitation and I didn't quite know how I would compensate for that.

However, I was thinking about this theory that I heard a while back. Supposedly, when the earth was first created, it was surrounded by a film of water that protected it from the radiation of the sun (like the atmosphere does today) and kept the environment inside the orb perfect for living creatures. Then a cataclysmic event occurred, destroying that orb.

My thought was that I could use my star orb as a shield like the one in the above theory. It could equilize the pressure inside the orb, keeping the inhabitants from floating away.

Thoughts?

I love this idea it sounds really cool unfortunately I love this stuff but I don't know stuff about physics

I'd suggest looking at Terry Pratchett's Discworld series. https://en.wikipedia.org/wiki/Discworld
It is a flat world on the back of four massive elephants atop a gigantic flying space turtle and yet no one screams about the unbelievability of it…

physics physics physics physics physics

Krystal that sounds great XD

Basically gravity is not a thing anymore. Neither is atmosphere. Which means life literally should not be able to exist. So this can't be a normal world. But maybe if you make it an alternate universe, mirror universe, or pocket universe. Maybe this place is a collection of things that black holes have collected are (and maybe when the black hole tore them apart, it tried to reform itself when it was disposed of in a pocket universe, but the laws of physics couldn't reorganize themselves so you end up with stuff like gravity gone, and things in different places, but something that resembles "life" is still sustainable). Anyway that's just my idea, do what you will with it, lol.