Thoughts when looking at those fantasy worlds: If a world is thousands or millions of times wider than earth and have...

Thoughts when looking at those fantasy worlds: If a world is thousands or millions of times wider than earth and have normal day/night circle, how it's structure could be?
For example a ring world will not have normal sunrise/sunset and giant planet will have too fast rotation speed

>If a world is thousands or millions of times wider than earth
it's automatically not a planet anymore but a star and pretty fucking big one at that

The rotation would be very slow, the wider it is the slower it can be to maintain 1g.. The atmosphere would block most of the surrounding scenery in the distance. Looking up, you'd be able to see the rest of the ring though. Like a far away arch over you disappearing into the distance somewhere through thick atmosphere. Dusk and dawn would look like a flat eclipse when they start.

I think if you read the Ringworld series of books you may get most of your answers.

Sorry I tried to say:
A ring world could have enough surface area, but will not have normal sunrise/sunset because of it's form, so not feasible
A giant planet which have 100 times diameter than earth could have enough surface area, but to maintain 24hours day/night circle it's surface rotation speed will be very fast

enough surface area for what?

To make a big fantasy world?
Sorry this is not actually sci but to look at fantasy with science fic way. It's just some random thoughts.
For example, if a dragon could fly at the speed of an airplane, he could fly around the earth within 24 hours, earth is such a small place for dragons, so a high fantasy world should be much more wider than earth.
That makes me think how a fantasy world will exists as a celestial body in real world

Why not have the ring be made up of cylindrical segments and spin the cylinders? Yeah, you would have uninhabitable 'triangles' on the back of the ring, but you've increased the total habitable amount of land.
Plus cylinders are the best form for colonies so we could just build super colonies and then construct them into a ring.

Then it's equatorial will be the same length with earth, a dragon or a wizard could still fly around a cylindrical segment through equatorial and find out that the world is a cylinder.
Is there a way to make "world" wider in any direction while with day/night circle and 4 seasons?

why not just make a slower dragon?

A slow dragon sounds so weak.
Just wondering if it's possible to design a world that is reasonable large for high fantasy, without breaking physical laws

Short of doing something like hitchhikers where you custom order a planet, I don't think so.

*super lazy math*
You could have a molten titanium core.
That lets you have density of like 280 instead of 500-600
So that gives a radius of 0.62 for iron/nickel/radio-element core
and a radius of 0.78 for titanium core
and a radius of ~1 for aluminum

So, your sa is:
12.6 for aluminum
7.7 for titanium
4.8 for erf

So 1.6x as much for titanium, and 2.6x as much for aluminum.


!!! Those numbers are wrong because gravity would be impacted by the changed radius, yet constant mass. !!!
So if you're willing to accept "the core isn't iron", then you can make the world as big or as small as you like, as long as you remember to make gravity at the surface the same.

Looks like the sky isn't the limit, and you can't go more than 4X the surface area of erf without a hollow planet.
If you're cool with metalic foams, then you could make it even bigger.

>could
That is an absurd surface area. Literally 100000 times as much surface area.

>but to maintain 24hours day/night circle it's surface rotation speed will be very fast
Center of a binary star system. You get to halve the rotational speed.

>24 hour day/night cycle.

A sufficiently variable star would do it. In a fantasy setting you could get away with that.

If you drain all the water off earth you'd have 71% more land to build on. 2.44x more land.

The ring world is unstable.

You don't need a day / night cycle, yes we evolved with one but really we could adapt to constant daylight, not least by building "dark rooms" where we spend some of our time (and where we sleep).

In said future world I would hope we could cure the sleep pandemic, with in the very least, a pill.

or "oh, it's 6pm? let me put on sunglasses"

Binary star system sounds interesting,
So if we have a Dyson sphere around a sun which have 330,000 times mass of earth,
To maintain about 1G gravity on it's surface, the Dyson sphere diameter should be 600 times of earth right? And with 330,000 times surface area.
But to maintain 24 hours day/night how fast will the rotation speed be? How fast are the movement of binary stars?

>How fast are the movement of binary stars?
Do the escape velocity equation.

>Dyson sphere

Dyson "swarm", not sphere.