Dyson Spheres don't "orbit"

[wyldmage]

For the love of science, can the developers please update their game description and information?
Dyson spheres do not "orbit" anything. Same with ring worlds. They require high strength construction capable of withstanding the inward pull of the star's gravity.

There is no orbit, and a heavy-science game like this getting such a simple point wrong is embarrassing at the minimum, and mostly just insulting.

[umop-apisdn]

引用自 wyldmage：

引用自 umop-apisdn：

If it's not an orbit, what is it?

Apparently a statite

No, that is incorrect. A statite is a satellite (an object that orbits another object) that employs a solar sail to continuously modify its orbit in ways that gravity alone would not allow. That motion (or lack thereof), which is what most of us are discussing in this thread (because you brought it up), is still called an orbit.

I'm not a professional physicist, but I'll do my best to lay this out in terms that will make it easier to understand. An ELI5, of sorts, but with slightly bigger words. Let's call it an ELI-12.

Here, let's try the car analogy...
You're arguing that a vehicle isn't "driving" if it's not a car, or not on a road. I asked what you call it when a truck is doing the same thing, and your answer was "motorized vehicle, apparently".

Yeah, okay. We get that a car is a motorized vehicle... but so is a truck. The directed motion of a motorized vehicle (what we're actually discussing) is still called "driving," whether it's a car or a truck, whether it's on a road or in the desert. Even if you paint the truck blue, it's still called "driving."

I hate to be the one to break it to you, but you'll need to learn some physics if you'd like to argue about physics.

Here's the deal: the gravity of a star is spherical. The Dyson Sphere is a... well, it's a hollow sphere, (surprise!) with its walls equidistant (that bit's important) from the star.

In simple terms, the gravity of the star pulls on all of it the same amount (because it's equidistant from the star - told ya that bit was important), and it doesn't collapse because of something called compressive strength. It's strong enough to resist the weight being enforced by the star's gravity, by pressing on the neighboring structures.

This is the same way that an arch works... except in this case, the arch is made entirely of keystones; the rest of the sphere plays the part of the abutments and footers, and every voussoir is also a keystone (A voussoir is the wedge-shaped stone that makes up most of an arch; the keystone is the top-most voussoir). More to the point, the arch has no springers (lowest voussoir, also known as a "footer"), because it's a complete sphere.

Each keystone is its own footer, after the force travels through literally the entire rest of the sphere. Gravity keeps it all in place, through compressive strength.

To put it another way, its very existence is what holds it up, due to the shape of the structure.

Let's try a meme; imagine a picture of Thanos saying,
"We use the stones to hold up the stones."

"To orbit" is "to move through a gravitationally curved trajectory". The curve in this case is flat, relative to the center of gravity, because it's a sphere around a star. Any lateral motion (or lack thereof) is completely irrelevant to the fact that it's still in an orbit, with gravity providing the centripetal (inward) force and compressive strength providing the centrifugal (outward) force; no spin is required.

Today you learned. Maybe. You're welcome.

[wyldmage]

引用自 umop-apisdn：

Today you learned. Maybe. You're welcome.

:sphere:

Yes, I am learning, thanks to people like you who ACTUALLY take the time to post in depth arguments with rational train of thought.

Not people like Alien who just accuse me of trolling, when my entire point of view has made perfect sense to me, and they just throw dumb 'explanations' or completely skip bothering to explain, and just tell me that "a hemisphere orbits", even if it would crash into the star due to a lack of counter-force for the part of it at the poles.

The last page or two have been the most helpful in understanding how/why I'm wrong, instead of imbeciles just throwing random posts at me that don't actually attempt to teach or correct, just make noise.

I do/did absolutely understand the physics behind a physical dyson sphere holding itself up, that was never in question. My issue was the use of orbit, which has always in my educational history been associated with movement/speed. I have literally NEVER seen it used to describe a superstructure maintaining it's physical location by structural integrity (not velocity).

I would love if you could provide a link to some scientific text for learning about the concept you covered at the end (because your definition is completely different than the one available anywhere I've found online).

[wyldmage]

引用自 Nekogod：

Are you sure about that? It doesn't sound right, the effect on Mercury from the other planets would be negligible considering how close it is to the Sun, and their gravity would only act to help Mercury when it was between the other planets and the Sun. Any time the Sun was between the other planets and Mercury they would instead be pulling Mercury towards the Sun.

Though it is true that orbital resonance with various planets at various times is affecting it's orbit over time, it's an incredibly slow process.

It would probably be true to say that the other planets have a stabilising effect on it's orbit, though resonance with Jupiter may cause Mercury's eccentricity to increase to such an extent that it collides with Venus, but that's billions of years away.

This is why he's just a troll. Over half of what he says isn't even directly relevant or relatable. He's just spouting a ton of BS and accusing me of being a troll. But I'm actually doing my best to read, and respond to the quality posts, and just hand-waving off the dumb ones like his.

[umop-apisdn]

引用自 wyldmage：

I would love if you could provide a link to some scientific text for learning about the concept you covered at the end (because your definition is completely different than the one available anywhere I've found online).

Literally everything I said was taken almost directly from Wikipedia or verified by typing "(word) definition" into Google. I used those two sites as a "quick reference" to be certain I was explaining things correctly and according to known paradigms.

[wyldmage]

引用自 umop-apisdn：

引用自 wyldmage：

I would love if you could provide a link to some scientific text for learning about the concept you covered at the end (because your definition is completely different than the one available anywhere I've found online).

Literally everything I said was taken almost directly from Wikipedia or verified by typing "(word) definition" into Google. I used those two sites as a "quick reference" to be certain I was explaining things correctly and according to known paradigms.

If you type "definition orbit", you get

引用自 Dictionary：

1. the curved path of a celestial object or spacecraft around a star, planet, or moon, especially a periodic elliptical revolution.
"the Earth's orbit around the sun"
2. a sphere of activity, interest, or application.

(of a celestial object or spacecraft) move in orbit around (a star or planet).
"Mercury orbits the Sun"

Nothing about the curve not mattering.
Even the result "What is an Orbit?" from NASA is the same. They all only talk about stereotypical orbits (like a planet and star).

Looking at the Wikipedia page atm, and it looks to be all the same as well, just discussing orbit as it pertains to actual motion. Which category in the page talks about what you are covering (there's a lot of categories to slowly work my way through)?

[umop-apisdn]

To be completely fair to wyldmage, I think the core problem is a misconceived premise (a previous statement or proposition from which another is inferred or follows as a conclusion).

Namely, that premise is that an orbiter does not, technically speaking, actually require "motion" relative to the orbitee; all that is required is that gravity keeps the orbiter from escaping, while some other force prevents the orbiter from smashing into whatever it's orbiting due to the centripetal force of the orbited body's gravity. That centrifugal force is often, but not always, applied by means of perpendicular motion.

[wyldmage]

引用自 umop-apisdn：

To be completely fair to wyldmage, I think the core problem is a misconceived premise (a previous statement or proposition from which another is inferred or follows as a conclusion).

Namely, that premise is that an orbiter does not, technically speaking, actually require "motion" relative to the orbitee; all that is required is that gravity keeps the orbiter from escaping, while some other force prevents the orbiter from smashing into whatever it's orbiting due to the centripetal force of the orbited body's gravity. That centrifugal force is often, but not always, applied by means of perpendicular motion.

Yup. And the fact that half of the responses were just things like:

Technically the dyson swarm and sphere parts are orbiting star up until it becomes a whole ring. When you design a sphere you are still making orbits for the foundations.

Remember that none of what happens in the game is real. Nothing is orbiting anything. The planets do not orbit the sun. They simply follow the path the game creates for them.

OP obviously has experience with Dyson Spheres in real life, using the existing ones as reference.

yes but have you considered, the Dyson Sphere is around a star, thus it is orbiting. if it weren't orbiting it would fall into the sun.

But it will require velocity to stay in position, and not drift, therefor it does orbit the star. Even the earths mantel ORBITS the molten core of the planet, just as a Sphere would orbit a Star.

objects either orbits the sun, leaves the solar system, or falls into the sun.

Which either fail to explain anything, or are simply antagonistic with no purpose.

In the first 2 pages of this thread only 2 posts (1 person) provided any actual insight to correct me.

I've been completely open to ACTUAL logic and explanations. Being proven wrong means I learn why and how I'm wrong, and that's all good for me. And I did my 'research' beforehand (looking it up via google, double checking, etc). I was unable to find anything that indicated an orbit could exist without a traditional/stereotypical orbital path.

[Zok]

引用自 AlienWired：

Earths crust, which would be your "Dysons sphere", orbits it's core.

Source ?

This would mean that the only difference between the crust of the Earth and its core and a Dyson Sphere and it's star is the density of the material in the space between the outer and inner object.
That means if the material between Earth's crust and its core would be removed, the crust would stay in place (if the crust were a perfect sphere) orbiting its core.

[umop-apisdn]

引用自 wyldmage：

Nothing about the curve not mattering.

The curve totally matters, because spacetime is curved. It's relativity, and I've forgotten how to explain it to someone who doesn't already understand. For that matter, I don't see where I said anything even remotely resembling that, unless you completely misunderstood my statement about the distance between the sphere and the orbited star being constant.

It's the motion that "doesn't matter", not the curve. You have to understand that all motion is relative; quantifying some object's speed requires a second object to compare speed to. An object able to stay "motionless" relative to another body is, by physical necessity, orbiting that other body (or vice versa)... because there is motion relative to the frame of reference containing both the previously described bodies and some other body, yet they are "motionless" in relation to one another.

Consider the following statement: "A geostationary position is synonymous with a geosynchronous orbit."

An orbit does not require motion in relation to the two bodies. An orbit is defined by position over time, full stop. The laws of motion/inertia require gravity (providing the centripetal (inward) force) and some other centrifugal (outward) force.

[umop-apisdn]

引用自 Zok：

引用自 AlienWired：

Earths crust, which would be your "Dysons sphere", orbits it's core.

Source ?

This would mean that the only difference between the crust of the Earth and its core and a Dyson Sphere and it's star is the density of the material in the space between the outer and inner object.
That means if the material between Earth's crust and its core would be removed, the crust would stay in place (if the crust were a perfect sphere) orbiting its core.

Source: Physics and relativity.

Density has nothing to do with it, merely the fact that the crust and the core are able to move independently of one another; they are, for the purposes of determining whether or not one is orbiting the other, two separate bodies.

The mantle (and the pressure provided by the crust being a mostly contiguous and impermeable (to the mantle) surface) that separates them provides the centrifugal force that counteracts gravity's centripetal force. Two separate bodies, one relatively motionless in position in reference to the position of the other; gravity is trying to pull the external object into the internal object, but some force is preventing that... et voila: Orbit, by definition.

"An orbit is a regular, repeating path that one object in space takes around another one."
"Stationary" can be defined as "infinite positional repetition."

QED.

[wyldmage]

引用自 umop-apisdn：

引用自 Zok：

Source ?

This would mean that the only difference between the crust of the Earth and its core and a Dyson Sphere and it's star is the density of the material in the space between the outer and inner object.
That means if the material between Earth's crust and its core would be removed, the crust would stay in place (if the crust were a perfect sphere) orbiting its core.

Source: Physics and relativity.

Density has nothing to do with it, merely the fact that the crust and the core are able to move independently of one another; they are, for the purposes of determining whether or not one is orbiting the other, two separate bodies.

The mantle that separates them provides the centrifugal force that counteracts gravity's centripetal force. Two separate bodies, one relatively motionless in position in reference to the position of the other; gravity is trying to pull the external object into the internal object, but some force is preventing that... et voila: Orbit, by definition.

"An orbit is a regular, repeating path that one object in space takes around another one."
"Stationary" can be defined as "infinite positional repetition."

QED.

However, the continents are not stationary. They are drifting in non-repeating directions.

In fairness, this digresses from the original topic, as a manmade structure around the sun would in theory hold constant motion or lack of motion.

[umop-apisdn]

引用自 wyldmage：

However, the continents are not stationary. They are drifting in non-repeating directions.

Taken as a whole, the crust can be considered a single homogenous entity for the purposes of deciding whether or not it orbits the core (it does), much like the Kuiper Belt (the asteroid field just outside Neptune's orbit), taken as a whole, can be considered a homogenous entity when considering whether it orbits Sol or not (it does).

引用自 wyldmage：

In fairness, this digresses from the original topic, as a manmade structure around the sun would in theory hold constant motion or lack of motion.

Unless and until we stop discussing orbits and orbital mechanics, I believe we are still "on-topic". I will, however, admit that my patience has limits; I am not a teacher, by trade, and there are reasons.

I recommend you seek further guidance from your local library and/or college to learn more about relativity, motion, spacetime, and other physics topics.

Good day, and thank you for the discussion.

[wyldmage]

引用自 umop-apisdn：

引用自 wyldmage：

In fairness, this digresses from the original topic, as a manmade structure around the sun would in theory hold constant motion or lack of motion.

Unless and until we stop discussing orbits and orbital mechanics, I believe we are still "on-topic". I will, however, admit that my patience has limits; I am not a teacher, by trade, and there are reasons.

I recommend you seek further guidance from your local library and/or college to learn more about relativity, motion, spacetime, and other physics topics.

Good day, and thank you for the discussion.

I meant that debating whether a given continent counted as orbitting was the digression (my own post), not accusing anyone else of going off topic.

The problem with learning on my own, as I've pointed out so far, is that Google (and similarly using a library) is limited by your ability to know which sources to find. I had several impressions and understanding fueled by what you CAN find without knowledge/guidance.

Now I have ideas about what I don't know, but not about where to find that information in a specific context. "The library" is tens or hundreds of thousands of books. Narrowing it down to science/physics still leaves hundreds (thousands at the local college library). Not something I'm capable of wading through without any clue what I'm looking for.

[umop-apisdn]

引用自 wyldmage：

引用自 umop-apisdn：

I recommend you seek further guidance from your local library and/or college to learn more about relativity, motion, spacetime, and other physics topics.

The problem with learning on my own, as I've pointed out so far, is that Google (and similarly using a library) is limited by your ability to know which sources to find. I had several impressions and understanding fueled by what you CAN find without knowledge/guidance.

Now I have ideas about what I don't know, but not about where to find that information in a specific context. "The library" is tens or hundreds of thousands of books. Narrowing it down to science/physics still leaves hundreds (thousands at the local college library). Not something I'm capable of wading through without any clue what I'm looking for.

Perhaps the topics I listed in the exact same sentence you quoted would be good search terms to start with?

Although to be fair, you might wish to start with "how to research". I'm not attempting to be mean, this is a genuine attempt to be helpful - most people who "do their research" online don't have the first clue what "research" actually is, and we all have to start learning somewhere. There are many guides available that can teach you how to learn what you don't know, so that you can start learning it.

In that same vein, the Wikipedia articles on "critical thinking" and "logic" have some excellent information that you might do well to be aware of, and are chock-full of phenomenal search terms; many of them are already hyperlinks, with "previews" available by hovering your cursor over them. This can be wonderfully informative, especially if you just need a quick overview of the concept you just discovered you knew nothing about without losing your current context.

Remember: this is honest advice, not an attack. Slow down, breathe, and pay attention instead of puffing up, turning red, and shutting down. A lot of people take criticism poorly, I'm hoping you're not one of them. Criticism can be constructive, if used as a learning tool.

Good luck!

[wyldmage]

引用自 umop-apisdn：

Perhaps the topics I listed in the exact same sentence you quoted would be good search terms to start with?

Although to be fair, you might wish to start with "how to research". I'm not attempting to be mean, this is a genuine attempt to be helpful - most people who "do their research" online don't have the first clue what "research" actually is, and we all have to start learning somewhere. There are many guides available that can teach you how to learn what you don't know, so that you can start learning it.

Hence why I called what I did 'research' with the quotes. I fully know how to research, and you need something to start with. I know what my end-goal here is to find. But there's a disconnect. The books I've read do not talk about it, nor connect to it. Searching those terms involved has gotten me nowhere except what I've already seen.

That is why I was asking for a pointer. Some starting source. Because that disconnect means there is something missing. Something that when I sit down to view on a topic does not connect from what learning I have already done into what is out there.

I've done extensive reading on topics such as string theory, particle colliders, relativity, and so forth. Because you can find tons of good sources and links starting from entry level inquisitiveness.

I've taken college physics courses, and the concept of an orbit being velocity-independent never occured.

We're on the same page in terms of knowledge about how the various forces involved function. I'm on a different page when it comes to terminology and such. I read the entire wikipedia article, and still didn't find a reference to what you were saying about an orbit not involving velocity. Everything, including the dense section with tons of newtonian concepts still talks about velocity as best as I can understand (there's a LOT of higher level math that I can't easily keep up with).

Which, again, is why I asked, which PART of the wiki page. It's a giant amount of text, and I may have missed something while trying to slog through it all.

If you don't even want to point, admit that yourself, don't tell me I'm bad at learning/researching. Because I absolutely understand how to go about it. I'm telling you that I've tried. And gotten nowhere related to the concepts of stationary orbit that you discuss. It's just not talked about.