I don’t believe the world is flat, but what is the evidence for the theory that it is a sphere?

Is it approximately a sphere? And why would the planets form as a sphere in the first place? Would you say intelligent design or gravity is circular?

Why can’t it be a cube with an irregular 3d surface that approximates a sphere?

I’m quite serious. Why are we not looking for planets in different shapes? And why are black holes logarithmic spirals?

I want to write a sci-fi story where instead of using ships to explore space we instead grow the Earths atmosphere. I mean we make space livable by growing the Earth’s protective atmosphere layers. No need for oxygen you already have it. Gravity and the fact you have to travel in an airplane just might be some drawbacks.

I have some ideas, but the story telling part is where it takes literarily talent.

Any plot ideas?

You will need a universe with different physics to get planets that are not close to spherical. At fine scale it may look very uneven but viewed from space Earth looks close to spherical, the unevenness too small to pick out by eye. With accurate measurement, shown to be oblate - fatter around the equator due to centripetal force from spinning. Gravity tends to make stuff higher than that around it to tumble and flow to fill lower places.

How do we know? Does someone really have to count the ways for you? That could be a homework assignment. Google and Wikipedia would probably give a start. Google Scholar for the more technical, published papers.

30 minutes ago, Trurl said:

Why can’t it be a cube with an irregular 3d surface that approximates a sphere?

Which would be spherical.

It’s an oblate spheroid; the rotation means there is an equatorial bulge. Gravity, being spherically symmetric, dictates the shape, as long as the object is massive enough so that gravity can overpower any structural forces (hydrostatic equilibrium). That’s one of the criteria for calling something a planet.

38 minutes ago, Trurl said:

I want to write a sci-fi story where instead of using ships to explore space we instead grow the Earths atmosphere. I mean we make space livable by growing the Earth’s protective atmosphere layers. No need for oxygen you already have it. Gravity and the fact you have to travel in an airplane just might be some drawbacks.

Not really feasible. Our atmosphere is breathable for of order 10 km, on top of a radius of ~6400 km. It’s a thin layer. Extending it - and not even by very far - would mean a thicker atmosphere at ground level.

On 6/1/2025 at 11:18 PM, Ken Fabian said:

How do we know? Does someone really have to count the ways for you? That could be a homework assignment. Google and Wikipedia would probably give a start. Google Scholar for the more technical, published papers.

Thanks for the reply. I do need to research further.

I can’t remember who said it but the question to ask a physicist is, “Could God have built the universe in a different way?”

On 6/1/2025 at 11:32 PM, swansont said:

It’s an oblate spheroid; the rotation means there is an equatorial bulge. Gravity, being spherically symmetric, dictates the shape, as long as the object is massive enough so that gravity can overpower any structural forces (hydrostatic equilibrium). That’s one of the criteria for calling something a planet.

That is a problem: more atmospheric pressure. I choose to extend the atmosphere because the building blocks already exist. If we could control gravity it would make it easier to work.

Obviously we don’t have the technology, but what if you build “atmospheric bridges” in the sky? You could put a structure of invisible gases and anchor them the surface in order to reduce atmospheric pressure. And before you answer remember it just hypothetical.

7 hours ago, Trurl said:

That is a problem: more atmospheric pressure. I choose to extend the atmosphere because the building blocks already exist. If we could control gravity it would make it easier to work.

If you could reduce gravity then the atmosphere can more easily escape the planet completely.

7 hours ago, Trurl said:

Obviously we don’t have the technology, but what if you build “atmospheric bridges” in the sky? You could put a structure of invisible gases and anchor them the surface in order to reduce atmospheric pressure. And before you answer remember it just hypothetical.

To reduce atmosphere? Why? You aren't moving very fast near the surface, and it’s a relatively small part of your trip (<100 km). Maintaining the vacuum wouldn’t be easy.

If you were far from gravity, or if you made the tube in a circle around a planet you could fill them with gases but then you’re in a situation where a vacuum is likely preferable because atmosphere gives you drag

9 hours ago, Trurl said:

Thanks for the reply. I do need to research further.

I can’t remember who said it but the question to ask a physicist is, “Could God have built the universe in a different way?”

That is a problem: more atmospheric pressure. I choose to extend the atmosphere because the building blocks already exist. If we could control gravity it would make it easier to work.

Obviously we don’t have the technology, but what if you build “atmospheric bridges” in the sky? You could put a structure of invisible gases and anchor them the surface in order to reduce atmospheric pressure. And before you answer remember it just hypothetical.

If you want it to be sci-fi then it has to have an internal logical consistency, that at least correlates, however loosely, to current scientific thinking; otherwise it's just another story, in which magic happens...

I think the current Dr who writer, has forgotten the rules...

1 hour ago, dimreepr said:

If you want it to be sci-fi then it has to have an internal logical consistency, that at least correlates, however loosely, to current scientific thinking; otherwise it's just another story, in which magic happens...

I think the current Dr who writer, has forgotten the rules...

I agree that consistency is far more important. Getting detailed actually boxes you in if you invoke some technology of dubious (at best) feasibility.

There are stories that flat-out ignore some scientific principles, but they generally don’t try to do too much to explain anything regarding the contradiction. Anything with FTL travel/hyperspace or even just very fast travel, where relativity ignored (e.g. Star Wars, Forbidden Planet). Star Trek mentioned “Heisenberg compensators” for the transporter, but no detail beyond that.

14 hours ago, swansont said:

where a vacuum is likely preferable because atmosphere gives you drag

I chose to increase the atmosphere because humans can’t live in the vacuum. Traveling in the vacuum would increase speed but humans can’t withstand it. But I suppose if you could alter the atmosphere you could build a ship that had an atmosphere. But altering Earth’s atmosphere has advantages like stopping climate change.

Also would it be possible to increase the layers of the atmosphere to give a plane more lift? I remember that Popular Mechanics always predicted a plane could take off and fly then reach an altitude and escape into space.I don’t know if the project ever worked.

13 hours ago, dimreepr said:

If you want it to be sci-fi then it has to have an internal logical consistency,

I think the current Dr who writer, has forgotten the rules...

I agree. I don’t know enough about the atmosphere to avoid plot holes. But what if it was not written as traditional science fiction but a lesson plan to research things like the velocity a plane would need to escape the atmosphere? I am not an expert story teller. Sometimes a good story teller is all you need. But something like this the science has to be real.

I’ve heard the transporter was invented because it was the only way to get to the planet and have it flow in the show. It basically breaks down the molecules of your body and sends them through space. I don’t know how it reassembles them or how this affects living organisms.

12 hours ago, Trurl said:

I’ve heard the transporter was invented because it was the only way to get to the planet and have it flow in the show.

I never understood that. Implying that they took a shuttle to the surface of the planet worked on many episodes. You don't have to break up the action by actually showing them in the shuttlecraft.

12 hours ago, Trurl said:

It basically breaks down the molecules of your body and sends them through space. I don’t know how it reassembles them or how this affects living organisms.

IIRC, it makes a copy of you at the new destination, based on a scan at the origin, then destroys/recycles the original once the copy is safely delivered.

Each week a new crew who only imagine that they survived each transporter trip and whose memories are all just simulated. Every trip is fatal, with new duplicates who falsely believed they survived. "Energize!"

Always kind of bothered me, the philosophical issues the transporter raised.

1 hour ago, TheVat said:

Each week a new crew who only imagine that they survived each transporter trip and whose memories are all just simulated. Every trip is fatal, with new duplicates who falsely believed they survived. "Energize!"

Always kind of bothered me, the philosophical issues the transporter raised.

Oh, aye. And if you're just creating a copy of you in the new location, why not just travel across the galaxy like that instead of using a ship? Is it slower to relay a teleporter scan than to take a starship there?

In the beginning, I think the transporter really was supposed to throw your broken-down molecules a short distance where they were then reassembled. That's why it couldn't be used to travel long distances in the blink of an eye, just short hops down to the planet's surface or to another ship.

30 minutes ago, Phi for All said:

Oh, aye. And if you're just creating a copy of you in the new location, why not just travel across the galaxy like that instead of using a ship? Is it slower to relay a teleporter scan than to take a starship there?

In the beginning, I think the transporter really was supposed to throw your broken-down molecules a short distance where they were then reassembled. That's why it couldn't be used to travel long distances in the blink of an eye, just short hops down to the planet's surface or to another ship.

Star Trek is pretty consistent about this - normal transporters have a limited range, so you can’t go planet-to-planet, much less to the next system. They used it when they are in close proximity (a few tens of thousands of km)

I think they ginned up a special kind that went longer, because a story line required it.

On 6/5/2025 at 4:51 AM, Trurl said:

Also would it be possible to increase the layers of the atmosphere to give a plane more lift? I remember that Popular Mechanics always predicted a plane could take off and fly then reach an altitude and escape into space.I don’t know if the project ever worked.

Your physical knowledge is even worse than your mathematical knowledge..

Get started with this article::

https://en.wikipedia.org/wiki/Escape_velocity

23 minutes ago, Sensei said:

Your physical knowledge is even worse than your mathematical knowledge..

Get started with this article::

https://en.wikipedia.org/wiki/Escape_velocity

While there are issues with a plane being able to fly high in the atmosphere and then get to space, it’s not really an issue of escape velocity, since 1) you can be in space and still be in the earth’s gravity well and 2) if you have thrust while in flight, you don’t have to achieve escape velocity even if you do want to leave the gravity well, which is prominently pointed out in your link.

1 hour ago, swansont said:

While there are issues with a plane being able to fly high in the atmosphere and then get to space, it’s not really an issue of escape velocity, since 1) you can be in space and still be in the earth’s gravity well and 2) if you have thrust while in flight, you don’t have to achieve escape velocity even if you do want to leave the gravity well, which is prominently pointed out in your link.

His idea from the previous post, at least that's how I understood it, was to increase the density of the Earth's air...

22 minutes ago, Sensei said:

His idea from the previous post, at least that's how I understood it, was to increase the density of the Earth's air...

Which also has nothing directly to do with escape velocity..

1 minute ago, swansont said:

Which also has nothing directly to do with escape velocity..

The denser the atmosphere, the greater the drag and the more fuel required to reach escape velocity.

IOW, it works exactly the opposite of what he said. It's easier to take off from an Earth-like planet without an atmosphere than from an Earth-like planet with an atmosphere like now, and even worse from an Earth-like planet with a denser atmosphere.

I don't know what you don't understand that you question it?

Everything is interrelated in a complicated way. Without understanding escape velocity, there is no point in dwelling on other things, since his main goal was to reach space more easily than today.

Edited June 6Jun 6 by Sensei

1 hour ago, Sensei said:

The denser the atmosphere, the greater the drag and the more fuel required to reach escape velocity.

IOW, it works exactly the opposite of what he said. It's easier to take off from an Earth-like planet without an atmosphere than from an Earth-like planet with an atmosphere like now, and even worse from an Earth-like planet with a denser atmosphere.

I don't know what you don't understand that you question it?

Everything is interrelated in a complicated way. Without understanding escape velocity, there is no point in dwelling on other things, since his main goal was to reach space more easily than today.

You need to reread the post you quoted. It’s about a plane getting into space. Yes there are issues that would be worse with a thicker atmosphere. But it still has nothing to do with escape velocity. I don’t know why you think it does.

7 hours ago, swansont said:

You need to reread the post you quoted. It’s about a plane getting into space. Yes there are issues that would be worse with a thicker atmosphere. But it still has nothing to do with escape velocity. I don’t know why you think it does.

I don't know what got into you today, maybe you read about Musk and decided to follow in his footsteps, but I'm afraid you need to read the title of this thread, because it's about space exploration, from what I read..

If space exploration has nothing to do with escape velocity from Earth, you better knock yourself on the head..

Edited June 7Jun 7 by Sensei

2 hours ago, Sensei said:

I don't know what got into you today, maybe you read about Musk and decided to follow in his footsteps, but I'm afraid you need to read the title of this thread, because it's about space exploration, from what I read..

If space exploration has nothing to do with escape velocity from Earth, you better knock yourself on the head..

I think the point being made is that getting into space , which was what the post about planes was discussing, does not require reaching escape velocity, that’s all.

Once you are in space, in Earth orbit (achievable at a speed well below escape velocity), you can use rockets or whatever to boost your spaceship to escape velocity, from whatever altitude the orbit is at, if that is what you want to do.

6 hours ago, Sensei said:

I don't know what got into you today, maybe you read about Musk and decided to follow in his footsteps, but I'm afraid you need to read the title of this thread, because it's about space exploration, from what I read..

If space exploration has nothing to do with escape velocity from Earth, you better knock yourself on the head..

The post you replied to was on a very specific topic. If you wanted to make your point about escape velocity, which doesn’t apply to vehicles exerting thrust (only for ballistic travel) and, as exchemist has also pointed out, only getting to space (e.g. LEO), you should have chosen a different post to quote.

And really, don’t try and guess peoples’ motivations. It’s inappropriate (personal attack, so a bit insulting), and says more about you and your biases.

13 hours ago, swansont said:

While there are issues with a plane being able to fly high in the atmosphere and then get to space, it’s not really an issue of escape velocity, since 1) you can be in space and still be in the earth’s gravity well and 2) if you have thrust while in flight, you don’t have to achieve escape velocity even if you do want to leave the gravity well, which is prominently pointed out in your link.

This is one of the best summaries of escape velocity without maths that I've seen in a long time.

So many get this wrong.

+1

Well if you launch a rocket from a plane there are several advantages. You can launch it anywhere in the world and you don’t have to worry about the launch site being bombed.

But I admit my science wasn’t very good. I’m just trying to brainstorm new ideas. Stuff that ai doesn’t ruin. I post a picture of a space elevator. Now I don’t think anchoring the elevator to an asteroid is going to work, but there is a valid problem that needs solved and that is to build a 20,000 mile structure that doesn’t collapse.

I believe that impossible problems make excellent learn examples. If you gave a student a problem to make structures out of the atmosphere it may seem like kaka but it is a problem that ai would have trouble solving and if the student did use it, that would only be a starting point.

On 6/5/2025 at 6:45 PM, Phi for All said:

Oh, aye. And if you're just creating a copy of you in the new location, why not just travel across the galaxy like that instead of using a ship? Is it slower to relay a teleporter scan than to take a starship there?

In the beginning, I think the transporter really was supposed to throw your broken-down molecules a short distance where they were then reassembled. That's why it couldn't be used to travel long distances in the blink of an eye, just short hops down to the planet's surface or to another ship.

The Enterprise is a culteral affectation, it represents a platform of extended power, from which to pr/teach the American accent... 😉

8 hours ago, Trurl said:

Well if you launch a rocket from a plane there are several advantages. You can launch it anywhere in the world and you don’t have to worry about the launch site being bombed.

But I admit my science wasn’t very good. I’m just trying to brainstorm new ideas. Stuff that ai doesn’t ruin. I post a picture of a space elevator. Now I don’t think anchoring the elevator to an asteroid is going to work, but there is a valid problem that needs solved and that is to build a 20,000 mile structure that doesn’t collapse.

I believe that impossible problems make excellent learn examples. If you gave a student a problem to make structures out of the atmosphere it may seem like kaka but it is a problem that ai would have trouble solving and if the student did use it, that would only be a starting point.

Why not use space elevators to transport everything we need to a space station and launch from there?

On 6/2/2025 at 4:55 AM, Trurl said:

I don’t believe the world is flat, but what is the evidence for the theory that it is a sphere?

Is it approximately a sphere? And why would the planets form as a sphere in the first place? Would you say intelligent design or gravity is circular?

Why can’t it be a cube with an irregular 3d surface that approximates a sphere?

I’m quite serious. Why are we not looking for planets in different shapes? And why are black holes logarithmic spirals?

I want to write a sci-fi story where instead of using ships to explore space we instead grow the Earths atmosphere. I mean we make space livable by growing the Earth’s protective atmosphere layers. No need for oxygen you already have it. Gravity and the fact you have to travel in an airplane just might be some drawbacks.

I have some ideas, but the story telling part is where it takes literarily talent.

Any plot ideas?

There is a good sci fi story titled “Mission of Gravity” by Hal Clement, in which a rapidly rotating planet has an almost disk-like shape and in which the refraction of light in the atmosphere creates the illusion of living in a bowl. https://en.wikipedia.org/wiki/Mission_of_Gravity

This may not be what you were hoping for but it does seem physically plausible and is certainly different.