Quick Question

They think we see the same stars in different patterns but they believe the stars are projected onto a large dome in the sky.

Quote from: flat_earth_debunker on June 16, 2018, 07:57:19 PM

They think we see the same stars in different patterns but they believe the stars are projected onto a large dome in the sky.

This is not true.

The stars are different at different latitudes because of near uniform spatial distortion across the surface. They are different stars, it is a different sky, but above a shared surface.

How come we see different constellations at different latitudes if the earth is "flat" I can't come up with an excuse.

The stars are different at different latitudes because of near uniform spatial distortion across the surface. They are different stars, it is a different sky, but above a shared surface.

Do you mean they see a different section of the sky?

Quote from: JackBlack on June 17, 2018, 02:20:07 PM

Do you mean they see a different section of the sky?

I mean that the spatial distortion across the surface ensures they see a different spherical sector of the sky. Apologies for the confusion. Your objections are totally justified based on my previous poor wording.

How come we see different constellations at different latitudes if the earth is "flat" I can't come up with an excuse.

You see different constellations at different latitudes precisely the same way you would able to see different constellations inside any planetarium.

A planetarium is the perfect model of the celestial sphere encircling the flat surface of the flat earth.

Just what do you mean by "the spatial distortion across the surface"?

Quote from: rabinoz on June 18, 2018, 01:35:49 AM

Just what do you mean by "the spatial distortion across the surface"?

On the flat Earth, there is a (near) uniform spatial distortion across the surface due to the fact it is a 2-manifold (somewhat) immersed in Euclidean space. I'm using it as a shorthand for describing the Earth's counterintuitive geometry.

I'm using it as a shorthand for describing the Earth's counterintuitive geometry.

If the earth, neglecting very small features, were a flat surface why would there be any spatial distortion across the surface?

Quote from: Tessa Yuri on June 18, 2018, 05:04:14 PM

I'm using it as a shorthand for describing the Earth's counterintuitive geometry.

i.e. as a way of pretending it is flat when it really isn't?

Quote from: rabinoz on June 19, 2018, 12:23:11 AM

If the earth, neglecting very small features, were a flat surface why would there be any spatial distortion across the surface?

'Why' is a question that science can't usually address, but 'how' is much simpler. It is because every object in our universe (barring some exotic objects) has surface distortion from our perspective. By that I mean because space is nearly Euclidean but not quite, objects in our universe aren't orientable in true Euclidean space (not perfectly, at least). Given this, if we are to interpret everything as if it is in Euclidean space, every object will have surface distortion. The Earth itself (and other planets, and however further you want to take this argument), is actually a real projective plane, because it is a non-orientable 2-dimensional manifold.

PS. Why not both?

Quote from: JackBlack on June 19, 2018, 02:13:59 AM

Quote from: Tessa Yuri on June 18, 2018, 05:04:14 PM

I'm using it as a shorthand for describing the Earth's counterintuitive geometry.

i.e. as a way of pretending it is flat when it really isn't?

That is not an honest question, so forgive me if I do not offer you any honest answer.

By that I mean because space is nearly Euclidean but not quite

The Earth itself (and other planets, and however further you want to take this argument), is actually a real projective plane, because it is a non-orientable 2-dimensional manifold.

PS. Why not both?

That is not an honest question, so forgive me if I do not offer you any honest answer.

Youve already admitted you are not good with math.

I suppose you'd probably classify me as being unable to understand maths.

Why switch to a more complicated model?

Quote from: Tessa Yuri on June 19, 2018, 04:06:53 AM

Quote from: rabinoz on June 19, 2018, 12:23:11 AM

If the earth, neglecting very small features, were a flat surface why would there be any spatial distortion across the surface?

'Why' is a question that science can't usually address, but 'how' is much simpler. It is because every object in our universe (barring some exotic objects) has surface distortion from our perspective. By that I mean because space is nearly Euclidean but not quite, objects in our universe aren't orientable in true Euclidean space (not perfectly, at least). Given this, if we are to interpret everything as if it is in Euclidean space, every object will have surface distortion. The Earth itself (and other planets, and however further you want to take this argument), is actually a real projective plane, because it is a non-orientable 2-dimensional manifold.

PS. Why not both?

Quote from: JackBlack on June 19, 2018, 02:13:59 AM

Quote from: Tessa Yuri on June 18, 2018, 05:04:14 PM

I'm using it as a shorthand for describing the Earth's counterintuitive geometry.

i.e. as a way of pretending it is flat when it really isn't?

That is not an honest question, so forgive me if I do not offer you any honest answer.

Youve already admitted you are not good with math.
Why switch to a more complicated model?
Geocentric heliocentric round warped into 2d flat...
These are all conventions used to predict and model.
Car manufacturers have their 0-0-0 coordinates a foot infront to account for design changes.
If the math is overly complicated for no reason...why use it?


Amazing they were able to use and build this but it is not practical.
Look at mars and moon wobble all had to be accounted for.
Doable
But not neccessary.

Quote from: Tessa Yuri on June 19, 2018, 04:06:53 AM

By that I mean because space is nearly Euclidean but not quite

Spacetime is non-Euclidean. The jury is still out on space itself. Regardless of which one you mean, the curvature is insignificant. It cannot make a flat object the size of Earth appear round.
You would need something the size of the universe.

Quote from: Tessa Yuri on June 19, 2018, 04:06:53 AM

The Earth itself (and other planets, and however further you want to take this argument), is actually a real projective plane, because it is a non-orientable 2-dimensional manifold.

No it is not.
Being a 2D manifold doesn't make it flat or a "projective plane" for non-Euclidean space(time).

Quote from: Tessa Yuri on June 19, 2018, 04:06:53 AM

PS. Why not both?

Because flat and curved are fundamentally different.
The only time an object can be "flat" and "curved" is when you use different meanings.
For the purposes of math, using gaussian curvature, the surface of an infinite cylinder is flat, even though it has a principle curvature in one direction.

PS Am I replying to Tessa or Yuri .

Quote from: Tessa Yuri on June 19, 2018, 04:06:53 AM

That is not an honest question, so forgive me if I do not offer you any honest answer.

It is an honest, rhetorical question, pointing out your dishonesty.

I was trying to communicate (and I realise in hindsight I was not perfectly clear), that the geometry of the Earth itself causes it to appear round from space.

Agreed. My assertion that Earth is a real projective plane was based more on the conclusion that it is non-orientable. I can see how my sentence implies what you suggest, but I offer that we already both agree that the Earth is a real projective plane. I'll make a thread specifically addressing this later today if you're interested.

The P.S. was in response to:

Putting aside the question of how an honest question can be rhetorical, how have I been dishonest? Or more precisely, where have I lied?

Quote from: rabinoz on June 19, 2018, 12:23:11 AM

If the earth, neglecting very small features, were a flat surface why would there be any spatial distortion across the surface?

'Why' is a question that science can't usually address, but 'how' is much simpler. It is because every object in our universe (barring some exotic objects) has surface distortion from our perspective. By that I mean because space is nearly Euclidean but not quite, objects in our universe aren't orientable in true Euclidean space (not perfectly, at least). Given this, if we are to interpret everything as if it is in Euclidean space, every object will have surface distortion. The Earth itself (and other planets, and however further you want to take this argument), is actually a real projective plane, because it is a non-orientable 2-dimensional manifold.

• v << c,
  
  
• Gravitational fields are static and
  
  
• The magnitude of the gravitation potential is small, ie the "particle" is far outside the Schwarzschild radius, r_s, of the mass, M where r_s = 2GM/c².

PS. Why not both?

Quote from: Tessa Yuri on June 15, 2018, 11:12:39 AM

Quote from: Themightykabool on June 19, 2018, 10:35:20 AM

Why switch to a more complicated model?

Because it is more correct. Every time a scientific theory is overthrown or corrected, it is usually always in favour of a more complicated one.

As someone with a keen interest in science, I find it a little sad that you criticise scientific pursuits because they are 'overly complicated', 'not necessary' or 'not practical'. So while I understand your objections, I do not agree with them or their implications.

Pff
For the purpose of discovering stars galaxies super novas black holes gravity waves light etcetc sure we need better and improved math...
When we are debating is the earth a spheriod or an flat plane, overly complicated and N/A.

You misunderstood.   
I like scientific pursuits.
Thats why the electron between grade 9-10 science changes from rings to clouds.
For the purpose of modeling and convention they are simplified.
Are you asking us the unwrap the earths skin just so that it can be shown, mathmatically, as flat?
Whats your point here?

For the purpose of discovering stars galaxies super novas black holes gravity waves light etcetc sure we need better and improved math...
When we are debating is the earth a spheriod or an flat plane, overly complicated and N/A.

Quote from: Tessa Yuri

PS. Why not both?

Well, Tessa might accept that the earth is an almost perfect sphere, GR and Newtonian mechanics but
Yuri can't do that because all it needs to demolish a flat stationary earth is either GR or Newtonian mechanics.

And to think that the topic is "Quick Question" - one thing leads to another!

Quote from: rabinoz on June 19, 2018, 06:07:03 PM

And to think that the topic is "Quick Question" - one thing leads to another!

Quite, but I hope you find these conversations as productive and worthwhile as I do. I very much enjoy having them with you.