Is Earth round or flat ?

[rattlesnake]

6 hours ago, BillyBid said:

 

Whats your point?  

 

It is fairly self-explanatory.

[rattlesnake]

9 hours ago, Mike_Hunt said:

1. Drop Over Distance

A common approximation is:

• Over 1 mile (1.61 km), the Earth's surface drops about 8 inches (20 cm).
• Over 10 miles (16.1 km), the drop is about 66.7 feet (20.3 m).
• Over 100 miles (161 km), the drop is about 6,667 feet (2,032 m).

 

Thanks Mike.

 

@BillyBid, any additional insights?

[0ffshore360]

Is it not possible that a round circle can be flat ? But if the earth is flat what does the "underside" look like?

I am wondering if it would be like someone sitting naked on a glass table ? All revealing like?

 

 

[HotMama]

1 hour ago, rattlesnake said:

8 hours ago, BillyBid said:

Whats your point?  

 

It is fairly self-explanatory.

 

Not really.  There are direct flights between Perth and Johannesburg that go over the ocean and nowhere near Dubai..  Why did you post this???  Did you think there weren't flights?  Seriously, I really don't understand.

 

 

 

[rattlesnake]

13 minutes ago, HotMama said:

 

Not really.  There are direct flights between Perth and Johannesburg that go over the ocean and nowhere near Dubai..  Why did you post this???  Did you think there weren't flights?  Seriously, I really don't understand.

 

 

 

 

Research it and you will see the overwhelming majority of airlines do not offer direct flights, South African Airlines being pretty much the only exception.

[HotMama]

10 hours ago, Mike_Hunt said:

Would you like a specific calculation for a given distance?

 

Sure, give me the calculation for 99% of the radius.  Say 6300km to make it a nice easy round number for you.  What would the drop be for that value?  

 

On a sphere that would very obviously be nearly the same as the radius, but using your formula I get a value of many thousands of times larger than that. 

[HotMama]

9 minutes ago, rattlesnake said:

Research it and you will see the overwhelming majority of airlines do not offer direct flights, South African Airlines being pretty much the only exception.

 

Qantas also flies it.  What a surprise that the only two airlines that fly between south Africa and Australia are Qantas and South African.....

 

 

[richard_smith237]

13 minutes ago, rattlesnake said:

 

Research it and you will see the overwhelming majority of airlines do not offer direct flights, South African Airlines being pretty much the only exception.

 

Please do not make a very basic error in sense and mistake basic economics for the earths 'shape' as the reason certain routes are taken. 

[rattlesnake]

4 minutes ago, richard_smith237 said:

 

Please do not make a very basic error in sense and mistake basic economics for the earths 'shape' as the reason certain routes are taken. 

 

A very astute remark indeed.

[rattlesnake]

10 minutes ago, HotMama said:

 

Qantas also flies it.  What a surprise that the only two airlines that fly between south Africa and Australia are Qantas and South African.....

 

 

 

A possibly valid remark.

 

If this were the only example given, I would agree on its limited relevance. I believe, however, that when there is a body of circumstancial evidence, then it warrants closer observation.

 

There are plenty of examples, I will look into them a bit later.

 

[Stiddle Mump]

1 hour ago, rattlesnake said:

 

A possibly valid remark.

 

If this were the only example given, I would agree on its limited relevance. I believe, however, that when there is a body of circumstancial evidence, then it warrants closer observation.

 

There are plenty of examples, I will look into them a bit later.

 

Why can't a plane fly around the coast of Antarctica? Is it because a plane can't fly 120,000 kms in one go?

 

I've looked, and I can't find any flights.

[HotMama]

34 minutes ago, Stiddle Mump said:

Why can't a plane fly around the coast of Antarctica? Is it because a plane can't fly 120,000 kms in one go?

 

I've looked, and I can't find any flights.

 

And you don't think that maybe you can't find any flights because there are no airports or cities anywhere near the coast of Antartica?

[rattlesnake]

So regarding the flight paths, I found this website which provides all available routes between two airports:

 

https://www.flightconnections.com/

 

I did find some peculiar things, confirmed when checked on flightconnections.com:

 

Why does Buenos Aires - New Delhi not stop over in Africa?

 

 

 

Rio Gallegos - Johannesburg: why the detour via Sao Paulo?

 

 

 

There are also several flights which make seemingly massive detours through Europe (in fact most of them, even if the odd direct flight exists). Example here with Buenos AIres - Johannesburg:

 

 

[rattlesnake]

On 3/13/2025 at 12:13 PM, Stiddle Mump said:

Why can't a plane fly around the coast of Antarctica? Is it because a plane can't fly 120,000 kms in one go?

 

I've looked, and I can't find any flights.

 

Good question. Why indeed?

[rattlesnake]

On 3/12/2025 at 11:32 PM, Mike_Hunt said:

 

The Earth's curvature is typically expressed in terms of drop per distance, radius of curvature, or sagitta (chord height difference). Here are a few ways it's quantified:

1. Drop Over Distance

A common approximation is:

• Over 1 mile (1.61 km), the Earth's surface drops about 8 inches (20 cm).
• Over 10 miles (16.1 km), the drop is about 66.7 feet (20.3 m).
• Over 100 miles (161 km), the drop is about 6,667 feet (2,032 m).

The formula for the drop d due to curvature over a distance x on a sphere of radius R is:

d=R−R2−x2

For Earth, where R ≈ 3,959 miles (6,371 km), you can compute the drop for any distance.

2. Radius of Curvature

The Earth's mean radius is 6,371 km (3,959 miles). This value is used in many geophysical and engineering calculations.

3. Sagitta (Height of Arc Over a Chord)

If you draw a straight line (chord) between two points on Earth's surface, the maximum height h of Earth's curvature above the chord is given by:

h=x22R

where x is half the chord length.

Would you like a specific calculation for a given distance?

 

So how does one explain this?

 

[SillySam]

23 minutes ago, rattlesnake said:

So how does one explain this?

What needs explaining?

[Mike_Hunt]

48 minutes ago, rattlesnake said:

 

So how does one explain this?

 

Anyone who does math should understand.

[rattlesnake]

15 minutes ago, Mike_Hunt said:

Anyone who does math should understand.

 

I don't do math, please explain.

[Mike_Hunt]

1 hour ago, rattlesnake said:

 

I don't do math, please explain.

I can't help you at this point. 

[Stiddle Mump]

5 hours ago, rattlesnake said:

 

So how does one explain this?

 

This post seals the deal.

 

 

[JumpingJim]

4 hours ago, rattlesnake said:

I don't do math

 

That is quite obvious because entering 50 miles for X and 3959 miles for R into your equation d=R−R2−x2 would give a ridiculously large drop value of greater than the diameter of the earth.  Any high school student could see that.

 

 

[rattlesnake]

8 hours ago, Mike_Hunt said:

I can't help you at this point. 

 

I preferred yesterday's Mike, the one who would readily provide detailed explanations and formulas without being prompted to.

[rattlesnake]

5 hours ago, Stiddle Mump said:

This post seals the deal.

 

 

 

Indeed. A Google search yields convoluted explanations about this being a mirage of some sort… Or to put it simply, "don't trust your own eyes".

[Stiddle Mump]

2 minutes ago, rattlesnake said:

 

Indeed. A Google search yields convoluted explanations about this being a mirage of some sort… Or to put it simply, "don't trust your own eyes".

Bang on the money there Rattles.

 

Of course there will be some AN members who think differently. But you must press on in your crusade.

[gamb00ler]

On 3/12/2025 at 8:50 PM, Stiddle Mump said:

Another poster on this topic said you cannot. I trust his judgement.

 

Trips in the Northern Hemisphere are much shorter than trip of the same distance in the Southern Hemisphere. Can't get away from that.

I was wondering when you would descend into producing oxymorons.

[richard_smith237]

33 minutes ago, Stiddle Mump said:

38 minutes ago, rattlesnake said:

 

Indeed. A Google search yields convoluted explanations about this being a mirage of some sort… Or to put it simply, "don't trust your own eyes".

Bang on the money there Rattles.

 

Of course there will be some AN members who think differently. But you must press on in your crusade.

 

Its more basic science that you both seem to be ignoring... I come back to this thread from time to time and its quite depressing to see the depths of mediocrity that are being discussed.

 

Brace yourselves for the breakthrough: light refracts. Incredible. Truly earth-shattering. Apparently, this phenomenon; so rudimentary that it barely warrants discussion, is the explanation for why at when viewed from a distance over water ships seem to float and buildings appear to be the wrong height.

 

This phenomenon is an optical illusion caused by superior mirages. This occurs due to the refraction of light in layers of air with different temperatures.

 

 

I'll return later and become more depressed at the depths of mediocrity humanity is capable of reaching as evidenced by many comments in this thread already.

 

 

 

 

[JumpingJim]

23 minutes ago, richard_smith237 said:

Its more basic science that you both seem to be ignoring... I come back to this thread from time to time and its quite depressing to see the depths of mediocrity that are being discussed.

 

These guys frequently posting here are just trolls.  They don't even believe the earth is flat.  They just think they are being funny by promoting this nonsense.  You are wasting your time with them.

 

[rattlesnake]

1 hour ago, richard_smith237 said:

 

Its more basic science that you both seem to be ignoring... I come back to this thread from time to time and its quite depressing to see the depths of mediocrity that are being discussed.

 

Brace yourselves for the breakthrough: light refracts. Incredible. Truly earth-shattering. Apparently, this phenomenon; so rudimentary that it barely warrants discussion, is the explanation for why at when viewed from a distance over water ships seem to float and buildings appear to be the wrong height.

 

This phenomenon is an optical illusion caused by superior mirages. This occurs due to the refraction of light in layers of air with different temperatures.

 

 

I'll return later and become more depressed at the depths of mediocrity humanity is capable of reaching as evidenced by many comments in this thread already.

 

 

 

 

 

Your patience is much appreciated, Richard, as is your willingness to occasionally stoop to these abyssal depths of mundanity.

 

Regarding refraction, my uneducated mind doesn't understand how it works with the picture posted above. The refraction phenomenon only works with objects which are already in line of sight, as explained here:

 

https://www.britannica.com/topic/mirage-optical-illusion

 

The phenomenon called "Fata Morgana", for example, causes a superior mirage to be visible in a narrow band above the horizon, caused by a misinterpretation of what really is a "false horizon": the surface of the water takes on the color of the sky because of lighting, the position of clouds and the stillness of the water surface. But the sine qua non is that the object has to be visible to begin with.

 

In the above picture of Chicago, the buildings are 50 miles away. According to the well-established formula recalled by Mike, over a distance of 10 miles (16.1 km), the drop is about 66.7 feet (20.3 m).

 

So over a distance of 50 miles, that’s a drop of over 100 m, the smaller buildings should not be visible at all. Refraction does not cause hidden objects to appear.

[richard_smith237]

31 minutes ago, rattlesnake said:

So over a distance of 50 miles, that’s a drop of over 100 m, the smaller buildings should not be visible at all. Refraction does not cause hidden objects to appear.

 

Actually - thats exactly what refraction 'over water' can do... 

 

 

Key Principles of Refraction Over Water

 

Light Bending Due to Temperature Gradients

The atmosphere is not uniform; its density changes with altitude.

Over water, air near the surface is often cooler than the air above (especially in warm conditions). This creates a temperature gradient.

Light bends towards the denser (cooler) air, which means it curves downward, allowing us to see objects that would normally be below the geometric horizon.

 

Superior Mirage Effect

When the air near the surface is cooler than the air above, light rays bend downward, making distant objects appear higher than they actually are.

This is called a superior mirage, and it can make ships, landmasses, or even celestial bodies (like the sun) visible when they should be geometrically below the horizon.

 

Looming

A specific type of refraction where objects below the horizon appear lifted up.

This occurs when the temperature gradient is strong, and light follows a curved path, making the object visible despite being "hidden" by the Earth's curvature.

 

Ducting & Fata Morgana

In extreme cases, strong temperature inversions (where warm air sits above cool air) can trap light in a curved path, creating a "ducting" effect.

This can make objects appear stretched, distorted, or even duplicated.

 

Real-World Examples

Ships appearing to "float" above the horizon.

The sun setting later than expected.

Distant islands becoming visible in conditions of strong refraction.

 

 

This diagram below illustrates how refraction can make an object below the horizon visible. The curved light path (in orange) bends due to atmospheric refraction, allowing the observer to see the object that would normally be hidden.

 

[Stiddle Mump]

11 minutes ago, richard_smith237 said:

 

Actually - thats exactly what refraction 'over water' can do... 

 

 

Key Principles of Refraction Over Water

 

Light Bending Due to Temperature Gradients

The atmosphere is not uniform; its density changes with altitude.

Over water, air near the surface is often cooler than the air above (especially in warm conditions). This creates a temperature gradient.

Light bends towards the denser (cooler) air, which means it curves downward, allowing us to see objects that would normally be below the geometric horizon.

 

Superior Mirage Effect

When the air near the surface is cooler than the air above, light rays bend downward, making distant objects appear higher than they actually are.

This is called a superior mirage, and it can make ships, landmasses, or even celestial bodies (like the sun) visible when they should be geometrically below the horizon.

 

Looming

A specific type of refraction where objects below the horizon appear lifted up.

This occurs when the temperature gradient is strong, and light follows a curved path, making the object visible despite being "hidden" by the Earth's curvature.

 

Ducting & Fata Morgana

In extreme cases, strong temperature inversions (where warm air sits above cool air) can trap light in a curved path, creating a "ducting" effect.

This can make objects appear stretched, distorted, or even duplicated.

 

Real-World Examples

Ships appearing to "float" above the horizon.

The sun setting later than expected.

Distant islands becoming visible in conditions of strong refraction.

 

 

This diagram below illustrates how refraction can make an object below the horizon visible. The curved light path (in orange) bends due to atmospheric refraction, allowing the observer to see the object that would normally be hidden.

 

Wow!

 

Can see things 100 metres below the surface?! I'm getting an education on this curvy earth stuff..