Do you think the atmoplane / atmosphere extends indefinitely? No? Then there must be some sort of space medium. We know next to nothing about its properties,

That is completely untrue, we know plenty about the properties of the upper atmosphere, the transition to "space" and even interplanetary space and can

*infer* a great deal about interstellar and intergalactic space

*by indirect means*.

But we also know that flat Earthers will instantly claim that the methods of obtaining the extreme altitude information are "fake"!

Hence we try not to rely on such information until flat Earthers start making such inconsistent claims such as assuming that light travels in straight lines when it fits their hypotheses and denying it at other times.

So we know that:

Up to 100,000 ft (30,480 m) or so

*measurements of atmospheric properties* have been routinely found from

*high-altitude balloons*.

Above that the earliest measurements were from sounding rockets as described in:

**The History of Sounding Rockets and Their Contribution to European Space Research by ***Günther Seibert* **Rocket-borne in-situ measurements in the middle atmosphere by ***Jonas Hedin*And this summarises the properties of the "Standard Atmosphere" up to 80,000 metres:

**Engineering ToolBox: U.S. Standard Atmosphere**Then, based on those sounding rocket and later measurements there is the:

**MSISE-90 Model of Earth's Upper Atmosphere**So, we know more than enough about the transition between between the atmosphere and "space".

When dealing with the refractive index (

*n*) of gases the value is so close to unity that

*refractivity (**N*), defined as N = (

*n* - 1) x 10

^{6} is commonly used simply to make the numbers easier to read.

So, for example, air at sea-level has a refractive index of about 1.000277 so its refractivity would be 277.

The refractivity of a given type of gas if very nearly proportional to its density and the tables linked above give the densities at each altitude.

Hence the refractivity, refractive index and hence to the velocity of light compared to a perfect vacuum can readily be found at any altitude up to 35,786 km, the approximate altitude of geostationary satellites.

I'll let the reader work out the details.

aside from the wild unsupported claims given by Team Round.

If its so clear that space does not affect light's path or its speed, then it should be simple enough to show this.

I'd say that I have!

And your patron Saint Samuel Birley Rowbotham

*assumes* "that space does not affect light's path" in his "Measure of the True Height of the Sun" and he "measured" it to be

*not more than 700 statute miles*.

Glen Voliva also did his "measurement" by again

*assuming* "that space does not affect light's path" with this:

**On the Flat Earth, How High is the Sun?**

Wilbur Glenn Voliva (1870-1942) was the first radio evangelist, and a major proponent of the Flat Earth, offering $5000 for anyone who could disprove his flat earth theory.

This image is from the article "$5,000 for Proving the Earth is a Globe" (Modern Mechanics - Oct, 1931), which is available online at the Flat Earth Society. This graphic shows that, on the Equinox, an observer at 45 degrees north latitude would see the Sun at an elevation angle of 45 degrees. This makes sense in the globe model, where the sun is many millions of miles away, but can also be interpreted as the sun being small and nearby, being at the same distance (3000 miles) from the Equator that the Sun is above the earth (making a 45-degree right triangle).

*<< More details in the link. >>*

The above is also in

**Distance to the Sun: Sun's Distance - Modern Mechanics**.

So Glen Voliva "measured" it to be

*3000 miles* - who is right? I'd say it can easily be shown that neither are correct even over a flat Earth.

But it seems acceptable for flat Earthers to

*assume* that light travels in straight lines

*when it suits them* but not others.

I guess flat Earthers need these inconsistencies and this ignorance of their own choosing to support their hypotheses.

Now when will some flat Earther address "The Bishop Challenge" of proving that:

**The Moon**

The moon is a sphere. It has a diameter of 32 miles and is located approximately 3000 miles above the surface of the earth.

as claimed in the FE Wiki?