Earth's shadow in the atmosphere

[marellasunny]

If a clear view is available of the horizon,theory says that I'll be able to view the Earth's shadow(the curvature of the Earth in the direction of sunlight). Is it possible to calculate the curvature of the Earth just by looking at this different colored band in the horizon?

Was it done before and if yes,please suggest some references.

 

[Baluncore]

No, it is not possible because the Earth is not a perfect sphere and you need to know your height and the distance to your horizon. Atmospheric refraction would also make the Earth's radius appear greater than it really is since light wraps slightly around the Earth due to the pressure gradient in the atmosphere.