Neil
angle-diagram
Diagram produced for the funding proposal, showing how the glass bead rainbow (glassbow) appears at a 22 degree angle.
A natural "water" rainbow appears at the much wider angle of 42 degrees. In most cases this covers much of the sky and the ground. This is why you almost never see it as a full circle -- the dry ground gets in the way, or the atmospheric conditions don't hold over such a large area. Full-circle water rainbows are sometimes visible from airplanes or very high buildings.
angle-diagram
Diagram produced for the funding proposal, showing how the glass bead rainbow (glassbow) appears at a 22 degree angle.
A natural "water" rainbow appears at the much wider angle of 42 degrees. In most cases this covers much of the sky and the ground. This is why you almost never see it as a full circle -- the dry ground gets in the way, or the atmospheric conditions don't hold over such a large area. Full-circle water rainbows are sometimes visible from airplanes or very high buildings.