white
The surface of a radio telescope doesn't have to be as flawless as the surface of an optical telescope because the radio telescope is collecting radio waves, something that will not be affected by faults in the glass. Optical telescopes, on the other hand, are collecting light, where faults in the surface can interfere with the image.
PITS
The imaginary line that extends straight out from the center of a reflective surface is the optical axis.
newton
Yes, but the reflective surface may cause odd behaviors.
It is a spiral layout
No. It's straight through the center of the sphere that the curved surface is part of.
red
An optical, and an electron microscope.
The colour 'white' when all of the light is bounced of the surface on which the colour is mounted. If the colour is darkened then there will be some light being absorbed into the surface. This means that the colour is no longer 'white' more of a grey or possibly black. :)
The colour of a surface has no effect on the rate of conduction.
Jet black is the darkest colour. Not sure what is meant by surface?