In a Newtonian reflecting telescope, light rays from distant objects, which are essentially parallel (because they come from so far away), strike the concave main mirror at the same angle.

Instеad, thе rеflеctеd rays appеar to divеrgе from a virtual focal point bеhind thе mirror. Focal Lеngth (f): Thе focal lеngth for a convеx mirror is considеrеd nеgativе (-f ...

It’s called a mirror lens because it’s all done with ... By reflecting the light rays back and forth inside the barrel, the mirrors effectively ‘fold up’ the focal length.

Mirror is of two types; concave and convex mirror where as lens is a transparent or a piece of glass having a curved side for the dispersion of light rays. Lenses are used in all optical ...

While the glass is molten, the furnace spins at five revolutions per minute; the centrifugal force pushes the glass’ surface into the concave ... rays reflected by different locations on the mirror.

Crookes in 1879, to show the incandescence of platinum under impact of the projected molecules which were focussed on it by a concave kathode. I have been using such a tube for my best work up to now.

Giant manta rays have been filmed checking out their reflections in a way that suggests they are self-aware. Only a small number of animals, mostly primates, have passed the mirror test ...