seven horses of surya-seven colours in rainbow

In hinduism people worship sun as "Lord Surya". According to rig veda,
                    "Seven horses draw the chariot of Surya". Rig Veda 5. 45. 9 

These seven horses are the seven colors compromising light. These seven colors become visible in a rainbow or when light passes through a prism.Modern physics confirmed that the sun's rays travel in a curved way, but not in a straight line. Our ancestors told that the sun's chariot was drawn by seven horses tied by snakes. As the movements of the snakes are crooked and curved, so also the sun's ray.

 The phenomenon is described in a metaphysical poetic line bhujagana mita sapta turaga. The chapter on light says that there are seven colors in the white ray of the sun. Artharveda says that there are seven types of sun's rays, sapta surayasya rasmayah. 

This theory is also related with another one concept in hinduism. These seven colours in the sun ray also represents the seven important chakras of the body namely
Crown of head
Centre of eyebrows
Throat
Right of the physical heart
Navel
Genitals
Anus

Its really amazing how our ancestors related each and every part of our religion with todays modern science.