Question

why it seems flittering above an fire give reason

Answer 1

if it is about holi fire then it has to be mirage

this happens coz above the fire there is a layer of warm air because of heat and above it there is a layer of cool air.

due to this layers of different temleratures the refractive index goes on changing

hence the phenomenon can be observed

Answer 2

Heya,

It seems flickering/shaking above an hot fire. This is because of the air just above the fire becomes hotter. The hotter air is optically rarer. But the cooler air around the fire is optically denser. There occurs refraction of light due to various optical densities in the air layer. Hence the fire appears to move or shake slightly.

Hope it helps you!

Regards,
Shobana

^_^