Question

a apple falls down due to gravity of earth which pulls it down.so we think that tha apple falls down but can it be earth accelerating upwards to meet the apple ? if yes then by which frame of reference we will be able to see it?

Answer 1

no it is not possible to notice the earth acceleration by our eyes with any frame of reference with the comparison of the acceleration of the apple.
An apple is so much less massive than Earth, so its effects are negligible go unnoticed. The forces of attraction will be equal and opposite. However, you must take inertia into account. The inertia of the Earth is very great, but the ineria of the apple is small. The force is strong enough to move the apple, but not strong enough to noticeably move the Earth.