Question

is it proven by science that black magic does exist?

Answer 1

There's no evidence that events external to the brain and body can be caused by unmediated will.    150 years of psychical/parapsychological research have yielded no reproducible results.    Through biofeedback, you could probably control your blood pressure or your gooseflesh, but not the weather or your friend's car. 

And there's no evidence that rituals cause brain-external physical events other than those that constitute the performance of the ritual itself.   This is true regardless of whether the ritual consists of a few magic words or an elaborate show involving swords and candles.

So there's no reason to believe in the efficacy of black magic, other than the possible effects that suggestion might have on people who believe in it.

Answer 2

Science have no evidences that black magic really exist .. many are in search of that