To show that problem is NP-hard, we take a known NP-hard problem and reduce it to the problem whose NP-hardness we want to prove.
The reduction we need is polynomial time reduction.
But If I take known NP-hard problem and reduce it to some unknown problem by Turing reduction then what I can say about the unknown problem?
I am sure that I can't say it is NP-hard, as the reduction is Turing.
