You are just repeating a myth. A quick look from wikipedia:

Logicians and philosophers of logic reject the notion that it is intrinsically impossible to prove negative claims.[11][12][13][14][15][10][16][17] Philosophers Steven D. Hale and Stephen Law state that the phrase “you cannot prove a negative” is itself a negative claim that would not be true if it could be proven true.[10][18] Many negative claims can be rewritten into logically equivalent positive claims (for example, “No Jewish person was at the party” is logically equivalent to “Everyone at the party was a gentile”).[19] In formal logic and mathematics, the negation of a proposition can be proven using procedures such as modus tollens and reductio ad absurdum.[15][10] In empirical contexts (such as the evaluating the existence or nonexistence of unicorns), inductive reasoning is often used for establishing the plausibility of a claim based on observed evidence.[20][10][21] Though inductive reasoning may not provide absolute certainty about negative claims, this is only due to the nature of inductive reasoning; inductive reasoning provides proof from probability rather than certainty. Inductive reasoning also does not provide absolute certainty about positive claims.[19][10]