> One can't prove a negative. Fine. One can't necessarily prove a negative. Only if you can prove the negation of the assertion can you "prove the negative".

> One can't prove a negative. Fine. One can't necessarily prove a negative. Only if you can prove the negation of the assertion can you "prove the negative". Now apply that logic to: <Musk> I can reduce the cost of boring by an order of magnitude. Can you prove that he can't? The gp was (over)simply stating that just because no other digging project has done what Musk claims to be able to do doesn't necessarily mean that Musk can't do it.