"That can be proven ."
"No it ca n't . Scientific theories are n't `` proven `` . You can observe the fact of gravity but you ca n't `` prove `` that the theory that explains it is correct . In fact , the theory of gravitation is one of the least secure theories of modern science ."
"That can be proven ."
"No it ca n't . Scientific theories are n't `` proven `` . You can observe the fact of gravity but you ca n't `` prove `` that the theory that explains it is correct ."