Complex sentence: However, these theories were incorrect, as they did not correctly incorporate general relativity-in the former case, because general relativity had yet to be formulated, and in the latter due to an appararent lack of understanding.
Split into simpler sentences: However, these theories were incorrect, as they did not correctly incorporate General Relativity. In the former case because General Relativity had yet to be formulated, and in the latter due to an appararent lack of understanding.