"I know of electromagnetism as I know of fire.  But if this is a masquerade by you, well-done on selecting what would plausibly be a grand accomplishment of another world, that truly had no idea at all what was already known here."

"It doesn't seem likely that you'd know personally how to create any grand constructs of electromagnetism; what your putative civilization could do there exceeding any facet of our world, if indeed it had invested more skill there, would probably be a complex of arts not contained within any one individual."

"Any other ideas?"

"I know of electromagnetism as I know of fire.  But if this is a masquerade by you, well-done on selecting what would plausibly be a grand accomplishment of another world, that truly had no idea at all what was already known here."

"It doesn't seem likely that you'd know personally how to create any grand constructs of electromagnetism; what your putative civilization could do there exceeding any facet of our world, if indeed it had invested more skill there, would probably be a complex of arts not contained within any one individual.  Though I'm open to hearing differently."

"Otherwise, any other ideas?"