> as long as we lived somewhere EM existed had a noticeable effect, which is just about everywhere.

You should have understood that I meant otherwise. Of course, if we could notice the effect of EM, that could trigger an investigation eventually leading to the discovery.

>we know our sensory understanding has sever limits...

Did you really think I implied that no one knows the limits of our built in senses? When I said sensory capabilities I meant the stuff we can sense, directly or indirectly (By indirectly, I mean by the help of another device, to make it very clear).