What range of the electro-magnetic spectrum? How about detection via gravity distortions?
If you have no gravitational field you'll get flying into the bargain too, just not very controllable flying. Tho leaving footprints would mean you are susceptible to gravity.
If you have no gravitational field you'll get flying into the bargain too, just not very controllable flying. Tho leaving footprints would mean you are susceptible to gravity.