There would be a temporary weakening of the magnetic field during the reversal. After the reversal the only noticeable difference would be that compasses now point south instead of north. Navigation systems that use the magnetic field would need to be recalibrated.
the population of the moth would have change if its reversed by having
the population of the moth would have change if its reversed by having
The idea is that the magnetic field of the device reacts with the external magnetic field. If the current is reversed, the magnetic field would also be reversed, and the reading would be the opposite.
The temperature would be different on Earth.
it would become to cold
The length of the day
we would die
our sun and moon will go backwards in the sky
it would decay
Everything will be backwards and we will fly. Also we will marry the same gender as our own. It will happen someday so practice.
we would only have one season
Probably very little would change if you either doubled the magnetic field strength, reversed it, or made it zero. If you reversed it, the larger hole might form over the north pole. UV-C from the Sun makes ozone in the ozone layer, most solar wind (the stuff affected by our magnetic field) does not survive to reach the ozone layer. The poles might retain a bit more ozone into the late spring, with a nearly unmeasureable decrease in overall ozone levels to match.