Do electromagnetic waves moving upside down change?

[rickyyeungyeung]

do electricmagnetic wave moving in upside down form? So the highest position is wave crest and the lowest is wave trough?

 

[BvU]

Hi,

As in the other thread: google is your friend

Your perception of electromagnetic waves might need some fine tuning: there is no position and no upside down. There are just $\vec E$ and $\vec B$ field vectors, closely related through the Maxwell equations.

Google e.g. this

 

[kuruman]

Google may be your friend, but you can answer your own question with a simple experiment:
1. Shine a flashlight with fresh batteries and bulb onto a wall.
2. Slowly rotate the flashlight along its axis until it's upside down watching for any changes in the spot on the wall as you do so.
3. If you see no changes, the conclusion is that light travels just as well upside down as right side up which is equivalent to what @BvU said, "there is no position and no upside down."