Ok to move laptop around while dvd is running?

Sorry if it's a dumb question, but I'm getting a notebook with an optical drive for the first time, and so I'm wondering if there's any risk of scratching a dvd by moving the notebook around, or even tilting it at an angle or turning it upside down.
What about if it's shaken around for example when driving on a bumpy road? Also, is it bad to leave a disc in the drive while traveling with the notebook?

Thanks.