Experience zero gravity the only way possible without going to space. Parabolic flight is the same method NASA has used to train its astronauts for the last 45 years and the same way Tom Hanks floated in Apollo 13.
The weightlessness experienced by everyone inside the airplane is actually equivalent to the type of "free fall" you experience when sky diving. In this case however, the body of the aircraft surrounds you and protects you from the on-rushing wind. At the end of the free fall period, the aircraft also scoops you up and carries you back up to the top of the arc to begin the free fall process again.
All passengers will be asked to sign a Medical History Form that includes a series of questions pertaining to certain medical conditions. If you do not have any of these conditions, it will not be necessary to consult with a doctor. If you do have any of the indicated conditions, you must confer with your personal physician and obtain his/her sign-off (a 'fit to fly' letter). If you are pregnant, have heart or back problems, you should consult your physician to see if this experience is appropriate for you.