Why is it that when you're "beamed down" from the transporter room,you need to stay on the little circle on the floor? It must be important since Spock physically moves the 60's air force guy onto the circle in "Tomorrow is Yesterday." When they aren't on the ship,they can be beamed from anywhere,and sometimes they beam from/onto the bridge. (at least in TNG they do,not sure about Original.) So,does anyone know?