Can I walk in Newark Airport and just hang out there without getting a plane ticket?

Ok here's the case. I've been to Newark Airport before and my parents have no plan of going any where on a plane in the near future. But I've had fun at all the shops and the feeling of being in an airport. So can I just like have my passport and go through security and just hang out around the place? The shops? The Food court? Sit in the seat and watch planes go by?Can I walk in Newark Airport and just hang out there without getting a plane ticket?no sorry, you need a boarding pass to go through security