Knotty art installation planned for pope's visit to Philadelphia symbolizes life's challenges

In this Friday, May 22, 2015, photo, artist Meg Saligman pushes a mock-up of an art installation at her studio in Philadelphia. The installation is planned to be in the shape of a latticed grotto and will greet Pope Francis and millions of others when they travel to Philadelphia this fall. Visitors will be invited to leave their own problems behind in the form of knots affixed to its walls, or help others by loosening and removing a knot already in place. (AP Photo/Matt Slocum) (The Associated Press)

In this Friday, May 22, 2015, photo, artist Meg Saligman talks about a mock-up of an art installation with a reporter at her studio in Philadelphia. The installation is planned to be in the shape of a latticed grotto and will greet Pope Francis and millions of others when they travel to Philadelphia this fall. Visitors will be invited to leave their own problems behind in the form of knots affixed to its walls, or help others by loosening and removing a knot already in place. (AP Photo/Matt Slocum) (The Associated Press)

In this Friday, May 22, 2015, photo, artist Meg Saligman shows knots tied to a mock-up of an art installation at her studio in Philadelphia. The installation is planned to be in the shape of a latticed grotto and will greet Pope Francis and millions of others when they travel to Philadelphia this fall. Visitors will be invited to leave their own problems behind in the form of knots affixed to its walls, or help others by loosening and removing a knot already in place. (AP Photo/Matt Slocum) (The Associated Press)