When is a tunnel not a tunnel?

In Rome's Revolution, during the 35th century, most of the travel between the stars takes place using PPT tunnels. However the word tunnel is misleading. We all think of a tunnel as dark hole that extends over some distance with a distinct entry and exit point. However, a PPT tunnel is infinitely thin. So thin that its edge is sharper than the sharpest blade ever constructed. It has been used to slice off hands, construct a campus (like in The Ark Lords) and yield other miracles.

Rei Bierak had the same notion as we do when it comes to the word tunnel. Here is a little passage to illustrate the first time he entered and exited one made by PPTs:

     Rei watched in wonder as they passed through the tunnel but he felt no sensation other than the acceleration due to the engines. As soon as they were through, Rome told him to release the throttle. The plasma thrusters cut out and they coasted forward.
     Rei look up and around. “Did we do it? Where’s Tabit?” he asked.
     “Behind us,” Rome replied. “Here,” she said and took over the controls, twisting the navigation stick, rotating the tug so that it was facing the harsh glow of Tabit which now stood in front of them once again. The glint of the star reflected off the silver nose of the shuttle.
     “How is that possible? We never entered a tunnel,” Rei noted.
     “The word tunnel is meant figuratively, not literally like a tunnel on Earth,” Rome replied. “The word tunnel is from a perspective outside the ship. From inside, the tunnel would appear infinitely thin.”
     “I still would have expected something,” Rei said. “Does your bloco and stilo work out here?”
     “Insofar as it receives data from the on-board computer. Not from OMCOM,” Rome said, “not from this distance.”
     “So do you know how far we jumped?” he asked Rome.
     She closed her eyes for a second then said, “approximately one hundred light minutes.”

Pretty cool, huh? An infinitely thin tunnel that lets you travel between stars. Way better than a wormhole built from a black hole.