Aperture Science Hard Light Bridge

"These bridges are made from natural light that I pump in from the surface. If you rubbed your cheek on one, it would be like standing outside with the sun shining on your face. It would also set your hair on fire, so don't actually do it."

- GLaDOS

The Aperture Science Hard Light Bridge is a testing element in Portal 2 that is used throughout the Aperture Science Enrichment Center.

Overview
The Hard Light Bridge is a translucent but solid walkway that can be redirected through portals to reach certain areas.

Bridges may be emitted horizontally or vertically. Horizontal bridges can be walked upon, and players can continue seamlessly along them through any portals they pass (given enough headroom). Vertical bridges act more as portable walls that can be used as obstacles (for example, to intercept Weighted Storage Cubes).

Mobility Gels can be placed on the bridge, allowing the player to use the gels in places where it normally would just fall through. The players must utilize this ability to pass one of the chambers of the Mobility Gels Cooperative Testing Course.

Trivia

 * The Hard Light Bridge appears to be similar in nature to the Combine Field Bridge.
 * The Thermal Discouragement Beam is unaffected by Hard Light Bridges.
 * According to the screens seen at the start of certain test chambers, the light used to create the bridges are absorbed through vast farm fields, then filtered to create the bridges. The field shown in this video resembles the field Chell is sent to at the end of the game.
 * The Hard Light Bridge appears to be opaque to Sentry Turrets. Unlike glass, turrets do not appear to recognize Chell if she stands behind one; however, since the turrets appear to aim with infrared lasers, it could be argued that the light from the bridge interferes with a turret's ability to detect targets (as both are very close on the electromagnetic spectrum, as seen here).
 * When standing near the bridge, Cara Mia can be heard playing slowly about 30 seconds into the audio file.

List of appearances

 * Portal 2