DescriptionEditCreated from at least 1998, Excursion Funnels are used by Aperture Science as part of an investigation into how well Test Subjects can solve problems while traveling violently through a churning funnel of liquid asbestos. According to the Aperture Science scientists, results as far as 1998 were highly informative; they cannot. Acting as a tractor beam, the Excursion Funnel is powered by a round emitter placed on a wall, containing three gleaming, blue orbs. From each orb leaves a thread that swirls on itself in a spiral, the three threads making up the Funnel itself, a seemingly infinite transparent blue cylinder. Combined with portals, it can transport Test Subjects or objects to otherwise unreachable areas.
The Excursion Funnel can be reversed in certain test chambers by activating a 1500 Megawatt Aperture Science Heavy Duty Super-Colliding Super Button. This causes the funnel to turn orange and attract objects instead of repelling them. If the player is about to die whilst having portals redirecting an Excursion Funnel, the game corrects for placing the incorrect portal to save themselves.