Skipping the light bridge scene
From Halopedia, the Halo wiki
Skipping the light bridge scene refers to two glitches present in the Campaigns of Halo: Combat Evolved and Halo 3. The glitches allow players to skip the cutscenes in which the Master Chief activates an Energy Bridge.
Halo: Combat Evolved
On Halo, at the part where you need to press the switch to activate the "light bridge", it is possible to skip the clip.
In Halo 3, near the end of the level The Covenant, players will need to activate and cross a light bridge to reach and confront the Prophet of Truth. It is possible in this case to get to Truth without actually activating the light bridge, though the resulting cutscene will still play. Even if you manage to get on Keyes' Pelican, the cutscene will still play. Simply get to the switch, plant a grenade (preferably a Plasma Grenade), and jump forward, swinging the Gravity Hammer at the peak of the jump. If done correctly, you crossed it without using the bridge.