Take The Test

Test Chamber 13: Place portals as shown in the image. Use a portal to move the laser sideways and a time portal to send it into the future. Enter the time portal to advance. You may take some damage from the laser to ensure you travel into the future. Once in the future, rearrange portals so the laser hits the target directly. Proceed through the exit door.

Test Chamber 14: First, travel to the present using a time portal. Summon a reflector cube from the central switch and position it in the present as indicated. Use a portal to direct a laser through the first node, then use this to reflect the laser into the next two nodes. Travel to the future. Use portals as shown to bring a laser into the present through the time portal, ensuring it passes through the node. Retrieve the reflector cube from the future and bring it to the present via a time portal. Ensure the present reflector cube hits all three nodes, adjusting its position as needed. If you moved the future reflector cube, you may need to return to the future to retrieve it again. Finally, position the future reflector cube to reflect the laser into the receiver, completing the chamber.

Test Chamber 15: Begin by passing through the particle field to the left. Place a portal where the laser hits the wall and a time portal on the opposite wall. Travel through the time portal to the future to bypass the particle field. Proceed to the other side of the room and use another time portal to return to the present, now on the far side of the particle field. Place a new portal on the upper wall above the laser room so the laser hits the first receiver. Return to the future and place a portal on the small wall in the laser room to aim at the receiver. Return to the present; the laser should now be hitting the upper receiver, powering an elevating platform near the switch. Stand on the platform and place a time portal behind the node to raise the platform further, allowing you to summon a reflector cube. Place this reflector cube on the lip above the second receiver. Travel to the future. Retrieve the future reflector cube and run into the laser room. Place a time portal in the laser room to bring the future reflector cube into the present. Position it to reflect the laser into the second receiver through the node. To reach the other side of the particle field without passing through it, use a portal on the other side or a time portal to bypass it. You need to be in the present on the other side. Climb the stairs and use a portal on the upper wall to hit the third receiver. Move the reflector cube onto the switch to complete the chamber.