Head To The Bar

Test Chamber 13: Place portals as shown in the image. Use a portal to redirect the laser sideways and a time portal to send it into the future. Travel through the time portal (taking some damage is acceptable) to reach the future. Rearrange portals in the future to direct the laser into the target, then exit through the door.

Test Chamber 14: Travel to the present using a time portal. Summon a reflector cube and position it in the present as indicated. Use a portal to bring a laser through the first node, then use it to reflect the laser into the next two nodes. Travel to the future. Use portals 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. Adjust the present reflector cube to hit all three nodes. If necessary, return to the future to retrieve the future reflector cube again. Finally, position the future reflector cube to reflect the laser into the receiver, completing the chamber.

Test Chamber 15: Start 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 bypass the particle field in the future. Once on the other side, use another time portal to return to the present. Place a new portal on the upper wall above the laser room to direct the laser to the first receiver. Travel back to the future and place a portal on the small wall in the laser room to aim at the receiver. Return to the present. An elevating platform near the switch will power up. Stand on it and place a time portal behind the node to raise the platform further, allowing you to summon a reflector cube. Place this cube on the lip above the second receiver. Travel to the future and retrieve the future reflector cube. Bring it back to the present by placing a time portal in the laser room. Position this cube to reflect the laser into the second receiver through the node. To proceed, get to 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. Climb the stairs and use a portal on the upper wall to hit the third receiver. Finally, move the reflector cube onto the switch to complete the test chamber.