 In Alice's frame she remains at rest at position "x" = 0, while Bob is moving in the positive "x" direction at 0.8"c"; in Bob's frame he remains at rest at position "x′" = 0, and Alice is moving in the negative "x′" direction at 0.8"c".Each one also has a tachyon transmitter aboard their ship, which sends out signals that move at 2.4"c" in the ship's own frame.When Alice's clock shows that 300 days have elapsed since she passed next to Bob ("t" = 300 days in her frame), she uses the tachyon transmitter to send a message to Bob, saying "Ugh, I just ate some bad shrimp".