5. (15 points) An astronaut on board a spaceship does an experiment to measure the half-life of the element "Be. The astronaut finds the half-life to be 13.8 seconds. The spaceship is moving at 0.8c in the -x direction as measured by an observer on Earth. An observer on Earth watches the experiment using a telescope. What is the half-life of "Be as measured by the observer on Earth? (Give your answer in seconds)