In the first stanza of "To an Athlete Dying Young," the speaker uses apostrophe to talk about the athlete as if he is still alive? Why does the speaker use this technique?

“the globe theatre is housed in an open arena the layout of the open air arena, featured the ‘ pit’ or the ‘yard’. the globe had a raised stage at one end and was surrounded by three tires of roofed galleries with balconies overlooking the back of the stage. the stage projected halfway into the ‘pit’”. i hope this information you .