Time capsules are meant to give future generations a glimpse of what life was like many years ago. But humans tend to fill time capsules with only the good artefacts of a civilisation, making the story seem rosier than it really was. So when archaeologists and researchers want to find out the real story of a given era, they turn to garbage instead.
Now digging through a mountain of ancient garbage sounds particularly unpleasant, so archaeologists came up with a more pleasant name for them: middens. And to date, middens have revealed fascinating facts about past civilisations that the history books tend to leave out. So instead of blasting Voyager into space with a gold record documenting humanity, maybe we should've strapped a Hefty garbage bag to it instead?