Dark Matter in the Universe: What in the world is it?
The more we learn about the universe, the less we understand it. Research suggests that dark matter and dark energy make up most of the universe, up to 70 per cent, in fact, in the case of dark energy. But as James MacDonald, writing in JSTOR Daily points out, we also have no clue what this dark matter and energy consists of. We are, quite literally, in the dark about it.
From JSTOR Daily