Thanks to gravity, at least we're aware dark matter exists. We also know it's eerily abundant, accounting for about 85 percent of all matter in the Universe.
Aside from that, though, we're pretty clueless. We don't know what dark matter is or where it came from, and if it is made of some kind of weakly-interacting form of matter, we still can't directly detect a single particle of it.
According to a theoretical study by two researchers from Colgate University in the US, our ongoing failure to unmask dark matter – even with newer, highly sensitive detection methods – warrants rethinking the nature and potential origins of this mysterious stuff.
Rather than emerging from the Big Bang along with ordinary baryonic matter, dark matter could have arisen slightly later in its own 'Dark Big Bang,' the study's authors write. It may now inhabit a dark sector mostly detached from our visible sector, interacting exclusively through gravity.
Gravity has taught us what little we do know about dark matter so far. We call the ghostly substance dark matter because it doesn't interact with light or other electromagnetic radiation, rendering it invisible to us.