Will We Ever Know What Dark Matter Is?
Dark matter is as tangible as stars and planets to most astronomers. We routinely map it out. We conceive of galaxies as lumps of dark matter with dabs of luminous material. We understand the formation of cosmic structure, as well as the evolution of the universe as a whole, in terms of dark matter. Yet a decade of sophisticated searches has failed to detect the material directly. We see the shadow it casts, but are completely unaware of what the dark side of the universe may contain.
Eighty-five percent of all matter is unknown. Our greatest fear is that it will always remain so.