Searching in the dark

摘要

Visible matter represents everything we can touch and see, yet it makes up less than five cent of the universe. The vast majority of the universe is dark, and does not emit or reflect - and cannot be detected with -light. The existence of dark matter has been inferred by astronomers as a result of the gravitational effects on visible matter, radiation and the structure in space, rather than it being observed through direct or indirect methods.