暗物质 Dark matter

暗物质是宇宙中不可见，总质量是普通物质6倍且在宇宙能量密度中占1/4，主导了宇宙结构形成的一个谜。Dark matter is invisible in the universe, whose gross mass is six times to ordinary matters, and occupies
one quarter of mass energy density of the observable universe.
Dark matter is the key to the secret of universe comprising.