The Universe is overwhelmingly empty!
Up in the heavens, galaxies are interspersed by huge empty spaces. Matter constitutes less than one percent of the universe – about one atom in ten cubic meters of space. 
Within an atom too, there is more empty space than substance. If the atom is magnified to the size of a football stadium, matter (nucleus) in it will be no bigger than a golf ball, the remaining space being just emptiness. However, many ancient Indian scriptures hold that there is energy aplenty in space. Physicists unhesitatingly agree. Evidence for energy in empty space comes both from Cosmology that deals with the astronomical objects of huge proportions and Quantum Physics which studies atomic- and subatomic-sized particles.