Modern physics sheepishly concedes that 83% of the matter of the visible universe appears to be missing. What you say? Well, scientists assume that celestial bodies are solid and composed of a certain portion of matter according to our accepted notions of gravity. They observe the interractions of these bodies and attribute a certain interrelationship of matter to gravity based upon these assumptions and observations. Fast forward this interrelationship to the known universe where they witness lensing effects and other weighty gravitational interactions. The problem arises, however, as they are unable to pin this observable gravitational interaction to the appropriate amount of visible matter based upon the aforestated assumptions about gravitation (which, correspondingly depends upon the glaring assumption that celestial bodies are solid and composed of a certain amount of matter — Sounds like a house of cards to me!)
Physicist (Dave Goldberg) posted an article on io9 stating that all this could potentially be cleared up if we accept the notion that some extraterrestrial civilization had built Dyson spheres around all these massive objects (or at least 83% of the known universe), thus obscuring their starlight and making it impossible for us to observe them directly. Well, I'm not buying that, but what if you take the corollary argument and say that all celestial bodies are already naturally occuring Dyson spheres (a fancy way of saying 'hollow'), and hence the gravitational effects we witness are actually attributable to far less matter to begin with (83% to be exact)! ... Then the scientific types can finally balance out their equations and go home happy. Everybody wins.