In this video the JK experts remove the engine bolts from a Volkswagen in preparation to for removal of the engine.
Dark matter. Written By: Dark matter, a component of the universe whose presence is discerned from its gravitational attraction rather than its luminosity. Dark matter makes up 26.5 percent of the matter-energy composition of the universe; the rest is dark energy (73 percent) and âordinaryâ visible matter (0.5 percent).
The idea of dark matter arose to explain gravitational effects observed in galaxies and clusters of galaxies. However, studies of the early universe (especially of the cosmic microwave background and of chemical abundances) also tell us something about dark matter.