DARK MATTER

Of all the claims made by the cold dark model, the least controversial by far is its assertion that most of the universe is invisible. At least 90 percent of the cosmos, by weight , and perhaps as much of 99 percent, has escaped detection. No one has ever seen it. It gives off no radiation whatever; no infrared,visible, or ultraviolet light,no radio waves, no X-rays, no nothing-or at least so close to nothing that it has never been found, despite careful searches with every sort of telescope known to astronomy.Yet virtually every astronomer is convinced that the dark matter exists. Dark it may be, but it is matter, and that means that it exerts gravity on other types of matter, including the stars and galaxies and clouds of gas we once thought that was all there was to the universe. The dark matter's presence can be inferred by the way it knocks visible things around. If a star or a galaxy appears to be responding to a gravitational tug, there must be something doing the tugging, whether or not the something can be seen.