Mysterious Dark Matter
16/07/2013 09:24
MessageToEagle.com - In general, astronomers learn about the Universe by the electromagnetic radiation (or light) that we see from it. The light we see is in the form of radio waves, infrared, optical, ultraviolet, X-ray, and gamma-ray emission. But what if there is material in the Universe that does not glow? How will we ever know it is there? How can we tell how much of it there is? How do we know what it is? [Read more] ...