The Absorption of Radio Waves in Space
In 1951 it was found that clouds of hydrogen between the stars radiate 21-centimeter radio, waves. The clouds also absorb these waves, providing a sensitive new tool for the radio astronomer
In 1951 it was found that clouds of hydrogen between the stars radiate 21-centimeter radio, waves. The clouds also absorb these waves, providing a sensitive new tool for the radio astronomer