Electromagnetic spectrum observing universe

Interrogating the light from stars and the absorption features of atoms and molecules in-between requires some fairly complicated optics in the form of a telescope. However, the telescopes are not restricted to the parts of the electromagnetic spectrum that you can see but use radiation from microwaves to gamma rays to observe the Universe. There is too much to learn about the optics or even adaptive optics of telescopes to be discussed here but there are some properties of telescopes that we must know because they are important for the identification of atoms and molecules. We shall discuss three telescope considerations the atmosphere, the spatial resolution and the spectral resolution. 

Much of the electromagnetic spectrum has been used to investigate the structure of matter in the laboratory but the atmospheric windows restrict astronomical observations from Earth. Irritating as this is for astronomers on the ground, the chemical structure of the atmosphere and the radiation that it traps is important to the origins of life on Earth. The light that does get through the atmosphere, however, when analysed with all of the tools of spectroscopy, tells the molecular story of chemistry in distant places around the Universe. 

An online resource on this topic is available at (30). This webpage was developed by Aeree Chung and Ben Johnson at Columbia University in conjunction with their astronomy lab. The pages give an overview of the electromagnetic spectrum, and outline applications of spectroscopy to astronomical studies. Included are pictorial representations of astronomical observations with brief descriptions, and information on observational instrumentation. Also discussed are the distinctions between continuum,... 

The first reliable device for generating fixed-frequency MW radiation was designed by Randall and Booth at the University of Birmingham, UK, during World War II. MW radiation is a part of the broader electromagnetic spectrum and it was well known that infrared and visible light accelerated chemical reactions, and therefore when it was first observed that microwave radiation was able to heat foodstuffs it did not come as a complete surprise. The first patent for MW dielectric heating was filed by the Raytheon Company in 1946 and commercial MW ovens became available in 1947. 

If we look at the simplified schematic diagram presented in Figiue 13.7, which presents the whole electromagnetic spectrum, we will notice that direct visual observable universe is very narrow. 

---