How have optical astronomy & radio astronomy aided in the study of the universe??

Question

How have optical astronomy & radio astronomy aided in the study of the universe??

Answer 1

Our eye can see only visible part of the huge electromagnetic spectrum.

Stars and Galaxies are emiting other forms of radiation and our atmosphere has limitations allowing them to surface level.

Radio waves and light waves are coming down to surface of earth through atmosphere. But the dust and gas clouds does not allow us to see through the centre of oue Galaxy Milky way.But radio waves can penentrate the dust clouds and see through the centre.

Answer 2

Optical astronomy contributed a lion's share to our knowledge of Universe around Earth as of now . Interior of astronomical bodies revealed itself in Spectroscopic studies. Further refinements culminating in measurement of Red shift resulted in the knowledge about the extent of universe due to Hubble's efforts. It also gave clues to the past as light reaching us now must have started years ago or even a million years ago. It gave us the chronology of Universal events.

Then JC Maxwell combined all known laws of electricity & magnetism into a set of 4 equations and derived an expression for speed of Electro magnetic waves. He conjectured that 'these (EM waves) have  same speed as that of light waves'. It was established then, that light is a mere sliver in the vast electromagnetic spectrum. Now the activity started to 'see' universe through different parts of the EM spectrum. This thinking led Jansky to conjecture that the noise he heard on radio was actually the emission from the heavenly bodies in sky, just as light that reaches us on Earth. Using well-refined techniques of radio reception more sensitive receiving systems were deviced. The chief feature in these is the sharpness of the beam so that energy from a tiny solid angle can be picked up for energy reception. Antenna systems were designed for that, along with reception methods with devices that add less noise of their own to the natural noise. That way it became possible to distinguish the desired signal from it getting drowned in noise.

There was a constant exchange of approach and attack of the problem between optical & radio segments of spectrum. But the techniques of receiving the energy differed in both. Such a huge body of engineering needed to refine their methds constantly to meet the demands of accuracies required by later generations of astronomers.

Radio methods revealed sources that were optically poor radiators. This is so because surface temperature of some stars belonging to spectral classes R, N & S and certain gaseous regions (Nubelae) are strong radio emitters. This follows Wien's law (for Blackbody radiation) that says wavelength of maximum radiation & temperature is

2.898 X 10^(-3)m K.

Now other windows in EMspectrum are also used like X rays for which sensors are required to be placed above the atmosphere ('Chandra').

Answer 3

Well, optical astronomy has lead to the fact that there's more to the "universe" than meets the eye.  All we can "see", without the aide of a telescope, is just a part of our own galaxy (The part where our Solar System is located).  Our galaxy is one of many, now seen, by the aide of optical astronomy, (I'm assuming that you mean the "telescope", by the use of the words "optical astronomy").  And that's only one "thing" now seen.  We have been able to "see" nebula, supernova's, gamma ray bursts, the formation of neutron stars, and many, many more "things"  

Radio Astronomy & Optical Astronomy has lead to the fact that the universe is expanding, even more than originally realized, and more quickly.  I think that SETI uses "radio astronomy" and the fact that "they" (SETI and other scientists) haven't "found" anything yet, doesn't mean anything.  I say "Give them more time," because, after all, they've only been "looking" for a miniscule amount of years, depending------